* [PATCH v8 0/5] usb: early: add support for early printk through USB3 debug port
@ 2017-03-21 8:01 Lu Baolu
2017-03-21 8:01 ` [PATCH v8 1/5] x86: add simple udelay calibration Lu Baolu
` (5 more replies)
0 siblings, 6 replies; 42+ messages in thread
From: Lu Baolu @ 2017-03-21 8:01 UTC (permalink / raw)
To: Greg Kroah-Hartman, Ingo Molnar
Cc: Mathias Nyman, tglx, peterz, linux-usb, x86, linux-kernel, Lu Baolu
xHCI debug capability (DbC) is an optional but standalone
functionality provided by an xHCI host controller. With DbC
hardware initialized, the system will present a debug device
through the USB3 debug port (normally the first USB3 port).
The debug device is fully compliant with the USB framework
and provides the equivalent of a very high performance (USB3)
full-duplex serial link between the debug host and target.
The DbC functionality is independent of xHCI host.
This patch set adds support for early printk functionality
through a USB3 debug port by 1) initializing and enabling
the DbC hardware during early boot; 2) registering a boot
console to the system so that early printk messages can go
through the USB3 debug port. It also includes some lines
of changes in usb_debug driver so that it can be bound when
a USB3 debug device is enumerated.
---
Change log:
v7->v8:
- refine the Kconfig help text.
- cleanup the unnecessary USB_EARLY_PRINTK bool.
- refine comments and trace messages in the driver.
- update usb3-debug-port.rst after internal reivew.
v6->v7:
- add a new patch "[PATCH 1/5] x86: add simple udelay
calibration" to make udelay() work for early drivers.
- [PATCH 2/5] usb: dbc: early driver for xhci debug capability
- add a kernel thread to handle error cases, such as cable
unplugging.
- Fixed several code styles pointed out by Ingo.
v5->v6:
- rebase the patches on top of the latest 4.10-rc4
- run successfully in a 32-bit kernel
- [PATCH 1/4]
- remove ugly linebreaks to make code more readable
- rename config names to make them consistency
- move sleep-able ioremap() out of the lock area
- rename reserved fields of register structures
- make the vertical tabulation of struct fields consistent
- [PATCH 2/4]
- remove "#ifdef" in the generic code by creating proper
wrappers in header file
- [PATCH 3/4]
- refine the title and commit message
- [PATCH 4/4]
- fix several typos and grammar errors in the document
v4->v5:
- add raw_spin_lock to make xdbc_bulk_write() reentrant.
v3->v4:
- Rename the document with .dst suffix.
- Add the list of hardware that has been succesfuly
tested on in the document.
v2->v3:
- Removed spinlock usage.
- Removed work queue usage.
- Refined the user guide document.
v1->v2:
- Refactor the duplicate code in xdbc_early_start() and
xdbc_handle_external_reset().
- Free resources when hardware not used any more.
- Refine the user guide document.
Lu Baolu (5):
x86: add simple udelay calibration
usb: early: add driver for xhci debug capability
x86: add support for earlyprintk via USB3 debug port
usb: serial: add dbc debug device support to usb_debug
usb: doc: add document for USB3 debug port usage
Documentation/admin-guide/kernel-parameters.txt | 1 +
Documentation/usb/usb3-debug-port.rst | 100 +++
arch/x86/Kconfig.debug | 23 +
arch/x86/kernel/early_printk.c | 5 +
arch/x86/kernel/setup.c | 26 +
drivers/usb/Makefile | 2 +-
drivers/usb/early/Makefile | 1 +
drivers/usb/early/xhci-dbc.c | 1014 +++++++++++++++++++++++
drivers/usb/early/xhci-dbc.h | 211 +++++
drivers/usb/serial/usb_debug.c | 28 +-
include/linux/usb/xhci-dbgp.h | 29 +
11 files changed, 1436 insertions(+), 4 deletions(-)
create mode 100644 Documentation/usb/usb3-debug-port.rst
create mode 100644 drivers/usb/early/xhci-dbc.c
create mode 100644 drivers/usb/early/xhci-dbc.h
create mode 100644 include/linux/usb/xhci-dbgp.h
--
2.1.4
^ permalink raw reply [flat|nested] 42+ messages in thread
* [PATCH v8 1/5] x86: add simple udelay calibration
2017-03-21 8:01 [PATCH v8 0/5] usb: early: add support for early printk through USB3 debug port Lu Baolu
@ 2017-03-21 8:01 ` Lu Baolu
2017-03-21 12:19 ` [tip:x86/debug] x86/timers: Add " tip-bot for Lu Baolu
` (2 more replies)
2017-03-21 8:01 ` [PATCH v8 2/5] usb: early: add driver for xhci debug capability Lu Baolu
` (4 subsequent siblings)
5 siblings, 3 replies; 42+ messages in thread
From: Lu Baolu @ 2017-03-21 8:01 UTC (permalink / raw)
To: Greg Kroah-Hartman, Ingo Molnar
Cc: Mathias Nyman, tglx, peterz, linux-usb, x86, linux-kernel, Lu Baolu
Add a simple udelay calibration in x86 architecture-specific
boot-time initializations. This will get a workable estimate
for loops_per_jiffy. Hence, udelay() could be used after this
initialization.
Cc: Ingo Molnar <mingo@redhat.com>
Cc: x86@kernel.org
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
arch/x86/kernel/setup.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 4bf0c89..e70204e 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -837,6 +837,26 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
return 0;
}
+static void __init simple_udelay_calibration(void)
+{
+ unsigned int tsc_khz, cpu_khz;
+ unsigned long lpj;
+
+ if (!boot_cpu_has(X86_FEATURE_TSC))
+ return;
+
+ cpu_khz = x86_platform.calibrate_cpu();
+ tsc_khz = x86_platform.calibrate_tsc();
+
+ tsc_khz = tsc_khz ? : cpu_khz;
+ if (!tsc_khz)
+ return;
+
+ lpj = tsc_khz * 1000;
+ do_div(lpj, HZ);
+ loops_per_jiffy = lpj;
+}
+
/*
* Determine if we were loaded by an EFI loader. If so, then we have also been
* passed the efi memmap, systab, etc., so we should use these data structures
@@ -985,6 +1005,8 @@ void __init setup_arch(char **cmdline_p)
*/
x86_configure_nx();
+ simple_udelay_calibration();
+
parse_early_param();
#ifdef CONFIG_MEMORY_HOTPLUG
--
2.1.4
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH v8 2/5] usb: early: add driver for xhci debug capability
2017-03-21 8:01 [PATCH v8 0/5] usb: early: add support for early printk through USB3 debug port Lu Baolu
2017-03-21 8:01 ` [PATCH v8 1/5] x86: add simple udelay calibration Lu Baolu
@ 2017-03-21 8:01 ` Lu Baolu
2017-03-21 12:19 ` [tip:x86/debug] usb/early: Add " tip-bot for Lu Baolu
2017-05-30 13:46 ` [PATCH v8 2/5] usb: early: add " Vlastimil Babka
2017-03-21 8:01 ` [PATCH v8 3/5] x86: add support for earlyprintk via USB3 debug port Lu Baolu
` (3 subsequent siblings)
5 siblings, 2 replies; 42+ messages in thread
From: Lu Baolu @ 2017-03-21 8:01 UTC (permalink / raw)
To: Greg Kroah-Hartman, Ingo Molnar
Cc: Mathias Nyman, tglx, peterz, linux-usb, x86, linux-kernel, Lu Baolu
XHCI debug capability (DbC) is an optional but standalone
functionality provided by an xHCI host controller. Software
learns this capability by walking through the extended
capability list of the host. XHCI specification describes
DbC in the section 7.6.
This patch introduces the code to probe and initialize the
debug capability hardware during early boot. With hardware
initialized, the debug target (system on which this code is
running) will present a debug device through the debug port
(normally the first USB3 port). The debug device is fully
compliant with the USB framework and provides the equivalent
of a very high performance (USB3) full-duplex serial link
between the debug host and target. The DbC functionality is
independent of the xHCI host. There isn't any precondition
from the xHCI host side for the DbC to work.
One use for this feature is kernel debugging, for example
when your machine crashes very early before the regular
console code is initialized. Other uses include simpler,
lockless logging instead of a full-blown printk console
driver and klogd.
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
arch/x86/Kconfig.debug | 23 +
drivers/usb/Makefile | 2 +-
drivers/usb/early/Makefile | 1 +
drivers/usb/early/xhci-dbc.c | 1014 +++++++++++++++++++++++++++++++++++++++++
drivers/usb/early/xhci-dbc.h | 211 +++++++++
include/linux/usb/xhci-dbgp.h | 29 ++
6 files changed, 1279 insertions(+), 1 deletion(-)
create mode 100644 drivers/usb/early/xhci-dbc.c
create mode 100644 drivers/usb/early/xhci-dbc.h
create mode 100644 include/linux/usb/xhci-dbgp.h
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index 63c1d13..f586462 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -5,6 +5,9 @@ config TRACE_IRQFLAGS_SUPPORT
source "lib/Kconfig.debug"
+config EARLY_PRINTK_USB
+ bool
+
config X86_VERBOSE_BOOTUP
bool "Enable verbose x86 bootup info messages"
default y
@@ -29,6 +32,7 @@ config EARLY_PRINTK
config EARLY_PRINTK_DBGP
bool "Early printk via EHCI debug port"
depends on EARLY_PRINTK && PCI
+ select EARLY_PRINTK_USB
---help---
Write kernel log output directly into the EHCI debug port.
@@ -48,6 +52,25 @@ config EARLY_PRINTK_EFI
This is useful for kernel debugging when your machine crashes very
early before the console code is initialized.
+config EARLY_PRINTK_USB_XDBC
+ bool "Early printk via the xHCI debug port"
+ depends on EARLY_PRINTK && PCI
+ select EARLY_PRINTK_USB
+ ---help---
+ Write kernel log output directly into the xHCI debug port.
+
+ One use for this feature is kernel debugging, for example when your
+ machine crashes very early before the regular console code is
+ initialized. Other uses include simpler, lockless logging instead of
+ a full-blown printk console driver + klogd.
+
+ For normal production environments this is normally not recommended,
+ because it doesn't feed events into klogd/syslogd and doesn't try to
+ print anything on the screen.
+
+ You should normally N here, unless you want to debug early crashes or
+ need a very simple printk logging facility.
+
config X86_PTDUMP_CORE
def_bool n
diff --git a/drivers/usb/Makefile b/drivers/usb/Makefile
index 7791af6..53d1356 100644
--- a/drivers/usb/Makefile
+++ b/drivers/usb/Makefile
@@ -49,7 +49,7 @@ obj-$(CONFIG_USB_MICROTEK) += image/
obj-$(CONFIG_USB_SERIAL) += serial/
obj-$(CONFIG_USB) += misc/
-obj-$(CONFIG_EARLY_PRINTK_DBGP) += early/
+obj-$(CONFIG_EARLY_PRINTK_USB) += early/
obj-$(CONFIG_USB_ATM) += atm/
obj-$(CONFIG_USB_SPEEDTOUCH) += atm/
diff --git a/drivers/usb/early/Makefile b/drivers/usb/early/Makefile
index 24bbe51..fcde228 100644
--- a/drivers/usb/early/Makefile
+++ b/drivers/usb/early/Makefile
@@ -3,3 +3,4 @@
#
obj-$(CONFIG_EARLY_PRINTK_DBGP) += ehci-dbgp.o
+obj-$(CONFIG_EARLY_PRINTK_USB_XDBC) += xhci-dbc.o
diff --git a/drivers/usb/early/xhci-dbc.c b/drivers/usb/early/xhci-dbc.c
new file mode 100644
index 0000000..1268818
--- /dev/null
+++ b/drivers/usb/early/xhci-dbc.c
@@ -0,0 +1,1014 @@
+/**
+ * xhci-dbc.c - xHCI debug capability early driver
+ *
+ * Copyright (C) 2016 Intel Corporation
+ *
+ * Author: Lu Baolu <baolu.lu@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
+
+#include <linux/console.h>
+#include <linux/pci_regs.h>
+#include <linux/pci_ids.h>
+#include <linux/bootmem.h>
+#include <linux/io.h>
+#include <asm/pci-direct.h>
+#include <asm/fixmap.h>
+#include <linux/bcd.h>
+#include <linux/export.h>
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
+
+#include "../host/xhci.h"
+#include "xhci-dbc.h"
+
+static struct xdbc_state xdbc;
+static bool early_console_keep;
+
+#define XDBC_TRACE
+#ifdef XDBC_TRACE
+#define xdbc_trace trace_printk
+#else
+static inline void xdbc_trace(const char *fmt, ...) { }
+#endif /* XDBC_TRACE */
+
+static void __iomem * __init xdbc_map_pci_mmio(u32 bus, u32 dev, u32 func)
+{
+ u64 val64, sz64, mask64;
+ void __iomem *base;
+ u32 val, sz;
+ u8 byte;
+
+ val = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0);
+ write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0, ~0);
+ sz = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0);
+ write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0, val);
+
+ if (val == 0xffffffff || sz == 0xffffffff) {
+ pr_notice("invalid mmio bar\n");
+ return NULL;
+ }
+
+ val64 = val & PCI_BASE_ADDRESS_MEM_MASK;
+ sz64 = sz & PCI_BASE_ADDRESS_MEM_MASK;
+ mask64 = PCI_BASE_ADDRESS_MEM_MASK;
+
+ if ((val & PCI_BASE_ADDRESS_MEM_TYPE_MASK) == PCI_BASE_ADDRESS_MEM_TYPE_64) {
+ val = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4);
+ write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4, ~0);
+ sz = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4);
+ write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4, val);
+
+ val64 |= (u64)val << 32;
+ sz64 |= (u64)sz << 32;
+ mask64 |= ~0ULL << 32;
+ }
+
+ sz64 &= mask64;
+
+ if (!sz64) {
+ pr_notice("invalid mmio address\n");
+ return NULL;
+ }
+
+ sz64 = 1ULL << __ffs64(sz64);
+
+ /* Check if the mem space is enabled: */
+ byte = read_pci_config_byte(bus, dev, func, PCI_COMMAND);
+ if (!(byte & PCI_COMMAND_MEMORY)) {
+ byte |= PCI_COMMAND_MEMORY;
+ write_pci_config_byte(bus, dev, func, PCI_COMMAND, byte);
+ }
+
+ xdbc.xhci_start = val64;
+ xdbc.xhci_length = sz64;
+ base = early_ioremap(val64, sz64);
+
+ return base;
+}
+
+static void * __init xdbc_get_page(dma_addr_t *dma_addr)
+{
+ void *virt;
+
+ virt = alloc_bootmem_pages_nopanic(PAGE_SIZE);
+ if (!virt)
+ return NULL;
+
+ if (dma_addr)
+ *dma_addr = (dma_addr_t)__pa(virt);
+
+ return virt;
+}
+
+static u32 __init xdbc_find_dbgp(int xdbc_num, u32 *b, u32 *d, u32 *f)
+{
+ u32 bus, dev, func, class;
+
+ for (bus = 0; bus < XDBC_PCI_MAX_BUSES; bus++) {
+ for (dev = 0; dev < XDBC_PCI_MAX_DEVICES; dev++) {
+ for (func = 0; func < XDBC_PCI_MAX_FUNCTION; func++) {
+
+ class = read_pci_config(bus, dev, func, PCI_CLASS_REVISION);
+ if ((class >> 8) != PCI_CLASS_SERIAL_USB_XHCI)
+ continue;
+
+ if (xdbc_num-- != 0)
+ continue;
+
+ *b = bus;
+ *d = dev;
+ *f = func;
+
+ return 0;
+ }
+ }
+ }
+
+ return -1;
+}
+
+static int handshake(void __iomem *ptr, u32 mask, u32 done, int wait, int delay)
+{
+ u32 result;
+
+ do {
+ result = readl(ptr);
+ result &= mask;
+ if (result == done)
+ return 0;
+ udelay(delay);
+ wait -= delay;
+ } while (wait > 0);
+
+ return -ETIMEDOUT;
+}
+
+static void __init xdbc_bios_handoff(void)
+{
+ int offset, timeout;
+ u32 val;
+
+ offset = xhci_find_next_ext_cap(xdbc.xhci_base, 0, XHCI_EXT_CAPS_LEGACY);
+ val = readl(xdbc.xhci_base + offset);
+
+ if (val & XHCI_HC_BIOS_OWNED) {
+ writel(val | XHCI_HC_OS_OWNED, xdbc.xhci_base + offset);
+ timeout = handshake(xdbc.xhci_base + offset, XHCI_HC_BIOS_OWNED, 0, 5000, 10);
+
+ if (timeout) {
+ pr_notice("failed to hand over xHCI control from BIOS\n");
+ writel(val & ~XHCI_HC_BIOS_OWNED, xdbc.xhci_base + offset);
+ }
+ }
+
+ /* Disable BIOS SMIs and clear all SMI events: */
+ val = readl(xdbc.xhci_base + offset + XHCI_LEGACY_CONTROL_OFFSET);
+ val &= XHCI_LEGACY_DISABLE_SMI;
+ val |= XHCI_LEGACY_SMI_EVENTS;
+ writel(val, xdbc.xhci_base + offset + XHCI_LEGACY_CONTROL_OFFSET);
+}
+
+static int __init
+xdbc_alloc_ring(struct xdbc_segment *seg, struct xdbc_ring *ring)
+{
+ seg->trbs = xdbc_get_page(&seg->dma);
+ if (!seg->trbs)
+ return -ENOMEM;
+
+ ring->segment = seg;
+
+ return 0;
+}
+
+static void __init xdbc_free_ring(struct xdbc_ring *ring)
+{
+ struct xdbc_segment *seg = ring->segment;
+
+ if (!seg)
+ return;
+
+ free_bootmem(seg->dma, PAGE_SIZE);
+ ring->segment = NULL;
+}
+
+static void xdbc_reset_ring(struct xdbc_ring *ring)
+{
+ struct xdbc_segment *seg = ring->segment;
+ struct xdbc_trb *link_trb;
+
+ memset(seg->trbs, 0, PAGE_SIZE);
+
+ ring->enqueue = seg->trbs;
+ ring->dequeue = seg->trbs;
+ ring->cycle_state = 1;
+
+ if (ring != &xdbc.evt_ring) {
+ link_trb = &seg->trbs[XDBC_TRBS_PER_SEGMENT - 1];
+ link_trb->field[0] = cpu_to_le32(lower_32_bits(seg->dma));
+ link_trb->field[1] = cpu_to_le32(upper_32_bits(seg->dma));
+ link_trb->field[3] = cpu_to_le32(TRB_TYPE(TRB_LINK)) | cpu_to_le32(LINK_TOGGLE);
+ }
+}
+
+static inline void xdbc_put_utf16(u16 *s, const char *c, size_t size)
+{
+ int i;
+
+ for (i = 0; i < size; i++)
+ s[i] = cpu_to_le16(c[i]);
+}
+
+static void xdbc_mem_init(void)
+{
+ struct xdbc_ep_context *ep_in, *ep_out;
+ struct usb_string_descriptor *s_desc;
+ struct xdbc_erst_entry *entry;
+ struct xdbc_strings *strings;
+ struct xdbc_context *ctx;
+ unsigned int max_burst;
+ u32 string_length;
+ int index = 0;
+ u32 dev_info;
+
+ xdbc_reset_ring(&xdbc.evt_ring);
+ xdbc_reset_ring(&xdbc.in_ring);
+ xdbc_reset_ring(&xdbc.out_ring);
+ memset(xdbc.table_base, 0, PAGE_SIZE);
+ memset(xdbc.out_buf, 0, PAGE_SIZE);
+
+ /* Initialize event ring segment table: */
+ xdbc.erst_size = 16;
+ xdbc.erst_base = xdbc.table_base + index * XDBC_TABLE_ENTRY_SIZE;
+ xdbc.erst_dma = xdbc.table_dma + index * XDBC_TABLE_ENTRY_SIZE;
+
+ index += XDBC_ERST_ENTRY_NUM;
+ entry = (struct xdbc_erst_entry *)xdbc.erst_base;
+
+ entry->seg_addr = cpu_to_le64(xdbc.evt_seg.dma);
+ entry->seg_size = cpu_to_le32(XDBC_TRBS_PER_SEGMENT);
+ entry->__reserved_0 = 0;
+
+ /* Initialize ERST registers: */
+ writel(1, &xdbc.xdbc_reg->ersts);
+ xdbc_write64(xdbc.erst_dma, &xdbc.xdbc_reg->erstba);
+ xdbc_write64(xdbc.evt_seg.dma, &xdbc.xdbc_reg->erdp);
+
+ /* Debug capability contexts: */
+ xdbc.dbcc_size = 64 * 3;
+ xdbc.dbcc_base = xdbc.table_base + index * XDBC_TABLE_ENTRY_SIZE;
+ xdbc.dbcc_dma = xdbc.table_dma + index * XDBC_TABLE_ENTRY_SIZE;
+
+ index += XDBC_DBCC_ENTRY_NUM;
+
+ /* Popluate the strings: */
+ xdbc.string_size = sizeof(struct xdbc_strings);
+ xdbc.string_base = xdbc.table_base + index * XDBC_TABLE_ENTRY_SIZE;
+ xdbc.string_dma = xdbc.table_dma + index * XDBC_TABLE_ENTRY_SIZE;
+ strings = (struct xdbc_strings *)xdbc.string_base;
+
+ index += XDBC_STRING_ENTRY_NUM;
+
+ /* Serial string: */
+ s_desc = (struct usb_string_descriptor *)strings->serial;
+ s_desc->bLength = (strlen(XDBC_STRING_SERIAL) + 1) * 2;
+ s_desc->bDescriptorType = USB_DT_STRING;
+
+ xdbc_put_utf16(s_desc->wData, XDBC_STRING_SERIAL, strlen(XDBC_STRING_SERIAL));
+ string_length = s_desc->bLength;
+ string_length <<= 8;
+
+ /* Product string: */
+ s_desc = (struct usb_string_descriptor *)strings->product;
+ s_desc->bLength = (strlen(XDBC_STRING_PRODUCT) + 1) * 2;
+ s_desc->bDescriptorType = USB_DT_STRING;
+
+ xdbc_put_utf16(s_desc->wData, XDBC_STRING_PRODUCT, strlen(XDBC_STRING_PRODUCT));
+ string_length += s_desc->bLength;
+ string_length <<= 8;
+
+ /* Manufacture string: */
+ s_desc = (struct usb_string_descriptor *)strings->manufacturer;
+ s_desc->bLength = (strlen(XDBC_STRING_MANUFACTURER) + 1) * 2;
+ s_desc->bDescriptorType = USB_DT_STRING;
+
+ xdbc_put_utf16(s_desc->wData, XDBC_STRING_MANUFACTURER, strlen(XDBC_STRING_MANUFACTURER));
+ string_length += s_desc->bLength;
+ string_length <<= 8;
+
+ /* String0: */
+ strings->string0[0] = 4;
+ strings->string0[1] = USB_DT_STRING;
+ strings->string0[2] = 0x09;
+ strings->string0[3] = 0x04;
+
+ string_length += 4;
+
+ /* Populate info Context: */
+ ctx = (struct xdbc_context *)xdbc.dbcc_base;
+
+ ctx->info.string0 = cpu_to_le64(xdbc.string_dma);
+ ctx->info.manufacturer = cpu_to_le64(xdbc.string_dma + XDBC_MAX_STRING_LENGTH);
+ ctx->info.product = cpu_to_le64(xdbc.string_dma + XDBC_MAX_STRING_LENGTH * 2);
+ ctx->info.serial = cpu_to_le64(xdbc.string_dma + XDBC_MAX_STRING_LENGTH * 3);
+ ctx->info.length = cpu_to_le32(string_length);
+
+ /* Populate bulk out endpoint context: */
+ max_burst = DEBUG_MAX_BURST(readl(&xdbc.xdbc_reg->control));
+ ep_out = (struct xdbc_ep_context *)&ctx->out;
+
+ ep_out->ep_info1 = 0;
+ ep_out->ep_info2 = cpu_to_le32(EP_TYPE(BULK_OUT_EP) | MAX_PACKET(1024) | MAX_BURST(max_burst));
+ ep_out->deq = cpu_to_le64(xdbc.out_seg.dma | xdbc.out_ring.cycle_state);
+
+ /* Populate bulk in endpoint context: */
+ ep_in = (struct xdbc_ep_context *)&ctx->in;
+
+ ep_in->ep_info1 = 0;
+ ep_in->ep_info2 = cpu_to_le32(EP_TYPE(BULK_OUT_EP) | MAX_PACKET(1024) | MAX_BURST(max_burst));
+ ep_in->deq = cpu_to_le64(xdbc.in_seg.dma | xdbc.in_ring.cycle_state);
+
+ /* Set DbC context and info registers: */
+ xdbc_write64(xdbc.dbcc_dma, &xdbc.xdbc_reg->dccp);
+
+ dev_info = cpu_to_le32((XDBC_VENDOR_ID << 16) | XDBC_PROTOCOL);
+ writel(dev_info, &xdbc.xdbc_reg->devinfo1);
+
+ dev_info = cpu_to_le32((XDBC_DEVICE_REV << 16) | XDBC_PRODUCT_ID);
+ writel(dev_info, &xdbc.xdbc_reg->devinfo2);
+
+ xdbc.in_buf = xdbc.out_buf + XDBC_MAX_PACKET;
+ xdbc.in_dma = xdbc.out_dma + XDBC_MAX_PACKET;
+}
+
+static void xdbc_do_reset_debug_port(u32 id, u32 count)
+{
+ void __iomem *ops_reg;
+ void __iomem *portsc;
+ u32 val, cap_length;
+ int i;
+
+ cap_length = readl(xdbc.xhci_base) & 0xff;
+ ops_reg = xdbc.xhci_base + cap_length;
+
+ id--;
+ for (i = id; i < (id + count); i++) {
+ portsc = ops_reg + 0x400 + i * 0x10;
+ val = readl(portsc);
+ if (!(val & PORT_CONNECT))
+ writel(val | PORT_RESET, portsc);
+ }
+}
+
+static void xdbc_reset_debug_port(void)
+{
+ u32 val, port_offset, port_count;
+ int offset = 0;
+
+ do {
+ offset = xhci_find_next_ext_cap(xdbc.xhci_base, offset, XHCI_EXT_CAPS_PROTOCOL);
+ if (!offset)
+ break;
+
+ val = readl(xdbc.xhci_base + offset);
+ if (XHCI_EXT_PORT_MAJOR(val) != 0x3)
+ continue;
+
+ val = readl(xdbc.xhci_base + offset + 8);
+ port_offset = XHCI_EXT_PORT_OFF(val);
+ port_count = XHCI_EXT_PORT_COUNT(val);
+
+ xdbc_do_reset_debug_port(port_offset, port_count);
+ } while (1);
+}
+
+static void
+xdbc_queue_trb(struct xdbc_ring *ring, u32 field1, u32 field2, u32 field3, u32 field4)
+{
+ struct xdbc_trb *trb, *link_trb;
+
+ trb = ring->enqueue;
+ trb->field[0] = cpu_to_le32(field1);
+ trb->field[1] = cpu_to_le32(field2);
+ trb->field[2] = cpu_to_le32(field3);
+ trb->field[3] = cpu_to_le32(field4);
+
+ ++(ring->enqueue);
+ if (ring->enqueue >= &ring->segment->trbs[TRBS_PER_SEGMENT - 1]) {
+ link_trb = ring->enqueue;
+ if (ring->cycle_state)
+ link_trb->field[3] |= cpu_to_le32(TRB_CYCLE);
+ else
+ link_trb->field[3] &= cpu_to_le32(~TRB_CYCLE);
+
+ ring->enqueue = ring->segment->trbs;
+ ring->cycle_state ^= 1;
+ }
+}
+
+static void xdbc_ring_doorbell(int target)
+{
+ writel(DOOR_BELL_TARGET(target), &xdbc.xdbc_reg->doorbell);
+}
+
+static int xdbc_start(void)
+{
+ u32 ctrl, status;
+ int ret;
+
+ ctrl = readl(&xdbc.xdbc_reg->control);
+ writel(ctrl | CTRL_DBC_ENABLE | CTRL_PORT_ENABLE, &xdbc.xdbc_reg->control);
+ ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_ENABLE, CTRL_DBC_ENABLE, 100000, 100);
+ if (ret) {
+ xdbc_trace("failed to initialize hardware\n");
+ return ret;
+ }
+
+ /* Reset port to avoid bus hang: */
+ if (xdbc.vendor == PCI_VENDOR_ID_INTEL)
+ xdbc_reset_debug_port();
+
+ /* Wait for port connection: */
+ ret = handshake(&xdbc.xdbc_reg->portsc, PORTSC_CONN_STATUS, PORTSC_CONN_STATUS, 5000000, 100);
+ if (ret) {
+ xdbc_trace("waiting for connection timed out\n");
+ return ret;
+ }
+
+ /* Wait for debug device to be configured: */
+ ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_RUN, CTRL_DBC_RUN, 5000000, 100);
