* [PATCH v4 0/4] ACPI: parse the SPCR table
@ 2016-02-29 12:02 Aleksey Makarov
2016-02-29 12:02 ` [PATCH v4 1/4] ACPI: parse SPCR and enable matching console Aleksey Makarov
` (5 more replies)
0 siblings, 6 replies; 17+ messages in thread
From: Aleksey Makarov @ 2016-02-29 12:02 UTC (permalink / raw)
To: linux-arm-kernel
'ARM Server Base Boot Requirements' [1] mentions SPCR (Serial Port
Console Redirection Table) [2] as a mandatory ACPI table that
specifies the configuration of serial console.
Introduce a new function acpi_console_check(). At the uart port
registration, this function checks if the ACPI SPCR table specifies
its argument of type struct uart_port to be a console
and if so calls add_preferred_console().
Use SPCR to tell if SBSA serial driver should use 32-bit access to registers.
Based on the work by Leif Lindholm [3]
Should be applied to next-20160229.
Tested on QEMU. SPCR support is included in QEMU's ARM mach-virt
since 2.4 release.
v4:
- drop patch "ACPI: change __init to __ref for early_acpi_os_unmap_memory()"
ACPI developers work on a new API and asked not to do that.
Instead, use acpi_get_table_with_size()/early_acpi_os_unmap_memory() once
and cache the result. (Lv Zheng)
- fix some style issues (Yury Norov)
v3:
https://lkml.kernel.org/g/1455559532-8305-1-git-send-email-aleksey.makarov at linaro.org
Greg Kroah-Hartman did not like v2 so I have rewritten this patchset:
- drop acpi_match() member of struct console
- drop implementations of this member for pl011 and 8250
- drop the patch that renames some vars in printk.c as it is not needed anymore
- drop patch that introduces system wide acpi_table_parse2().
Instead introduce a custom acpi_table_parse_spcr() in spcr.c
Instead of introducing a new match_acpi() member of struct console,
this patchset introduces a new function acpi_console_check().
This function is called when a new uart is registered at serial_core.c
the same way OF code checks for console. If the registered uart is the
console specified by SPCR table, this function calls add_preferred_console()
The restrictions of this approach are:
- only serial consoles can be set up
- only consoles specified by the memory/io address can be set up
(SPCR can specify devices by PCI id/PCI address)
v2:
https://lkml.kernel.org/g/1455299022-11641-1-git-send-email-aleksey.makarov at linaro.org
- don't use SPCR if user specified console in command line
- fix initialization order of newcon->index = 0
- rename some variables at printk.c (Joe Perches, Peter Hurley)
- enable ACPI_SPCR_TABLE in a separate patch (Andy Shevchenko)
- remove the retry loop for console registering (Peter Hurley).
Instead, obtain SPCR with acpi_get_table(). That works after
call to acpi_early_init() i. e. in any *_initcall()
- describe design decision behind introducing acpi_match() (Peter Hurley)
- fix compilation for x86 + ACPI (Graeme Gregory)
- introduce DBG2 constants in a separate patch (Andy Shevchenko)
- fix a typo in DBG2 constants (Andy Shevchenko)
- add ACPI_DBG2_ARM_SBSA_32BIT constant (Christopher Covington)
- add support for ACPI_DBG2_ARM_SBSA_* consoles (Christopher Covington)
- add documentation for functions
- add a patch that uses SPCR to find if SBSA serial driver should use 32-bit
accessor functions (Christopher Covington)
- change __init to __ref for early_acpi_os_unmap_memory() in a separate patch
- introduce acpi_table_parse2() in a separate patch
- fix fetching the SPCR table early (Mark Salter)
- add a patch from Mark Salter that introduces support for matching 8250-based
consoles
v1:
https://lkml.kernel.org/g/1453722324-22407-1-git-send-email-aleksey.makarov at linaro.org
[1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.den0044a/index.html
[2] https://msdn.microsoft.com/en-us/library/windows/hardware/dn639132(v=vs.85).aspx
[3] https://lkml.kernel.org/g/1441716217-23786-1-git-send-email-leif.lindholm at linaro.org
Aleksey Makarov (4):
ACPI: parse SPCR and enable matching console
ACPI: enable ACPI_SPCR_TABLE on ARM64
ACPI: add definitions of DBG2 subtypes
serial: pl011: use ACPI SPCR to setup 32-bit access
arch/arm64/Kconfig | 1 +
drivers/acpi/Kconfig | 3 +
drivers/acpi/Makefile | 1 +
drivers/acpi/spcr.c | 138 +++++++++++++++++++++++++++++++++++++++
drivers/tty/serial/amba-pl011.c | 2 +
drivers/tty/serial/serial_core.c | 14 +++-
include/acpi/actbl2.h | 5 ++
include/linux/acpi.h | 15 +++++
8 files changed, 177 insertions(+), 2 deletions(-)
create mode 100644 drivers/acpi/spcr.c
--
2.7.1
^ permalink raw reply [flat|nested] 17+ messages in thread
* [PATCH v4 1/4] ACPI: parse SPCR and enable matching console
2016-02-29 12:02 [PATCH v4 0/4] ACPI: parse the SPCR table Aleksey Makarov
@ 2016-02-29 12:02 ` Aleksey Makarov
2016-02-29 13:29 ` Andy Shevchenko
2016-02-29 12:02 ` [PATCH v4 2/4] ACPI: enable ACPI_SPCR_TABLE on ARM64 Aleksey Makarov
` (4 subsequent siblings)
5 siblings, 1 reply; 17+ messages in thread
From: Aleksey Makarov @ 2016-02-29 12:02 UTC (permalink / raw)
To: linux-arm-kernel
'ARM Server Base Boot Requiremets' [1] mentions SPCR (Serial Port
Console Redirection Table) [2] as a mandatory ACPI table that
specifies the configuration of serial console.