+ if (ret) {
+ xdbc_trace("waiting for device configuration timed out\n");
+ return ret;
+ }
+
+ /* Check port number: */
+ status = readl(&xdbc.xdbc_reg->status);
+ if (!DCST_DEBUG_PORT(status)) {
+ xdbc_trace("invalid root hub port number\n");
+ return -ENODEV;
+ }
+
+ xdbc.port_number = DCST_DEBUG_PORT(status);
+
+ xdbc_trace("DbC is running now, control 0x%08x port ID %d\n",
+ readl(&xdbc.xdbc_reg->control), xdbc.port_number);
+
+ return 0;
+}
+
+static int xdbc_bulk_transfer(void *data, int size, bool read)
+{
+ struct xdbc_ring *ring;
+ struct xdbc_trb *trb;
+ u32 length, control;
+ u32 cycle;
+ u64 addr;
+
+ if (size > XDBC_MAX_PACKET) {
+ xdbc_trace("bad parameter, size %d\n", size);
+ return -EINVAL;
+ }
+
+ if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED) ||
+ !(xdbc.flags & XDBC_FLAGS_CONFIGURED) ||
+ (!read && (xdbc.flags & XDBC_FLAGS_OUT_STALL)) ||
+ (read && (xdbc.flags & XDBC_FLAGS_IN_STALL))) {
+
+ xdbc_trace("connection not ready, flags %08x\n", xdbc.flags);
+ return -EIO;
+ }
+
+ ring = (read ? &xdbc.in_ring : &xdbc.out_ring);
+ trb = ring->enqueue;
+ cycle = ring->cycle_state;
+ length = TRB_LEN(size);
+ control = TRB_TYPE(TRB_NORMAL) | TRB_IOC;
+
+ if (cycle)
+ control &= cpu_to_le32(~TRB_CYCLE);
+ else
+ control |= cpu_to_le32(TRB_CYCLE);
+
+ if (read) {
+ memset(xdbc.in_buf, 0, XDBC_MAX_PACKET);
+ addr = xdbc.in_dma;
+ xdbc.flags |= XDBC_FLAGS_IN_PROCESS;
+ } else {
+ memset(xdbc.out_buf, 0, XDBC_MAX_PACKET);
+ memcpy(xdbc.out_buf, data, size);
+ addr = xdbc.out_dma;
+ xdbc.flags |= XDBC_FLAGS_OUT_PROCESS;
+ }
+
+ xdbc_queue_trb(ring, lower_32_bits(addr), upper_32_bits(addr), length, control);
+
+ /*
+ * Add a barrier between writes of trb fields and flipping
+ * the cycle bit:
+ */
+ wmb();
+ if (cycle)
+ trb->field[3] |= cpu_to_le32(cycle);
+ else
+ trb->field[3] &= cpu_to_le32(~TRB_CYCLE);
+
+ xdbc_ring_doorbell(read ? IN_EP_DOORBELL : OUT_EP_DOORBELL);
+
+ return size;
+}
+
+static int xdbc_handle_external_reset(void)
+{
+ int ret = 0;
+
+ xdbc.flags = 0;
+ writel(0, &xdbc.xdbc_reg->control);
+ ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_ENABLE, 0, 100000, 10);
+ if (ret)
+ goto reset_out;
+
+ xdbc_mem_init();
+
+ mmiowb();
+
+ ret = xdbc_start();
+ if (ret < 0)
+ goto reset_out;
+
+ xdbc_trace("dbc recovered\n");
+
+ xdbc.flags |= XDBC_FLAGS_INITIALIZED | XDBC_FLAGS_CONFIGURED;
+
+ xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
+
+ return 0;
+
+reset_out:
+ xdbc_trace("failed to recover from external reset\n");
+ return ret;
+}
+
+static int __init xdbc_early_setup(void)
+{
+ int ret;
+
+ writel(0, &xdbc.xdbc_reg->control);
+ ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_ENABLE, 0, 100000, 100);
+ if (ret)
+ return ret;
+
+ /* Allocate the table page: */
+ xdbc.table_base = xdbc_get_page(&xdbc.table_dma);
+ if (!xdbc.table_base)
+ return -ENOMEM;
+
+ /* Get and store the transfer buffer: */
+ xdbc.out_buf = xdbc_get_page(&xdbc.out_dma);
+ if (!xdbc.out_buf)
+ return -ENOMEM;
+
+ /* Allocate the event ring: */
+ ret = xdbc_alloc_ring(&xdbc.evt_seg, &xdbc.evt_ring);
+ if (ret < 0)
+ return ret;
+
+ /* Allocate IN/OUT endpoint transfer rings: */
+ ret = xdbc_alloc_ring(&xdbc.in_seg, &xdbc.in_ring);
+ if (ret < 0)
+ return ret;
+
+ ret = xdbc_alloc_ring(&xdbc.out_seg, &xdbc.out_ring);
+ if (ret < 0)
+ return ret;
+
+ xdbc_mem_init();
+
+ mmiowb();
+
+ ret = xdbc_start();
+ if (ret < 0) {
+ writel(0, &xdbc.xdbc_reg->control);
+ return ret;
+ }
+
+ xdbc.flags |= XDBC_FLAGS_INITIALIZED | XDBC_FLAGS_CONFIGURED;
+
+ xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
+
+ return 0;
+}
+
+int __init early_xdbc_parse_parameter(char *s)
+{
+ unsigned long dbgp_num = 0;
+ u32 bus, dev, func, offset;
+ int ret;
+
+ if (!early_pci_allowed())
+ return -EPERM;
+
+ if (strstr(s, "keep"))
+ early_console_keep = true;
+
+ if (xdbc.xdbc_reg)
+ return 0;
+
+ if (*s && kstrtoul(s, 0, &dbgp_num))
+ dbgp_num = 0;
+
+ pr_notice("dbgp_num: %lu\n", dbgp_num);
+
+ /* Locate the host controller: */
+ ret = xdbc_find_dbgp(dbgp_num, &bus, &dev, &func);
+ if (ret) {
+ pr_notice("failed to locate xhci host\n");
+ return -ENODEV;
+ }
+
+ xdbc.vendor = read_pci_config_16(bus, dev, func, PCI_VENDOR_ID);
+ xdbc.device = read_pci_config_16(bus, dev, func, PCI_DEVICE_ID);
+ xdbc.bus = bus;
+ xdbc.dev = dev;
+ xdbc.func = func;
+
+ /* Map the IO memory: */
+ xdbc.xhci_base = xdbc_map_pci_mmio(bus, dev, func);
+ if (!xdbc.xhci_base)
+ return -EINVAL;
+
+ /* Locate DbC registers: */
+ offset = xhci_find_next_ext_cap(xdbc.xhci_base, 0, XHCI_EXT_CAPS_DEBUG);
+ if (!offset) {
+ pr_notice("xhci host doesn't support debug capability\n");
+ early_iounmap(xdbc.xhci_base, xdbc.xhci_length);
+ xdbc.xhci_base = NULL;
+ xdbc.xhci_length = 0;
+
+ return -ENODEV;
+ }
+ xdbc.xdbc_reg = (struct xdbc_regs __iomem *)(xdbc.xhci_base + offset);
+
+ return 0;
+}
+
+int __init early_xdbc_setup_hardware(void)
+{
+ int ret;
+
+ if (!xdbc.xdbc_reg)
+ return -ENODEV;
+
+ xdbc_bios_handoff();
+
+ raw_spin_lock_init(&xdbc.lock);
+
+ ret = xdbc_early_setup();
+ if (ret) {
+ pr_notice("failed to setup the connection to host\n");
+
+ xdbc_free_ring(&xdbc.evt_ring);
+ xdbc_free_ring(&xdbc.out_ring);
+ xdbc_free_ring(&xdbc.in_ring);
+
+ if (xdbc.table_dma)
+ free_bootmem(xdbc.table_dma, PAGE_SIZE);
+
+ if (xdbc.out_dma)
+ free_bootmem(xdbc.out_dma, PAGE_SIZE);
+
+ xdbc.table_base = NULL;
+ xdbc.out_buf = NULL;
+ }
+
+ return ret;
+}
+
+static void xdbc_handle_port_status(struct xdbc_trb *evt_trb)
+{
+ u32 port_reg;
+
+ port_reg = readl(&xdbc.xdbc_reg->portsc);
+ if (port_reg & PORTSC_CONN_CHANGE) {
+ xdbc_trace("connect status change event\n");
+
+ /* Check whether cable unplugged: */
+ if (!(port_reg & PORTSC_CONN_STATUS)) {
+ xdbc.flags = 0;
+ xdbc_trace("cable unplugged\n");
+ }
+ }
+
+ if (port_reg & PORTSC_RESET_CHANGE)
+ xdbc_trace("port reset change event\n");
+
+ if (port_reg & PORTSC_LINK_CHANGE)
+ xdbc_trace("port link status change event\n");
+
+ if (port_reg & PORTSC_CONFIG_CHANGE)
+ xdbc_trace("config error change\n");
+
+ /* Write back the value to clear RW1C bits: */
+ writel(port_reg, &xdbc.xdbc_reg->portsc);
+}
+
+static void xdbc_handle_tx_event(struct xdbc_trb *evt_trb)
+{
+ size_t remain_length;
+ u32 comp_code;
+ int ep_id;
+
+ comp_code = GET_COMP_CODE(le32_to_cpu(evt_trb->field[2]));
+ remain_length = EVENT_TRB_LEN(le32_to_cpu(evt_trb->field[2]));
+ ep_id = TRB_TO_EP_ID(le32_to_cpu(evt_trb->field[3]));
+
+ switch (comp_code) {
+ case COMP_SUCCESS:
+ remain_length = 0;
+ case COMP_SHORT_PACKET:
+ break;
+ case COMP_TRB_ERROR:
+ case COMP_BABBLE_DETECTED_ERROR:
+ case COMP_USB_TRANSACTION_ERROR:
+ case COMP_STALL_ERROR:
+ default:
+ if (ep_id == XDBC_EPID_OUT)
+ xdbc.flags |= XDBC_FLAGS_OUT_STALL;
+ if (ep_id == XDBC_EPID_IN)
+ xdbc.flags |= XDBC_FLAGS_IN_STALL;
+
+ xdbc_trace("endpoint %d stalled\n", ep_id);
+ break;
+ }
+
+ if (ep_id == XDBC_EPID_IN) {
+ xdbc.flags &= ~XDBC_FLAGS_IN_PROCESS;
+ xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
+ } else if (ep_id == XDBC_EPID_OUT) {
+ xdbc.flags &= ~XDBC_FLAGS_OUT_PROCESS;
+ } else {
+ xdbc_trace("invalid endpoint id %d\n", ep_id);
+ }
+}
+
+static void xdbc_handle_events(void)
+{
+ struct xdbc_trb *evt_trb;
+ bool update_erdp = false;
+ u32 reg;
+ u8 cmd;
+
+ cmd = read_pci_config_byte(xdbc.bus, xdbc.dev, xdbc.func, PCI_COMMAND);
+ if (!(cmd & PCI_COMMAND_MASTER)) {
+ cmd |= PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY;
+ write_pci_config_byte(xdbc.bus, xdbc.dev, xdbc.func, PCI_COMMAND, cmd);
+ }
+
+ if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED))
+ return;
+
+ /* Handle external reset events: */
+ reg = readl(&xdbc.xdbc_reg->control);
+ if (!(reg & CTRL_DBC_ENABLE)) {
+ if (xdbc_handle_external_reset()) {
+ xdbc_trace("failed to recover connection\n");
+ return;
+ }
+ }
+
+ /* Handle configure-exit event: */
+ reg = readl(&xdbc.xdbc_reg->control);
+ if (reg & CTRL_DBC_RUN_CHANGE) {
+ writel(reg, &xdbc.xdbc_reg->control);
+ if (reg & CTRL_DBC_RUN)
+ xdbc.flags |= XDBC_FLAGS_CONFIGURED;
+ else
+ xdbc.flags &= ~XDBC_FLAGS_CONFIGURED;
+ }
+
+ /* Handle endpoint stall event: */
+ reg = readl(&xdbc.xdbc_reg->control);
+ if (reg & CTRL_HALT_IN_TR) {
+ xdbc.flags |= XDBC_FLAGS_IN_STALL;
+ } else {
+ xdbc.flags &= ~XDBC_FLAGS_IN_STALL;
+ if (!(xdbc.flags & XDBC_FLAGS_IN_PROCESS))
+ xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
+ }
+
+ if (reg & CTRL_HALT_OUT_TR)
+ xdbc.flags |= XDBC_FLAGS_OUT_STALL;
+ else
+ xdbc.flags &= ~XDBC_FLAGS_OUT_STALL;
+
+ /* Handle the events in the event ring: */
+ evt_trb = xdbc.evt_ring.dequeue;
+ while ((le32_to_cpu(evt_trb->field[3]) & TRB_CYCLE) == xdbc.evt_ring.cycle_state) {
+ /*
+ * Add a barrier between reading the cycle flag and any
+ * reads of the event's flags/data below:
+ */
+ rmb();
+
+ switch ((le32_to_cpu(evt_trb->field[3]) & TRB_TYPE_BITMASK)) {
+ case TRB_TYPE(TRB_PORT_STATUS):
+ xdbc_handle_port_status(evt_trb);
+ break;
+ case TRB_TYPE(TRB_TRANSFER):
+ xdbc_handle_tx_event(evt_trb);
+ break;
+ default:
+ break;
+ }
+
+ ++(xdbc.evt_ring.dequeue);
+ if (xdbc.evt_ring.dequeue == &xdbc.evt_seg.trbs[TRBS_PER_SEGMENT]) {
+ xdbc.evt_ring.dequeue = xdbc.evt_seg.trbs;
+ xdbc.evt_ring.cycle_state ^= 1;
+ }
+
+ evt_trb = xdbc.evt_ring.dequeue;
+ update_erdp = true;
+ }
+
+ /* Update event ring dequeue pointer: */
+ if (update_erdp)
+ xdbc_write64(__pa(xdbc.evt_ring.dequeue), &xdbc.xdbc_reg->erdp);
+}
+
+static int xdbc_bulk_write(const char *bytes, int size)
+{
+ int ret, timeout = 0;
+ unsigned long flags;
+
+retry:
+ if (in_nmi()) {
+ if (!raw_spin_trylock_irqsave(&xdbc.lock, flags))
+ return -EAGAIN;
+ } else {
+ raw_spin_lock_irqsave(&xdbc.lock, flags);
+ }
+
+ xdbc_handle_events();
+
+ /* Check completion of the previous request: */
+ if ((xdbc.flags & XDBC_FLAGS_OUT_PROCESS) && (timeout < 2000000)) {
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+ udelay(100);
+ timeout += 100;
+ goto retry;
+ }
+
+ if (xdbc.flags & XDBC_FLAGS_OUT_PROCESS) {
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+ xdbc_trace("previous transfer not completed yet\n");
+
+ return -ETIMEDOUT;
+ }
+
+ ret = xdbc_bulk_transfer((void *)bytes, size, false);
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+
+ return ret;
+}
+
+static void early_xdbc_write(struct console *con, const char *str, u32 n)
+{
+ static char buf[XDBC_MAX_PACKET];
+ int chunk, ret;
+ int use_cr = 0;
+
+ if (!xdbc.xdbc_reg)
+ return;
+ memset(buf, 0, XDBC_MAX_PACKET);
+ while (n > 0) {
+ for (chunk = 0; chunk < XDBC_MAX_PACKET && n > 0; str++, chunk++, n--) {
+
+ if (!use_cr && *str == '\n') {
+ use_cr = 1;
+ buf[chunk] = '\r';
+ str--;
+ n++;
+ continue;
+ }
+
+ if (use_cr)
+ use_cr = 0;
+ buf[chunk] = *str;
+ }
+
+ if (chunk > 0) {
+ ret = xdbc_bulk_write(buf, chunk);
+ if (ret < 0)
+ xdbc_trace("missed message {%s}\n", buf);
+ }
+ }
+}
+
+static struct console early_xdbc_console = {
+ .name = "earlyxdbc",
+ .write = early_xdbc_write,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+};
+
+void __init early_xdbc_register_console(void)
+{
+ if (early_console)
+ return;
+
+ early_console = &early_xdbc_console;
+ if (early_console_keep)
+ early_console->flags &= ~CON_BOOT;
+ else
+ early_console->flags |= CON_BOOT;
+ register_console(early_console);
+}
+
+static void xdbc_unregister_console(void)
+{
+ if (early_xdbc_console.flags & CON_ENABLED)
+ unregister_console(&early_xdbc_console);
+}
+
+static int xdbc_scrub_function(void *ptr)
+{
+ unsigned long flags;
+
+ while (true) {
+ raw_spin_lock_irqsave(&xdbc.lock, flags);
+ xdbc_handle_events();
+
+ if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED)) {
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+ break;
+ }
+
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+ schedule_timeout_interruptible(1);
+ }
+
+ xdbc_unregister_console();
+ writel(0, &xdbc.xdbc_reg->control);
+ xdbc_trace("dbc scrub function exits\n");
+
+ return 0;
+}
+
+static int __init xdbc_init(void)
+{
+ unsigned long flags;
+ void __iomem *base;
+ int ret = 0;
+ u32 offset;
+
+ if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED))
+ return 0;
+
+ /*
+ * It's time to shut down the DbC, so that the debug
+ * port can be reused by the host controller:
+ */
+ if (early_xdbc_console.index == -1 ||
+ (early_xdbc_console.flags & CON_BOOT)) {
+ xdbc_trace("hardware not used anymore\n");
+ goto free_and_quit;
+ }
+
+ base = ioremap_nocache(xdbc.xhci_start, xdbc.xhci_length);
+ if (!base) {
+ xdbc_trace("failed to remap the io address\n");
+ ret = -ENOMEM;
+ goto free_and_quit;
+ }
+
+ raw_spin_lock_irqsave(&xdbc.lock, flags);
+ early_iounmap(xdbc.xhci_base, xdbc.xhci_length);
+ xdbc.xhci_base = base;
+ offset = xhci_find_next_ext_cap(xdbc.xhci_base, 0, XHCI_EXT_CAPS_DEBUG);
+ xdbc.xdbc_reg = (struct xdbc_regs __iomem *)(xdbc.xhci_base + offset);
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+
+ kthread_run(xdbc_scrub_function, NULL, "%s", "xdbc");
+
+ return 0;
+
+free_and_quit:
+ xdbc_free_ring(&xdbc.evt_ring);
+ xdbc_free_ring(&xdbc.out_ring);
+ xdbc_free_ring(&xdbc.in_ring);
+ free_bootmem(xdbc.table_dma, PAGE_SIZE);
+ free_bootmem(xdbc.out_dma, PAGE_SIZE);
+ writel(0, &xdbc.xdbc_reg->control);
+ early_iounmap(xdbc.xhci_base, xdbc.xhci_length);
+
+ return ret;
+}
+subsys_initcall(xdbc_init);
diff --git a/drivers/usb/early/xhci-dbc.h b/drivers/usb/early/xhci-dbc.h
new file mode 100644
index 0000000..2df0f6e
--- /dev/null
+++ b/drivers/usb/early/xhci-dbc.h
@@ -0,0 +1,211 @@
+/*
+ * xhci-dbc.h - xHCI debug capability early driver
+ *
+ * Copyright (C) 2016 Intel Corporation
+ *
+ * Author: Lu Baolu <baolu.lu@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __LINUX_XHCI_DBC_H
+#define __LINUX_XHCI_DBC_H
+
+#include <linux/types.h>
+#include <linux/usb/ch9.h>
+
+/*
+ * xHCI Debug Capability Register interfaces:
+ */
+struct xdbc_regs {
+ __le32 capability;
+ __le32 doorbell;
+ __le32 ersts; /* Event Ring Segment Table Size*/
+ __le32 __reserved_0; /* 0c~0f reserved bits */
+ __le64 erstba; /* Event Ring Segment Table Base Address */
+ __le64 erdp; /* Event Ring Dequeue Pointer */
+ __le32 control;
+ __le32 status;
+ __le32 portsc; /* Port status and control */
+ __le32 __reserved_1; /* 2b~28 reserved bits */
+ __le64 dccp; /* Debug Capability Context Pointer */
+ __le32 devinfo1; /* Device Descriptor Info Register 1 */
+ __le32 devinfo2; /* Device Descriptor Info Register 2 */
+};
+
+#define DEBUG_MAX_BURST(p) (((p) >> 16) & 0xff)
+
+#define CTRL_DBC_RUN BIT(0)
+#define CTRL_PORT_ENABLE BIT(1)
+#define CTRL_HALT_OUT_TR BIT(2)
+#define CTRL_HALT_IN_TR BIT(3)
+#define CTRL_DBC_RUN_CHANGE BIT(4)
+#define CTRL_DBC_ENABLE BIT(31)
+
+#define DCST_DEBUG_PORT(p) (((p) >> 24) & 0xff)
+
+#define PORTSC_CONN_STATUS BIT(0)
+#define PORTSC_CONN_CHANGE BIT(17)
+#define PORTSC_RESET_CHANGE BIT(21)
+#define PORTSC_LINK_CHANGE BIT(22)
+#define PORTSC_CONFIG_CHANGE BIT(23)
+
+/*
+ * xHCI Debug Capability data structures:
+ */
+struct xdbc_trb {
+ __le32 field[4];
+};
+
+struct xdbc_erst_entry {
+ __le64 seg_addr;
+ __le32 seg_size;
+ __le32 __reserved_0;
+};
+
+struct xdbc_info_context {
+ __le64 string0;
+ __le64 manufacturer;
+ __le64 product;
+ __le64 serial;
+ __le32 length;
+ __le32 __reserved_0[7];
+};
+
+struct xdbc_ep_context {
+ __le32 ep_info1;
+ __le32 ep_info2;
+ __le64 deq;
+ __le32 tx_info;
+ __le32 __reserved_0[11];
+};
+
+struct xdbc_context {
+ struct xdbc_info_context info;
+ struct xdbc_ep_context out;
+ struct xdbc_ep_context in;
+};
+
+#define XDBC_INFO_CONTEXT_SIZE 48
+#define XDBC_MAX_STRING_LENGTH 64
+#define XDBC_STRING_MANUFACTURER "Linux"
+#define XDBC_STRING_PRODUCT "Remote GDB"
+#define XDBC_STRING_SERIAL "0001"
+
+struct xdbc_strings {
+ char string0[XDBC_MAX_STRING_LENGTH];
+ char manufacturer[XDBC_MAX_STRING_LENGTH];
+ char product[XDBC_MAX_STRING_LENGTH];
+ char serial[XDBC_MAX_STRING_LENGTH];
+};
+
+#define XDBC_PROTOCOL 1 /* GNU Remote Debug Command Set */
+#define XDBC_VENDOR_ID 0x1d6b /* Linux Foundation 0x1d6b */
+#define XDBC_PRODUCT_ID 0x0004 /* __le16 idProduct; device 0004 */
+#define XDBC_DEVICE_REV 0x0010 /* 0.10 */
+
+/*
+ * xHCI Debug Capability software state structures:
+ */
+struct xdbc_segment {
+ struct xdbc_trb *trbs;
+ dma_addr_t dma;
+};
+
+#define XDBC_TRBS_PER_SEGMENT 256
+
+struct xdbc_ring {
+ struct xdbc_segment *segment;
+ struct xdbc_trb *enqueue;
+ struct xdbc_trb *dequeue;
+ u32 cycle_state;
+};
+
+#define XDBC_EPID_OUT 2
+#define XDBC_EPID_IN 3
+
+struct xdbc_state {
+ u16 vendor;
+ u16 device;
+ u32 bus;
+ u32 dev;
+ u32 func;
+ void __iomem *xhci_base;
+ u64 xhci_start;
+ size_t xhci_length;
+ int port_number;
+
+ /* DbC register base */
+ struct xdbc_regs __iomem *xdbc_reg;
+
+ /* DbC table page */
+ dma_addr_t table_dma;
+ void *table_base;
+
+ /* event ring segment table */
+ dma_addr_t erst_dma;
+ size_t erst_size;
+ void *erst_base;
+
+ /* event ring segments */
+ struct xdbc_ring evt_ring;
+ struct xdbc_segment evt_seg;
+
+ /* debug capability contexts */
+ dma_addr_t dbcc_dma;
+ size_t dbcc_size;
+ void *dbcc_base;
+
+ /* descriptor strings */
+ dma_addr_t string_dma;
+ size_t string_size;
+ void *string_base;
+
+ /* bulk OUT endpoint */
+ struct xdbc_ring out_ring;
+ struct xdbc_segment out_seg;
+ void *out_buf;
+ dma_addr_t out_dma;
+
+ /* bulk IN endpoint */
+ struct xdbc_ring in_ring;
+ struct xdbc_segment in_seg;
+ void *in_buf;
+ dma_addr_t in_dma;
+
+ u32 flags;
+
+ /* spinlock for early_xdbc_write() reentrancy */
+ raw_spinlock_t lock;
+};
+
+#define XDBC_PCI_MAX_BUSES 256
+#define XDBC_PCI_MAX_DEVICES 32
+#define XDBC_PCI_MAX_FUNCTION 8
+
+#define XDBC_TABLE_ENTRY_SIZE 64
+#define XDBC_ERST_ENTRY_NUM 1
+#define XDBC_DBCC_ENTRY_NUM 3
+#define XDBC_STRING_ENTRY_NUM 4
+
+/* Bits definitions for xdbc_state.flags: */
+#define XDBC_FLAGS_INITIALIZED BIT(0)
+#define XDBC_FLAGS_IN_STALL BIT(1)
+#define XDBC_FLAGS_OUT_STALL BIT(2)
+#define XDBC_FLAGS_IN_PROCESS BIT(3)
+#define XDBC_FLAGS_OUT_PROCESS BIT(4)
+#define XDBC_FLAGS_CONFIGURED BIT(5)
+
+#define XDBC_MAX_PACKET 1024
+
+/* Door bell target: */
+#define OUT_EP_DOORBELL 0
+#define IN_EP_DOORBELL 1
+#define DOOR_BELL_TARGET(p) (((p) & 0xff) << 8)
+
+#define xdbc_read64(regs) xhci_read_64(NULL, (regs))
+#define xdbc_write64(val, regs) xhci_write_64(NULL, (val), (regs))
+
+#endif /* __LINUX_XHCI_DBC_H */
diff --git a/include/linux/usb/xhci-dbgp.h b/include/linux/usb/xhci-dbgp.h
new file mode 100644
index 0000000..80c1cca
--- /dev/null
+++ b/include/linux/usb/xhci-dbgp.h
@@ -0,0 +1,29 @@
+/*
+ * Standalone xHCI debug capability driver
+ *
+ * Copyright (C) 2016 Intel Corporation
+ *
+ * Author: Lu Baolu <baolu.lu@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __LINUX_XHCI_DBGP_H
+#define __LINUX_XHCI_DBGP_H
+
+#ifdef CONFIG_EARLY_PRINTK_USB_XDBC
+int __init early_xdbc_parse_parameter(char *s);
+int __init early_xdbc_setup_hardware(void);
+void __init early_xdbc_register_console(void);
+#else
+static inline int __init early_xdbc_setup_hardware(void)
+{
+ return -ENODEV;
+}
+static inline void __init early_xdbc_register_console(void)
+{
+}
+#endif /* CONFIG_EARLY_PRINTK_USB_XDBC */
+#endif /* __LINUX_XHCI_DBGP_H */
--
2.1.4
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH v8 3/5] x86: add support for earlyprintk via USB3 debug port
2017-03-21 8:01 [PATCH v8 0/5] usb: early: add support for early printk through USB3 debug port Lu Baolu
2017-03-21 8:01 ` [PATCH v8 1/5] x86: add simple udelay calibration Lu Baolu
2017-03-21 8:01 ` [PATCH v8 2/5] usb: early: add driver for xhci debug capability Lu Baolu
@ 2017-03-21 8:01 ` Lu Baolu
2017-03-21 12:20 ` [tip:x86/debug] x86/earlyprintk: Add " tip-bot for Lu Baolu
2017-03-21 8:01 ` [PATCH v8 4/5] usb: serial: add dbc debug device support to usb_debug Lu Baolu
` (2 subsequent siblings)
5 siblings, 1 reply; 42+ messages in thread
From: Lu Baolu @ 2017-03-21 8:01 UTC (permalink / raw)
To: Greg Kroah-Hartman, Ingo Molnar
Cc: Mathias Nyman, tglx, peterz, linux-usb, x86, linux-kernel, Lu Baolu
Add support for earlyprintk by writing debug messages to the
USB3 debug port. Users can use this type of early printk by
specifying the kernel parameter of "earlyprintk=xdbc". This
gives users a chance of providing debugging output.
The hardware for USB3 debug port requires DMA memory blocks.
This requires to delay setting up debugging hardware and
registering boot console until the memblocks are filled.
Cc: Ingo Molnar <mingo@redhat.com>
Cc: x86@kernel.org
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
Documentation/admin-guide/kernel-parameters.txt | 1 +
arch/x86/kernel/early_printk.c | 5 +++++
arch/x86/kernel/setup.c | 4 ++++
3 files changed, 10 insertions(+)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 2ba45ca..ea1293d 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -989,6 +989,7 @@
earlyprintk=ttySn[,baudrate]
earlyprintk=dbgp[debugController#]
earlyprintk=pciserial,bus:device.function[,baudrate]
+ earlyprintk=xdbc[xhciController#]
earlyprintk is useful when the kernel crashes before
the normal console is initialized. It is not enabled by
diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c
index 8a12199..0f08403 100644
--- a/arch/x86/kernel/early_printk.c
+++ b/arch/x86/kernel/early_printk.c
@@ -17,6 +17,7 @@
#include <asm/intel-mid.h>
#include <asm/pgtable.h>
#include <linux/usb/ehci_def.h>
+#include <linux/usb/xhci-dbgp.h>
#include <linux/efi.h>
#include <asm/efi.h>
#include <asm/pci_x86.h>
@@ -381,6 +382,10 @@ static int __init setup_early_printk(char *buf)
if (!strncmp(buf, "efi", 3))
early_console_register(&early_efi_console, keep);
#endif
+#ifdef CONFIG_EARLY_PRINTK_USB_XDBC
+ if (!strncmp(buf, "xdbc", 4))
+ early_xdbc_parse_parameter(buf + 4);
+#endif
buf++;
}
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index e70204e..2600b1d 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -70,6 +70,7 @@
#include <linux/tboot.h>
#include <linux/jiffies.h>
+#include <linux/usb/xhci-dbgp.h>
#include <video/edid.h>
#include <asm/mtrr.h>
@@ -1144,6 +1145,9 @@ void __init setup_arch(char **cmdline_p)
memblock_set_current_limit(ISA_END_ADDRESS);
memblock_x86_fill();
+ if (!early_xdbc_setup_hardware())
+ early_xdbc_register_console();
+
reserve_bios_regions();
if (efi_enabled(EFI_MEMMAP)) {
--
2.1.4
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH v8 4/5] usb: serial: add dbc debug device support to usb_debug
2017-03-21 8:01 [PATCH v8 0/5] usb: early: add support for early printk through USB3 debug port Lu Baolu
` (2 preceding siblings ...)