Parse this table and check if any registered console match the
description. If it does, enable that console.
Introduce a new function acpi_console_check(). At the uart port
registration, this function checks if the ACPI SPCR table specifies
its argument of type struct uart_port to be a console
and if so calls add_preferred_console().
[1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.den0044a/index.html
[2] http://msdn.microsoft.com/en-us/library/windows/hardware/dn639131(v=vs.85).aspx
Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
---
drivers/acpi/Kconfig | 3 +
drivers/acpi/Makefile | 1 +
drivers/acpi/spcr.c | 116 +++++++++++++++++++++++++++++++++++++++
drivers/tty/serial/serial_core.c | 14 ++++-
include/linux/acpi.h | 10 ++++
5 files changed, 142 insertions(+), 2 deletions(-)
create mode 100644 drivers/acpi/spcr.c
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 65fb483..5611eb6 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -77,6 +77,9 @@ config ACPI_DEBUGGER_USER
endif
+config ACPI_SPCR_TABLE
+ bool
+
config ACPI_SLEEP
bool
depends on SUSPEND || HIBERNATION
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 7395928..f70ae14 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -82,6 +82,7 @@ obj-$(CONFIG_ACPI_EC_DEBUGFS) += ec_sys.o
obj-$(CONFIG_ACPI_CUSTOM_METHOD)+= custom_method.o
obj-$(CONFIG_ACPI_BGRT) += bgrt.o
obj-$(CONFIG_ACPI_CPPC_LIB) += cppc_acpi.o
+obj-$(CONFIG_ACPI_SPCR_TABLE) += spcr.o
obj-$(CONFIG_ACPI_DEBUGGER_USER) += acpi_dbg.o
# processor has its own "processor." module_param namespace
diff --git a/drivers/acpi/spcr.c b/drivers/acpi/spcr.c
new file mode 100644
index 0000000..c460cb1
--- /dev/null
+++ b/drivers/acpi/spcr.c
@@ -0,0 +1,116 @@
+/*
+ * Copyright (c) 2012, Intel Corporation
+ * Copyright (c) 2015, Red Hat, Inc.
+ * Copyright (c) 2015, 2016 Linaro Ltd.
+ *
+ * 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) "ACPI: SPCR: " fmt
+
+#include <linux/acpi.h>
+#include <linux/console.h>
+#include <linux/kernel.h>
+#include <linux/serial_core.h>
+
+static char *options;
+static struct acpi_generic_address address;
+
+static int __init parse_spcr_init(void)
+{
+ struct acpi_table_spcr *table;
+ acpi_size table_size;
+ acpi_status status;
+ int err = 0;
+
+ status = acpi_get_table_with_size(ACPI_SIG_SPCR, 0,
+ (struct acpi_table_header **)&table,
+ &table_size);
+
+ if (ACPI_FAILURE(status)) {
+ pr_err("could not get the table\n");
+ return -ENOENT;
+ }
+
+ if (table->header.revision < 2) {
+ err = -EINVAL;
+ pr_err("wrong table version\n");
+ goto done;
+ }
+
+ switch (table->baud_rate) {
+ case 3:
+ options = "9600";
+ break;
+ case 4:
+ options = "19200";
+ break;
+ case 6:
+ options = "57600";
+ break;
+ case 7:
+ options = "115200";
+ break;
+ default:
+ options = "";
+ break;
+ }
+
+ address = table->serial_port;
+
+done:
+ early_acpi_os_unmap_memory((void __iomem *)table, table_size);
+ return err;
+}
+
+/*
+ * This function calls __init parse_spcr_init() so it needs __ref.
+ * It is referenced by the arch_inicall() macros so it will be called
+ * at initialization and the 'parsed' variable will be set.
+ * So it's safe to make it __ref.
+ */
+static int __ref parse_spcr(void)
+{
+ static bool parsed;
+ static int parse_error;
+
+ if (!parsed) {
+ parse_error = parse_spcr_init();
+ parsed = true;
+ }
+
+ return parse_error;
+}
+
+arch_initcall(parse_spcr);
+
+/**
+ * acpi_console_check - Check if uart matches the console specified by SPCR.
+ *
+ * @uport: uart port to check
+ *
+ * This function checks if the ACPI SPCR table specifies @uport to be a console
+ * and if so calls add_preferred_console()
+ *
+ * Return: a non-error value if the console matches.
+ */
+bool acpi_console_check(struct uart_port *uport)
+{
+ if (acpi_disabled || console_set_on_cmdline || parse_spcr() < 0)
+ return false;
+
+ if ((address.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY &&
+ address.address == (u64)uport->mapbase) ||
+ (address.space_id == ACPI_ADR_SPACE_SYSTEM_IO &&
+ address.address == (u64)uport->iobase)) {
+ pr_info("adding preferred console [%s%d]\n", uport->cons->name,
+ uport->line);
+ add_preferred_console(uport->cons->name, uport->line, options);
+ return true;
+ }
+
+ return false;
+}
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index a126a60..459ab54 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -34,6 +34,7 @@
#include <linux/serial_core.h>
#include <linux/delay.h>
#include <linux/mutex.h>
+#include <linux/acpi.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
@@ -2654,8 +2655,17 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
spin_lock_init(&uport->lock);
lockdep_set_class(&uport->lock, &port_lock_key);
}
- if (uport->cons && uport->dev)
- of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
+
+ /*
+ * Support both open FW and ACPI access to console definitions.
+ * Both of_console_check() and acpi_console_check() will call
+ * add_preferred_console() if a console definition is found.
+ */
+ if (uport->cons && uport->dev) {
+ if (!acpi_console_check(uport))
+ of_console_check(uport->dev->of_node, uport->cons->name,
+ uport->line);
+ }
uart_configure_port(drv, state, uport);
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 06ed7e5..ea0c297 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -1004,4 +1004,14 @@ static inline struct fwnode_handle *acpi_get_next_subnode(struct device *dev,
#define acpi_probe_device_table(t) ({ int __r = 0; __r;})
#endif
+struct uart_port;
+#ifdef CONFIG_ACPI_SPCR_TABLE
+bool acpi_console_check(struct uart_port *uport);
+#else
+static inline bool acpi_console_check(struct uart_port *uport)
+{
+ return FALSE;
+}
+#endif
+
#endif /*_LINUX_ACPI_H*/
--
2.7.1
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH v4 2/4] ACPI: enable ACPI_SPCR_TABLE on ARM64
2016-02-29 12:02 [PATCH v4 0/4] ACPI: parse the SPCR table Aleksey Makarov
2016-02-29 12:02 ` [PATCH v4 1/4] ACPI: parse SPCR and enable matching console Aleksey Makarov
@ 2016-02-29 12:02 ` Aleksey Makarov
2016-03-01 15:27 ` Peter Hurley
2016-03-17 17:20 ` Timur Tabi
2016-02-29 12:02 ` [PATCH v4 3/4] ACPI: add definitions of DBG2 subtypes Aleksey Makarov
` (3 subsequent siblings)
5 siblings, 2 replies; 17+ messages in thread
From: Aleksey Makarov @ 2016-02-29 12:02 UTC (permalink / raw)
To: linux-arm-kernel
SBBR mentions SPCR as a mandatory ACPI table.
So enable it for ARM64
Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
---
arch/arm64/Kconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 9dc5209..544af2e 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -3,6 +3,7 @@ config ARM64
select ACPI_CCA_REQUIRED if ACPI
select ACPI_GENERIC_GSI if ACPI
select ACPI_REDUCED_HARDWARE_ONLY if ACPI
+ select ACPI_SPCR_TABLE if ACPI
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
select ARCH_HAS_ELF_RANDOMIZE
--
2.7.1
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH v4 3/4] ACPI: add definitions of DBG2 subtypes
2016-02-29 12:02 [PATCH v4 0/4] ACPI: parse the SPCR table Aleksey Makarov
2016-02-29 12:02 ` [PATCH v4 1/4] ACPI: parse SPCR and enable matching console Aleksey Makarov
2016-02-29 12:02 ` [PATCH v4 2/4] ACPI: enable ACPI_SPCR_TABLE on ARM64 Aleksey Makarov
@ 2016-02-29 12:02 ` Aleksey Makarov
2016-02-29 12:02 ` [PATCH v4 4/4] serial: pl011: use ACPI SPCR to setup 32-bit access Aleksey Makarov
` (2 subsequent siblings)
5 siblings, 0 replies; 17+ messages in thread
From: Aleksey Makarov @ 2016-02-29 12:02 UTC (permalink / raw)
To: linux-arm-kernel
The recent version of Microsoft Debug Port Table 2 (DBG2) [1]
specifies additional serial debug port subtypes. These constants
are also referred by Serial Port Console Redirection Table (SPCR) [2]
Add these constants.