2017-03-21 8:01 ` [PATCH v8 3/5] x86: add support for earlyprintk via USB3 debug port Lu Baolu
@ 2017-03-21 8:01 ` Lu Baolu
2017-03-21 12:21 ` [tip:x86/debug] usb/serial: Add DBC " tip-bot for Lu Baolu
2017-03-21 8:01 ` [PATCH v8 5/5] usb: doc: add document for USB3 debug port usage Lu Baolu
2017-03-21 11:33 ` [PATCH v8 0/5] usb: early: add support for early printk through USB3 debug port Ingo Molnar
5 siblings, 1 reply; 42+ messages in thread
From: Lu Baolu @ 2017-03-21 8:01 UTC (permalink / raw)
To: Greg Kroah-Hartman, Ingo Molnar
Cc: Mathias Nyman, tglx, peterz, linux-usb, x86, linux-kernel, Lu Baolu
This patch adds dbc debug device support to the usb_debug driver.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Acked-by: Johan Hovold <johan@kernel.org>
---
drivers/usb/serial/usb_debug.c | 28 +++++++++++++++++++++++++---
1 file changed, 25 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/serial/usb_debug.c b/drivers/usb/serial/usb_debug.c
index ca2fa5b..92f7e5c 100644
--- a/drivers/usb/serial/usb_debug.c
+++ b/drivers/usb/serial/usb_debug.c
@@ -32,7 +32,18 @@ static const struct usb_device_id id_table[] = {
{ USB_DEVICE(0x0525, 0x127a) },
{ },
};
-MODULE_DEVICE_TABLE(usb, id_table);
+
+static const struct usb_device_id dbc_id_table[] = {
+ { USB_DEVICE(0x1d6b, 0x0004) },
+ { },
+};
+
+static const struct usb_device_id id_table_combined[] = {
+ { USB_DEVICE(0x0525, 0x127a) },
+ { USB_DEVICE(0x1d6b, 0x0004) },
+ { },
+};
+MODULE_DEVICE_TABLE(usb, id_table_combined);
/* This HW really does not support a serial break, so one will be
* emulated when ever the break state is set to true.
@@ -71,9 +82,20 @@ static struct usb_serial_driver debug_device = {
.process_read_urb = usb_debug_process_read_urb,
};
+static struct usb_serial_driver dbc_device = {
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "xhci_dbc",
+ },
+ .id_table = dbc_id_table,
+ .num_ports = 1,
+ .break_ctl = usb_debug_break_ctl,
+ .process_read_urb = usb_debug_process_read_urb,
+};
+
static struct usb_serial_driver * const serial_drivers[] = {
- &debug_device, NULL
+ &debug_device, &dbc_device, NULL
};
-module_usb_serial_driver(serial_drivers, id_table);
+module_usb_serial_driver(serial_drivers, id_table_combined);
MODULE_LICENSE("GPL");
--
2.1.4
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [PATCH v8 5/5] usb: doc: add document for USB3 debug port usage
2017-03-21 8:01 [PATCH v8 0/5] usb: early: add support for early printk through USB3 debug port Lu Baolu
` (3 preceding siblings ...)
2017-03-21 8:01 ` [PATCH v8 4/5] usb: serial: add dbc debug device support to usb_debug Lu Baolu
@ 2017-03-21 8:01 ` Lu Baolu
2017-03-21 12:21 ` [tip:x86/debug] usb/doc: Add " tip-bot for Lu Baolu
2017-03-21 11:33 ` [PATCH v8 0/5] usb: early: add support for early printk through USB3 debug port Ingo Molnar
5 siblings, 1 reply; 42+ messages in thread
From: Lu Baolu @ 2017-03-21 8:01 UTC (permalink / raw)
To: Greg Kroah-Hartman, Ingo Molnar
Cc: Mathias Nyman, tglx, peterz, linux-usb, x86, linux-kernel,
Lu Baolu, linux-doc
Add Documentation/usb/usb3-debug-port.rst. This document includes
the guide for using USB3 debug port.
Cc: linux-doc@vger.kernel.org
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
Documentation/usb/usb3-debug-port.rst | 100 ++++++++++++++++++++++++++++++++++
1 file changed, 100 insertions(+)
create mode 100644 Documentation/usb/usb3-debug-port.rst
diff --git a/Documentation/usb/usb3-debug-port.rst b/Documentation/usb/usb3-debug-port.rst
new file mode 100644
index 0000000..feb1a36
--- /dev/null
+++ b/Documentation/usb/usb3-debug-port.rst
@@ -0,0 +1,100 @@
+===============
+USB3 debug port
+===============
+
+:Author: Lu Baolu <baolu.lu@linux.intel.com>
+:Date: March 2017
+
+GENERAL
+=======
+
+This is a HOWTO for using the USB3 debug port on x86 systems.
+
+Before using any kernel debugging functionality based on USB3
+debug port, you need to::
+
+ 1) check whether any USB3 debug port is available in
+ your system;
+ 2) check which port is used for debugging purposes;
+ 3) have a USB 3.0 super-speed A-to-A debugging cable.
+
+INTRODUCTION
+============
+
+The xHCI debug capability (DbC) is an optional but standalone
+functionality provided by the xHCI host controller. The xHCI
+specification describes DbC in the section 7.6.
+
+When DbC is initialized and enabled, it will present a debug
+device through the debug port (normally the first USB3
+super-speed port). The debug device is fully compliant with
+the USB framework and provides the equivalent of a very high
+performance full-duplex serial link between the debug target
+(the system under debugging) and a debug host.
+
+EARLY PRINTK
+============
+
+DbC has been designed to log early printk messages. One use for
+this feature is kernel debugging. For example, when your machine
+crashes very early before the regular console code is initialized.
+Other uses include simpler, lockless logging instead of a full-
+blown printk console driver and klogd.
+
+On the debug target system, you need to customize a debugging
+kernel with CONFIG_EARLY_PRINTK_USB_XDBC enabled. And, add below
+kernel boot parameter::
+
+ "earlyprintk=xdbc"
+
+If there are multiple xHCI controllers in your system, you can
+append a host contoller index to this kernel parameter. This
+index starts from 0.
+
+Current design doesn't support DbC runtime suspend/resume. As
+the result, you'd better disable runtime power management for
+USB subsystem by adding below kernel boot parameter::
+
+ "usbcore.autosuspend=-1"
+
+Before starting the debug target, you should connect the debug
+port to a USB port (root port or port of any external hub) on
+the debug host. The cable used to connect these two ports
+should be a USB 3.0 super-speed A-to-A debugging cable.
+
+During early boot of the debug target, DbC will be detected and
+initialized. After initialization, the debug host should be able
+to enumerate the debug device in debug target. The debug host
+will then bind the debug device with the usb_debug driver module
+and create the /dev/ttyUSB device.
+
+If the debug device enumeration goes smoothly, you should be able
+to see below kernel messages on the debug host::
+
+ # tail -f /var/log/kern.log
+ [ 1815.983374] usb 4-3: new SuperSpeed USB device number 4 using xhci_hcd
+ [ 1815.999595] usb 4-3: LPM exit latency is zeroed, disabling LPM.
+ [ 1815.999899] usb 4-3: New USB device found, idVendor=1d6b, idProduct=0004
+ [ 1815.999902] usb 4-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
+ [ 1815.999903] usb 4-3: Product: Remote GDB
+ [ 1815.999904] usb 4-3: Manufacturer: Linux
+ [ 1815.999905] usb 4-3: SerialNumber: 0001
+ [ 1816.000240] usb_debug 4-3:1.0: xhci_dbc converter detected
+ [ 1816.000360] usb 4-3: xhci_dbc converter now attached to ttyUSB0
+
+You can use any communication program, for example minicom, to
+read and view the messages. Below simple bash scripts can help
+you to check the sanity of the setup.
+
+.. code-block:: sh
+
+ ===== start of bash scripts =============
+ #!/bin/bash
+
+ while true ; do
+ while [ ! -d /sys/class/tty/ttyUSB0 ] ; do
+ :
+ done
+ cat /dev/ttyUSB0
+ done
+ ===== end of bash scripts ===============
--
2.1.4
^ permalink raw reply related [flat|nested] 42+ messages in thread
* Re: [PATCH v8 0/5] usb: early: add support for early printk through USB3 debug port
2017-03-21 8:01 [PATCH v8 0/5] usb: early: add support for early printk through USB3 debug port Lu Baolu
` (4 preceding siblings ...)
2017-03-21 8:01 ` [PATCH v8 5/5] usb: doc: add document for USB3 debug port usage Lu Baolu
@ 2017-03-21 11:33 ` Ingo Molnar
2017-03-21 12:27 ` Greg Kroah-Hartman
2017-03-22 2:23 ` Lu Baolu
5 siblings, 2 replies; 42+ messages in thread
From: Ingo Molnar @ 2017-03-21 11:33 UTC (permalink / raw)
To: Lu Baolu
Cc: Greg Kroah-Hartman, Ingo Molnar, Mathias Nyman, tglx, peterz,
linux-usb, x86, linux-kernel, Johan Hovold, H. Peter Anvin,
Peter Zijlstra
* Lu Baolu <baolu.lu@linux.intel.com> wrote:
> xHCI debug capability (DbC) is an optional but standalone
> functionality provided by an xHCI host controller. With DbC
> hardware initialized, the system will present a debug device
> through the USB3 debug port (normally the first USB3 port).
> The debug device is fully compliant with the USB framework
> and provides the equivalent of a very high performance (USB3)
> full-duplex serial link between the debug host and target.
> The DbC functionality is independent of xHCI host.
>
> This patch set adds support for early printk functionality
> through a USB3 debug port by 1) initializing and enabling
> the DbC hardware during early boot; 2) registering a boot
> console to the system so that early printk messages can go
> through the USB3 debug port. It also includes some lines
> of changes in usb_debug driver so that it can be bound when
> a USB3 debug device is enumerated.
>
[...]
>
> Lu Baolu (5):
> x86: add simple udelay calibration
> usb: early: add driver for xhci debug capability
> x86: add support for earlyprintk via USB3 debug port
> usb: serial: add dbc debug device support to usb_debug
> usb: doc: add document for USB3 debug port usage
>
> Documentation/admin-guide/kernel-parameters.txt | 1 +
> Documentation/usb/usb3-debug-port.rst | 100 +++
> arch/x86/Kconfig.debug | 23 +
> arch/x86/kernel/early_printk.c | 5 +
> arch/x86/kernel/setup.c | 26 +
> drivers/usb/Makefile | 2 +-
> drivers/usb/early/Makefile | 1 +
> drivers/usb/early/xhci-dbc.c | 1014 +++++++++++++++++++++++
> drivers/usb/early/xhci-dbc.h | 211 +++++
> drivers/usb/serial/usb_debug.c | 28 +-
> include/linux/usb/xhci-dbgp.h | 29 +
> 11 files changed, 1436 insertions(+), 4 deletions(-)
> create mode 100644 Documentation/usb/usb3-debug-port.rst
> create mode 100644 drivers/usb/early/xhci-dbc.c
> create mode 100644 drivers/usb/early/xhci-dbc.h
> create mode 100644 include/linux/usb/xhci-dbgp.h
Ok, this has now become a high quality series with picture-perfect patches AFAICS.
Thomas also gave his Acked-by to all the patches.
I've applied them locally to -tip (it appears the USB maintainers are still fine
with this being carried in tip:x86/debug for a v4.12 merge, right?), and will push
them out and will propagate them to linux-next as well if they pass testing.
Thanks for the great work!
Ingo
^ permalink raw reply [flat|nested] 42+ messages in thread
* [tip:x86/debug] x86/timers: Add simple udelay calibration
2017-03-21 8:01 ` [PATCH v8 1/5] x86: add simple udelay calibration Lu Baolu
@ 2017-03-21 12:19 ` tip-bot for Lu Baolu
2017-05-24 16:56 ` Jan Kiszka
2017-05-02 22:38 ` [PATCH v8 1/5] x86: add " Boris Ostrovsky
2017-05-02 22:38 ` Boris Ostrovsky
2 siblings, 1 reply; 42+ messages in thread
From: tip-bot for Lu Baolu @ 2017-03-21 12:19 UTC (permalink / raw)
To: linux-tip-commits
Cc: bp, dvlasenk, tglx, peterz, brgerst, mathias.nyman, mingo, hpa,
gregkh, linux-kernel, jpoimboe, luto, torvalds, baolu.lu
Commit-ID: dd759d93f4dd4fd2f345a78ad1223bb3edf3ee7b
Gitweb: http://git.kernel.org/tip/dd759d93f4dd4fd2f345a78ad1223bb3edf3ee7b
Author: Lu Baolu <baolu.lu@linux.intel.com>
AuthorDate: Tue, 21 Mar 2017 16:01:29 +0800
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 21 Mar 2017 12:28:45 +0100
x86/timers: Add simple udelay calibration
Add a simple udelay calibration in x86 architecture-specific
boot-time initializations. This will get a workable estimate
for loops_per_jiffy. Hence, udelay() could be used after this
initialization.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-usb@vger.kernel.org
Link: http://lkml.kernel.org/r/1490083293-3792-2-git-send-email-baolu.lu@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/setup.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 4bf0c89..e70204e 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -837,6 +837,26 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
return 0;
}
+static void __init simple_udelay_calibration(void)
+{
+ unsigned int tsc_khz, cpu_khz;
+ unsigned long lpj;
+
+ if (!boot_cpu_has(X86_FEATURE_TSC))
+ return;
+
+ cpu_khz = x86_platform.calibrate_cpu();
+ tsc_khz = x86_platform.calibrate_tsc();
+
+ tsc_khz = tsc_khz ? : cpu_khz;
+ if (!tsc_khz)
+ return;
+
+ lpj = tsc_khz * 1000;
+ do_div(lpj, HZ);
+ loops_per_jiffy = lpj;
+}
+
/*
* Determine if we were loaded by an EFI loader. If so, then we have also been
* passed the efi memmap, systab, etc., so we should use these data structures
@@ -985,6 +1005,8 @@ void __init setup_arch(char **cmdline_p)
*/
x86_configure_nx();
+ simple_udelay_calibration();
+
parse_early_param();
#ifdef CONFIG_MEMORY_HOTPLUG
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [tip:x86/debug] usb/early: Add driver for xhci debug capability
2017-03-21 8:01 ` [PATCH v8 2/5] usb: early: add driver for xhci debug capability Lu Baolu
@ 2017-03-21 12:19 ` tip-bot for Lu Baolu
2017-05-30 13:46 ` [PATCH v8 2/5] usb: early: add " Vlastimil Babka
1 sibling, 0 replies; 42+ messages in thread
From: tip-bot for Lu Baolu @ 2017-03-21 12:19 UTC (permalink / raw)
To: linux-tip-commits
Cc: peterz, hpa, baolu.lu, linux-kernel, mingo, gregkh,
mathias.nyman, tglx, torvalds
Commit-ID: aeb9dd1de98c1a5f2007ea5d2a154c1244caf8a0
Gitweb: http://git.kernel.org/tip/aeb9dd1de98c1a5f2007ea5d2a154c1244caf8a0
Author: Lu Baolu <baolu.lu@linux.intel.com>
AuthorDate: Tue, 21 Mar 2017 16:01:30 +0800
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 21 Mar 2017 12:30:05 +0100
usb/early: Add driver for xhci debug capability
XHCI debug capability (DbC) is an optional but standalone
functionality provided by an xHCI host controller. Software
learns this capability by walking through the extended
capability list of the host. XHCI specification describes
DbC in section 7.6.
This patch introduces the code to probe and initialize the
debug capability hardware during early boot. With hardware
initialized, the debug target (system on which this code is
running) will present a debug device through the debug port
(normally the first USB3 port). The debug device is fully
compliant with the USB framework and provides the equivalent
of a very high performance (USB3) full-duplex serial link
between the debug host and target. The DbC functionality is
independent of the xHCI host. There isn't any precondition
from the xHCI host side for the DbC to work.
One use for this feature is kernel debugging, for example
when your machine crashes very early before the regular
console code is initialized. Other uses include simpler,
lockless logging instead of a full-blown printk console
driver and klogd.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-usb@vger.kernel.org
Link: http://lkml.kernel.org/r/1490083293-3792-3-git-send-email-baolu.lu@linux.intel.com
[ Small fix to the Kconfig help text. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/Kconfig.debug | 27 +-
drivers/usb/Makefile | 2 +-
drivers/usb/early/Makefile | 1 +
drivers/usb/early/xhci-dbc.c | 1014 +++++++++++++++++++++++++++++++++++++++++
drivers/usb/early/xhci-dbc.h | 211 +++++++++
include/linux/usb/xhci-dbgp.h | 29 ++
6 files changed, 1281 insertions(+), 3 deletions(-)
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index 63c1d13..fcb7604 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -5,6 +5,9 @@ config TRACE_IRQFLAGS_SUPPORT
source "lib/Kconfig.debug"
+config EARLY_PRINTK_USB
+ bool
+
config X86_VERBOSE_BOOTUP
bool "Enable verbose x86 bootup info messages"
default y
@@ -23,19 +26,20 @@ config EARLY_PRINTK
This is useful for kernel debugging when your machine crashes very
early before the console code is initialized. For normal operation
it is not recommended because it looks ugly and doesn't cooperate
- with klogd/syslogd or the X server. You should normally N here,
+ with klogd/syslogd or the X server. You should normally say N here,
unless you want to debug such a crash.
config EARLY_PRINTK_DBGP
bool "Early printk via EHCI debug port"
depends on EARLY_PRINTK && PCI
+ select EARLY_PRINTK_USB
---help---
Write kernel log output directly into the EHCI debug port.
This is useful for kernel debugging when your machine crashes very
early before the console code is initialized. For normal operation
it is not recommended because it looks ugly and doesn't cooperate
- with klogd/syslogd or the X server. You should normally N here,
+ with klogd/syslogd or the X server. You should normally say N here,
unless you want to debug such a crash. You need usb debug device.
config EARLY_PRINTK_EFI
@@ -48,6 +52,25 @@ config EARLY_PRINTK_EFI
This is useful for kernel debugging when your machine crashes very
early before the console code is initialized.
+config EARLY_PRINTK_USB_XDBC
+ bool "Early printk via the xHCI debug port"
+ depends on EARLY_PRINTK && PCI
+ select EARLY_PRINTK_USB
+ ---help---
+ Write kernel log output directly into the xHCI debug port.
+
+ One use for this feature is kernel debugging, for example when your
+ machine crashes very early before the regular console code is
+ initialized. Other uses include simpler, lockless logging instead of
+ a full-blown printk console driver + klogd.
+
+ For normal production environments this is normally not recommended,
+ because it doesn't feed events into klogd/syslogd and doesn't try to
+ print anything on the screen.
+
+ You should normally say N here, unless you want to debug early
+ crashes or need a very simple printk logging facility.
+
config X86_PTDUMP_CORE
def_bool n
diff --git a/drivers/usb/Makefile b/drivers/usb/Makefile
index 7791af6..53d1356 100644
--- a/drivers/usb/Makefile
+++ b/drivers/usb/Makefile
@@ -49,7 +49,7 @@ obj-$(CONFIG_USB_MICROTEK) += image/
obj-$(CONFIG_USB_SERIAL) += serial/
obj-$(CONFIG_USB) += misc/
-obj-$(CONFIG_EARLY_PRINTK_DBGP) += early/
+obj-$(CONFIG_EARLY_PRINTK_USB) += early/
obj-$(CONFIG_USB_ATM) += atm/
obj-$(CONFIG_USB_SPEEDTOUCH) += atm/
diff --git a/drivers/usb/early/Makefile b/drivers/usb/early/Makefile
index 24bbe51..fcde228 100644
--- a/drivers/usb/early/Makefile
+++ b/drivers/usb/early/Makefile
@@ -3,3 +3,4 @@
#
obj-$(CONFIG_EARLY_PRINTK_DBGP) += ehci-dbgp.o
+obj-$(CONFIG_EARLY_PRINTK_USB_XDBC) += xhci-dbc.o
diff --git a/drivers/usb/early/xhci-dbc.c b/drivers/usb/early/xhci-dbc.c
new file mode 100644
index 0000000..1268818
--- /dev/null
+++ b/drivers/usb/early/xhci-dbc.c
@@ -0,0 +1,1014 @@
+/**
+ * xhci-dbc.c - xHCI debug capability early driver
+ *
+ * Copyright (C) 2016 Intel Corporation
+ *
+ * Author: Lu Baolu <baolu.lu@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
+
+#include <linux/console.h>
+#include <linux/pci_regs.h>
+#include <linux/pci_ids.h>
+#include <linux/bootmem.h>
+#include <linux/io.h>
+#include <asm/pci-direct.h>
+#include <asm/fixmap.h>
+#include <linux/bcd.h>
+#include <linux/export.h>
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
+
+#include "../host/xhci.h"
+#include "xhci-dbc.h"
+
+static struct xdbc_state xdbc;
+static bool early_console_keep;
+
+#define XDBC_TRACE
+#ifdef XDBC_TRACE
+#define xdbc_trace trace_printk
+#else
+static inline void xdbc_trace(const char *fmt, ...) { }
+#endif /* XDBC_TRACE */
+
+static void __iomem * __init xdbc_map_pci_mmio(u32 bus, u32 dev, u32 func)
+{
+ u64 val64, sz64, mask64;
+ void __iomem *base;
+ u32 val, sz;
+ u8 byte;
+
+ val = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0);
+ write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0, ~0);
+ sz = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0);
+ write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0, val);
+
+ if (val == 0xffffffff || sz == 0xffffffff) {
+ pr_notice("invalid mmio bar\n");
+ return NULL;
+ }
+
+ val64 = val & PCI_BASE_ADDRESS_MEM_MASK;
+ sz64 = sz & PCI_BASE_ADDRESS_MEM_MASK;
+ mask64 = PCI_BASE_ADDRESS_MEM_MASK;
+
+ if ((val & PCI_BASE_ADDRESS_MEM_TYPE_MASK) == PCI_BASE_ADDRESS_MEM_TYPE_64) {
+ val = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4);
+ write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4, ~0);
+ sz = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4);
+ write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4, val);
+
+ val64 |= (u64)val << 32;
+ sz64 |= (u64)sz << 32;
+ mask64 |= ~0ULL << 32;
+ }
+
+ sz64 &= mask64;
+
+ if (!sz64) {
+ pr_notice("invalid mmio address\n");
+ return NULL;
+ }
+
+ sz64 = 1ULL << __ffs64(sz64);
+
+ /* Check if the mem space is enabled: */
+ byte = read_pci_config_byte(bus, dev, func, PCI_COMMAND);
+ if (!(byte & PCI_COMMAND_MEMORY)) {
+ byte |= PCI_COMMAND_MEMORY;
+ write_pci_config_byte(bus, dev, func, PCI_COMMAND, byte);
+ }
+
+ xdbc.xhci_start = val64;
+ xdbc.xhci_length = sz64;
+ base = early_ioremap(val64, sz64);
+
+ return base;
+}
+
+static void * __init xdbc_get_page(dma_addr_t *dma_addr)
+{
+ void *virt;
+
+ virt = alloc_bootmem_pages_nopanic(PAGE_SIZE);
+ if (!virt)
+ return NULL;
+
+ if (dma_addr)
+ *dma_addr = (dma_addr_t)__pa(virt);
+
+ return virt;
+}
+
+static u32 __init xdbc_find_dbgp(int xdbc_num, u32 *b, u32 *d, u32 *f)
+{
+ u32 bus, dev, func, class;
+
+ for (bus = 0; bus < XDBC_PCI_MAX_BUSES; bus++) {
+ for (dev = 0; dev < XDBC_PCI_MAX_DEVICES; dev++) {
+ for (func = 0; func < XDBC_PCI_MAX_FUNCTION; func++) {
+
+ class = read_pci_config(bus, dev, func, PCI_CLASS_REVISION);
+ if ((class >> 8) != PCI_CLASS_SERIAL_USB_XHCI)
+ continue;
+
+ if (xdbc_num-- != 0)
+ continue;
+
+ *b = bus;
+ *d = dev;
+ *f = func;
+
+ return 0;
+ }
+ }
+ }
+
+ return -1;
+}
+
+static int handshake(void __iomem *ptr, u32 mask, u32 done, int wait, int delay)
+{
+ u32 result;
+
+ do {
+ result = readl(ptr);
+ result &= mask;
+ if (result == done)
+ return 0;
+ udelay(delay);
+ wait -= delay;
+ } while (wait > 0);
+
+ return -ETIMEDOUT;
+}
+
+static void __init xdbc_bios_handoff(void)
+{
+ int offset, timeout;
+ u32 val;
+
+ offset = xhci_find_next_ext_cap(xdbc.xhci_base, 0, XHCI_EXT_CAPS_LEGACY);
+ val = readl(xdbc.xhci_base + offset);
+
+ if (val & XHCI_HC_BIOS_OWNED) {
+ writel(val | XHCI_HC_OS_OWNED, xdbc.xhci_base + offset);
+ timeout = handshake(xdbc.xhci_base + offset, XHCI_HC_BIOS_OWNED, 0, 5000, 10);
+
+ if (timeout) {
+ pr_notice("failed to hand over xHCI control from BIOS\n");
+ writel(val & ~XHCI_HC_BIOS_OWNED, xdbc.xhci_base + offset);
+ }
+ }
+
+ /* Disable BIOS SMIs and clear all SMI events: */
+ val = readl(xdbc.xhci_base + offset + XHCI_LEGACY_CONTROL_OFFSET);
+ val &= XHCI_LEGACY_DISABLE_SMI;
+ val |= XHCI_LEGACY_SMI_EVENTS;
+ writel(val, xdbc.xhci_base + offset + XHCI_LEGACY_CONTROL_OFFSET);
+}
+
+static int __init
+xdbc_alloc_ring(struct xdbc_segment *seg, struct xdbc_ring *ring)
+{
+ seg->trbs = xdbc_get_page(&seg->dma);
+ if (!seg->trbs)
+ return -ENOMEM;
+
+ ring->segment = seg;
+
+ return 0;
+}
+
+static void __init xdbc_free_ring(struct xdbc_ring *ring)
+{
+ struct xdbc_segment *seg = ring->segment;
+
+ if (!seg)
+ return;
+
+ free_bootmem(seg->dma, PAGE_SIZE);
+ ring->segment = NULL;
+}
+
+static void xdbc_reset_ring(struct xdbc_ring *ring)
+{
+ struct xdbc_segment *seg = ring->segment;
+ struct xdbc_trb *link_trb;
+
+ memset(seg->trbs, 0, PAGE_SIZE);
+
+ ring->enqueue = seg->trbs;
+ ring->dequeue = seg->trbs;
+ ring->cycle_state = 1;
+
+ if (ring != &xdbc.evt_ring) {
+ link_trb = &seg->trbs[XDBC_TRBS_PER_SEGMENT - 1];
+ link_trb->field[0] = cpu_to_le32(lower_32_bits(seg->dma));
+ link_trb->field[1] = cpu_to_le32(upper_32_bits(seg->dma));
+ link_trb->field[3] = cpu_to_le32(TRB_TYPE(TRB_LINK)) | cpu_to_le32(LINK_TOGGLE);
+ }
+}
+
+static inline void xdbc_put_utf16(u16 *s, const char *c, size_t size)
+{
+ int i;
+
+ for (i = 0; i < size; i++)
+ s[i] = cpu_to_le16(c[i]);
+}
+
+static void xdbc_mem_init(void)
+{
+ struct xdbc_ep_context *ep_in, *ep_out;
+ struct usb_string_descriptor *s_desc;
+ struct xdbc_erst_entry *entry;
+ struct xdbc_strings *strings;
+ struct xdbc_context *ctx;
+ unsigned int max_burst;
+ u32 string_length;
+ int index = 0;
+ u32 dev_info;
+
+ xdbc_reset_ring(&xdbc.evt_ring);
+ xdbc_reset_ring(&xdbc.in_ring);
+ xdbc_reset_ring(&xdbc.out_ring);
+ memset(xdbc.table_base, 0, PAGE_SIZE);
+ memset(xdbc.out_buf, 0, PAGE_SIZE);
+
+ /* Initialize event ring segment table: */
+ xdbc.erst_size = 16;
+ xdbc.erst_base = xdbc.table_base + index * XDBC_TABLE_ENTRY_SIZE;
+ xdbc.erst_dma = xdbc.table_dma + index * XDBC_TABLE_ENTRY_SIZE;
+
+ index += XDBC_ERST_ENTRY_NUM;
+ entry = (struct xdbc_erst_entry *)xdbc.erst_base;
+
+ entry->seg_addr = cpu_to_le64(xdbc.evt_seg.dma);
+ entry->seg_size = cpu_to_le32(XDBC_TRBS_PER_SEGMENT);
+ entry->__reserved_0 = 0;
+
+ /* Initialize ERST registers: */
+ writel(1, &xdbc.xdbc_reg->ersts);
+ xdbc_write64(xdbc.erst_dma, &xdbc.xdbc_reg->erstba);
+ xdbc_write64(xdbc.evt_seg.dma, &xdbc.xdbc_reg->erdp);
+
+ /* Debug capability contexts: */
+ xdbc.dbcc_size = 64 * 3;
+ xdbc.dbcc_base = xdbc.table_base + index * XDBC_TABLE_ENTRY_SIZE;
+ xdbc.dbcc_dma = xdbc.table_dma + index * XDBC_TABLE_ENTRY_SIZE;
+
+ index += XDBC_DBCC_ENTRY_NUM;
+
+ /* Popluate the strings: */
+ xdbc.string_size = sizeof(struct xdbc_strings);
+ xdbc.string_base = xdbc.table_base + index * XDBC_TABLE_ENTRY_SIZE;
+ xdbc.string_dma = xdbc.table_dma + index * XDBC_TABLE_ENTRY_SIZE;
+ strings = (struct xdbc_strings *)xdbc.string_base;
+
+ index += XDBC_STRING_ENTRY_NUM;
+
+ /* Serial string: */
+ s_desc = (struct usb_string_descriptor *)strings->serial;
+ s_desc->bLength = (strlen(XDBC_STRING_SERIAL) + 1) * 2;