[1] https://msdn.microsoft.com/en-us/library/windows/hardware/dn639131(v=vs.85).aspx
[2] https://msdn.microsoft.com/en-us/library/windows/hardware/dn639132(v=vs.85).aspx
Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
---
include/acpi/actbl2.h | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/include/acpi/actbl2.h b/include/acpi/actbl2.h
index a4ef625..652f747 100644
--- a/include/acpi/actbl2.h
+++ b/include/acpi/actbl2.h
@@ -371,6 +371,11 @@ struct acpi_dbg2_device {
#define ACPI_DBG2_16550_COMPATIBLE 0x0000
#define ACPI_DBG2_16550_SUBSET 0x0001
+#define ACPI_DBG2_ARM_PL011 0x0003
+#define ACPI_DBG2_ARM_SBSA_32BIT 0x000D
+#define ACPI_DBG2_ARM_SBSA_GENERIC 0x000E
+#define ACPI_DBG2_ARM_DCC 0x000F
+#define ACPI_DBG2_BCM2835 0x0010
#define ACPI_DBG2_1394_STANDARD 0x0000
--
2.7.1
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH v4 4/4] serial: pl011: use ACPI SPCR to setup 32-bit access
2016-02-29 12:02 [PATCH v4 0/4] ACPI: parse the SPCR table Aleksey Makarov
` (2 preceding siblings ...)
2016-02-29 12:02 ` [PATCH v4 3/4] ACPI: add definitions of DBG2 subtypes Aleksey Makarov
@ 2016-02-29 12:02 ` Aleksey Makarov
2016-03-01 15:27 ` [PATCH v4 0/4] ACPI: parse the SPCR table Peter Hurley
2016-03-01 15:31 ` Peter Hurley
5 siblings, 0 replies; 17+ messages in thread
From: Aleksey Makarov @ 2016-02-29 12:02 UTC (permalink / raw)
To: linux-arm-kernel
Some implementations of ARM SBSA serial port hardware require that access
to the registers should be 32-bit. Unfortunately, the only way for
the driver to tell if it's the case is to use the data from ACPI SPCR/DBG2
tables. In this case the value of the 'Interface Type' field of the SPCR
table is ACPI_DBG2_ARM_SBSA_32BIT.
How this value is described in the DBG2 spec:
"(deprecated) ARM SBSA (2.x only) Generic UART supporting only
32-bit accesses"
Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
---
drivers/acpi/spcr.c | 22 ++++++++++++++++++++++
drivers/tty/serial/amba-pl011.c | 2 ++
include/linux/acpi.h | 5 +++++
3 files changed, 29 insertions(+)
diff --git a/drivers/acpi/spcr.c b/drivers/acpi/spcr.c
index c460cb1..f2e81af 100644
--- a/drivers/acpi/spcr.c
+++ b/drivers/acpi/spcr.c
@@ -18,6 +18,7 @@
static char *options;
static struct acpi_generic_address address;
+static bool sbsa_32_bit;
static int __init parse_spcr_init(void)
{
@@ -60,6 +61,7 @@ static int __init parse_spcr_init(void)
}
address = table->serial_port;
+ sbsa_32_bit = table->interface_type == ACPI_DBG2_ARM_SBSA_32BIT;
done:
early_acpi_os_unmap_memory((void __iomem *)table, table_size);
@@ -114,3 +116,23 @@ bool acpi_console_check(struct uart_port *uport)
return false;
}
+
+/**
+ * acpi_console_sbsa_32bit - Tell if SPCR specifies 32-bit SBSA.
+ *
+ * Some implementations of ARM SBSA serial port hardware require that access
+ * to the registers should be 32-bit. Unfortunately, the only way for
+ * the driver to tell if it's the case is to use the data from ACPI SPCR/DBG2
+ * tables. In this case the value of the 'Interface Type' field of the SPCR
+ * table is ACPI_DBG2_ARM_SBSA_32BIT.
+ *
+ * Return: true if access should be 32-bit wide.
+ */
+bool acpi_console_sbsa_32bit(void)
+{
+ if (acpi_disabled || parse_spcr() < 0)
+ return false;
+
+ return sbsa_32_bit;
+}
+EXPORT_SYMBOL(acpi_console_sbsa_32bit);
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 500232a..d9ca3a4 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -2541,6 +2541,8 @@ static int sbsa_uart_probe(struct platform_device *pdev)
baudrate = 115200;
}
+ vendor_sbsa.access_32b = acpi_console_sbsa_32bit();
+
portnr = pl011_find_free_port();
if (portnr < 0)
return portnr;
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index ea0c297..da1eb23 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -1007,11 +1007,16 @@ static inline struct fwnode_handle *acpi_get_next_subnode(struct device *dev,
struct uart_port;
#ifdef CONFIG_ACPI_SPCR_TABLE
bool acpi_console_check(struct uart_port *uport);
+bool acpi_console_sbsa_32bit(void);
#else
static inline bool acpi_console_check(struct uart_port *uport)
{
return FALSE;
}
+static inline bool acpi_console_sbsa_32bit(void)
+{
+ return false;
+}
#endif
#endif /*_LINUX_ACPI_H*/
--
2.7.1
^ permalink raw reply related [flat|nested] 17+ messages in thread
* [PATCH v4 1/4] ACPI: parse SPCR and enable matching console
2016-02-29 12:02 ` [PATCH v4 1/4] ACPI: parse SPCR and enable matching console Aleksey Makarov
@ 2016-02-29 13:29 ` Andy Shevchenko
2016-02-29 13:47 ` Aleksey Makarov
0 siblings, 1 reply; 17+ messages in thread
From: Andy Shevchenko @ 2016-02-29 13:29 UTC (permalink / raw)
To: linux-arm-kernel
On Mon, Feb 29, 2016 at 2:02 PM, Aleksey Makarov
<aleksey.makarov@linaro.org> wrote:
> 'ARM Server Base Boot Requiremets' [1] mentions SPCR (Serial Port
> Console Redirection Table) [2] as a mandatory ACPI table that
> specifies the configuration of serial console.