+ s_desc->bDescriptorType = USB_DT_STRING;
+
+ xdbc_put_utf16(s_desc->wData, XDBC_STRING_SERIAL, strlen(XDBC_STRING_SERIAL));
+ string_length = s_desc->bLength;
+ string_length <<= 8;
+
+ /* Product string: */
+ s_desc = (struct usb_string_descriptor *)strings->product;
+ s_desc->bLength = (strlen(XDBC_STRING_PRODUCT) + 1) * 2;
+ s_desc->bDescriptorType = USB_DT_STRING;
+
+ xdbc_put_utf16(s_desc->wData, XDBC_STRING_PRODUCT, strlen(XDBC_STRING_PRODUCT));
+ string_length += s_desc->bLength;
+ string_length <<= 8;
+
+ /* Manufacture string: */
+ s_desc = (struct usb_string_descriptor *)strings->manufacturer;
+ s_desc->bLength = (strlen(XDBC_STRING_MANUFACTURER) + 1) * 2;
+ s_desc->bDescriptorType = USB_DT_STRING;
+
+ xdbc_put_utf16(s_desc->wData, XDBC_STRING_MANUFACTURER, strlen(XDBC_STRING_MANUFACTURER));
+ string_length += s_desc->bLength;
+ string_length <<= 8;
+
+ /* String0: */
+ strings->string0[0] = 4;
+ strings->string0[1] = USB_DT_STRING;
+ strings->string0[2] = 0x09;
+ strings->string0[3] = 0x04;
+
+ string_length += 4;
+
+ /* Populate info Context: */
+ ctx = (struct xdbc_context *)xdbc.dbcc_base;
+
+ ctx->info.string0 = cpu_to_le64(xdbc.string_dma);
+ ctx->info.manufacturer = cpu_to_le64(xdbc.string_dma + XDBC_MAX_STRING_LENGTH);
+ ctx->info.product = cpu_to_le64(xdbc.string_dma + XDBC_MAX_STRING_LENGTH * 2);
+ ctx->info.serial = cpu_to_le64(xdbc.string_dma + XDBC_MAX_STRING_LENGTH * 3);
+ ctx->info.length = cpu_to_le32(string_length);
+
+ /* Populate bulk out endpoint context: */
+ max_burst = DEBUG_MAX_BURST(readl(&xdbc.xdbc_reg->control));
+ ep_out = (struct xdbc_ep_context *)&ctx->out;
+
+ ep_out->ep_info1 = 0;
+ ep_out->ep_info2 = cpu_to_le32(EP_TYPE(BULK_OUT_EP) | MAX_PACKET(1024) | MAX_BURST(max_burst));
+ ep_out->deq = cpu_to_le64(xdbc.out_seg.dma | xdbc.out_ring.cycle_state);
+
+ /* Populate bulk in endpoint context: */
+ ep_in = (struct xdbc_ep_context *)&ctx->in;
+
+ ep_in->ep_info1 = 0;
+ ep_in->ep_info2 = cpu_to_le32(EP_TYPE(BULK_OUT_EP) | MAX_PACKET(1024) | MAX_BURST(max_burst));
+ ep_in->deq = cpu_to_le64(xdbc.in_seg.dma | xdbc.in_ring.cycle_state);
+
+ /* Set DbC context and info registers: */
+ xdbc_write64(xdbc.dbcc_dma, &xdbc.xdbc_reg->dccp);
+
+ dev_info = cpu_to_le32((XDBC_VENDOR_ID << 16) | XDBC_PROTOCOL);
+ writel(dev_info, &xdbc.xdbc_reg->devinfo1);
+
+ dev_info = cpu_to_le32((XDBC_DEVICE_REV << 16) | XDBC_PRODUCT_ID);
+ writel(dev_info, &xdbc.xdbc_reg->devinfo2);
+
+ xdbc.in_buf = xdbc.out_buf + XDBC_MAX_PACKET;
+ xdbc.in_dma = xdbc.out_dma + XDBC_MAX_PACKET;
+}
+
+static void xdbc_do_reset_debug_port(u32 id, u32 count)
+{
+ void __iomem *ops_reg;
+ void __iomem *portsc;
+ u32 val, cap_length;
+ int i;
+
+ cap_length = readl(xdbc.xhci_base) & 0xff;
+ ops_reg = xdbc.xhci_base + cap_length;
+
+ id--;
+ for (i = id; i < (id + count); i++) {
+ portsc = ops_reg + 0x400 + i * 0x10;
+ val = readl(portsc);
+ if (!(val & PORT_CONNECT))
+ writel(val | PORT_RESET, portsc);
+ }
+}
+
+static void xdbc_reset_debug_port(void)
+{
+ u32 val, port_offset, port_count;
+ int offset = 0;
+
+ do {
+ offset = xhci_find_next_ext_cap(xdbc.xhci_base, offset, XHCI_EXT_CAPS_PROTOCOL);
+ if (!offset)
+ break;
+
+ val = readl(xdbc.xhci_base + offset);
+ if (XHCI_EXT_PORT_MAJOR(val) != 0x3)
+ continue;
+
+ val = readl(xdbc.xhci_base + offset + 8);
+ port_offset = XHCI_EXT_PORT_OFF(val);
+ port_count = XHCI_EXT_PORT_COUNT(val);
+
+ xdbc_do_reset_debug_port(port_offset, port_count);
+ } while (1);
+}
+
+static void
+xdbc_queue_trb(struct xdbc_ring *ring, u32 field1, u32 field2, u32 field3, u32 field4)
+{
+ struct xdbc_trb *trb, *link_trb;
+
+ trb = ring->enqueue;
+ trb->field[0] = cpu_to_le32(field1);
+ trb->field[1] = cpu_to_le32(field2);
+ trb->field[2] = cpu_to_le32(field3);
+ trb->field[3] = cpu_to_le32(field4);
+
+ ++(ring->enqueue);
+ if (ring->enqueue >= &ring->segment->trbs[TRBS_PER_SEGMENT - 1]) {
+ link_trb = ring->enqueue;
+ if (ring->cycle_state)
+ link_trb->field[3] |= cpu_to_le32(TRB_CYCLE);
+ else
+ link_trb->field[3] &= cpu_to_le32(~TRB_CYCLE);
+
+ ring->enqueue = ring->segment->trbs;
+ ring->cycle_state ^= 1;
+ }
+}
+
+static void xdbc_ring_doorbell(int target)
+{
+ writel(DOOR_BELL_TARGET(target), &xdbc.xdbc_reg->doorbell);
+}
+
+static int xdbc_start(void)
+{
+ u32 ctrl, status;
+ int ret;
+
+ ctrl = readl(&xdbc.xdbc_reg->control);
+ writel(ctrl | CTRL_DBC_ENABLE | CTRL_PORT_ENABLE, &xdbc.xdbc_reg->control);
+ ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_ENABLE, CTRL_DBC_ENABLE, 100000, 100);
+ if (ret) {
+ xdbc_trace("failed to initialize hardware\n");
+ return ret;
+ }
+
+ /* Reset port to avoid bus hang: */
+ if (xdbc.vendor == PCI_VENDOR_ID_INTEL)
+ xdbc_reset_debug_port();
+
+ /* Wait for port connection: */
+ ret = handshake(&xdbc.xdbc_reg->portsc, PORTSC_CONN_STATUS, PORTSC_CONN_STATUS, 5000000, 100);
+ if (ret) {
+ xdbc_trace("waiting for connection timed out\n");
+ return ret;
+ }
+
+ /* Wait for debug device to be configured: */
+ ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_RUN, CTRL_DBC_RUN, 5000000, 100);
+ if (ret) {
+ xdbc_trace("waiting for device configuration timed out\n");
+ return ret;
+ }
+
+ /* Check port number: */
+ status = readl(&xdbc.xdbc_reg->status);
+ if (!DCST_DEBUG_PORT(status)) {
+ xdbc_trace("invalid root hub port number\n");
+ return -ENODEV;
+ }
+
+ xdbc.port_number = DCST_DEBUG_PORT(status);
+
+ xdbc_trace("DbC is running now, control 0x%08x port ID %d\n",
+ readl(&xdbc.xdbc_reg->control), xdbc.port_number);
+
+ return 0;
+}
+
+static int xdbc_bulk_transfer(void *data, int size, bool read)
+{
+ struct xdbc_ring *ring;
+ struct xdbc_trb *trb;
+ u32 length, control;
+ u32 cycle;
+ u64 addr;
+
+ if (size > XDBC_MAX_PACKET) {
+ xdbc_trace("bad parameter, size %d\n", size);
+ return -EINVAL;
+ }
+
+ if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED) ||
+ !(xdbc.flags & XDBC_FLAGS_CONFIGURED) ||
+ (!read && (xdbc.flags & XDBC_FLAGS_OUT_STALL)) ||
+ (read && (xdbc.flags & XDBC_FLAGS_IN_STALL))) {
+
+ xdbc_trace("connection not ready, flags %08x\n", xdbc.flags);
+ return -EIO;
+ }
+
+ ring = (read ? &xdbc.in_ring : &xdbc.out_ring);
+ trb = ring->enqueue;
+ cycle = ring->cycle_state;
+ length = TRB_LEN(size);
+ control = TRB_TYPE(TRB_NORMAL) | TRB_IOC;
+
+ if (cycle)
+ control &= cpu_to_le32(~TRB_CYCLE);
+ else
+ control |= cpu_to_le32(TRB_CYCLE);
+
+ if (read) {
+ memset(xdbc.in_buf, 0, XDBC_MAX_PACKET);
+ addr = xdbc.in_dma;
+ xdbc.flags |= XDBC_FLAGS_IN_PROCESS;
+ } else {
+ memset(xdbc.out_buf, 0, XDBC_MAX_PACKET);
+ memcpy(xdbc.out_buf, data, size);
+ addr = xdbc.out_dma;
+ xdbc.flags |= XDBC_FLAGS_OUT_PROCESS;
+ }
+
+ xdbc_queue_trb(ring, lower_32_bits(addr), upper_32_bits(addr), length, control);
+
+ /*
+ * Add a barrier between writes of trb fields and flipping
+ * the cycle bit:
+ */
+ wmb();
+ if (cycle)
+ trb->field[3] |= cpu_to_le32(cycle);
+ else
+ trb->field[3] &= cpu_to_le32(~TRB_CYCLE);
+
+ xdbc_ring_doorbell(read ? IN_EP_DOORBELL : OUT_EP_DOORBELL);
+
+ return size;
+}
+
+static int xdbc_handle_external_reset(void)
+{
+ int ret = 0;
+
+ xdbc.flags = 0;
+ writel(0, &xdbc.xdbc_reg->control);
+ ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_ENABLE, 0, 100000, 10);
+ if (ret)
+ goto reset_out;
+
+ xdbc_mem_init();
+
+ mmiowb();
+
+ ret = xdbc_start();
+ if (ret < 0)
+ goto reset_out;
+
+ xdbc_trace("dbc recovered\n");
+
+ xdbc.flags |= XDBC_FLAGS_INITIALIZED | XDBC_FLAGS_CONFIGURED;
+
+ xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
+
+ return 0;
+
+reset_out:
+ xdbc_trace("failed to recover from external reset\n");
+ return ret;
+}
+
+static int __init xdbc_early_setup(void)
+{
+ int ret;
+
+ writel(0, &xdbc.xdbc_reg->control);
+ ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_ENABLE, 0, 100000, 100);
+ if (ret)
+ return ret;
+
+ /* Allocate the table page: */
+ xdbc.table_base = xdbc_get_page(&xdbc.table_dma);
+ if (!xdbc.table_base)
+ return -ENOMEM;
+
+ /* Get and store the transfer buffer: */
+ xdbc.out_buf = xdbc_get_page(&xdbc.out_dma);
+ if (!xdbc.out_buf)
+ return -ENOMEM;
+
+ /* Allocate the event ring: */
+ ret = xdbc_alloc_ring(&xdbc.evt_seg, &xdbc.evt_ring);
+ if (ret < 0)
+ return ret;
+
+ /* Allocate IN/OUT endpoint transfer rings: */
+ ret = xdbc_alloc_ring(&xdbc.in_seg, &xdbc.in_ring);
+ if (ret < 0)
+ return ret;
+
+ ret = xdbc_alloc_ring(&xdbc.out_seg, &xdbc.out_ring);
+ if (ret < 0)
+ return ret;
+
+ xdbc_mem_init();
+
+ mmiowb();
+
+ ret = xdbc_start();
+ if (ret < 0) {
+ writel(0, &xdbc.xdbc_reg->control);
+ return ret;
+ }
+
+ xdbc.flags |= XDBC_FLAGS_INITIALIZED | XDBC_FLAGS_CONFIGURED;
+
+ xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
+
+ return 0;
+}
+
+int __init early_xdbc_parse_parameter(char *s)
+{
+ unsigned long dbgp_num = 0;
+ u32 bus, dev, func, offset;
+ int ret;
+
+ if (!early_pci_allowed())
+ return -EPERM;
+
+ if (strstr(s, "keep"))
+ early_console_keep = true;
+
+ if (xdbc.xdbc_reg)
+ return 0;
+
+ if (*s && kstrtoul(s, 0, &dbgp_num))
+ dbgp_num = 0;
+
+ pr_notice("dbgp_num: %lu\n", dbgp_num);
+
+ /* Locate the host controller: */
+ ret = xdbc_find_dbgp(dbgp_num, &bus, &dev, &func);
+ if (ret) {
+ pr_notice("failed to locate xhci host\n");
+ return -ENODEV;
+ }
+
+ xdbc.vendor = read_pci_config_16(bus, dev, func, PCI_VENDOR_ID);
+ xdbc.device = read_pci_config_16(bus, dev, func, PCI_DEVICE_ID);
+ xdbc.bus = bus;
+ xdbc.dev = dev;
+ xdbc.func = func;
+
+ /* Map the IO memory: */
+ xdbc.xhci_base = xdbc_map_pci_mmio(bus, dev, func);
+ if (!xdbc.xhci_base)
+ return -EINVAL;
+
+ /* Locate DbC registers: */
+ offset = xhci_find_next_ext_cap(xdbc.xhci_base, 0, XHCI_EXT_CAPS_DEBUG);
+ if (!offset) {
+ pr_notice("xhci host doesn't support debug capability\n");
+ early_iounmap(xdbc.xhci_base, xdbc.xhci_length);
+ xdbc.xhci_base = NULL;
+ xdbc.xhci_length = 0;
+
+ return -ENODEV;
+ }
+ xdbc.xdbc_reg = (struct xdbc_regs __iomem *)(xdbc.xhci_base + offset);
+
+ return 0;
+}
+
+int __init early_xdbc_setup_hardware(void)
+{
+ int ret;
+
+ if (!xdbc.xdbc_reg)
+ return -ENODEV;
+
+ xdbc_bios_handoff();
+
+ raw_spin_lock_init(&xdbc.lock);
+
+ ret = xdbc_early_setup();
+ if (ret) {
+ pr_notice("failed to setup the connection to host\n");
+
+ xdbc_free_ring(&xdbc.evt_ring);
+ xdbc_free_ring(&xdbc.out_ring);
+ xdbc_free_ring(&xdbc.in_ring);
+
+ if (xdbc.table_dma)
+ free_bootmem(xdbc.table_dma, PAGE_SIZE);
+
+ if (xdbc.out_dma)
+ free_bootmem(xdbc.out_dma, PAGE_SIZE);
+
+ xdbc.table_base = NULL;
+ xdbc.out_buf = NULL;
+ }
+
+ return ret;
+}
+
+static void xdbc_handle_port_status(struct xdbc_trb *evt_trb)
+{
+ u32 port_reg;
+
+ port_reg = readl(&xdbc.xdbc_reg->portsc);
+ if (port_reg & PORTSC_CONN_CHANGE) {
+ xdbc_trace("connect status change event\n");
+
+ /* Check whether cable unplugged: */
+ if (!(port_reg & PORTSC_CONN_STATUS)) {
+ xdbc.flags = 0;
+ xdbc_trace("cable unplugged\n");
+ }
+ }
+
+ if (port_reg & PORTSC_RESET_CHANGE)
+ xdbc_trace("port reset change event\n");
+
+ if (port_reg & PORTSC_LINK_CHANGE)
+ xdbc_trace("port link status change event\n");
+
+ if (port_reg & PORTSC_CONFIG_CHANGE)
+ xdbc_trace("config error change\n");
+
+ /* Write back the value to clear RW1C bits: */
+ writel(port_reg, &xdbc.xdbc_reg->portsc);
+}
+
+static void xdbc_handle_tx_event(struct xdbc_trb *evt_trb)
+{
+ size_t remain_length;
+ u32 comp_code;
+ int ep_id;
+
+ comp_code = GET_COMP_CODE(le32_to_cpu(evt_trb->field[2]));
+ remain_length = EVENT_TRB_LEN(le32_to_cpu(evt_trb->field[2]));
+ ep_id = TRB_TO_EP_ID(le32_to_cpu(evt_trb->field[3]));
+
+ switch (comp_code) {
+ case COMP_SUCCESS:
+ remain_length = 0;
+ case COMP_SHORT_PACKET:
+ break;
+ case COMP_TRB_ERROR:
+ case COMP_BABBLE_DETECTED_ERROR:
+ case COMP_USB_TRANSACTION_ERROR:
+ case COMP_STALL_ERROR:
+ default:
+ if (ep_id == XDBC_EPID_OUT)
+ xdbc.flags |= XDBC_FLAGS_OUT_STALL;
+ if (ep_id == XDBC_EPID_IN)
+ xdbc.flags |= XDBC_FLAGS_IN_STALL;
+
+ xdbc_trace("endpoint %d stalled\n", ep_id);
+ break;
+ }
+
+ if (ep_id == XDBC_EPID_IN) {
+ xdbc.flags &= ~XDBC_FLAGS_IN_PROCESS;
+ xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
+ } else if (ep_id == XDBC_EPID_OUT) {
+ xdbc.flags &= ~XDBC_FLAGS_OUT_PROCESS;
+ } else {
+ xdbc_trace("invalid endpoint id %d\n", ep_id);
+ }
+}
+
+static void xdbc_handle_events(void)
+{
+ struct xdbc_trb *evt_trb;
+ bool update_erdp = false;
+ u32 reg;
+ u8 cmd;
+
+ cmd = read_pci_config_byte(xdbc.bus, xdbc.dev, xdbc.func, PCI_COMMAND);
+ if (!(cmd & PCI_COMMAND_MASTER)) {
+ cmd |= PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY;
+ write_pci_config_byte(xdbc.bus, xdbc.dev, xdbc.func, PCI_COMMAND, cmd);
+ }
+
+ if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED))
+ return;
+
+ /* Handle external reset events: */
+ reg = readl(&xdbc.xdbc_reg->control);
+ if (!(reg & CTRL_DBC_ENABLE)) {
+ if (xdbc_handle_external_reset()) {
+ xdbc_trace("failed to recover connection\n");
+ return;
+ }
+ }
+
+ /* Handle configure-exit event: */
+ reg = readl(&xdbc.xdbc_reg->control);
+ if (reg & CTRL_DBC_RUN_CHANGE) {
+ writel(reg, &xdbc.xdbc_reg->control);
+ if (reg & CTRL_DBC_RUN)
+ xdbc.flags |= XDBC_FLAGS_CONFIGURED;
+ else
+ xdbc.flags &= ~XDBC_FLAGS_CONFIGURED;
+ }
+
+ /* Handle endpoint stall event: */
+ reg = readl(&xdbc.xdbc_reg->control);
+ if (reg & CTRL_HALT_IN_TR) {
+ xdbc.flags |= XDBC_FLAGS_IN_STALL;
+ } else {
+ xdbc.flags &= ~XDBC_FLAGS_IN_STALL;
+ if (!(xdbc.flags & XDBC_FLAGS_IN_PROCESS))
+ xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
+ }
+
+ if (reg & CTRL_HALT_OUT_TR)
+ xdbc.flags |= XDBC_FLAGS_OUT_STALL;
+ else
+ xdbc.flags &= ~XDBC_FLAGS_OUT_STALL;
+
+ /* Handle the events in the event ring: */
+ evt_trb = xdbc.evt_ring.dequeue;
+ while ((le32_to_cpu(evt_trb->field[3]) & TRB_CYCLE) == xdbc.evt_ring.cycle_state) {
+ /*
+ * Add a barrier between reading the cycle flag and any
+ * reads of the event's flags/data below:
+ */
+ rmb();
+
+ switch ((le32_to_cpu(evt_trb->field[3]) & TRB_TYPE_BITMASK)) {
+ case TRB_TYPE(TRB_PORT_STATUS):
+ xdbc_handle_port_status(evt_trb);
+ break;
+ case TRB_TYPE(TRB_TRANSFER):
+ xdbc_handle_tx_event(evt_trb);
+ break;
+ default:
+ break;
+ }
+
+ ++(xdbc.evt_ring.dequeue);
+ if (xdbc.evt_ring.dequeue == &xdbc.evt_seg.trbs[TRBS_PER_SEGMENT]) {
+ xdbc.evt_ring.dequeue = xdbc.evt_seg.trbs;
+ xdbc.evt_ring.cycle_state ^= 1;
+ }
+
+ evt_trb = xdbc.evt_ring.dequeue;
+ update_erdp = true;
+ }
+
+ /* Update event ring dequeue pointer: */
+ if (update_erdp)
+ xdbc_write64(__pa(xdbc.evt_ring.dequeue), &xdbc.xdbc_reg->erdp);
+}
+
+static int xdbc_bulk_write(const char *bytes, int size)
+{
+ int ret, timeout = 0;
+ unsigned long flags;
+
+retry:
+ if (in_nmi()) {
+ if (!raw_spin_trylock_irqsave(&xdbc.lock, flags))
+ return -EAGAIN;
+ } else {
+ raw_spin_lock_irqsave(&xdbc.lock, flags);
+ }
+
+ xdbc_handle_events();
+
+ /* Check completion of the previous request: */
+ if ((xdbc.flags & XDBC_FLAGS_OUT_PROCESS) && (timeout < 2000000)) {
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+ udelay(100);
+ timeout += 100;
+ goto retry;
+ }
+
+ if (xdbc.flags & XDBC_FLAGS_OUT_PROCESS) {
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+ xdbc_trace("previous transfer not completed yet\n");
+
+ return -ETIMEDOUT;
+ }
+
+ ret = xdbc_bulk_transfer((void *)bytes, size, false);
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+
+ return ret;
+}
+
+static void early_xdbc_write(struct console *con, const char *str, u32 n)
+{
+ static char buf[XDBC_MAX_PACKET];
+ int chunk, ret;
+ int use_cr = 0;
+
+ if (!xdbc.xdbc_reg)
+ return;
+ memset(buf, 0, XDBC_MAX_PACKET);
+ while (n > 0) {
+ for (chunk = 0; chunk < XDBC_MAX_PACKET && n > 0; str++, chunk++, n--) {
+
+ if (!use_cr && *str == '\n') {
+ use_cr = 1;
+ buf[chunk] = '\r';
+ str--;
+ n++;
+ continue;
+ }
+
+ if (use_cr)
+ use_cr = 0;
+ buf[chunk] = *str;
+ }
+
+ if (chunk > 0) {
+ ret = xdbc_bulk_write(buf, chunk);
+ if (ret < 0)
+ xdbc_trace("missed message {%s}\n", buf);
+ }
+ }
+}
+
+static struct console early_xdbc_console = {
+ .name = "earlyxdbc",
+ .write = early_xdbc_write,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+};
+
+void __init early_xdbc_register_console(void)
+{
+ if (early_console)
+ return;
+
+ early_console = &early_xdbc_console;
+ if (early_console_keep)
+ early_console->flags &= ~CON_BOOT;
+ else
+ early_console->flags |= CON_BOOT;
+ register_console(early_console);
+}
+
+static void xdbc_unregister_console(void)
+{
+ if (early_xdbc_console.flags & CON_ENABLED)
+ unregister_console(&early_xdbc_console);
+}
+
+static int xdbc_scrub_function(void *ptr)
+{
+ unsigned long flags;
+
+ while (true) {
+ raw_spin_lock_irqsave(&xdbc.lock, flags);
+ xdbc_handle_events();
+
+ if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED)) {
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+ break;
+ }
+
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+ schedule_timeout_interruptible(1);
+ }
+
+ xdbc_unregister_console();
+ writel(0, &xdbc.xdbc_reg->control);
+ xdbc_trace("dbc scrub function exits\n");
+
+ return 0;
+}
+
+static int __init xdbc_init(void)
+{
+ unsigned long flags;
+ void __iomem *base;
+ int ret = 0;
+ u32 offset;
+
+ if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED))
+ return 0;
+
+ /*
+ * It's time to shut down the DbC, so that the debug
+ * port can be reused by the host controller:
+ */
+ if (early_xdbc_console.index == -1 ||
+ (early_xdbc_console.flags & CON_BOOT)) {
+ xdbc_trace("hardware not used anymore\n");
+ goto free_and_quit;
+ }
+
+ base = ioremap_nocache(xdbc.xhci_start, xdbc.xhci_length);
+ if (!base) {
+ xdbc_trace("failed to remap the io address\n");
+ ret = -ENOMEM;
+ goto free_and_quit;
+ }
+
+ raw_spin_lock_irqsave(&xdbc.lock, flags);
+ early_iounmap(xdbc.xhci_base, xdbc.xhci_length);
+ xdbc.xhci_base = base;
+ offset = xhci_find_next_ext_cap(xdbc.xhci_base, 0, XHCI_EXT_CAPS_DEBUG);
+ xdbc.xdbc_reg = (struct xdbc_regs __iomem *)(xdbc.xhci_base + offset);
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+
+ kthread_run(xdbc_scrub_function, NULL, "%s", "xdbc");
+
+ return 0;
+
+free_and_quit:
+ xdbc_free_ring(&xdbc.evt_ring);
+ xdbc_free_ring(&xdbc.out_ring);
+ xdbc_free_ring(&xdbc.in_ring);
+ free_bootmem(xdbc.table_dma, PAGE_SIZE);
+ free_bootmem(xdbc.out_dma, PAGE_SIZE);
+ writel(0, &xdbc.xdbc_reg->control);
+ early_iounmap(xdbc.xhci_base, xdbc.xhci_length);
+
+ return ret;
+}
+subsys_initcall(xdbc_init);
diff --git a/drivers/usb/early/xhci-dbc.h b/drivers/usb/early/xhci-dbc.h
new file mode 100644
index 0000000..2df0f6e
--- /dev/null
+++ b/drivers/usb/early/xhci-dbc.h
@@ -0,0 +1,211 @@
+/*
+ * xhci-dbc.h - xHCI debug capability early driver
+ *
+ * Copyright (C) 2016 Intel Corporation
+ *
+ * Author: Lu Baolu <baolu.lu@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __LINUX_XHCI_DBC_H
+#define __LINUX_XHCI_DBC_H
+
+#include <linux/types.h>
+#include <linux/usb/ch9.h>
+
+/*
+ * xHCI Debug Capability Register interfaces:
+ */
+struct xdbc_regs {
+ __le32 capability;
+ __le32 doorbell;
+ __le32 ersts; /* Event Ring Segment Table Size*/
+ __le32 __reserved_0; /* 0c~0f reserved bits */
+ __le64 erstba; /* Event Ring Segment Table Base Address */
+ __le64 erdp; /* Event Ring Dequeue Pointer */
+ __le32 control;
+ __le32 status;
+ __le32 portsc; /* Port status and control */
+ __le32 __reserved_1; /* 2b~28 reserved bits */
+ __le64 dccp; /* Debug Capability Context Pointer */
+ __le32 devinfo1; /* Device Descriptor Info Register 1 */
+ __le32 devinfo2; /* Device Descriptor Info Register 2 */
+};
+
+#define DEBUG_MAX_BURST(p) (((p) >> 16) & 0xff)
+
+#define CTRL_DBC_RUN BIT(0)
+#define CTRL_PORT_ENABLE BIT(1)
+#define CTRL_HALT_OUT_TR BIT(2)
+#define CTRL_HALT_IN_TR BIT(3)
+#define CTRL_DBC_RUN_CHANGE BIT(4)
+#define CTRL_DBC_ENABLE BIT(31)
+
+#define DCST_DEBUG_PORT(p) (((p) >> 24) & 0xff)
+
+#define PORTSC_CONN_STATUS BIT(0)
+#define PORTSC_CONN_CHANGE BIT(17)
+#define PORTSC_RESET_CHANGE BIT(21)
+#define PORTSC_LINK_CHANGE BIT(22)
+#define PORTSC_CONFIG_CHANGE BIT(23)
+
+/*
+ * xHCI Debug Capability data structures:
+ */
+struct xdbc_trb {
+ __le32 field[4];
+};
+
+struct xdbc_erst_entry {
+ __le64 seg_addr;
+ __le32 seg_size;
+ __le32 __reserved_0;
+};
+
+struct xdbc_info_context {
+ __le64 string0;
+ __le64 manufacturer;
+ __le64 product;
+ __le64 serial;
+ __le32 length;
+ __le32 __reserved_0[7];
+};
+
+struct xdbc_ep_context {
+ __le32 ep_info1;
+ __le32 ep_info2;
+ __le64 deq;
+ __le32 tx_info;
+ __le32 __reserved_0[11];
+};
+
+struct xdbc_context {
+ struct xdbc_info_context info;
+ struct xdbc_ep_context out;
+ struct xdbc_ep_context in;
+};
+
+#define XDBC_INFO_CONTEXT_SIZE 48
+#define XDBC_MAX_STRING_LENGTH 64
+#define XDBC_STRING_MANUFACTURER "Linux"
+#define XDBC_STRING_PRODUCT "Remote GDB"
+#define XDBC_STRING_SERIAL "0001"
+
+struct xdbc_strings {
+ char string0[XDBC_MAX_STRING_LENGTH];
+ char manufacturer[XDBC_MAX_STRING_LENGTH];
+ char product[XDBC_MAX_STRING_LENGTH];
+ char serial[XDBC_MAX_STRING_LENGTH];
+};
+
+#define XDBC_PROTOCOL 1 /* GNU Remote Debug Command Set */
+#define XDBC_VENDOR_ID 0x1d6b /* Linux Foundation 0x1d6b */
+#define XDBC_PRODUCT_ID 0x0004 /* __le16 idProduct; device 0004 */
+#define XDBC_DEVICE_REV 0x0010 /* 0.10 */
+
+/*
+ * xHCI Debug Capability software state structures:
+ */
+struct xdbc_segment {
+ struct xdbc_trb *trbs;
+ dma_addr_t dma;
+};
+
+#define XDBC_TRBS_PER_SEGMENT 256
+
+struct xdbc_ring {
+ struct xdbc_segment *segment;
+ struct xdbc_trb *enqueue;
+ struct xdbc_trb *dequeue;
+ u32 cycle_state;
+};
+
+#define XDBC_EPID_OUT 2
+#define XDBC_EPID_IN 3
+
+struct xdbc_state {
+ u16 vendor;
+ u16 device;
+ u32 bus;
+ u32 dev;
+ u32 func;
+ void __iomem *xhci_base;
+ u64 xhci_start;
+ size_t xhci_length;
+ int port_number;
+
+ /* DbC register base */
+ struct xdbc_regs __iomem *xdbc_reg;
+
+ /* DbC table page */
+ dma_addr_t table_dma;
+ void *table_base;
+
+ /* event ring segment table */
+ dma_addr_t erst_dma;
+ size_t erst_size;
+ void *erst_base;
+
+ /* event ring segments */
+ struct xdbc_ring evt_ring;
+ struct xdbc_segment evt_seg;
+
+ /* debug capability contexts */
+ dma_addr_t dbcc_dma;
+ size_t dbcc_size;
+ void *dbcc_base;
+
+ /* descriptor strings */
+ dma_addr_t string_dma;
+ size_t string_size;
+ void *string_base;
+
+ /* bulk OUT endpoint */
+ struct xdbc_ring out_ring;
+ struct xdbc_segment out_seg;
+ void *out_buf;
+ dma_addr_t out_dma;
+
+ /* bulk IN endpoint */
+ struct xdbc_ring in_ring;
+ struct xdbc_segment in_seg;
+ void *in_buf;
+ dma_addr_t in_dma;
+
+ u32 flags;
+
+ /* spinlock for early_xdbc_write() reentrancy */
+ raw_spinlock_t lock;
+};
+
+#define XDBC_PCI_MAX_BUSES 256
+#define XDBC_PCI_MAX_DEVICES 32
+#define XDBC_PCI_MAX_FUNCTION 8
+
+#define XDBC_TABLE_ENTRY_SIZE 64
+#define XDBC_ERST_ENTRY_NUM 1
+#define XDBC_DBCC_ENTRY_NUM 3
+#define XDBC_STRING_ENTRY_NUM 4
+
+/* Bits definitions for xdbc_state.flags: */
+#define XDBC_FLAGS_INITIALIZED BIT(0)
+#define XDBC_FLAGS_IN_STALL BIT(1)
+#define XDBC_FLAGS_OUT_STALL BIT(2)
+#define XDBC_FLAGS_IN_PROCESS BIT(3)
+#define XDBC_FLAGS_OUT_PROCESS BIT(4)
+#define XDBC_FLAGS_CONFIGURED BIT(5)
+
+#define XDBC_MAX_PACKET 1024
+
+/* Door bell target: */
+#define OUT_EP_DOORBELL 0
+#define IN_EP_DOORBELL 1
+#define DOOR_BELL_TARGET(p) (((p) & 0xff) << 8)
+
+#define xdbc_read64(regs) xhci_read_64(NULL, (regs))
+#define xdbc_write64(val, regs) xhci_write_64(NULL, (val), (regs))
+
+#endif /* __LINUX_XHCI_DBC_H */
diff --git a/include/linux/usb/xhci-dbgp.h b/include/linux/usb/xhci-dbgp.h
new file mode 100644
index 0000000..80c1cca
--- /dev/null
+++ b/include/linux/usb/xhci-dbgp.h
@@ -0,0 +1,29 @@
+/*
+ * Standalone xHCI debug capability driver
+ *
+ * Copyright (C) 2016 Intel Corporation
+ *
+ * Author: Lu Baolu <baolu.lu@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __LINUX_XHCI_DBGP_H
+#define __LINUX_XHCI_DBGP_H
+
+#ifdef CONFIG_EARLY_PRINTK_USB_XDBC
+int __init early_xdbc_parse_parameter(char *s);
+int __init early_xdbc_setup_hardware(void);
+void __init early_xdbc_register_console(void);
+#else
+static inline int __init early_xdbc_setup_hardware(void)
+{
+ return -ENODEV;
+}
+static inline void __init early_xdbc_register_console(void)
+{
+}
+#endif /* CONFIG_EARLY_PRINTK_USB_XDBC */
+#endif /* __LINUX_XHCI_DBGP_H */
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [tip:x86/debug] x86/earlyprintk: Add support for earlyprintk via USB3 debug port
2017-03-21 8:01 ` [PATCH v8 3/5] x86: add support for earlyprintk via USB3 debug port Lu Baolu
@ 2017-03-21 12:20 ` tip-bot for Lu Baolu
0 siblings, 0 replies; 42+ messages in thread
From: tip-bot for Lu Baolu @ 2017-03-21 12:20 UTC (permalink / raw)
To: linux-tip-commits
Cc: peterz, hpa, torvalds, baolu.lu, linux-kernel, gregkh, mingo,
tglx, mathias.nyman
Commit-ID: 1b5aeebf3a92273b4d85aeff37a16037bc3c3abf
Gitweb: http://git.kernel.org/tip/1b5aeebf3a92273b4d85aeff37a16037bc3c3abf
Author: Lu Baolu <baolu.lu@linux.intel.com>
AuthorDate: Tue, 21 Mar 2017 16:01:31 +0800
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 21 Mar 2017 12:30:16 +0100
x86/earlyprintk: Add support for earlyprintk via USB3 debug port
Add support for earlyprintk by writing debug messages to the
USB3 debug port. Users can use this type of early printk by
specifying the kernel parameter of "earlyprintk=xdbc". This
gives users a chance of providing debugging output.