>
> Parse this table and check if any registered console match the
> description. If it does, enable that console.
>
> Introduce a new function acpi_console_check(). At the uart port
> registration, this function checks if the ACPI SPCR table specifies
> its argument of type struct uart_port to be a console
> and if so calls add_preferred_console().
> + if (ACPI_FAILURE(status)) {
> + pr_err("could not get the table\n");
Is it worse to have on error level? Is it possible to have firmware
without this table? I think it would be a normal case for non-arm
world.
I'm also not sure if this message useful even on warn level.
> + return -ENOENT;
> + }
> +
> + if (table->header.revision < 2) {
> + err = -EINVAL;
> + pr_err("wrong table version\n");
And this one quite good to have, indeed.
> + * acpi_console_check - Check if uart matches the console specified by SPCR.
> + *
> + * @uport: uart port to check
> + *
Since you use sections, you may add:
+ * Description:
> + * This function checks if the ACPI SPCR table specifies @uport to be a console
> + * and if so calls add_preferred_console()
> + *
> + * Return: a non-error value if the console matches.
> @@ -2654,8 +2655,17 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
> spin_lock_init(&uport->lock);
> lockdep_set_class(&uport->lock, &port_lock_key);
> }
> - if (uport->cons && uport->dev)
> - of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
> +
> + /*
> + * Support both open FW and ACPI access to console definitions.
> + * Both of_console_check() and acpi_console_check() will call
> + * add_preferred_console() if a console definition is found.
> + */
> + if (uport->cons && uport->dev) {
> + if (!acpi_console_check(uport))
if (cond1) {
if (cond2) {
...
}
}
is equivalent to
if (cond1 && cond2) {
...
}
> + of_console_check(uport->dev->of_node, uport->cons->name,
> + uport->line);
> + }
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 17+ messages in thread
* [PATCH v4 1/4] ACPI: parse SPCR and enable matching console
2016-02-29 13:29 ` Andy Shevchenko
@ 2016-02-29 13:47 ` Aleksey Makarov
0 siblings, 0 replies; 17+ messages in thread
From: Aleksey Makarov @ 2016-02-29 13:47 UTC (permalink / raw)
To: linux-arm-kernel
Hi Andy,
Thank you for review.
On 02/29/2016 04:29 PM, Andy Shevchenko wrote:
> On Mon, Feb 29, 2016 at 2:02 PM, Aleksey Makarov
> <aleksey.makarov@linaro.org> wrote:
>> 'ARM Server Base Boot Requiremets' [1] mentions SPCR (Serial Port
>> Console Redirection Table) [2] as a mandatory ACPI table that
>> specifies the configuration of serial console.
>>
>> Parse this table and check if any registered console match the
>> description. If it does, enable that console.
>>
>> Introduce a new function acpi_console_check(). At the uart port
>> registration, this function checks if the ACPI SPCR table specifies
>> its argument of type struct uart_port to be a console
>> and if so calls add_preferred_console().
>
>> + if (ACPI_FAILURE(status)) {
>> + pr_err("could not get the table\n");
>
> Is it worse to have on error level? Is it possible to have firmware
> without this table? I think it would be a normal case for non-arm
> world.
> I'm also not sure if this message useful even on warn level.
I will delete the message in the next version, thank you.
>> + return -ENOENT;
>> + }
>> +
>> + if (table->header.revision < 2) {
>> + err = -EINVAL;
>> + pr_err("wrong table version\n");
>
> And this one quite good to have, indeed.
>
>> + * acpi_console_check - Check if uart matches the console specified by SPCR.
>> + *
>> + * @uport: uart port to check
>> + *
>
> Since you use sections, you may add:
> + * Description:
According to kernel-doc-nano-HOWTO.txt "Description: " is optional.
>> + * This function checks if the ACPI SPCR table specifies @uport to be a console
>> + * and if so calls add_preferred_console()
>> + *
>> + * Return: a non-error value if the console matches.
>
>> @@ -2654,8 +2655,17 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
>> spin_lock_init(&uport->lock);
>> lockdep_set_class(&uport->lock, &port_lock_key);
>> }
>> - if (uport->cons && uport->dev)
>> - of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
>> +
>> + /*
>> + * Support both open FW and ACPI access to console definitions.
>> + * Both of_console_check() and acpi_console_check() will call
>> + * add_preferred_console() if a console definition is found.