The hardware for USB3 debug port requires DMA memory blocks.
This requires to delay setting up debugging hardware and
registering boot console until the memblocks are filled.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-usb@vger.kernel.org
Link: http://lkml.kernel.org/r/1490083293-3792-4-git-send-email-baolu.lu@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
Documentation/admin-guide/kernel-parameters.txt | 1 +
arch/x86/kernel/early_printk.c | 5 +++++
arch/x86/kernel/setup.c | 4 ++++
3 files changed, 10 insertions(+)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 2ba45ca..ea1293d 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -989,6 +989,7 @@
earlyprintk=ttySn[,baudrate]
earlyprintk=dbgp[debugController#]
earlyprintk=pciserial,bus:device.function[,baudrate]
+ earlyprintk=xdbc[xhciController#]
earlyprintk is useful when the kernel crashes before
the normal console is initialized. It is not enabled by
diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c
index 8a12199..0f08403 100644
--- a/arch/x86/kernel/early_printk.c
+++ b/arch/x86/kernel/early_printk.c
@@ -17,6 +17,7 @@
#include <asm/intel-mid.h>
#include <asm/pgtable.h>
#include <linux/usb/ehci_def.h>
+#include <linux/usb/xhci-dbgp.h>
#include <linux/efi.h>
#include <asm/efi.h>
#include <asm/pci_x86.h>
@@ -381,6 +382,10 @@ static int __init setup_early_printk(char *buf)
if (!strncmp(buf, "efi", 3))
early_console_register(&early_efi_console, keep);
#endif
+#ifdef CONFIG_EARLY_PRINTK_USB_XDBC
+ if (!strncmp(buf, "xdbc", 4))
+ early_xdbc_parse_parameter(buf + 4);
+#endif
buf++;
}
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index e70204e..2600b1d 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -70,6 +70,7 @@
#include <linux/tboot.h>
#include <linux/jiffies.h>
+#include <linux/usb/xhci-dbgp.h>
#include <video/edid.h>
#include <asm/mtrr.h>
@@ -1144,6 +1145,9 @@ void __init setup_arch(char **cmdline_p)
memblock_set_current_limit(ISA_END_ADDRESS);
memblock_x86_fill();
+ if (!early_xdbc_setup_hardware())
+ early_xdbc_register_console();
+
reserve_bios_regions();
if (efi_enabled(EFI_MEMMAP)) {
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [tip:x86/debug] usb/serial: Add DBC debug device support to usb_debug
2017-03-21 8:01 ` [PATCH v8 4/5] usb: serial: add dbc debug device support to usb_debug Lu Baolu
@ 2017-03-21 12:21 ` tip-bot for Lu Baolu
0 siblings, 0 replies; 42+ messages in thread
From: tip-bot for Lu Baolu @ 2017-03-21 12:21 UTC (permalink / raw)
To: linux-tip-commits
Cc: mathias.nyman, baolu.lu, johan, tglx, peterz, gregkh, mingo,
linux-kernel, hpa, torvalds
Commit-ID: 57fb47279a04cd53641dc5ae55a6d47e4f32a2fd
Gitweb: http://git.kernel.org/tip/57fb47279a04cd53641dc5ae55a6d47e4f32a2fd
Author: Lu Baolu <baolu.lu@linux.intel.com>
AuthorDate: Tue, 21 Mar 2017 16:01:32 +0800
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 21 Mar 2017 12:30:17 +0100
usb/serial: Add DBC debug device support to usb_debug
This patch adds DBC debug device support to the usb_debug driver.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Johan Hovold <johan@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-usb@vger.kernel.org
Link: http://lkml.kernel.org/r/1490083293-3792-5-git-send-email-baolu.lu@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
drivers/usb/serial/usb_debug.c | 28 +++++++++++++++++++++++++---
1 file changed, 25 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/serial/usb_debug.c b/drivers/usb/serial/usb_debug.c
index ca2fa5b..92f7e5c 100644
--- a/drivers/usb/serial/usb_debug.c
+++ b/drivers/usb/serial/usb_debug.c
@@ -32,7 +32,18 @@ static const struct usb_device_id id_table[] = {
{ USB_DEVICE(0x0525, 0x127a) },
{ },
};
-MODULE_DEVICE_TABLE(usb, id_table);
+
+static const struct usb_device_id dbc_id_table[] = {
+ { USB_DEVICE(0x1d6b, 0x0004) },
+ { },
+};
+
+static const struct usb_device_id id_table_combined[] = {
+ { USB_DEVICE(0x0525, 0x127a) },
+ { USB_DEVICE(0x1d6b, 0x0004) },
+ { },
+};
+MODULE_DEVICE_TABLE(usb, id_table_combined);
/* This HW really does not support a serial break, so one will be
* emulated when ever the break state is set to true.
@@ -71,9 +82,20 @@ static struct usb_serial_driver debug_device = {
.process_read_urb = usb_debug_process_read_urb,
};
+static struct usb_serial_driver dbc_device = {
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "xhci_dbc",
+ },
+ .id_table = dbc_id_table,
+ .num_ports = 1,
+ .break_ctl = usb_debug_break_ctl,
+ .process_read_urb = usb_debug_process_read_urb,
+};
+
static struct usb_serial_driver * const serial_drivers[] = {
- &debug_device, NULL
+ &debug_device, &dbc_device, NULL
};
-module_usb_serial_driver(serial_drivers, id_table);
+module_usb_serial_driver(serial_drivers, id_table_combined);
MODULE_LICENSE("GPL");
^ permalink raw reply related [flat|nested] 42+ messages in thread
* [tip:x86/debug] usb/doc: Add document for USB3 debug port usage
2017-03-21 8:01 ` [PATCH v8 5/5] usb: doc: add document for USB3 debug port usage Lu Baolu
@ 2017-03-21 12:21 ` tip-bot for Lu Baolu
0 siblings, 0 replies; 42+ messages in thread
From: tip-bot for Lu Baolu @ 2017-03-21 12:21 UTC (permalink / raw)
To: linux-tip-commits
Cc: tglx, mathias.nyman, linux-kernel, gregkh, hpa, peterz, baolu.lu,
torvalds, mingo
Commit-ID: 1b326277798aa820c1043617786609b9bb4bee78
Gitweb: http://git.kernel.org/tip/1b326277798aa820c1043617786609b9bb4bee78
Author: Lu Baolu <baolu.lu@linux.intel.com>
AuthorDate: Tue, 21 Mar 2017 16:01:33 +0800
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 21 Mar 2017 12:30:17 +0100
usb/doc: Add document for USB3 debug port usage
Add Documentation/usb/usb3-debug-port.rst. This document includes
the guide for using USB3 debug port.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Link: http://lkml.kernel.org/r/1490083293-3792-6-git-send-email-baolu.lu@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
Documentation/usb/usb3-debug-port.rst | 100 ++++++++++++++++++++++++++++++++++
1 file changed, 100 insertions(+)
diff --git a/Documentation/usb/usb3-debug-port.rst b/Documentation/usb/usb3-debug-port.rst
new file mode 100644
index 0000000..feb1a36
--- /dev/null
+++ b/Documentation/usb/usb3-debug-port.rst
@@ -0,0 +1,100 @@
+===============
+USB3 debug port
+===============
+
+:Author: Lu Baolu <baolu.lu@linux.intel.com>
+:Date: March 2017
+
+GENERAL
+=======
+
+This is a HOWTO for using the USB3 debug port on x86 systems.
+
+Before using any kernel debugging functionality based on USB3
+debug port, you need to::
+
+ 1) check whether any USB3 debug port is available in
+ your system;
+ 2) check which port is used for debugging purposes;
+ 3) have a USB 3.0 super-speed A-to-A debugging cable.
+
+INTRODUCTION
+============
+
+The xHCI debug capability (DbC) is an optional but standalone
+functionality provided by the xHCI host controller. The xHCI
+specification describes DbC in the section 7.6.
+
+When DbC is initialized and enabled, it will present a debug
+device through the debug port (normally the first USB3
+super-speed port). The debug device is fully compliant with
+the USB framework and provides the equivalent of a very high
+performance full-duplex serial link between the debug target
+(the system under debugging) and a debug host.
+
+EARLY PRINTK
+============
+
+DbC has been designed to log early printk messages. One use for
+this feature is kernel debugging. For example, when your machine
+crashes very early before the regular console code is initialized.
+Other uses include simpler, lockless logging instead of a full-
+blown printk console driver and klogd.
+
+On the debug target system, you need to customize a debugging
+kernel with CONFIG_EARLY_PRINTK_USB_XDBC enabled. And, add below
+kernel boot parameter::
+
+ "earlyprintk=xdbc"
+
+If there are multiple xHCI controllers in your system, you can
+append a host contoller index to this kernel parameter. This
+index starts from 0.
+
+Current design doesn't support DbC runtime suspend/resume. As
+the result, you'd better disable runtime power management for
+USB subsystem by adding below kernel boot parameter::
+
+ "usbcore.autosuspend=-1"
+
+Before starting the debug target, you should connect the debug
+port to a USB port (root port or port of any external hub) on
+the debug host. The cable used to connect these two ports
+should be a USB 3.0 super-speed A-to-A debugging cable.
+
+During early boot of the debug target, DbC will be detected and
+initialized. After initialization, the debug host should be able
+to enumerate the debug device in debug target. The debug host
+will then bind the debug device with the usb_debug driver module
+and create the /dev/ttyUSB device.
+
+If the debug device enumeration goes smoothly, you should be able
+to see below kernel messages on the debug host::
+
+ # tail -f /var/log/kern.log
+ [ 1815.983374] usb 4-3: new SuperSpeed USB device number 4 using xhci_hcd
+ [ 1815.999595] usb 4-3: LPM exit latency is zeroed, disabling LPM.
+ [ 1815.999899] usb 4-3: New USB device found, idVendor=1d6b, idProduct=0004
+ [ 1815.999902] usb 4-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
+ [ 1815.999903] usb 4-3: Product: Remote GDB
+ [ 1815.999904] usb 4-3: Manufacturer: Linux
+ [ 1815.999905] usb 4-3: SerialNumber: 0001
+ [ 1816.000240] usb_debug 4-3:1.0: xhci_dbc converter detected
+ [ 1816.000360] usb 4-3: xhci_dbc converter now attached to ttyUSB0
+
+You can use any communication program, for example minicom, to
+read and view the messages. Below simple bash scripts can help
+you to check the sanity of the setup.
+
+.. code-block:: sh
+
+ ===== start of bash scripts =============
+ #!/bin/bash
+
+ while true ; do
+ while [ ! -d /sys/class/tty/ttyUSB0 ] ; do
+ :
+ done
+ cat /dev/ttyUSB0
+ done
+ ===== end of bash scripts ===============
^ permalink raw reply related [flat|nested] 42+ messages in thread
* Re: [PATCH v8 0/5] usb: early: add support for early printk through USB3 debug port
2017-03-21 11:33 ` [PATCH v8 0/5] usb: early: add support for early printk through USB3 debug port Ingo Molnar
@ 2017-03-21 12:27 ` Greg Kroah-Hartman
2017-03-21 12:46 ` Ingo Molnar
2017-03-22 2:23 ` Lu Baolu
1 sibling, 1 reply; 42+ messages in thread
From: Greg Kroah-Hartman @ 2017-03-21 12:27 UTC (permalink / raw)
To: Ingo Molnar
Cc: Lu Baolu, Ingo Molnar, Mathias Nyman, tglx, peterz, linux-usb,
x86, linux-kernel, Johan Hovold, H. Peter Anvin, Peter Zijlstra
On Tue, Mar 21, 2017 at 12:33:28PM +0100, Ingo Molnar wrote:
>
> * Lu Baolu <baolu.lu@linux.intel.com> wrote:
>
> > xHCI debug capability (DbC) is an optional but standalone
> > functionality provided by an xHCI host controller. With DbC
> > hardware initialized, the system will present a debug device
> > through the USB3 debug port (normally the first USB3 port).
> > The debug device is fully compliant with the USB framework
> > and provides the equivalent of a very high performance (USB3)
> > full-duplex serial link between the debug host and target.
> > The DbC functionality is independent of xHCI host.
> >
> > This patch set adds support for early printk functionality
> > through a USB3 debug port by 1) initializing and enabling
> > the DbC hardware during early boot; 2) registering a boot
> > console to the system so that early printk messages can go
> > through the USB3 debug port. It also includes some lines
> > of changes in usb_debug driver so that it can be bound when
> > a USB3 debug device is enumerated.
> >
> [...]
> >
> > Lu Baolu (5):
> > x86: add simple udelay calibration
> > usb: early: add driver for xhci debug capability
> > x86: add support for earlyprintk via USB3 debug port
> > usb: serial: add dbc debug device support to usb_debug
> > usb: doc: add document for USB3 debug port usage
> >
> > Documentation/admin-guide/kernel-parameters.txt | 1 +
> > Documentation/usb/usb3-debug-port.rst | 100 +++
> > arch/x86/Kconfig.debug | 23 +
> > arch/x86/kernel/early_printk.c | 5 +
> > arch/x86/kernel/setup.c | 26 +
> > drivers/usb/Makefile | 2 +-
> > drivers/usb/early/Makefile | 1 +
> > drivers/usb/early/xhci-dbc.c | 1014 +++++++++++++++++++++++
> > drivers/usb/early/xhci-dbc.h | 211 +++++
> > drivers/usb/serial/usb_debug.c | 28 +-
> > include/linux/usb/xhci-dbgp.h | 29 +
> > 11 files changed, 1436 insertions(+), 4 deletions(-)
> > create mode 100644 Documentation/usb/usb3-debug-port.rst
> > create mode 100644 drivers/usb/early/xhci-dbc.c
> > create mode 100644 drivers/usb/early/xhci-dbc.h
> > create mode 100644 include/linux/usb/xhci-dbgp.h
>
> Ok, this has now become a high quality series with picture-perfect patches AFAICS.
>
> Thomas also gave his Acked-by to all the patches.
>
> I've applied them locally to -tip (it appears the USB maintainers are still fine
> with this being carried in tip:x86/debug for a v4.12 merge, right?), and will push
> them out and will propagate them to linux-next as well if they pass testing.
Yes, no objection from me.
thanks,
greg k-h
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 0/5] usb: early: add support for early printk through USB3 debug port
2017-03-21 12:27 ` Greg Kroah-Hartman
@ 2017-03-21 12:46 ` Ingo Molnar
0 siblings, 0 replies; 42+ messages in thread
From: Ingo Molnar @ 2017-03-21 12:46 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Lu Baolu, Ingo Molnar, Mathias Nyman, tglx, peterz, linux-usb,
x86, linux-kernel, Johan Hovold, H. Peter Anvin, Peter Zijlstra
* Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote:
> > I've applied them locally to -tip (it appears the USB maintainers are still
> > fine with this being carried in tip:x86/debug for a v4.12 merge, right?), and
> > will push them out and will propagate them to linux-next as well if they pass
> > testing.
>
> Yes, no objection from me.
Cool, thanks!
Ingo
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 0/5] usb: early: add support for early printk through USB3 debug port
2017-03-21 11:33 ` [PATCH v8 0/5] usb: early: add support for early printk through USB3 debug port Ingo Molnar
2017-03-21 12:27 ` Greg Kroah-Hartman
@ 2017-03-22 2:23 ` Lu Baolu
1 sibling, 0 replies; 42+ messages in thread
From: Lu Baolu @ 2017-03-22 2:23 UTC (permalink / raw)
To: Ingo Molnar
Cc: Greg Kroah-Hartman, Ingo Molnar, Mathias Nyman, tglx, peterz,
linux-usb, x86, linux-kernel, Johan Hovold, H. Peter Anvin,
Peter Zijlstra
Hi,
On 03/21/2017 07:33 PM, Ingo Molnar wrote:
>> Lu Baolu (5):
>> > x86: add simple udelay calibration
>> > usb: early: add driver for xhci debug capability
>> > x86: add support for earlyprintk via USB3 debug port
>> > usb: serial: add dbc debug device support to usb_debug
>> > usb: doc: add document for USB3 debug port usage
>> >
>> > Documentation/admin-guide/kernel-parameters.txt | 1 +
>> > Documentation/usb/usb3-debug-port.rst | 100 +++
>> > arch/x86/Kconfig.debug | 23 +
>> > arch/x86/kernel/early_printk.c | 5 +
>> > arch/x86/kernel/setup.c | 26 +
>> > drivers/usb/Makefile | 2 +-
>> > drivers/usb/early/Makefile | 1 +
>> > drivers/usb/early/xhci-dbc.c | 1014 +++++++++++++++++++++++
>> > drivers/usb/early/xhci-dbc.h | 211 +++++
>> > drivers/usb/serial/usb_debug.c | 28 +-
>> > include/linux/usb/xhci-dbgp.h | 29 +
>> > 11 files changed, 1436 insertions(+), 4 deletions(-)
>> > create mode 100644 Documentation/usb/usb3-debug-port.rst
>> > create mode 100644 drivers/usb/early/xhci-dbc.c
>> > create mode 100644 drivers/usb/early/xhci-dbc.h
>> > create mode 100644 include/linux/usb/xhci-dbgp.h
> Ok, this has now become a high quality series with picture-perfect patches AFAICS.
>
> Thomas also gave his Acked-by to all the patches.
>
> I've applied them locally to -tip (it appears the USB maintainers are still fine
> with this being carried in tip:x86/debug for a v4.12 merge, right?), and will push
> them out and will propagate them to linux-next as well if they pass testing.
>
> Thanks for the great work!
Thank you!
Best regards,
Lu Baolu
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 1/5] x86: add simple udelay calibration
2017-03-21 8:01 ` [PATCH v8 1/5] x86: add simple udelay calibration Lu Baolu
2017-03-21 12:19 ` [tip:x86/debug] x86/timers: Add " tip-bot for Lu Baolu
2017-05-02 22:38 ` [PATCH v8 1/5] x86: add " Boris Ostrovsky
@ 2017-05-02 22:38 ` Boris Ostrovsky
2017-05-05 5:41 ` Lu Baolu
2017-05-05 5:41 ` Lu Baolu
2 siblings, 2 replies; 42+ messages in thread
From: Boris Ostrovsky @ 2017-05-02 22:38 UTC (permalink / raw)
To: Lu Baolu, Greg Kroah-Hartman, Ingo Molnar
Cc: Mathias Nyman, tglx, peterz, linux-usb, x86, linux-kernel,
Juergen Gross, xen-devel
On 03/21/2017 04:01 AM, Lu Baolu wrote:
> Add a simple udelay calibration in x86 architecture-specific
> boot-time initializations. This will get a workable estimate
> for loops_per_jiffy. Hence, udelay() could be used after this
> initialization.
This breaks Xen PV guests since at this point, and until
x86_init.paging.pagetable_init() which is when pvclock_vcpu_time_info is
mapped, they cannot access pvclock.
Is it reasonable to do this before tsc_init() is called? (The failure
has nothing to do with tsc_init(), really --- it's just that it is
called late enough that Xen PV guests get properly initialized.) If it
is, would it be possible to move simple_udelay_calibration() after
x86_init.paging.pagetable_init()?
-boris
>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: x86@kernel.org
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
> arch/x86/kernel/setup.c | 22 ++++++++++++++++++++++
> 1 file changed, 22 insertions(+)
>
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index 4bf0c89..e70204e 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -837,6 +837,26 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
> return 0;
> }
>
> +static void __init simple_udelay_calibration(void)
> +{
> + unsigned int tsc_khz, cpu_khz;
> + unsigned long lpj;
> +
> + if (!boot_cpu_has(X86_FEATURE_TSC))
> + return;
> +
> + cpu_khz = x86_platform.calibrate_cpu();
> + tsc_khz = x86_platform.calibrate_tsc();
> +
> + tsc_khz = tsc_khz ? : cpu_khz;
> + if (!tsc_khz)
> + return;
> +
> + lpj = tsc_khz * 1000;
> + do_div(lpj, HZ);
> + loops_per_jiffy = lpj;
> +}
> +
> /*
> * Determine if we were loaded by an EFI loader. If so, then we have also been
> * passed the efi memmap, systab, etc., so we should use these data structures
> @@ -985,6 +1005,8 @@ void __init setup_arch(char **cmdline_p)
> */
> x86_configure_nx();
>
> + simple_udelay_calibration();
> +
> parse_early_param();
>
> #ifdef CONFIG_MEMORY_HOTPLUG
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 1/5] x86: add simple udelay calibration
2017-03-21 8:01 ` [PATCH v8 1/5] x86: add simple udelay calibration Lu Baolu
2017-03-21 12:19 ` [tip:x86/debug] x86/timers: Add " tip-bot for Lu Baolu
@ 2017-05-02 22:38 ` Boris Ostrovsky
2017-05-02 22:38 ` Boris Ostrovsky
2 siblings, 0 replies; 42+ messages in thread
From: Boris Ostrovsky @ 2017-05-02 22:38 UTC (permalink / raw)
To: Lu Baolu, Greg Kroah-Hartman, Ingo Molnar
Cc: Juergen Gross, x86, Mathias Nyman, peterz, linux-usb,
linux-kernel, xen-devel, tglx
On 03/21/2017 04:01 AM, Lu Baolu wrote:
> Add a simple udelay calibration in x86 architecture-specific
> boot-time initializations. This will get a workable estimate
> for loops_per_jiffy. Hence, udelay() could be used after this
> initialization.
This breaks Xen PV guests since at this point, and until
x86_init.paging.pagetable_init() which is when pvclock_vcpu_time_info is
mapped, they cannot access pvclock.
Is it reasonable to do this before tsc_init() is called? (The failure
has nothing to do with tsc_init(), really --- it's just that it is
called late enough that Xen PV guests get properly initialized.) If it
is, would it be possible to move simple_udelay_calibration() after
x86_init.paging.pagetable_init()?
-boris
>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: x86@kernel.org
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
> arch/x86/kernel/setup.c | 22 ++++++++++++++++++++++
> 1 file changed, 22 insertions(+)
>
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index 4bf0c89..e70204e 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -837,6 +837,26 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
> return 0;
> }
>
> +static void __init simple_udelay_calibration(void)
> +{
> + unsigned int tsc_khz, cpu_khz;
> + unsigned long lpj;
> +
> + if (!boot_cpu_has(X86_FEATURE_TSC))
> + return;
> +
> + cpu_khz = x86_platform.calibrate_cpu();
> + tsc_khz = x86_platform.calibrate_tsc();
> +
> + tsc_khz = tsc_khz ? : cpu_khz;
> + if (!tsc_khz)
> + return;
> +
> + lpj = tsc_khz * 1000;
> + do_div(lpj, HZ);
> + loops_per_jiffy = lpj;
> +}
> +
> /*
> * Determine if we were loaded by an EFI loader. If so, then we have also been
> * passed the efi memmap, systab, etc., so we should use these data structures
> @@ -985,6 +1005,8 @@ void __init setup_arch(char **cmdline_p)
> */
> x86_configure_nx();
>
> + simple_udelay_calibration();
> +
> parse_early_param();
>
> #ifdef CONFIG_MEMORY_HOTPLUG
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 1/5] x86: add simple udelay calibration
2017-05-02 22:38 ` Boris Ostrovsky
2017-05-05 5:41 ` Lu Baolu
@ 2017-05-05 5:41 ` Lu Baolu
2017-05-05 12:50 ` Boris Ostrovsky
2017-05-05 12:50 ` Boris Ostrovsky
1 sibling, 2 replies; 42+ messages in thread
From: Lu Baolu @ 2017-05-05 5:41 UTC (permalink / raw)
To: Boris Ostrovsky, Greg Kroah-Hartman, Ingo Molnar
Cc: Mathias Nyman, tglx, peterz, linux-usb, x86, linux-kernel,
Juergen Gross, xen-devel
Hi,
On 05/03/2017 06:38 AM, Boris Ostrovsky wrote:
> On 03/21/2017 04:01 AM, Lu Baolu wrote:
>> Add a simple udelay calibration in x86 architecture-specific
>> boot-time initializations. This will get a workable estimate
>> for loops_per_jiffy. Hence, udelay() could be used after this
>> initialization.
> This breaks Xen PV guests since at this point, and until
> x86_init.paging.pagetable_init() which is when pvclock_vcpu_time_info is
> mapped, they cannot access pvclock.
>
> Is it reasonable to do this before tsc_init() is called? (The failure
> has nothing to do with tsc_init(), really --- it's just that it is
> called late enough that Xen PV guests get properly initialized.) If it
> is, would it be possible to move simple_udelay_calibration() after
> x86_init.paging.pagetable_init()?
This is currently only used for bare metal. How about by-pass it
for Xen PV guests?
Best regards,
Lu Baolu
>
> -boris
>
>
>> Cc: Ingo Molnar <mingo@redhat.com>
>> Cc: x86@kernel.org
>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>> ---
>> arch/x86/kernel/setup.c | 22 ++++++++++++++++++++++
>> 1 file changed, 22 insertions(+)
>>
>> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
>> index 4bf0c89..e70204e 100644
>> --- a/arch/x86/kernel/setup.c
>> +++ b/arch/x86/kernel/setup.c
>> @@ -837,6 +837,26 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
>> return 0;
>> }
>>
>> +static void __init simple_udelay_calibration(void)
>> +{
>> + unsigned int tsc_khz, cpu_khz;
>> + unsigned long lpj;
>> +
>> + if (!boot_cpu_has(X86_FEATURE_TSC))
>> + return;
>> +
>> + cpu_khz = x86_platform.calibrate_cpu();
>> + tsc_khz = x86_platform.calibrate_tsc();
>> +
>> + tsc_khz = tsc_khz ? : cpu_khz;
>> + if (!tsc_khz)
>> + return;
>> +
>> + lpj = tsc_khz * 1000;
>> + do_div(lpj, HZ);
>> + loops_per_jiffy = lpj;
>> +}
>> +
>> /*
>> * Determine if we were loaded by an EFI loader. If so, then we have also been
>> * passed the efi memmap, systab, etc., so we should use these data structures
>> @@ -985,6 +1005,8 @@ void __init setup_arch(char **cmdline_p)
>> */
>> x86_configure_nx();
>>
>> + simple_udelay_calibration();
>> +
>> parse_early_param();
>>
>> #ifdef CONFIG_MEMORY_HOTPLUG
>
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 1/5] x86: add simple udelay calibration
2017-05-02 22:38 ` Boris Ostrovsky
@ 2017-05-05 5:41 ` Lu Baolu
2017-05-05 5:41 ` Lu Baolu
1 sibling, 0 replies; 42+ messages in thread
From: Lu Baolu @ 2017-05-05 5:41 UTC (permalink / raw)
To: Boris Ostrovsky, Greg Kroah-Hartman, Ingo Molnar
Cc: Juergen Gross, x86, Mathias Nyman, peterz, linux-usb,
linux-kernel, xen-devel, tglx
Hi,
On 05/03/2017 06:38 AM, Boris Ostrovsky wrote:
> On 03/21/2017 04:01 AM, Lu Baolu wrote:
>> Add a simple udelay calibration in x86 architecture-specific
>> boot-time initializations. This will get a workable estimate
>> for loops_per_jiffy. Hence, udelay() could be used after this
>> initialization.
> This breaks Xen PV guests since at this point, and until
> x86_init.paging.pagetable_init() which is when pvclock_vcpu_time_info is
> mapped, they cannot access pvclock.
>
> Is it reasonable to do this before tsc_init() is called? (The failure
> has nothing to do with tsc_init(), really --- it's just that it is
> called late enough that Xen PV guests get properly initialized.) If it
> is, would it be possible to move simple_udelay_calibration() after
> x86_init.paging.pagetable_init()?
This is currently only used for bare metal. How about by-pass it
for Xen PV guests?
Best regards,
Lu Baolu
>
> -boris
>
>
>> Cc: Ingo Molnar <mingo@redhat.com>
>> Cc: x86@kernel.org
>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>> ---
>> arch/x86/kernel/setup.c | 22 ++++++++++++++++++++++
>> 1 file changed, 22 insertions(+)
>>
>> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
>> index 4bf0c89..e70204e 100644
>> --- a/arch/x86/kernel/setup.c
>> +++ b/arch/x86/kernel/setup.c
>> @@ -837,6 +837,26 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
>> return 0;
>> }
>>
>> +static void __init simple_udelay_calibration(void)
>> +{
>> + unsigned int tsc_khz, cpu_khz;
>> + unsigned long lpj;
>> +
>> + if (!boot_cpu_has(X86_FEATURE_TSC))
>> + return;
>> +
>> + cpu_khz = x86_platform.calibrate_cpu();
>> + tsc_khz = x86_platform.calibrate_tsc();
>> +
>> + tsc_khz = tsc_khz ? : cpu_khz;
>> + if (!tsc_khz)
>> + return;
>> +
>> + lpj = tsc_khz * 1000;
>> + do_div(lpj, HZ);
>> + loops_per_jiffy = lpj;
>> +}
>> +
>> /*
>> * Determine if we were loaded by an EFI loader. If so, then we have also been
>> * passed the efi memmap, systab, etc., so we should use these data structures
>> @@ -985,6 +1005,8 @@ void __init setup_arch(char **cmdline_p)
>> */
>> x86_configure_nx();
>>
>> + simple_udelay_calibration();
>> +
>> parse_early_param();
>>
>> #ifdef CONFIG_MEMORY_HOTPLUG
>
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 1/5] x86: add simple udelay calibration
2017-05-05 5:41 ` Lu Baolu
@ 2017-05-05 12:50 ` Boris Ostrovsky
2017-07-12 8:02 ` Dou Liyang
2017-07-12 8:02 ` Dou Liyang
2017-05-05 12:50 ` Boris Ostrovsky
1 sibling, 2 replies; 42+ messages in thread
From: Boris Ostrovsky @ 2017-05-05 12:50 UTC (permalink / raw)
To: Lu Baolu, Greg Kroah-Hartman, Ingo Molnar
Cc: Mathias Nyman, tglx, peterz, linux-usb, x86, linux-kernel,
Juergen Gross, xen-devel
On 05/05/2017 01:41 AM, Lu Baolu wrote:
> Hi,
>
> On 05/03/2017 06:38 AM, Boris Ostrovsky wrote:
>> On 03/21/2017 04:01 AM, Lu Baolu wrote:
>>> Add a simple udelay calibration in x86 architecture-specific
>>> boot-time initializations. This will get a workable estimate
>>> for loops_per_jiffy. Hence, udelay() could be used after this
>>> initialization.
>> This breaks Xen PV guests since at this point, and until
>> x86_init.paging.pagetable_init() which is when pvclock_vcpu_time_info is
>> mapped, they cannot access pvclock.
>>
>> Is it reasonable to do this before tsc_init() is called? (The failure
>> has nothing to do with tsc_init(), really --- it's just that it is
>> called late enough that Xen PV guests get properly initialized.) If it
>> is, would it be possible to move simple_udelay_calibration() after
>> x86_init.paging.pagetable_init()?
> This is currently only used for bare metal. How about by-pass it
> for Xen PV guests?
It is fixed this for Xen PV guests now (in the sense that we don't crash
anymore) but my question is still whether this is not too early. Besides
tsc_init() (which might not be important here), at the time when
simple_udelay_calibration() is invoked we haven't yet called:
* kvmclock_init(), which sets calibration routines for KVM
* init_hypervisor_platform(), which sets calibration routines for vmware
and Xen HVM
* x86_init.paging.pagetable_init(), which sets calibration routines for
Xen PV
-boris
>
> Best regards,
> Lu Baolu
>
>> -boris
>>
>>
>>> Cc: Ingo Molnar <mingo@redhat.com>
>>> Cc: x86@kernel.org
>>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>>> ---
>>> arch/x86/kernel/setup.c | 22 ++++++++++++++++++++++
>>> 1 file changed, 22 insertions(+)
>>>
>>> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
>>> index 4bf0c89..e70204e 100644
>>> --- a/arch/x86/kernel/setup.c
>>> +++ b/arch/x86/kernel/setup.c
>>> @@ -837,6 +837,26 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
>>> return 0;
>>> }
>>>
>>> +static void __init simple_udelay_calibration(void)
>>> +{
>>> + unsigned int tsc_khz, cpu_khz;
>>> + unsigned long lpj;
>>> +
>>> + if (!boot_cpu_has(X86_FEATURE_TSC))
>>> + return;
>>> +
>>> + cpu_khz = x86_platform.calibrate_cpu();
>>> + tsc_khz = x86_platform.calibrate_tsc();
>>> +
>>> + tsc_khz = tsc_khz ? : cpu_khz;
>>> + if (!tsc_khz)
>>> + return;
>>> +
>>> + lpj = tsc_khz * 1000;
>>> + do_div(lpj, HZ);
>>> + loops_per_jiffy = lpj;
>>> +}
>>> +
>>> /*
>>> * Determine if we were loaded by an EFI loader. If so, then we have also been
>>> * passed the efi memmap, systab, etc., so we should use these data structures
>>> @@ -985,6 +1005,8 @@ void __init setup_arch(char **cmdline_p)
>>> */
>>> x86_configure_nx();
>>>
>>> + simple_udelay_calibration();
>>> +
>>> parse_early_param();
>>>
>>> #ifdef CONFIG_MEMORY_HOTPLUG
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 1/5] x86: add simple udelay calibration
2017-05-05 5:41 ` Lu Baolu
2017-05-05 12:50 ` Boris Ostrovsky
@ 2017-05-05 12:50 ` Boris Ostrovsky
1 sibling, 0 replies; 42+ messages in thread
From: Boris Ostrovsky @ 2017-05-05 12:50 UTC (permalink / raw)
To: Lu Baolu, Greg Kroah-Hartman, Ingo Molnar
Cc: Juergen Gross, x86, Mathias Nyman, peterz, linux-usb,
linux-kernel, xen-devel, tglx
On 05/05/2017 01:41 AM, Lu Baolu wrote:
> Hi,
>
> On 05/03/2017 06:38 AM, Boris Ostrovsky wrote:
>> On 03/21/2017 04:01 AM, Lu Baolu wrote:
>>> Add a simple udelay calibration in x86 architecture-specific
>>> boot-time initializations. This will get a workable estimate
>>> for loops_per_jiffy. Hence, udelay() could be used after this
>>> initialization.
>> This breaks Xen PV guests since at this point, and until
>> x86_init.paging.pagetable_init() which is when pvclock_vcpu_time_info is
>> mapped, they cannot access pvclock.
>>
>> Is it reasonable to do this before tsc_init() is called? (The failure
>> has nothing to do with tsc_init(), really --- it's just that it is
>> called late enough that Xen PV guests get properly initialized.) If it
>> is, would it be possible to move simple_udelay_calibration() after
>> x86_init.paging.pagetable_init()?
> This is currently only used for bare metal. How about by-pass it
> for Xen PV guests?
It is fixed this for Xen PV guests now (in the sense that we don't crash
anymore) but my question is still whether this is not too early. Besides
tsc_init() (which might not be important here), at the time when
simple_udelay_calibration() is invoked we haven't yet called:
* kvmclock_init(), which sets calibration routines for KVM
* init_hypervisor_platform(), which sets calibration routines for vmware
and Xen HVM
* x86_init.paging.pagetable_init(), which sets calibration routines for
Xen PV
-boris
>
> Best regards,
> Lu Baolu
>
>> -boris
>>
>>
>>> Cc: Ingo Molnar <mingo@redhat.com>
>>> Cc: x86@kernel.org
>>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>>> ---
>>> arch/x86/kernel/setup.c | 22 ++++++++++++++++++++++
>>> 1 file changed, 22 insertions(+)
>>>
>>> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
>>> index 4bf0c89..e70204e 100644
>>> --- a/arch/x86/kernel/setup.c
>>> +++ b/arch/x86/kernel/setup.c
>>> @@ -837,6 +837,26 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
>>> return 0;
>>> }
>>>
>>> +static void __init simple_udelay_calibration(void)
>>> +{
>>> + unsigned int tsc_khz, cpu_khz;
>>> + unsigned long lpj;
>>> +
>>> + if (!boot_cpu_has(X86_FEATURE_TSC))
>>> + return;
>>> +
>>> + cpu_khz = x86_platform.calibrate_cpu();
>>> + tsc_khz = x86_platform.calibrate_tsc();
>>> +
>>> + tsc_khz = tsc_khz ? : cpu_khz;
>>> + if (!tsc_khz)
>>> + return;
>>> +
>>> + lpj = tsc_khz * 1000;
>>> + do_div(lpj, HZ);
>>> + loops_per_jiffy = lpj;
>>> +}
>>> +
>>> /*
>>> * Determine if we were loaded by an EFI loader. If so, then we have also been
>>> * passed the efi memmap, systab, etc., so we should use these data structures
>>> @@ -985,6 +1005,8 @@ void __init setup_arch(char **cmdline_p)
>>> */
>>> x86_configure_nx();
>>>
>>> + simple_udelay_calibration();
>>> +
>>> parse_early_param();
>>>
>>> #ifdef CONFIG_MEMORY_HOTPLUG
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [tip:x86/debug] x86/timers: Add simple udelay calibration
2017-03-21 12:19 ` [tip:x86/debug] x86/timers: Add " tip-bot for Lu Baolu
@ 2017-05-24 16:56 ` Jan Kiszka
2017-05-25 0:49 ` Lu Baolu
0 siblings, 1 reply; 42+ messages in thread
From: Jan Kiszka @ 2017-05-24 16:56 UTC (permalink / raw)
To: brgerst, mathias.nyman, dvlasenk, tglx, peterz, bp, luto,
torvalds, baolu.lu, hpa, jpoimboe, gregkh, linux-kernel, mingo,
linux-tip-commits
On 2017-03-21 13:19, tip-bot for Lu Baolu wrote:
> Commit-ID: dd759d93f4dd4fd2f345a78ad1223bb3edf3ee7b
> Gitweb: http://git.kernel.org/tip/dd759d93f4dd4fd2f345a78ad1223bb3edf3ee7b
> Author: Lu Baolu <baolu.lu@linux.intel.com>
> AuthorDate: Tue, 21 Mar 2017 16:01:29 +0800
> Committer: Ingo Molnar <mingo@kernel.org>
> CommitDate: Tue, 21 Mar 2017 12:28:45 +0100
>
> x86/timers: Add simple udelay calibration
>
> Add a simple udelay calibration in x86 architecture-specific
> boot-time initializations. This will get a workable estimate
> for loops_per_jiffy. Hence, udelay() could be used after this
> initialization.
>
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> Acked-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: Andy Lutomirski <luto@kernel.org>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: Brian Gerst <brgerst@gmail.com>
> Cc: Denys Vlasenko <dvlasenk@redhat.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: H. Peter Anvin <hpa@zytor.com>
> Cc: Josh Poimboeuf <jpoimboe@redhat.com>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: linux-usb@vger.kernel.org
> Link: http://lkml.kernel.org/r/1490083293-3792-2-git-send-email-baolu.lu@linux.intel.com
> Signed-off-by: Ingo Molnar <mingo@kernel.org>
> ---
> arch/x86/kernel/setup.c | 22 ++++++++++++++++++++++
> 1 file changed, 22 insertions(+)
>
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index 4bf0c89..e70204e 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -837,6 +837,26 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
> return 0;
> }
>
> +static void __init simple_udelay_calibration(void)
> +{
> + unsigned int tsc_khz, cpu_khz;
> + unsigned long lpj;
> +
> + if (!boot_cpu_has(X86_FEATURE_TSC))
> + return;
> +
> + cpu_khz = x86_platform.calibrate_cpu();
> + tsc_khz = x86_platform.calibrate_tsc();
> +
> + tsc_khz = tsc_khz ? : cpu_khz;
> + if (!tsc_khz)
> + return;
> +
> + lpj = tsc_khz * 1000;
> + do_div(lpj, HZ);
> + loops_per_jiffy = lpj;
> +}
> +
> /*
> * Determine if we were loaded by an EFI loader. If so, then we have also been
> * passed the efi memmap, systab, etc., so we should use these data structures
> @@ -985,6 +1005,8 @@ void __init setup_arch(char **cmdline_p)
> */
> x86_configure_nx();
>
> + simple_udelay_calibration();
> +
> parse_early_param();
>
> #ifdef CONFIG_MEMORY_HOTPLUG
>
Can we move this past init_hypervisor_platform()? Otherwise, the
x86_platform hooks aren't fully initialized yet, and we may use the
wrong functions.
Jan
--
Siemens AG, Corporate Technology, CT RDA ITP SES-DE
Corporate Competence Center Embedded Linux
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [tip:x86/debug] x86/timers: Add simple udelay calibration
2017-05-24 16:56 ` Jan Kiszka
@ 2017-05-25 0:49 ` Lu Baolu
0 siblings, 0 replies; 42+ messages in thread
From: Lu Baolu @ 2017-05-25 0:49 UTC (permalink / raw)
To: Jan Kiszka, brgerst, mathias.nyman, dvlasenk, tglx, peterz, bp,
luto, torvalds, hpa, jpoimboe, gregkh, linux-kernel, mingo,
linux-tip-commits
Hi,
On 05/25/2017 12:56 AM, Jan Kiszka wrote:
> On 2017-03-21 13:19, tip-bot for Lu Baolu wrote:
>> Commit-ID: dd759d93f4dd4fd2f345a78ad1223bb3edf3ee7b
>> Gitweb: http://git.kernel.org/tip/dd759d93f4dd4fd2f345a78ad1223bb3edf3ee7b
>> Author: Lu Baolu <baolu.lu@linux.intel.com>
>> AuthorDate: Tue, 21 Mar 2017 16:01:29 +0800
>> Committer: Ingo Molnar <mingo@kernel.org>
>> CommitDate: Tue, 21 Mar 2017 12:28:45 +0100
>>
>> x86/timers: Add simple udelay calibration
>>
>> Add a simple udelay calibration in x86 architecture-specific
>> boot-time initializations. This will get a workable estimate
>> for loops_per_jiffy. Hence, udelay() could be used after this
>> initialization.
>>
>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>> Acked-by: Thomas Gleixner <tglx@linutronix.de>
>> Cc: Andy Lutomirski <luto@kernel.org>
>> Cc: Borislav Petkov <bp@alien8.de>
>> Cc: Brian Gerst <brgerst@gmail.com>
>> Cc: Denys Vlasenko <dvlasenk@redhat.com>
>> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>> Cc: H. Peter Anvin <hpa@zytor.com>
>> Cc: Josh Poimboeuf <jpoimboe@redhat.com>
>> Cc: Linus Torvalds <torvalds@linux-foundation.org>
>> Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
>> Cc: Peter Zijlstra <peterz@infradead.org>
>> Cc: linux-usb@vger.kernel.org
>> Link: http://lkml.kernel.org/r/1490083293-3792-2-git-send-email-baolu.lu@linux.intel.com
>> Signed-off-by: Ingo Molnar <mingo@kernel.org>
>> ---
>> arch/x86/kernel/setup.c | 22 ++++++++++++++++++++++
>> 1 file changed, 22 insertions(+)
>>
>> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
>> index 4bf0c89..e70204e 100644
>> --- a/arch/x86/kernel/setup.c
>> +++ b/arch/x86/kernel/setup.c
>> @@ -837,6 +837,26 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
>> return 0;
>> }
>>
>> +static void __init simple_udelay_calibration(void)
>> +{
>> + unsigned int tsc_khz, cpu_khz;
>> + unsigned long lpj;
>> +
>> + if (!boot_cpu_has(X86_FEATURE_TSC))
>> + return;
>> +
>> + cpu_khz = x86_platform.calibrate_cpu();
>> + tsc_khz = x86_platform.calibrate_tsc();
>> +
>> + tsc_khz = tsc_khz ? : cpu_khz;
>> + if (!tsc_khz)
>> + return;
>> +
>> + lpj = tsc_khz * 1000;
>> + do_div(lpj, HZ);
>> + loops_per_jiffy = lpj;
>> +}
>> +
>> /*
>> * Determine if we were loaded by an EFI loader. If so, then we have also been
>> * passed the efi memmap, systab, etc., so we should use these data structures
>> @@ -985,6 +1005,8 @@ void __init setup_arch(char **cmdline_p)
>> */
>> x86_configure_nx();
>>
>> + simple_udelay_calibration();
>> +
>> parse_early_param();
>>
>> #ifdef CONFIG_MEMORY_HOTPLUG
>>
> Can we move this past init_hypervisor_platform()?
Yes, we can as far as I can see.
Best regards,
Lu Baolu
> Otherwise, the
> x86_platform hooks aren't fully initialized yet, and we may use the
> wrong functions.
>
> Jan
>
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 2/5] usb: early: add driver for xhci debug capability
2017-03-21 8:01 ` [PATCH v8 2/5] usb: early: add driver for xhci debug capability Lu Baolu
2017-03-21 12:19 ` [tip:x86/debug] usb/early: Add " tip-bot for Lu Baolu
@ 2017-05-30 13:46 ` Vlastimil Babka
2017-05-31 3:27 ` Lu Baolu
1 sibling, 1 reply; 42+ messages in thread
From: Vlastimil Babka @ 2017-05-30 13:46 UTC (permalink / raw)
To: Lu Baolu, Greg Kroah-Hartman, Ingo Molnar
Cc: Mathias Nyman, tglx, peterz, linux-usb, x86, linux-kernel,
Steven Rostedt
On 03/21/2017 09:01 AM, Lu Baolu wrote:
> XHCI debug capability (DbC) is an optional but standalone
> functionality provided by an xHCI host controller. Software
> learns this capability by walking through the extended
> capability list of the host. XHCI specification describes
> DbC in the section 7.6.
>
> This patch introduces the code to probe and initialize the
> debug capability hardware during early boot. With hardware
> initialized, the debug target (system on which this code is
> running) will present a debug device through the debug port
> (normally the first USB3 port). The debug device is fully
> compliant with the USB framework and provides the equivalent
> of a very high performance (USB3) full-duplex serial link
> between the debug host and target. The DbC functionality is
> independent of the xHCI host. There isn't any precondition
> from the xHCI host side for the DbC to work.
>
> One use for this feature is kernel debugging, for example
> when your machine crashes very early before the regular
> console code is initialized. Other uses include simpler,
> lockless logging instead of a full-blown printk console
> driver and klogd.
>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
...
> +
> +#define XDBC_TRACE
> +#ifdef XDBC_TRACE
> +#define xdbc_trace trace_printk
Did you forget to remove the #define XDBC_TRACE?
Enabling this driver brings the "trace_printk() being used. Allocating
extra memory. This means that this is a DEBUG kernel and it is unsafe
for production use." message in 4.12-rcX dmesg.
Thanks,
Vlastimil
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 2/5] usb: early: add driver for xhci debug capability
2017-05-30 13:46 ` [PATCH v8 2/5] usb: early: add " Vlastimil Babka
@ 2017-05-31 3:27 ` Lu Baolu
2017-05-31 6:24 ` Steven Rostedt
2017-05-31 9:38 ` Vlastimil Babka
0 siblings, 2 replies; 42+ messages in thread
From: Lu Baolu @ 2017-05-31 3:27 UTC (permalink / raw)
To: Vlastimil Babka, Greg Kroah-Hartman, Ingo Molnar
Cc: Mathias Nyman, tglx, peterz, linux-usb, x86, linux-kernel,
Steven Rostedt
Hi,
On 05/30/2017 09:46 PM, Vlastimil Babka wrote:
> On 03/21/2017 09:01 AM, Lu Baolu wrote:
>> XHCI debug capability (DbC) is an optional but standalone
>> functionality provided by an xHCI host controller. Software
>> learns this capability by walking through the extended
>> capability list of the host. XHCI specification describes
>> DbC in the section 7.6.
>>
>> This patch introduces the code to probe and initialize the
>> debug capability hardware during early boot. With hardware
>> initialized, the debug target (system on which this code is
>> running) will present a debug device through the debug port
>> (normally the first USB3 port). The debug device is fully
>> compliant with the USB framework and provides the equivalent
>> of a very high performance (USB3) full-duplex serial link
>> between the debug host and target. The DbC functionality is
>> independent of the xHCI host. There isn't any precondition
>> from the xHCI host side for the DbC to work.
>>
>> One use for this feature is kernel debugging, for example
>> when your machine crashes very early before the regular
>> console code is initialized. Other uses include simpler,
>> lockless logging instead of a full-blown printk console
>> driver and klogd.
>>
>> Cc: Ingo Molnar <mingo@redhat.com>
>> Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ...
>
>> +
>> +#define XDBC_TRACE
>> +#ifdef XDBC_TRACE
>> +#define xdbc_trace trace_printk
> Did you forget to remove the #define XDBC_TRACE?
>
> Enabling this driver brings the "trace_printk() being used. Allocating
> extra memory. This means that this is a DEBUG kernel and it is unsafe
> for production use." message in 4.12-rcX dmesg.
This feature is only for a DEBUG kernel, should not be enabled for
any production kernel. This was the reason I enabled trace_printk()
by default.
Best regards,
Lu Baolu
> Thanks,
> Vlastimil
>
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 2/5] usb: early: add driver for xhci debug capability
2017-05-31 3:27 ` Lu Baolu
@ 2017-05-31 6:24 ` Steven Rostedt
2017-06-01 3:35 ` Lu Baolu
2017-05-31 9:38 ` Vlastimil Babka
1 sibling, 1 reply; 42+ messages in thread
From: Steven Rostedt @ 2017-05-31 6:24 UTC (permalink / raw)
To: Lu Baolu
Cc: Vlastimil Babka, Greg Kroah-Hartman, Ingo Molnar, Mathias Nyman,
tglx, peterz, linux-usb, x86, linux-kernel
On Wed, 31 May 2017 11:27:19 +0800
Lu Baolu <baolu.lu@linux.intel.com> wrote:
> >> +
> >> +#define XDBC_TRACE
> >> +#ifdef XDBC_TRACE
> >> +#define xdbc_trace trace_printk
> > Did you forget to remove the #define XDBC_TRACE?
> >
> > Enabling this driver brings the "trace_printk() being used.
> > Allocating extra memory. This means that this is a DEBUG kernel and
> > it is unsafe for production use." message in 4.12-rcX dmesg.
>
> This feature is only for a DEBUG kernel, should not be enabled for
> any production kernel. This was the reason I enabled trace_printk()
> by default.
Yes, it is perfectly fine to use trace_printk() for debug only configs.
But if if you have it there and it is helpful to debug something that
happens in a production system, you may want to look into creating a
real tracepoint for the locations.
-- Steve
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 2/5] usb: early: add driver for xhci debug capability
2017-05-31 3:27 ` Lu Baolu
2017-05-31 6:24 ` Steven Rostedt
@ 2017-05-31 9:38 ` Vlastimil Babka
2017-06-01 3:37 ` Lu Baolu
1 sibling, 1 reply; 42+ messages in thread
From: Vlastimil Babka @ 2017-05-31 9:38 UTC (permalink / raw)
To: Lu Baolu, Greg Kroah-Hartman, Ingo Molnar
Cc: Mathias Nyman, tglx, peterz, linux-usb, x86, linux-kernel,
Steven Rostedt, Michal Kubecek
On 05/31/2017 05:27 AM, Lu Baolu wrote:
> Hi,
>
> On 05/30/2017 09:46 PM, Vlastimil Babka wrote:
>> On 03/21/2017 09:01 AM, Lu Baolu wrote:
>>> XHCI debug capability (DbC) is an optional but standalone
>>> functionality provided by an xHCI host controller. Software
>>> learns this capability by walking through the extended
>>> capability list of the host. XHCI specification describes
>>> DbC in the section 7.6.
>>>
>>> This patch introduces the code to probe and initialize the
>>> debug capability hardware during early boot. With hardware
>>> initialized, the debug target (system on which this code is
>>> running) will present a debug device through the debug port
>>> (normally the first USB3 port). The debug device is fully
>>> compliant with the USB framework and provides the equivalent
>>> of a very high performance (USB3) full-duplex serial link
>>> between the debug host and target. The DbC functionality is
>>> independent of the xHCI host. There isn't any precondition
>>> from the xHCI host side for the DbC to work.
>>>
>>> One use for this feature is kernel debugging, for example
>>> when your machine crashes very early before the regular
>>> console code is initialized. Other uses include simpler,
>>> lockless logging instead of a full-blown printk console
>>> driver and klogd.
>>>
>>> Cc: Ingo Molnar <mingo@redhat.com>
>>> Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
>>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>> ...
>>
>>> +
>>> +#define XDBC_TRACE
>>> +#ifdef XDBC_TRACE
>>> +#define xdbc_trace trace_printk
>> Did you forget to remove the #define XDBC_TRACE?
>>
>> Enabling this driver brings the "trace_printk() being used. Allocating
>> extra memory. This means that this is a DEBUG kernel and it is unsafe
>> for production use." message in 4.12-rcX dmesg.
>
> This feature is only for a DEBUG kernel, should not be enabled for
> any production kernel. This was the reason I enabled trace_printk()
> by default.
Hmm, but it seems we generally enable all these early printk
features/drivers in our distro kernels. They are not active without a
early_printk=X bootparam anyway, right? It's much more convenient to
e.g. just tell customer to change a param when debugging something than
to install a debug kernel. So I wouldn't agree that only a DEBUG kernel
should have this compiled in.
Thanks,
Vlastimil
> Best regards,
> Lu Baolu
>
>> Thanks,
>> Vlastimil
>>
>
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 2/5] usb: early: add driver for xhci debug capability
2017-05-31 6:24 ` Steven Rostedt
@ 2017-06-01 3:35 ` Lu Baolu
0 siblings, 0 replies; 42+ messages in thread
From: Lu Baolu @ 2017-06-01 3:35 UTC (permalink / raw)
To: Steven Rostedt
Cc: Vlastimil Babka, Greg Kroah-Hartman, Ingo Molnar, Mathias Nyman,
tglx, peterz, linux-usb, x86, linux-kernel
Hi,
On 05/31/2017 02:24 PM, Steven Rostedt wrote:
> On Wed, 31 May 2017 11:27:19 +0800
> Lu Baolu <baolu.lu@linux.intel.com> wrote:
>
>
>>>> +
>>>> +#define XDBC_TRACE
>>>> +#ifdef XDBC_TRACE
>>>> +#define xdbc_trace trace_printk
>>> Did you forget to remove the #define XDBC_TRACE?
>>>
>>> Enabling this driver brings the "trace_printk() being used.
>>> Allocating extra memory. This means that this is a DEBUG kernel and
>>> it is unsafe for production use." message in 4.12-rcX dmesg.
>> This feature is only for a DEBUG kernel, should not be enabled for
>> any production kernel. This was the reason I enabled trace_printk()
>> by default.
> Yes, it is perfectly fine to use trace_printk() for debug only configs.
> But if if you have it there and it is helpful to debug something that
> happens in a production system, you may want to look into creating a
> real tracepoint for the locations.
Yes. Good suggestion. I will try this.
Thank you!
Best regards,
Lu Baolu
>
> -- Steve
> --
> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 2/5] usb: early: add driver for xhci debug capability
2017-05-31 9:38 ` Vlastimil Babka
@ 2017-06-01 3:37 ` Lu Baolu
2017-06-01 8:15 ` Vlastimil Babka
0 siblings, 1 reply; 42+ messages in thread
From: Lu Baolu @ 2017-06-01 3:37 UTC (permalink / raw)
To: Vlastimil Babka, Greg Kroah-Hartman, Ingo Molnar
Cc: Mathias Nyman, tglx, peterz, linux-usb, x86, linux-kernel,
Steven Rostedt, Michal Kubecek
Hi,
On 05/31/2017 05:38 PM, Vlastimil Babka wrote:
> On 05/31/2017 05:27 AM, Lu Baolu wrote:
>> Hi,
>>
>> On 05/30/2017 09:46 PM, Vlastimil Babka wrote:
>>> On 03/21/2017 09:01 AM, Lu Baolu wrote:
>>>> XHCI debug capability (DbC) is an optional but standalone
>>>> functionality provided by an xHCI host controller. Software
>>>> learns this capability by walking through the extended
>>>> capability list of the host. XHCI specification describes
>>>> DbC in the section 7.6.