>> + */
>> + if (uport->cons && uport->dev) {
>> + if (!acpi_console_check(uport))
>
> if (cond1) {
> if (cond2) {
> ...
> }
> }
>
> is equivalent to
> if (cond1 && cond2) {
> ...
> }
It is, but it's a style decision. I would prefer to leave it as is because it emphasizes that
after meeting some condition we first call acpi_console_check() and then of_console_check().
Thank you
Aleksey Makarov
>
>> + of_console_check(uport->dev->of_node, uport->cons->name,
>> + uport->line);
>> + }
>
>
>
^ permalink raw reply [flat|nested] 17+ messages in thread
* [PATCH v4 0/4] ACPI: parse the SPCR table
2016-02-29 12:02 [PATCH v4 0/4] ACPI: parse the SPCR table Aleksey Makarov
` (3 preceding siblings ...)
2016-02-29 12:02 ` [PATCH v4 4/4] serial: pl011: use ACPI SPCR to setup 32-bit access Aleksey Makarov
@ 2016-03-01 15:27 ` Peter Hurley
2016-03-01 15:31 ` Peter Hurley
5 siblings, 0 replies; 17+ messages in thread
From: Peter Hurley @ 2016-03-01 15:27 UTC (permalink / raw)
To: linux-arm-kernel
It's customary to cc reviewers of your previous series.
Please review my comments to v3.
Regards,
Peter Hurley
On 02/29/2016 04:02 AM, Aleksey Makarov wrote:
> 'ARM Server Base Boot Requirements' [1] mentions SPCR (Serial Port
> Console Redirection Table) [2] as a mandatory ACPI table that
> specifies the configuration of serial console.
>
> Introduce a new function acpi_console_check(). At the uart port
> registration, this function checks if the ACPI SPCR table specifies
> its argument of type struct uart_port to be a console
> and if so calls add_preferred_console().
>
> Use SPCR to tell if SBSA serial driver should use 32-bit access to registers.
>
> Based on the work by Leif Lindholm [3]
>
> Should be applied to next-20160229.
>
> Tested on QEMU. SPCR support is included in QEMU's ARM mach-virt
> since 2.4 release.
>
> v4:
> - drop patch "ACPI: change __init to __ref for early_acpi_os_unmap_memory()"
> ACPI developers work on a new API and asked not to do that.
> Instead, use acpi_get_table_with_size()/early_acpi_os_unmap_memory() once
> and cache the result. (Lv Zheng)
> - fix some style issues (Yury Norov)
>
> v3:
> https://lkml.kernel.org/g/1455559532-8305-1-git-send-email-aleksey.makarov at linaro.org
>
> Greg Kroah-Hartman did not like v2 so I have rewritten this patchset:
>
> - drop acpi_match() member of struct console
> - drop implementations of this member for pl011 and 8250
> - drop the patch that renames some vars in printk.c as it is not needed anymore
> - drop patch that introduces system wide acpi_table_parse2().
> Instead introduce a custom acpi_table_parse_spcr() in spcr.c
>
> Instead of introducing a new match_acpi() member of struct console,
> this patchset introduces a new function acpi_console_check().
> This function is called when a new uart is registered at serial_core.c
> the same way OF code checks for console. If the registered uart is the
> console specified by SPCR table, this function calls add_preferred_console()
>
> The restrictions of this approach are:
>
> - only serial consoles can be set up
> - only consoles specified by the memory/io address can be set up
> (SPCR can specify devices by PCI id/PCI address)
>
> v2:
> https://lkml.kernel.org/g/1455299022-11641-1-git-send-email-aleksey.makarov at linaro.org
> - don't use SPCR if user specified console in command line
> - fix initialization order of newcon->index = 0
> - rename some variables at printk.c (Joe Perches, Peter Hurley)
> - enable ACPI_SPCR_TABLE in a separate patch (Andy Shevchenko)
> - remove the retry loop for console registering (Peter Hurley).