>>>>
>>>> This patch introduces the code to probe and initialize the
>>>> debug capability hardware during early boot. With hardware
>>>> initialized, the debug target (system on which this code is
>>>> running) will present a debug device through the debug port
>>>> (normally the first USB3 port). The debug device is fully
>>>> compliant with the USB framework and provides the equivalent
>>>> of a very high performance (USB3) full-duplex serial link
>>>> between the debug host and target. The DbC functionality is
>>>> independent of the xHCI host. There isn't any precondition
>>>> from the xHCI host side for the DbC to work.
>>>>
>>>> One use for this feature is kernel debugging, for example
>>>> when your machine crashes very early before the regular
>>>> console code is initialized. Other uses include simpler,
>>>> lockless logging instead of a full-blown printk console
>>>> driver and klogd.
>>>>
>>>> Cc: Ingo Molnar <mingo@redhat.com>
>>>> Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
>>>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>>> ...
>>>
>>>> +
>>>> +#define XDBC_TRACE
>>>> +#ifdef XDBC_TRACE
>>>> +#define xdbc_trace trace_printk
>>> Did you forget to remove the #define XDBC_TRACE?
>>>
>>> Enabling this driver brings the "trace_printk() being used. Allocating
>>> extra memory. This means that this is a DEBUG kernel and it is unsafe
>>> for production use." message in 4.12-rcX dmesg.
>> This feature is only for a DEBUG kernel, should not be enabled for
>> any production kernel. This was the reason I enabled trace_printk()
>> by default.
> Hmm, but it seems we generally enable all these early printk
> features/drivers in our distro kernels. They are not active without a
> early_printk=X bootparam anyway, right? It's much more convenient to
> e.g. just tell customer to change a param when debugging something than
> to install a debug kernel. So I wouldn't agree that only a DEBUG kernel
> should have this compiled in.
Okay, I will try to find a fix.
Best regards,
Lu Baolu
>
> Thanks,
> Vlastimil
>
>> Best regards,
>> Lu Baolu
>>
>>> Thanks,
>>> Vlastimil
>>>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 2/5] usb: early: add driver for xhci debug capability
2017-06-01 3:37 ` Lu Baolu
@ 2017-06-01 8:15 ` Vlastimil Babka
2017-06-01 12:25 ` Peter Zijlstra
0 siblings, 1 reply; 42+ messages in thread
From: Vlastimil Babka @ 2017-06-01 8:15 UTC (permalink / raw)
To: Lu Baolu, Greg Kroah-Hartman, Ingo Molnar
Cc: Mathias Nyman, tglx, peterz, linux-usb, x86, linux-kernel,
Steven Rostedt, Michal Kubecek
On 06/01/2017 05:37 AM, Lu Baolu wrote:
> Hi,
>
> On 05/31/2017 05:38 PM, Vlastimil Babka wrote:
>> On 05/31/2017 05:27 AM, Lu Baolu wrote:
>>> Hi,
>>>
>>> On 05/30/2017 09:46 PM, Vlastimil Babka wrote:
>>>> On 03/21/2017 09:01 AM, Lu Baolu wrote:
>>>> Did you forget to remove the #define XDBC_TRACE?
>>>>
>>>> Enabling this driver brings the "trace_printk() being used. Allocating
>>>> extra memory. This means that this is a DEBUG kernel and it is unsafe
>>>> for production use." message in 4.12-rcX dmesg.
>>> This feature is only for a DEBUG kernel, should not be enabled for
>>> any production kernel. This was the reason I enabled trace_printk()
>>> by default.
>> Hmm, but it seems we generally enable all these early printk
>> features/drivers in our distro kernels. They are not active without a
>> early_printk=X bootparam anyway, right? It's much more convenient to
>> e.g. just tell customer to change a param when debugging something than
>> to install a debug kernel. So I wouldn't agree that only a DEBUG kernel
>> should have this compiled in.
>
> Okay, I will try to find a fix.
Thanks. I didn't make it clear that the trace_printk() warning is there
even if the code using it doesn't actually execute (i.e. I didn't
specify any early_printk bootparam). There are some roastedy tricks to
detect the potential users, so that the buffers can be allocated in
advance to allow the first trace_printk() from any context, I guess.
I'm not sure if there's a way to change it so that your driver reports
the trace_printk usage only in response to the bootparam (which could
also be a safe point to allocate ftrace buffers?).
Vlastimil
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 2/5] usb: early: add driver for xhci debug capability
2017-06-01 8:15 ` Vlastimil Babka
@ 2017-06-01 12:25 ` Peter Zijlstra
2017-06-02 0:47 ` Steven Rostedt
0 siblings, 1 reply; 42+ messages in thread
From: Peter Zijlstra @ 2017-06-01 12:25 UTC (permalink / raw)
To: Vlastimil Babka
Cc: Lu Baolu, Greg Kroah-Hartman, Ingo Molnar, Mathias Nyman, tglx,
linux-usb, x86, linux-kernel, Steven Rostedt, Michal Kubecek
On Thu, Jun 01, 2017 at 10:15:24AM +0200, Vlastimil Babka wrote:
> Thanks. I didn't make it clear that the trace_printk() warning is there
> even if the code using it doesn't actually execute (i.e. I didn't
> specify any early_printk bootparam). There are some roastedy tricks to
> detect the potential users, so that the buffers can be allocated in
> advance to allow the first trace_printk() from any context, I guess.
>
> I'm not sure if there's a way to change it so that your driver reports
> the trace_printk usage only in response to the bootparam (which could
> also be a safe point to allocate ftrace buffers?).
No, nor do we want to. There should not be a single caller to
trace_printk() in normal kernels.
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 2/5] usb: early: add driver for xhci debug capability
2017-06-01 12:25 ` Peter Zijlstra
@ 2017-06-02 0:47 ` Steven Rostedt
0 siblings, 0 replies; 42+ messages in thread
From: Steven Rostedt @ 2017-06-02 0:47 UTC (permalink / raw)
To: Peter Zijlstra
Cc: Vlastimil Babka, Lu Baolu, Greg Kroah-Hartman, Ingo Molnar,
Mathias Nyman, tglx, linux-usb, x86, linux-kernel,
Michal Kubecek
On Thu, 1 Jun 2017 14:25:51 +0200
Peter Zijlstra <peterz@infradead.org> wrote:
> On Thu, Jun 01, 2017 at 10:15:24AM +0200, Vlastimil Babka wrote:
> > Thanks. I didn't make it clear that the trace_printk() warning is
> > there even if the code using it doesn't actually execute (i.e. I
> > didn't specify any early_printk bootparam). There are some roastedy
> > tricks to detect the potential users, so that the buffers can be
> > allocated in advance to allow the first trace_printk() from any
> > context, I guess.
> >
> > I'm not sure if there's a way to change it so that your driver
> > reports the trace_printk usage only in response to the bootparam
> > (which could also be a safe point to allocate ftrace buffers?).
>
> No, nor do we want to. There should not be a single caller to
> trace_printk() in normal kernels.
Correct. If you find a trace_printk() that would be useful in a
production environment, then make it a tracepoint.
That's why I have that nasty banner, to make sure trace_printk()s are
not the "quick way" to add tracepoint hacks.
-- Steve
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 1/5] x86: add simple udelay calibration
2017-05-05 12:50 ` Boris Ostrovsky
2017-07-12 8:02 ` Dou Liyang
@ 2017-07-12 8:02 ` Dou Liyang
2017-07-13 1:17 ` Lu Baolu
2017-07-13 1:17 ` Lu Baolu
1 sibling, 2 replies; 42+ messages in thread
From: Dou Liyang @ 2017-07-12 8:02 UTC (permalink / raw)
To: Boris Ostrovsky, Lu Baolu, Greg Kroah-Hartman, Ingo Molnar,
Mathias Nyman, tglx
Cc: peterz, linux-usb, x86, linux-kernel, Juergen Gross, xen-devel
Hi, Lu
At 05/05/2017 08:50 PM, Boris Ostrovsky wrote:
> On 05/05/2017 01:41 AM, Lu Baolu wrote:
>> Hi,
>>
>> On 05/03/2017 06:38 AM, Boris Ostrovsky wrote:
>>> On 03/21/2017 04:01 AM, Lu Baolu wrote:
>>>> Add a simple udelay calibration in x86 architecture-specific
>>>> boot-time initializations. This will get a workable estimate
>>>> for loops_per_jiffy. Hence, udelay() could be used after this
>>>> initialization.
>>> This breaks Xen PV guests since at this point, and until
>>> x86_init.paging.pagetable_init() which is when pvclock_vcpu_time_info is
>>> mapped, they cannot access pvclock.
>>>
>>> Is it reasonable to do this before tsc_init() is called? (The failure
>>> has nothing to do with tsc_init(), really --- it's just that it is
>>> called late enough that Xen PV guests get properly initialized.) If it
>>> is, would it be possible to move simple_udelay_calibration() after
>>> x86_init.paging.pagetable_init()?
>> This is currently only used for bare metal. How about by-pass it
>> for Xen PV guests?
>
> It is fixed this for Xen PV guests now (in the sense that we don't crash
> anymore) but my question is still whether this is not too early. Besides
> tsc_init() (which might not be important here), at the time when
> simple_udelay_calibration() is invoked we haven't yet called:
> * kvmclock_init(), which sets calibration routines for KVM
> * init_hypervisor_platform(), which sets calibration routines for vmware
> and Xen HVM
> * x86_init.paging.pagetable_init(), which sets calibration routines for
> Xen PV
>
I guess these may have been missed.
Do you have any comments about these?
> -boris
>
>
>>
>> Best regards,
>> Lu Baolu
>>
>>> -boris
>>>
>>>
>>>> Cc: Ingo Molnar <mingo@redhat.com>
>>>> Cc: x86@kernel.org
>>>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>>>> ---
>>>> arch/x86/kernel/setup.c | 22 ++++++++++++++++++++++
>>>> 1 file changed, 22 insertions(+)
>>>>
>>>> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
>>>> index 4bf0c89..e70204e 100644
>>>> --- a/arch/x86/kernel/setup.c
>>>> +++ b/arch/x86/kernel/setup.c
>>>> @@ -837,6 +837,26 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
>>>> return 0;
>>>> }
>>>>
>>>> +static void __init simple_udelay_calibration(void)
>>>> +{
>>>> + unsigned int tsc_khz, cpu_khz;
>>>> + unsigned long lpj;
>>>> +
>>>> + if (!boot_cpu_has(X86_FEATURE_TSC))
>>>> + return;
if it returns here, can we use udelay() correctly like before?
Thanks,
dou.
>>>> +
>>>> + cpu_khz = x86_platform.calibrate_cpu();
>>>> + tsc_khz = x86_platform.calibrate_tsc();
>>>> +
>>>> + tsc_khz = tsc_khz ? : cpu_khz;
>>>> + if (!tsc_khz)
>>>> + return;
>>>> +
>>>> + lpj = tsc_khz * 1000;
>>>> + do_div(lpj, HZ);
>>>> + loops_per_jiffy = lpj;
>>>> +}
>>>> +
>>>> /*
>>>> * Determine if we were loaded by an EFI loader. If so, then we have also been
>>>> * passed the efi memmap, systab, etc., so we should use these data structures
>>>> @@ -985,6 +1005,8 @@ void __init setup_arch(char **cmdline_p)
>>>> */
>>>> x86_configure_nx();
>>>>
>>>> + simple_udelay_calibration();
>>>> +
>>>> parse_early_param();
>>>>
>>>> #ifdef CONFIG_MEMORY_HOTPLUG
>
>
>
>
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 1/5] x86: add simple udelay calibration
2017-05-05 12:50 ` Boris Ostrovsky
@ 2017-07-12 8:02 ` Dou Liyang
2017-07-12 8:02 ` Dou Liyang
1 sibling, 0 replies; 42+ messages in thread
From: Dou Liyang @ 2017-07-12 8:02 UTC (permalink / raw)
To: Boris Ostrovsky, Lu Baolu, Greg Kroah-Hartman, Ingo Molnar,
Mathias Nyman, tglx
Cc: Juergen Gross, x86, peterz, linux-usb, linux-kernel, xen-devel
Hi, Lu
At 05/05/2017 08:50 PM, Boris Ostrovsky wrote:
> On 05/05/2017 01:41 AM, Lu Baolu wrote:
>> Hi,
>>
>> On 05/03/2017 06:38 AM, Boris Ostrovsky wrote:
>>> On 03/21/2017 04:01 AM, Lu Baolu wrote:
>>>> Add a simple udelay calibration in x86 architecture-specific
>>>> boot-time initializations. This will get a workable estimate
>>>> for loops_per_jiffy. Hence, udelay() could be used after this
>>>> initialization.
>>> This breaks Xen PV guests since at this point, and until
>>> x86_init.paging.pagetable_init() which is when pvclock_vcpu_time_info is
>>> mapped, they cannot access pvclock.
>>>
>>> Is it reasonable to do this before tsc_init() is called? (The failure
>>> has nothing to do with tsc_init(), really --- it's just that it is
>>> called late enough that Xen PV guests get properly initialized.) If it
>>> is, would it be possible to move simple_udelay_calibration() after
>>> x86_init.paging.pagetable_init()?
>> This is currently only used for bare metal. How about by-pass it
>> for Xen PV guests?
>
> It is fixed this for Xen PV guests now (in the sense that we don't crash
> anymore) but my question is still whether this is not too early. Besides
> tsc_init() (which might not be important here), at the time when
> simple_udelay_calibration() is invoked we haven't yet called:
> * kvmclock_init(), which sets calibration routines for KVM
> * init_hypervisor_platform(), which sets calibration routines for vmware
> and Xen HVM
> * x86_init.paging.pagetable_init(), which sets calibration routines for
> Xen PV
>
I guess these may have been missed.
Do you have any comments about these?
> -boris
>
>
>>
>> Best regards,
>> Lu Baolu
>>
>>> -boris
>>>
>>>
>>>> Cc: Ingo Molnar <mingo@redhat.com>
>>>> Cc: x86@kernel.org
>>>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>>>> ---
>>>> arch/x86/kernel/setup.c | 22 ++++++++++++++++++++++
>>>> 1 file changed, 22 insertions(+)
>>>>
>>>> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
>>>> index 4bf0c89..e70204e 100644
>>>> --- a/arch/x86/kernel/setup.c
>>>> +++ b/arch/x86/kernel/setup.c
>>>> @@ -837,6 +837,26 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
>>>> return 0;
>>>> }
>>>>
>>>> +static void __init simple_udelay_calibration(void)
>>>> +{
>>>> + unsigned int tsc_khz, cpu_khz;
>>>> + unsigned long lpj;
>>>> +
>>>> + if (!boot_cpu_has(X86_FEATURE_TSC))
>>>> + return;
if it returns here, can we use udelay() correctly like before?
Thanks,
dou.
>>>> +
>>>> + cpu_khz = x86_platform.calibrate_cpu();
>>>> + tsc_khz = x86_platform.calibrate_tsc();
>>>> +
>>>> + tsc_khz = tsc_khz ? : cpu_khz;
>>>> + if (!tsc_khz)
>>>> + return;
>>>> +
>>>> + lpj = tsc_khz * 1000;
>>>> + do_div(lpj, HZ);
>>>> + loops_per_jiffy = lpj;
>>>> +}
>>>> +
>>>> /*
>>>> * Determine if we were loaded by an EFI loader. If so, then we have also been
>>>> * passed the efi memmap, systab, etc., so we should use these data structures
>>>> @@ -985,6 +1005,8 @@ void __init setup_arch(char **cmdline_p)
>>>> */
>>>> x86_configure_nx();
>>>>
>>>> + simple_udelay_calibration();
>>>> +
>>>> parse_early_param();
>>>>
>>>> #ifdef CONFIG_MEMORY_HOTPLUG
>
>
>
>
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 1/5] x86: add simple udelay calibration
2017-07-12 8:02 ` Dou Liyang
2017-07-13 1:17 ` Lu Baolu
@ 2017-07-13 1:17 ` Lu Baolu
2017-07-13 1:39 ` Dou Liyang
2017-07-13 1:39 ` Dou Liyang
1 sibling, 2 replies; 42+ messages in thread
From: Lu Baolu @ 2017-07-13 1:17 UTC (permalink / raw)
To: Dou Liyang, Boris Ostrovsky, Greg Kroah-Hartman, Ingo Molnar,
Mathias Nyman, tglx
Cc: peterz, linux-usb, x86, linux-kernel, Juergen Gross, xen-devel
Hi,
On 07/12/2017 04:02 PM, Dou Liyang wrote:
> Hi, Lu
>
> At 05/05/2017 08:50 PM, Boris Ostrovsky wrote:
>> On 05/05/2017 01:41 AM, Lu Baolu wrote:
>>> Hi,
>>>
>>> On 05/03/2017 06:38 AM, Boris Ostrovsky wrote:
>>>> On 03/21/2017 04:01 AM, Lu Baolu wrote:
>>>>> Add a simple udelay calibration in x86 architecture-specific
>>>>> boot-time initializations. This will get a workable estimate
>>>>> for loops_per_jiffy. Hence, udelay() could be used after this
>>>>> initialization.
>>>> This breaks Xen PV guests since at this point, and until
>>>> x86_init.paging.pagetable_init() which is when pvclock_vcpu_time_info is
>>>> mapped, they cannot access pvclock.
>>>>
>>>> Is it reasonable to do this before tsc_init() is called? (The failure
>>>> has nothing to do with tsc_init(), really --- it's just that it is
>>>> called late enough that Xen PV guests get properly initialized.) If it
>>>> is, would it be possible to move simple_udelay_calibration() after
>>>> x86_init.paging.pagetable_init()?
>>> This is currently only used for bare metal. How about by-pass it
>>> for Xen PV guests?
>>
>> It is fixed this for Xen PV guests now (in the sense that we don't crash
>> anymore) but my question is still whether this is not too early. Besides
>> tsc_init() (which might not be important here), at the time when
>> simple_udelay_calibration() is invoked we haven't yet called:
>> * kvmclock_init(), which sets calibration routines for KVM
>> * init_hypervisor_platform(), which sets calibration routines for vmware
>> and Xen HVM
>> * x86_init.paging.pagetable_init(), which sets calibration routines for
>> Xen PV
>>
>
> I guess these may have been missed.
>
> Do you have any comments about these?
>
The patch will be available in 4.13-rc1.
Best regards,
Lu Baolu
>> -boris
>>
>>
>>>
>>> Best regards,
>>> Lu Baolu
>>>
>>>> -boris
>>>>
>>>>
>>>>> Cc: Ingo Molnar <mingo@redhat.com>
>>>>> Cc: x86@kernel.org
>>>>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>>>>> ---
>>>>> arch/x86/kernel/setup.c | 22 ++++++++++++++++++++++
>>>>> 1 file changed, 22 insertions(+)
>>>>>
>>>>> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
>>>>> index 4bf0c89..e70204e 100644
>>>>> --- a/arch/x86/kernel/setup.c
>>>>> +++ b/arch/x86/kernel/setup.c
>>>>> @@ -837,6 +837,26 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
>>>>> return 0;
>>>>> }
>>>>>
>>>>> +static void __init simple_udelay_calibration(void)
>>>>> +{
>>>>> + unsigned int tsc_khz, cpu_khz;
>>>>> + unsigned long lpj;
>>>>> +
>>>>> + if (!boot_cpu_has(X86_FEATURE_TSC))
>>>>> + return;
>
>
> if it returns here, can we use udelay() correctly like before?
>
> Thanks,
>
> dou.
>
>>>>> +
>>>>> + cpu_khz = x86_platform.calibrate_cpu();
>>>>> + tsc_khz = x86_platform.calibrate_tsc();
>>>>> +
>>>>> + tsc_khz = tsc_khz ? : cpu_khz;
>>>>> + if (!tsc_khz)
>>>>> + return;
>>>>> +
>>>>> + lpj = tsc_khz * 1000;
>>>>> + do_div(lpj, HZ);
>>>>> + loops_per_jiffy = lpj;
>>>>> +}
>>>>> +
>>>>> /*
>>>>> * Determine if we were loaded by an EFI loader. If so, then we have also been
>>>>> * passed the efi memmap, systab, etc., so we should use these data structures
>>>>> @@ -985,6 +1005,8 @@ void __init setup_arch(char **cmdline_p)
>>>>> */
>>>>> x86_configure_nx();
>>>>>
>>>>> + simple_udelay_calibration();
>>>>> +
>>>>> parse_early_param();
>>>>>
>>>>> #ifdef CONFIG_MEMORY_HOTPLUG
>>
>>
>>
>>
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 1/5] x86: add simple udelay calibration
2017-07-12 8:02 ` Dou Liyang
@ 2017-07-13 1:17 ` Lu Baolu
2017-07-13 1:17 ` Lu Baolu
1 sibling, 0 replies; 42+ messages in thread
From: Lu Baolu @ 2017-07-13 1:17 UTC (permalink / raw)
To: Dou Liyang, Boris Ostrovsky, Greg Kroah-Hartman, Ingo Molnar,
Mathias Nyman, tglx
Cc: Juergen Gross, x86, peterz, linux-usb, linux-kernel, xen-devel
Hi,
On 07/12/2017 04:02 PM, Dou Liyang wrote:
> Hi, Lu
>
> At 05/05/2017 08:50 PM, Boris Ostrovsky wrote:
>> On 05/05/2017 01:41 AM, Lu Baolu wrote:
>>> Hi,
>>>
>>> On 05/03/2017 06:38 AM, Boris Ostrovsky wrote:
>>>> On 03/21/2017 04:01 AM, Lu Baolu wrote:
>>>>> Add a simple udelay calibration in x86 architecture-specific
>>>>> boot-time initializations. This will get a workable estimate
>>>>> for loops_per_jiffy. Hence, udelay() could be used after this
>>>>> initialization.
>>>> This breaks Xen PV guests since at this point, and until
>>>> x86_init.paging.pagetable_init() which is when pvclock_vcpu_time_info is
>>>> mapped, they cannot access pvclock.
>>>>
>>>> Is it reasonable to do this before tsc_init() is called? (The failure
>>>> has nothing to do with tsc_init(), really --- it's just that it is
>>>> called late enough that Xen PV guests get properly initialized.) If it
>>>> is, would it be possible to move simple_udelay_calibration() after
>>>> x86_init.paging.pagetable_init()?
>>> This is currently only used for bare metal. How about by-pass it
>>> for Xen PV guests?
>>
>> It is fixed this for Xen PV guests now (in the sense that we don't crash
>> anymore) but my question is still whether this is not too early. Besides
>> tsc_init() (which might not be important here), at the time when
>> simple_udelay_calibration() is invoked we haven't yet called:
>> * kvmclock_init(), which sets calibration routines for KVM
>> * init_hypervisor_platform(), which sets calibration routines for vmware
>> and Xen HVM
>> * x86_init.paging.pagetable_init(), which sets calibration routines for
>> Xen PV
>>
>
> I guess these may have been missed.
>
> Do you have any comments about these?
>
The patch will be available in 4.13-rc1.
Best regards,
Lu Baolu
>> -boris
>>
>>
>>>
>>> Best regards,
>>> Lu Baolu
>>>
>>>> -boris
>>>>
>>>>
>>>>> Cc: Ingo Molnar <mingo@redhat.com>
>>>>> Cc: x86@kernel.org
>>>>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>>>>> ---
>>>>> arch/x86/kernel/setup.c | 22 ++++++++++++++++++++++
>>>>> 1 file changed, 22 insertions(+)
>>>>>
>>>>> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
>>>>> index 4bf0c89..e70204e 100644
>>>>> --- a/arch/x86/kernel/setup.c
>>>>> +++ b/arch/x86/kernel/setup.c
>>>>> @@ -837,6 +837,26 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
>>>>> return 0;
>>>>> }
>>>>>
>>>>> +static void __init simple_udelay_calibration(void)
>>>>> +{
>>>>> + unsigned int tsc_khz, cpu_khz;
>>>>> + unsigned long lpj;
>>>>> +
>>>>> + if (!boot_cpu_has(X86_FEATURE_TSC))
>>>>> + return;
>
>
> if it returns here, can we use udelay() correctly like before?
>
> Thanks,
>
> dou.
>
>>>>> +
>>>>> + cpu_khz = x86_platform.calibrate_cpu();
>>>>> + tsc_khz = x86_platform.calibrate_tsc();
>>>>> +
>>>>> + tsc_khz = tsc_khz ? : cpu_khz;
>>>>> + if (!tsc_khz)
>>>>> + return;
>>>>> +
>>>>> + lpj = tsc_khz * 1000;
>>>>> + do_div(lpj, HZ);
>>>>> + loops_per_jiffy = lpj;
>>>>> +}
>>>>> +
>>>>> /*
>>>>> * Determine if we were loaded by an EFI loader. If so, then we have also been
>>>>> * passed the efi memmap, systab, etc., so we should use these data structures
>>>>> @@ -985,6 +1005,8 @@ void __init setup_arch(char **cmdline_p)
>>>>> */
>>>>> x86_configure_nx();
>>>>>
>>>>> + simple_udelay_calibration();
>>>>> +
>>>>> parse_early_param();
>>>>>
>>>>> #ifdef CONFIG_MEMORY_HOTPLUG
>>
>>
>>
>>
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
_______________________________________________
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Xen-devel@lists.xen.org
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^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 1/5] x86: add simple udelay calibration
2017-07-13 1:17 ` Lu Baolu
2017-07-13 1:39 ` Dou Liyang
@ 2017-07-13 1:39 ` Dou Liyang
2017-07-13 3:00 ` Lu Baolu
2017-07-13 3:00 ` Lu Baolu
1 sibling, 2 replies; 42+ messages in thread
From: Dou Liyang @ 2017-07-13 1:39 UTC (permalink / raw)
To: Lu Baolu, Boris Ostrovsky, Greg Kroah-Hartman, Ingo Molnar,
Mathias Nyman, tglx
Cc: peterz, linux-usb, x86, linux-kernel, Juergen Gross, xen-devel
Hi, Lu
At 07/13/2017 09:17 AM, Lu Baolu wrote:
> Hi,
>
> On 07/12/2017 04:02 PM, Dou Liyang wrote:
>> Hi, Lu
>>
>> At 05/05/2017 08:50 PM, Boris Ostrovsky wrote:
>>> On 05/05/2017 01:41 AM, Lu Baolu wrote:
>>>> Hi,
>>>>
>>>> On 05/03/2017 06:38 AM, Boris Ostrovsky wrote:
>>>>> On 03/21/2017 04:01 AM, Lu Baolu wrote:
>>>>>> Add a simple udelay calibration in x86 architecture-specific
>>>>>> boot-time initializations. This will get a workable estimate
>>>>>> for loops_per_jiffy. Hence, udelay() could be used after this
>>>>>> initialization.
>>>>> This breaks Xen PV guests since at this point, and until
>>>>> x86_init.paging.pagetable_init() which is when pvclock_vcpu_time_info is
>>>>> mapped, they cannot access pvclock.
>>>>>
>>>>> Is it reasonable to do this before tsc_init() is called? (The failure
>>>>> has nothing to do with tsc_init(), really --- it's just that it is
>>>>> called late enough that Xen PV guests get properly initialized.) If it
>>>>> is, would it be possible to move simple_udelay_calibration() after
>>>>> x86_init.paging.pagetable_init()?
>>>> This is currently only used for bare metal. How about by-pass it
>>>> for Xen PV guests?
>>>
>>> It is fixed this for Xen PV guests now (in the sense that we don't crash
>>> anymore) but my question is still whether this is not too early. Besides
>>> tsc_init() (which might not be important here), at the time when
>>> simple_udelay_calibration() is invoked we haven't yet called:
>>> * kvmclock_init(), which sets calibration routines for KVM
>>> * init_hypervisor_platform(), which sets calibration routines for vmware
>>> and Xen HVM
>>> * x86_init.paging.pagetable_init(), which sets calibration routines for
>>> Xen PV
>>>
>>
>> I guess these may have been missed.
>>
>> Do you have any comments about these?
>>
>
> The patch will be available in 4.13-rc1.
Yes, I have seen it in the upstream.
Firstly, I also met this problem want to call udelay() earlier than
*loops_per_jiffy* setup like you[1]. So I am very interesting in this
patch. ;)
I am also confused about the questions which Boris asked:
whether do the CPU and TSC calibration too early just for using
udelay()?
this design broke our interface of x86_paltform.calibrate_cpu/tsc.
And I also have a question below.
[...]
>>>>>>
>>>>>> +static void __init simple_udelay_calibration(void)
>>>>>> +{
>>>>>> + unsigned int tsc_khz, cpu_khz;
>>>>>> + unsigned long lpj;
>>>>>> +
>>>>>> + if (!boot_cpu_has(X86_FEATURE_TSC))
>>>>>> + return;
if we don't have the TSC feature in booting CPU and
it returns here, can we use udelay() correctly like before?
[1] https://lkml.org/lkml/2017/7/3/276
Thanks,
dou.
>> Thanks,
>>
>> dou.
>>
>>>>>> +
>>>>>> + cpu_khz = x86_platform.calibrate_cpu();
>>>>>> + tsc_khz = x86_platform.calibrate_tsc();
>>>>>> +
>>>>>> + tsc_khz = tsc_khz ? : cpu_khz;
>>>>>> + if (!tsc_khz)
>>>>>> + return;
>>>>>> +
>>>>>> + lpj = tsc_khz * 1000;
>>>>>> + do_div(lpj, HZ);
>>>>>> + loops_per_jiffy = lpj;
>>>>>> +}
>>>>>> +
>>>>>> /*
>>>>>> * Determine if we were loaded by an EFI loader. If so, then we have also been
>>>>>> * passed the efi memmap, systab, etc., so we should use these data structures
>>>>>> @@ -985,6 +1005,8 @@ void __init setup_arch(char **cmdline_p)
>>>>>> */
>>>>>> x86_configure_nx();
>>>>>>
>>>>>> + simple_udelay_calibration();
>>>>>> +
>>>>>> parse_early_param();
>>>>>>
>>>>>> #ifdef CONFIG_MEMORY_HOTPLUG
>>>
>>>
>>>
>>>
>>
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>
>
>
>
>
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 1/5] x86: add simple udelay calibration
2017-07-13 1:17 ` Lu Baolu
@ 2017-07-13 1:39 ` Dou Liyang
2017-07-13 1:39 ` Dou Liyang
1 sibling, 0 replies; 42+ messages in thread
From: Dou Liyang @ 2017-07-13 1:39 UTC (permalink / raw)
To: Lu Baolu, Boris Ostrovsky, Greg Kroah-Hartman, Ingo Molnar,
Mathias Nyman, tglx
Cc: Juergen Gross, x86, peterz, linux-usb, linux-kernel, xen-devel
Hi, Lu
At 07/13/2017 09:17 AM, Lu Baolu wrote:
> Hi,
>
> On 07/12/2017 04:02 PM, Dou Liyang wrote:
>> Hi, Lu
>>
>> At 05/05/2017 08:50 PM, Boris Ostrovsky wrote:
>>> On 05/05/2017 01:41 AM, Lu Baolu wrote:
>>>> Hi,
>>>>
>>>> On 05/03/2017 06:38 AM, Boris Ostrovsky wrote:
>>>>> On 03/21/2017 04:01 AM, Lu Baolu wrote:
>>>>>> Add a simple udelay calibration in x86 architecture-specific
>>>>>> boot-time initializations. This will get a workable estimate
>>>>>> for loops_per_jiffy. Hence, udelay() could be used after this
>>>>>> initialization.