> Instead, obtain SPCR with acpi_get_table(). That works after
> call to acpi_early_init() i. e. in any *_initcall()
> - describe design decision behind introducing acpi_match() (Peter Hurley)
> - fix compilation for x86 + ACPI (Graeme Gregory)
> - introduce DBG2 constants in a separate patch (Andy Shevchenko)
> - fix a typo in DBG2 constants (Andy Shevchenko)
> - add ACPI_DBG2_ARM_SBSA_32BIT constant (Christopher Covington)
> - add support for ACPI_DBG2_ARM_SBSA_* consoles (Christopher Covington)
> - add documentation for functions
> - add a patch that uses SPCR to find if SBSA serial driver should use 32-bit
> accessor functions (Christopher Covington)
> - change __init to __ref for early_acpi_os_unmap_memory() in a separate patch
> - introduce acpi_table_parse2() in a separate patch
> - fix fetching the SPCR table early (Mark Salter)
> - add a patch from Mark Salter that introduces support for matching 8250-based
> consoles
>
> v1:
> https://lkml.kernel.org/g/1453722324-22407-1-git-send-email-aleksey.makarov at linaro.org
>
> [1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.den0044a/index.html
> [2] https://msdn.microsoft.com/en-us/library/windows/hardware/dn639132(v=vs.85).aspx
> [3] https://lkml.kernel.org/g/1441716217-23786-1-git-send-email-leif.lindholm at linaro.org
>
> Aleksey Makarov (4):
> ACPI: parse SPCR and enable matching console
> ACPI: enable ACPI_SPCR_TABLE on ARM64
> ACPI: add definitions of DBG2 subtypes
> serial: pl011: use ACPI SPCR to setup 32-bit access
>
> arch/arm64/Kconfig | 1 +
> drivers/acpi/Kconfig | 3 +
> drivers/acpi/Makefile | 1 +
> drivers/acpi/spcr.c | 138 +++++++++++++++++++++++++++++++++++++++
> drivers/tty/serial/amba-pl011.c | 2 +
> drivers/tty/serial/serial_core.c | 14 +++-
> include/acpi/actbl2.h | 5 ++
> include/linux/acpi.h | 15 +++++
> 8 files changed, 177 insertions(+), 2 deletions(-)
> create mode 100644 drivers/acpi/spcr.c
>
^ permalink raw reply [flat|nested] 17+ messages in thread
* [PATCH v4 2/4] ACPI: enable ACPI_SPCR_TABLE on ARM64
2016-02-29 12:02 ` [PATCH v4 2/4] ACPI: enable ACPI_SPCR_TABLE on ARM64 Aleksey Makarov
@ 2016-03-01 15:27 ` Peter Hurley
2016-03-01 17:35 ` Aleksey Makarov
2016-03-17 17:20 ` Timur Tabi
1 sibling, 1 reply; 17+ messages in thread
From: Peter Hurley @ 2016-03-01 15:27 UTC (permalink / raw)
To: linux-arm-kernel
On 02/29/2016 04:02 AM, Aleksey Makarov wrote:
> SBBR mentions SPCR as a mandatory ACPI table.
> So enable it for ARM64
Why is this opt-in per-arch?
> Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
> ---
> arch/arm64/Kconfig | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 9dc5209..544af2e 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -3,6 +3,7 @@ config ARM64
> select ACPI_CCA_REQUIRED if ACPI
> select ACPI_GENERIC_GSI if ACPI
> select ACPI_REDUCED_HARDWARE_ONLY if ACPI
> + select ACPI_SPCR_TABLE if ACPI
> select ARCH_HAS_DEVMEM_IS_ALLOWED
> select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
> select ARCH_HAS_ELF_RANDOMIZE
>
^ permalink raw reply [flat|nested] 17+ messages in thread
* [PATCH v4 0/4] ACPI: parse the SPCR table
2016-02-29 12:02 [PATCH v4 0/4] ACPI: parse the SPCR table Aleksey Makarov
` (4 preceding siblings ...)
2016-03-01 15:27 ` [PATCH v4 0/4] ACPI: parse the SPCR table Peter Hurley
@ 2016-03-01 15:31 ` Peter Hurley
2016-03-03 11:59 ` Aleksey Makarov
5 siblings, 1 reply; 17+ messages in thread
From: Peter Hurley @ 2016-03-01 15:31 UTC (permalink / raw)
To: linux-arm-kernel
On 02/29/2016 04:02 AM, Aleksey Makarov wrote:
> 'ARM Server Base Boot Requirements' [1] mentions SPCR (Serial Port
> Console Redirection Table) [2] as a mandatory ACPI table that
> specifies the configuration of serial console.
>
> Introduce a new function acpi_console_check(). At the uart port
> registration, this function checks if the ACPI SPCR table specifies
> its argument of type struct uart_port to be a console
> and if so calls add_preferred_console().
How will a user enable an earlycon on the same console as the SPCR
console if there is no DBG2 table?
> Use SPCR to tell if SBSA serial driver should use 32-bit access to registers.
>
> Based on the work by Leif Lindholm [3]
>
> Should be applied to next-20160229.
>
> Tested on QEMU. SPCR support is included in QEMU's ARM mach-virt
> since 2.4 release.
>
> v4:
> - drop patch "ACPI: change __init to __ref for early_acpi_os_unmap_memory()"
> ACPI developers work on a new API and asked not to do that.
> Instead, use acpi_get_table_with_size()/early_acpi_os_unmap_memory() once
> and cache the result. (Lv Zheng)
> - fix some style issues (Yury Norov)
>
> v3:
> https://lkml.kernel.org/g/1455559532-8305-1-git-send-email-aleksey.makarov at linaro.org
>
> Greg Kroah-Hartman did not like v2 so I have rewritten this patchset:
>
> - drop acpi_match() member of struct console
> - drop implementations of this member for pl011 and 8250
> - drop the patch that renames some vars in printk.c as it is not needed anymore
> - drop patch that introduces system wide acpi_table_parse2().