>>>>> This breaks Xen PV guests since at this point, and until
>>>>> x86_init.paging.pagetable_init() which is when pvclock_vcpu_time_info is
>>>>> mapped, they cannot access pvclock.
>>>>>
>>>>> Is it reasonable to do this before tsc_init() is called? (The failure
>>>>> has nothing to do with tsc_init(), really --- it's just that it is
>>>>> called late enough that Xen PV guests get properly initialized.) If it
>>>>> is, would it be possible to move simple_udelay_calibration() after
>>>>> x86_init.paging.pagetable_init()?
>>>> This is currently only used for bare metal. How about by-pass it
>>>> for Xen PV guests?
>>>
>>> It is fixed this for Xen PV guests now (in the sense that we don't crash
>>> anymore) but my question is still whether this is not too early. Besides
>>> tsc_init() (which might not be important here), at the time when
>>> simple_udelay_calibration() is invoked we haven't yet called:
>>> * kvmclock_init(), which sets calibration routines for KVM
>>> * init_hypervisor_platform(), which sets calibration routines for vmware
>>> and Xen HVM
>>> * x86_init.paging.pagetable_init(), which sets calibration routines for
>>> Xen PV
>>>
>>
>> I guess these may have been missed.
>>
>> Do you have any comments about these?
>>
>
> The patch will be available in 4.13-rc1.
Yes, I have seen it in the upstream.
Firstly, I also met this problem want to call udelay() earlier than
*loops_per_jiffy* setup like you[1]. So I am very interesting in this
patch. ;)
I am also confused about the questions which Boris asked:
whether do the CPU and TSC calibration too early just for using
udelay()?
this design broke our interface of x86_paltform.calibrate_cpu/tsc.
And I also have a question below.
[...]
>>>>>>
>>>>>> +static void __init simple_udelay_calibration(void)
>>>>>> +{
>>>>>> + unsigned int tsc_khz, cpu_khz;
>>>>>> + unsigned long lpj;
>>>>>> +
>>>>>> + if (!boot_cpu_has(X86_FEATURE_TSC))
>>>>>> + return;
if we don't have the TSC feature in booting CPU and
it returns here, can we use udelay() correctly like before?
[1] https://lkml.org/lkml/2017/7/3/276
Thanks,
dou.
>> Thanks,
>>
>> dou.
>>
>>>>>> +
>>>>>> + cpu_khz = x86_platform.calibrate_cpu();
>>>>>> + tsc_khz = x86_platform.calibrate_tsc();
>>>>>> +
>>>>>> + tsc_khz = tsc_khz ? : cpu_khz;
>>>>>> + if (!tsc_khz)
>>>>>> + return;
>>>>>> +
>>>>>> + lpj = tsc_khz * 1000;
>>>>>> + do_div(lpj, HZ);
>>>>>> + loops_per_jiffy = lpj;
>>>>>> +}
>>>>>> +
>>>>>> /*
>>>>>> * Determine if we were loaded by an EFI loader. If so, then we have also been
>>>>>> * passed the efi memmap, systab, etc., so we should use these data structures
>>>>>> @@ -985,6 +1005,8 @@ void __init setup_arch(char **cmdline_p)
>>>>>> */
>>>>>> x86_configure_nx();
>>>>>>
>>>>>> + simple_udelay_calibration();
>>>>>> +
>>>>>> parse_early_param();
>>>>>>
>>>>>> #ifdef CONFIG_MEMORY_HOTPLUG
>>>
>>>
>>>
>>>
>>
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>
>
>
>
>
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 1/5] x86: add simple udelay calibration
2017-07-13 1:39 ` Dou Liyang
2017-07-13 3:00 ` Lu Baolu
@ 2017-07-13 3:00 ` Lu Baolu
2017-07-14 3:21 ` Dou Liyang
2017-07-14 3:21 ` Dou Liyang
1 sibling, 2 replies; 42+ messages in thread
From: Lu Baolu @ 2017-07-13 3:00 UTC (permalink / raw)
To: Dou Liyang, Boris Ostrovsky, Greg Kroah-Hartman, Ingo Molnar,
Mathias Nyman, tglx
Cc: peterz, linux-usb, x86, linux-kernel, Juergen Gross, xen-devel
Hi,
On 07/13/2017 09:39 AM, Dou Liyang wrote:
> Hi, Lu
>
> At 07/13/2017 09:17 AM, Lu Baolu wrote:
>> Hi,
>>
>> On 07/12/2017 04:02 PM, Dou Liyang wrote:
>>> Hi, Lu
>>>
>>> At 05/05/2017 08:50 PM, Boris Ostrovsky wrote:
>>>> On 05/05/2017 01:41 AM, Lu Baolu wrote:
>>>>> Hi,
>>>>>
>>>>> On 05/03/2017 06:38 AM, Boris Ostrovsky wrote:
>>>>>> On 03/21/2017 04:01 AM, Lu Baolu wrote:
>>>>>>> Add a simple udelay calibration in x86 architecture-specific
>>>>>>> boot-time initializations. This will get a workable estimate
>>>>>>> for loops_per_jiffy. Hence, udelay() could be used after this
>>>>>>> initialization.
>>>>>> This breaks Xen PV guests since at this point, and until
>>>>>> x86_init.paging.pagetable_init() which is when pvclock_vcpu_time_info is
>>>>>> mapped, they cannot access pvclock.
>>>>>>
>>>>>> Is it reasonable to do this before tsc_init() is called? (The failure
>>>>>> has nothing to do with tsc_init(), really --- it's just that it is
>>>>>> called late enough that Xen PV guests get properly initialized.) If it
>>>>>> is, would it be possible to move simple_udelay_calibration() after
>>>>>> x86_init.paging.pagetable_init()?
>>>>> This is currently only used for bare metal. How about by-pass it
>>>>> for Xen PV guests?
>>>>
>>>> It is fixed this for Xen PV guests now (in the sense that we don't crash
>>>> anymore) but my question is still whether this is not too early. Besides
>>>> tsc_init() (which might not be important here), at the time when
>>>> simple_udelay_calibration() is invoked we haven't yet called:
>>>> * kvmclock_init(), which sets calibration routines for KVM
>>>> * init_hypervisor_platform(), which sets calibration routines for vmware
>>>> and Xen HVM
>>>> * x86_init.paging.pagetable_init(), which sets calibration routines for
>>>> Xen PV
>>>>
>>>
>>> I guess these may have been missed.
>>>
>>> Do you have any comments about these?
>>>
>>
>> The patch will be available in 4.13-rc1.
>
> Yes, I have seen it in the upstream.
>
> Firstly, I also met this problem want to call udelay() earlier than
> *loops_per_jiffy* setup like you[1]. So I am very interesting in this
> patch. ;)
>
> I am also confused about the questions which Boris asked:
>
> whether do the CPU and TSC calibration too early just for using
> udelay()?
>
> this design broke our interface of x86_paltform.calibrate_cpu/tsc.
>
> And I also have a question below.
>
> [...]
>
>>>>>>>
>>>>>>> +static void __init simple_udelay_calibration(void)
>>>>>>> +{
>>>>>>> + unsigned int tsc_khz, cpu_khz;
>>>>>>> + unsigned long lpj;
>>>>>>> +
>>>>>>> + if (!boot_cpu_has(X86_FEATURE_TSC))
>>>>>>> + return;
>
> if we don't have the TSC feature in booting CPU and
> it returns here, can we use udelay() correctly like before?
>
If we have TSC feature, we calculate a preciser loops_per_jiffy here.
Otherwise, we just keep it as before. This function doesn't broke the
use of udelay().
Best regards,
Lu Baolu
>
> [1] https://lkml.org/lkml/2017/7/3/276
>
> Thanks,
>
> dou.
>
>>> Thanks,
>>>
>>> dou.
>>>
>>>>>>> +
>>>>>>> + cpu_khz = x86_platform.calibrate_cpu();
>>>>>>> + tsc_khz = x86_platform.calibrate_tsc();
>>>>>>> +
>>>>>>> + tsc_khz = tsc_khz ? : cpu_khz;
>>>>>>> + if (!tsc_khz)
>>>>>>> + return;
>>>>>>> +
>>>>>>> + lpj = tsc_khz * 1000;
>>>>>>> + do_div(lpj, HZ);
>>>>>>> + loops_per_jiffy = lpj;
>>>>>>> +}
>>>>>>> +
>>>>>>> /*
>>>>>>> * Determine if we were loaded by an EFI loader. If so, then we have also been
>>>>>>> * passed the efi memmap, systab, etc., so we should use these data structures
>>>>>>> @@ -985,6 +1005,8 @@ void __init setup_arch(char **cmdline_p)
>>>>>>> */
>>>>>>> x86_configure_nx();
>>>>>>>
>>>>>>> + simple_udelay_calibration();
>>>>>>> +
>>>>>>> parse_early_param();
>>>>>>>
>>>>>>> #ifdef CONFIG_MEMORY_HOTPLUG
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
>>> the body of a message to majordomo@vger.kernel.org
>>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>>
>>
>>
>>
>>
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 1/5] x86: add simple udelay calibration
2017-07-13 1:39 ` Dou Liyang
@ 2017-07-13 3:00 ` Lu Baolu
2017-07-13 3:00 ` Lu Baolu
1 sibling, 0 replies; 42+ messages in thread
From: Lu Baolu @ 2017-07-13 3:00 UTC (permalink / raw)
To: Dou Liyang, Boris Ostrovsky, Greg Kroah-Hartman, Ingo Molnar,
Mathias Nyman, tglx
Cc: Juergen Gross, x86, peterz, linux-usb, linux-kernel, xen-devel
Hi,
On 07/13/2017 09:39 AM, Dou Liyang wrote:
> Hi, Lu
>
> At 07/13/2017 09:17 AM, Lu Baolu wrote:
>> Hi,
>>
>> On 07/12/2017 04:02 PM, Dou Liyang wrote:
>>> Hi, Lu
>>>
>>> At 05/05/2017 08:50 PM, Boris Ostrovsky wrote:
>>>> On 05/05/2017 01:41 AM, Lu Baolu wrote:
>>>>> Hi,
>>>>>
>>>>> On 05/03/2017 06:38 AM, Boris Ostrovsky wrote:
>>>>>> On 03/21/2017 04:01 AM, Lu Baolu wrote:
>>>>>>> Add a simple udelay calibration in x86 architecture-specific
>>>>>>> boot-time initializations. This will get a workable estimate
>>>>>>> for loops_per_jiffy. Hence, udelay() could be used after this
>>>>>>> initialization.
>>>>>> This breaks Xen PV guests since at this point, and until
>>>>>> x86_init.paging.pagetable_init() which is when pvclock_vcpu_time_info is
>>>>>> mapped, they cannot access pvclock.
>>>>>>
>>>>>> Is it reasonable to do this before tsc_init() is called? (The failure
>>>>>> has nothing to do with tsc_init(), really --- it's just that it is
>>>>>> called late enough that Xen PV guests get properly initialized.) If it
>>>>>> is, would it be possible to move simple_udelay_calibration() after
>>>>>> x86_init.paging.pagetable_init()?
>>>>> This is currently only used for bare metal. How about by-pass it
>>>>> for Xen PV guests?
>>>>
>>>> It is fixed this for Xen PV guests now (in the sense that we don't crash
>>>> anymore) but my question is still whether this is not too early. Besides
>>>> tsc_init() (which might not be important here), at the time when
>>>> simple_udelay_calibration() is invoked we haven't yet called:
>>>> * kvmclock_init(), which sets calibration routines for KVM
>>>> * init_hypervisor_platform(), which sets calibration routines for vmware
>>>> and Xen HVM
>>>> * x86_init.paging.pagetable_init(), which sets calibration routines for
>>>> Xen PV
>>>>
>>>
>>> I guess these may have been missed.
>>>
>>> Do you have any comments about these?
>>>
>>
>> The patch will be available in 4.13-rc1.
>
> Yes, I have seen it in the upstream.
>
> Firstly, I also met this problem want to call udelay() earlier than
> *loops_per_jiffy* setup like you[1]. So I am very interesting in this
> patch. ;)
>
> I am also confused about the questions which Boris asked:
>
> whether do the CPU and TSC calibration too early just for using
> udelay()?
>
> this design broke our interface of x86_paltform.calibrate_cpu/tsc.
>
> And I also have a question below.
>
> [...]
>
>>>>>>>
>>>>>>> +static void __init simple_udelay_calibration(void)
>>>>>>> +{
>>>>>>> + unsigned int tsc_khz, cpu_khz;
>>>>>>> + unsigned long lpj;
>>>>>>> +
>>>>>>> + if (!boot_cpu_has(X86_FEATURE_TSC))
>>>>>>> + return;
>
> if we don't have the TSC feature in booting CPU and
> it returns here, can we use udelay() correctly like before?
>
If we have TSC feature, we calculate a preciser loops_per_jiffy here.
Otherwise, we just keep it as before. This function doesn't broke the
use of udelay().
Best regards,
Lu Baolu
>
> [1] https://lkml.org/lkml/2017/7/3/276
>
> Thanks,
>
> dou.
>
>>> Thanks,
>>>
>>> dou.
>>>
>>>>>>> +
>>>>>>> + cpu_khz = x86_platform.calibrate_cpu();
>>>>>>> + tsc_khz = x86_platform.calibrate_tsc();
>>>>>>> +
>>>>>>> + tsc_khz = tsc_khz ? : cpu_khz;
>>>>>>> + if (!tsc_khz)
>>>>>>> + return;
>>>>>>> +
>>>>>>> + lpj = tsc_khz * 1000;
>>>>>>> + do_div(lpj, HZ);
>>>>>>> + loops_per_jiffy = lpj;
>>>>>>> +}
>>>>>>> +
>>>>>>> /*
>>>>>>> * Determine if we were loaded by an EFI loader. If so, then we have also been
>>>>>>> * passed the efi memmap, systab, etc., so we should use these data structures
>>>>>>> @@ -985,6 +1005,8 @@ void __init setup_arch(char **cmdline_p)
>>>>>>> */
>>>>>>> x86_configure_nx();
>>>>>>>
>>>>>>> + simple_udelay_calibration();
>>>>>>> +
>>>>>>> parse_early_param();
>>>>>>>
>>>>>>> #ifdef CONFIG_MEMORY_HOTPLUG
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
>>> the body of a message to majordomo@vger.kernel.org
>>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>>
>>
>>
>>
>>
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
_______________________________________________
Xen-devel mailing list
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https://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 1/5] x86: add simple udelay calibration
2017-07-13 3:00 ` Lu Baolu
@ 2017-07-14 3:21 ` Dou Liyang
2017-07-14 3:21 ` Dou Liyang
1 sibling, 0 replies; 42+ messages in thread
From: Dou Liyang @ 2017-07-14 3:21 UTC (permalink / raw)
To: Lu Baolu, Boris Ostrovsky, Greg Kroah-Hartman, Ingo Molnar,
Mathias Nyman, tglx
Cc: peterz, linux-usb, x86, linux-kernel, Juergen Gross, xen-devel
Hi, Lu
At 07/13/2017 11:00 AM, Lu Baolu wrote:
> Hi,
>
> On 07/13/2017 09:39 AM, Dou Liyang wrote:
>> Hi, Lu
>>
>> At 07/13/2017 09:17 AM, Lu Baolu wrote:
>>> Hi,
>>>
>>> On 07/12/2017 04:02 PM, Dou Liyang wrote:
>>>> Hi, Lu
>>>>
>>>> At 05/05/2017 08:50 PM, Boris Ostrovsky wrote:
>>>>> On 05/05/2017 01:41 AM, Lu Baolu wrote:
>>>>>> Hi,
>>>>>>
>>>>>> On 05/03/2017 06:38 AM, Boris Ostrovsky wrote:
>>>>>>> On 03/21/2017 04:01 AM, Lu Baolu wrote:
>>>>>>>> Add a simple udelay calibration in x86 architecture-specific
>>>>>>>> boot-time initializations. This will get a workable estimate
>>>>>>>> for loops_per_jiffy. Hence, udelay() could be used after this
>>>>>>>> initialization.
>>>>>>> This breaks Xen PV guests since at this point, and until
>>>>>>> x86_init.paging.pagetable_init() which is when pvclock_vcpu_time_info is
>>>>>>> mapped, they cannot access pvclock.
>>>>>>>
>>>>>>> Is it reasonable to do this before tsc_init() is called? (The failure
>>>>>>> has nothing to do with tsc_init(), really --- it's just that it is
>>>>>>> called late enough that Xen PV guests get properly initialized.) If it
>>>>>>> is, would it be possible to move simple_udelay_calibration() after
>>>>>>> x86_init.paging.pagetable_init()?
>>>>>> This is currently only used for bare metal. How about by-pass it
>>>>>> for Xen PV guests?
>>>>>
>>>>> It is fixed this for Xen PV guests now (in the sense that we don't crash
>>>>> anymore) but my question is still whether this is not too early. Besides
>>>>> tsc_init() (which might not be important here), at the time when
>>>>> simple_udelay_calibration() is invoked we haven't yet called:
>>>>> * kvmclock_init(), which sets calibration routines for KVM
>>>>> * init_hypervisor_platform(), which sets calibration routines for vmware
>>>>> and Xen HVM
>>>>> * x86_init.paging.pagetable_init(), which sets calibration routines for
>>>>> Xen PV
>>>>>
>>>>
>>>> I guess these may have been missed.
>>>>
>>>> Do you have any comments about these?
>>>>
>>>
>>> The patch will be available in 4.13-rc1.
>>
>> Yes, I have seen it in the upstream.
>>
>> Firstly, I also met this problem want to call udelay() earlier than
>> *loops_per_jiffy* setup like you[1]. So I am very interesting in this
>> patch. ;)
>>
>> I am also confused about the questions which Boris asked:
>>
>> whether do the CPU and TSC calibration too early just for using
>> udelay()?
>>
>> this design broke our interface of x86_paltform.calibrate_cpu/tsc.
>>
>> And I also have a question below.
>>
>> [...]
>>
>>>>>>>>
>>>>>>>> +static void __init simple_udelay_calibration(void)
>>>>>>>> +{
>>>>>>>> + unsigned int tsc_khz, cpu_khz;
>>>>>>>> + unsigned long lpj;
>>>>>>>> +
>>>>>>>> + if (!boot_cpu_has(X86_FEATURE_TSC))
>>>>>>>> + return;
>>
>> if we don't have the TSC feature in booting CPU and
>> it returns here, can we use udelay() correctly like before?
>>
>
> If we have TSC feature, we calculate a preciser loops_per_jiffy here.
> Otherwise, we just keep it as before. This function doesn't broke the
> use of udelay().
Oh, I see.
In XDbC (XHCI debug capability), we just want the udelay() work more
precisely in the TSC supported system.
It is different with my problem I missed.
Thanks for your kind explanation. :)
Thanks,
dou
>
> Best regards,
> Lu Baolu
>
>>
>> [1] https://lkml.org/lkml/2017/7/3/276
>>
>> Thanks,
>>
>> dou.
>>
>>>> Thanks,
>>>>
>>>> dou.
>>>>
>>>>>>>> +
>>>>>>>> + cpu_khz = x86_platform.calibrate_cpu();
>>>>>>>> + tsc_khz = x86_platform.calibrate_tsc();
>>>>>>>> +
>>>>>>>> + tsc_khz = tsc_khz ? : cpu_khz;
>>>>>>>> + if (!tsc_khz)
>>>>>>>> + return;
>>>>>>>> +
>>>>>>>> + lpj = tsc_khz * 1000;
>>>>>>>> + do_div(lpj, HZ);
>>>>>>>> + loops_per_jiffy = lpj;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> /*
>>>>>>>> * Determine if we were loaded by an EFI loader. If so, then we have also been
>>>>>>>> * passed the efi memmap, systab, etc., so we should use these data structures
>>>>>>>> @@ -985,6 +1005,8 @@ void __init setup_arch(char **cmdline_p)
>>>>>>>> */
>>>>>>>> x86_configure_nx();
>>>>>>>>
>>>>>>>> + simple_udelay_calibration();
>>>>>>>> +
>>>>>>>> parse_early_param();
>>>>>>>>
>>>>>>>> #ifdef CONFIG_MEMORY_HOTPLUG
>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
>>>> the body of a message to majordomo@vger.kernel.org
>>>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>>>
>>>
>>>
>>>
>>>
>>
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>
>
>
>
>
^ permalink raw reply [flat|nested] 42+ messages in thread
* Re: [PATCH v8 1/5] x86: add simple udelay calibration
2017-07-13 3:00 ` Lu Baolu
2017-07-14 3:21 ` Dou Liyang
@ 2017-07-14 3:21 ` Dou Liyang
1 sibling, 0 replies; 42+ messages in thread
From: Dou Liyang @ 2017-07-14 3:21 UTC (permalink / raw)
To: Lu Baolu, Boris Ostrovsky, Greg Kroah-Hartman, Ingo Molnar,
Mathias Nyman, tglx
Cc: Juergen Gross, x86, peterz, linux-usb, linux-kernel, xen-devel
Hi, Lu
At 07/13/2017 11:00 AM, Lu Baolu wrote:
> Hi,
>
> On 07/13/2017 09:39 AM, Dou Liyang wrote:
>> Hi, Lu
>>
>> At 07/13/2017 09:17 AM, Lu Baolu wrote:
>>> Hi,
>>>
>>> On 07/12/2017 04:02 PM, Dou Liyang wrote:
>>>> Hi, Lu
>>>>
>>>> At 05/05/2017 08:50 PM, Boris Ostrovsky wrote:
>>>>> On 05/05/2017 01:41 AM, Lu Baolu wrote:
>>>>>> Hi,
>>>>>>
>>>>>> On 05/03/2017 06:38 AM, Boris Ostrovsky wrote:
>>>>>>> On 03/21/2017 04:01 AM, Lu Baolu wrote:
>>>>>>>> Add a simple udelay calibration in x86 architecture-specific
>>>>>>>> boot-time initializations. This will get a workable estimate
>>>>>>>> for loops_per_jiffy. Hence, udelay() could be used after this
>>>>>>>> initialization.
>>>>>>> This breaks Xen PV guests since at this point, and until
>>>>>>> x86_init.paging.pagetable_init() which is when pvclock_vcpu_time_info is
>>>>>>> mapped, they cannot access pvclock.
>>>>>>>
>>>>>>> Is it reasonable to do this before tsc_init() is called? (The failure
>>>>>>> has nothing to do with tsc_init(), really --- it's just that it is
>>>>>>> called late enough that Xen PV guests get properly initialized.) If it
>>>>>>> is, would it be possible to move simple_udelay_calibration() after
>>>>>>> x86_init.paging.pagetable_init()?
>>>>>> This is currently only used for bare metal. How about by-pass it
>>>>>> for Xen PV guests?
>>>>>
>>>>> It is fixed this for Xen PV guests now (in the sense that we don't crash
>>>>> anymore) but my question is still whether this is not too early. Besides
>>>>> tsc_init() (which might not be important here), at the time when
>>>>> simple_udelay_calibration() is invoked we haven't yet called:
>>>>> * kvmclock_init(), which sets calibration routines for KVM
>>>>> * init_hypervisor_platform(), which sets calibration routines for vmware
>>>>> and Xen HVM
>>>>> * x86_init.paging.pagetable_init(), which sets calibration routines for
>>>>> Xen PV
>>>>>
>>>>
>>>> I guess these may have been missed.
>>>>
>>>> Do you have any comments about these?
>>>>
>>>
>>> The patch will be available in 4.13-rc1.
>>
>> Yes, I have seen it in the upstream.
>>
>> Firstly, I also met this problem want to call udelay() earlier than
>> *loops_per_jiffy* setup like you[1]. So I am very interesting in this
>> patch. ;)
>>
>> I am also confused about the questions which Boris asked:
>>
>> whether do the CPU and TSC calibration too early just for using
>> udelay()?
>>
>> this design broke our interface of x86_paltform.calibrate_cpu/tsc.
>>
>> And I also have a question below.
>>
>> [...]
>>
>>>>>>>>
>>>>>>>> +static void __init simple_udelay_calibration(void)
>>>>>>>> +{
>>>>>>>> + unsigned int tsc_khz, cpu_khz;
>>>>>>>> + unsigned long lpj;
>>>>>>>> +
>>>>>>>> + if (!boot_cpu_has(X86_FEATURE_TSC))
>>>>>>>> + return;
>>
>> if we don't have the TSC feature in booting CPU and
>> it returns here, can we use udelay() correctly like before?
>>
>
> If we have TSC feature, we calculate a preciser loops_per_jiffy here.
> Otherwise, we just keep it as before. This function doesn't broke the
> use of udelay().
Oh, I see.
In XDbC (XHCI debug capability), we just want the udelay() work more
precisely in the TSC supported system.
It is different with my problem I missed.
Thanks for your kind explanation. :)
Thanks,
dou
>
> Best regards,
> Lu Baolu
>
>>
>> [1] https://lkml.org/lkml/2017/7/3/276
>>
>> Thanks,
>>
>> dou.
>>
>>>> Thanks,
>>>>
>>>> dou.
>>>>
>>>>>>>> +
>>>>>>>> + cpu_khz = x86_platform.calibrate_cpu();
>>>>>>>> + tsc_khz = x86_platform.calibrate_tsc();
>>>>>>>> +
>>>>>>>> + tsc_khz = tsc_khz ? : cpu_khz;
>>>>>>>> + if (!tsc_khz)
>>>>>>>> + return;
>>>>>>>> +
>>>>>>>> + lpj = tsc_khz * 1000;
>>>>>>>> + do_div(lpj, HZ);
>>>>>>>> + loops_per_jiffy = lpj;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> /*
>>>>>>>> * Determine if we were loaded by an EFI loader. If so, then we have also been
>>>>>>>> * passed the efi memmap, systab, etc., so we should use these data structures
>>>>>>>> @@ -985,6 +1005,8 @@ void __init setup_arch(char **cmdline_p)
>>>>>>>> */
>>>>>>>> x86_configure_nx();
>>>>>>>>
>>>>>>>> + simple_udelay_calibration();
>>>>>>>> +
>>>>>>>> parse_early_param();
>>>>>>>>
>>>>>>>> #ifdef CONFIG_MEMORY_HOTPLUG
>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
>>>> the body of a message to majordomo@vger.kernel.org
>>>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>>>
>>>
>>>
>>>
>>>
>>
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>
>
>
>
>
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
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^ permalink raw reply [flat|nested] 42+ messages in thread
end of thread, other threads:[~2017-07-14 3:21 UTC | newest]
Thread overview: 42+ messages (download: mbox.gz / follow: Atom feed)
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2017-03-21 8:01 [PATCH v8 0/5] usb: early: add support for early printk through USB3 debug port Lu Baolu
2017-03-21 8:01 ` [PATCH v8 1/5] x86: add simple udelay calibration Lu Baolu
2017-03-21 12:19 ` [tip:x86/debug] x86/timers: Add " tip-bot for Lu Baolu
2017-05-24 16:56 ` Jan Kiszka
2017-05-25 0:49 ` Lu Baolu
2017-05-02 22:38 ` [PATCH v8 1/5] x86: add " Boris Ostrovsky
2017-05-02 22:38 ` Boris Ostrovsky
2017-05-05 5:41 ` Lu Baolu
2017-05-05 5:41 ` Lu Baolu
2017-05-05 12:50 ` Boris Ostrovsky
2017-07-12 8:02 ` Dou Liyang
2017-07-12 8:02 ` Dou Liyang
2017-07-13 1:17 ` Lu Baolu
2017-07-13 1:17 ` Lu Baolu
2017-07-13 1:39 ` Dou Liyang
2017-07-13 1:39 ` Dou Liyang
2017-07-13 3:00 ` Lu Baolu
2017-07-13 3:00 ` Lu Baolu
2017-07-14 3:21 ` Dou Liyang
2017-07-14 3:21 ` Dou Liyang
2017-05-05 12:50 ` Boris Ostrovsky
2017-03-21 8:01 ` [PATCH v8 2/5] usb: early: add driver for xhci debug capability Lu Baolu
2017-03-21 12:19 ` [tip:x86/debug] usb/early: Add " tip-bot for Lu Baolu
2017-05-30 13:46 ` [PATCH v8 2/5] usb: early: add " Vlastimil Babka
2017-05-31 3:27 ` Lu Baolu
2017-05-31 6:24 ` Steven Rostedt
2017-06-01 3:35 ` Lu Baolu
2017-05-31 9:38 ` Vlastimil Babka
2017-06-01 3:37 ` Lu Baolu
2017-06-01 8:15 ` Vlastimil Babka
2017-06-01 12:25 ` Peter Zijlstra
2017-06-02 0:47 ` Steven Rostedt
2017-03-21 8:01 ` [PATCH v8 3/5] x86: add support for earlyprintk via USB3 debug port Lu Baolu
2017-03-21 12:20 ` [tip:x86/debug] x86/earlyprintk: Add " tip-bot for Lu Baolu
2017-03-21 8:01 ` [PATCH v8 4/5] usb: serial: add dbc debug device support to usb_debug Lu Baolu
2017-03-21 12:21 ` [tip:x86/debug] usb/serial: Add DBC " tip-bot for Lu Baolu
2017-03-21 8:01 ` [PATCH v8 5/5] usb: doc: add document for USB3 debug port usage Lu Baolu
2017-03-21 12:21 ` [tip:x86/debug] usb/doc: Add " tip-bot for Lu Baolu
2017-03-21 11:33 ` [PATCH v8 0/5] usb: early: add support for early printk through USB3 debug port Ingo Molnar
2017-03-21 12:27 ` Greg Kroah-Hartman
2017-03-21 12:46 ` Ingo Molnar
2017-03-22 2:23 ` Lu Baolu
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