> Instead introduce a custom acpi_table_parse_spcr() in spcr.c
>
> Instead of introducing a new match_acpi() member of struct console,
> this patchset introduces a new function acpi_console_check().
> This function is called when a new uart is registered at serial_core.c
> the same way OF code checks for console. If the registered uart is the
> console specified by SPCR table, this function calls add_preferred_console()
>
> The restrictions of this approach are:
>
> - only serial consoles can be set up
> - only consoles specified by the memory/io address can be set up
> (SPCR can specify devices by PCI id/PCI address)
>
> v2:
> https://lkml.kernel.org/g/1455299022-11641-1-git-send-email-aleksey.makarov at linaro.org
> - don't use SPCR if user specified console in command line
> - fix initialization order of newcon->index = 0
> - rename some variables at printk.c (Joe Perches, Peter Hurley)
> - enable ACPI_SPCR_TABLE in a separate patch (Andy Shevchenko)
> - remove the retry loop for console registering (Peter Hurley).
> Instead, obtain SPCR with acpi_get_table(). That works after
> call to acpi_early_init() i. e. in any *_initcall()
> - describe design decision behind introducing acpi_match() (Peter Hurley)
> - fix compilation for x86 + ACPI (Graeme Gregory)
> - introduce DBG2 constants in a separate patch (Andy Shevchenko)
> - fix a typo in DBG2 constants (Andy Shevchenko)
> - add ACPI_DBG2_ARM_SBSA_32BIT constant (Christopher Covington)
> - add support for ACPI_DBG2_ARM_SBSA_* consoles (Christopher Covington)
> - add documentation for functions
> - add a patch that uses SPCR to find if SBSA serial driver should use 32-bit
> accessor functions (Christopher Covington)
> - change __init to __ref for early_acpi_os_unmap_memory() in a separate patch
> - introduce acpi_table_parse2() in a separate patch
> - fix fetching the SPCR table early (Mark Salter)
> - add a patch from Mark Salter that introduces support for matching 8250-based
> consoles
>
> v1:
> https://lkml.kernel.org/g/1453722324-22407-1-git-send-email-aleksey.makarov at linaro.org
>
> [1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.den0044a/index.html
> [2] https://msdn.microsoft.com/en-us/library/windows/hardware/dn639132(v=vs.85).aspx
> [3] https://lkml.kernel.org/g/1441716217-23786-1-git-send-email-leif.lindholm at linaro.org
>
> Aleksey Makarov (4):
> ACPI: parse SPCR and enable matching console
> ACPI: enable ACPI_SPCR_TABLE on ARM64
> ACPI: add definitions of DBG2 subtypes
> serial: pl011: use ACPI SPCR to setup 32-bit access
>
> arch/arm64/Kconfig | 1 +
> drivers/acpi/Kconfig | 3 +
> drivers/acpi/Makefile | 1 +
> drivers/acpi/spcr.c | 138 +++++++++++++++++++++++++++++++++++++++
> drivers/tty/serial/amba-pl011.c | 2 +
> drivers/tty/serial/serial_core.c | 14 +++-
> include/acpi/actbl2.h | 5 ++
> include/linux/acpi.h | 15 +++++
> 8 files changed, 177 insertions(+), 2 deletions(-)
> create mode 100644 drivers/acpi/spcr.c
>
^ permalink raw reply [flat|nested] 17+ messages in thread
* [PATCH v4 2/4] ACPI: enable ACPI_SPCR_TABLE on ARM64
2016-03-01 15:27 ` Peter Hurley
@ 2016-03-01 17:35 ` Aleksey Makarov
0 siblings, 0 replies; 17+ messages in thread
From: Aleksey Makarov @ 2016-03-01 17:35 UTC (permalink / raw)
To: linux-arm-kernel
On 03/01/2016 06:27 PM, Peter Hurley wrote:
> On 02/29/2016 04:02 AM, Aleksey Makarov wrote:
>> SBBR mentions SPCR as a mandatory ACPI table.
>> So enable it for ARM64
>
> Why is this opt-in per-arch?
It could depend only on CONFIG_ACPI.
I will do that in the next version, thank you
>> Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
>> ---
>> arch/arm64/Kconfig | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
>> index 9dc5209..544af2e 100644
>> --- a/arch/arm64/Kconfig
>> +++ b/arch/arm64/Kconfig
>> @@ -3,6 +3,7 @@ config ARM64
>> select ACPI_CCA_REQUIRED if ACPI
>> select ACPI_GENERIC_GSI if ACPI
>> select ACPI_REDUCED_HARDWARE_ONLY if ACPI
>> + select ACPI_SPCR_TABLE if ACPI
>> select ARCH_HAS_DEVMEM_IS_ALLOWED
>> select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
>> select ARCH_HAS_ELF_RANDOMIZE
>>
>
^ permalink raw reply [flat|nested] 17+ messages in thread
* [PATCH v4 0/4] ACPI: parse the SPCR table
2016-03-01 15:31 ` Peter Hurley
@ 2016-03-03 11:59 ` Aleksey Makarov
2016-03-03 15:35 ` Peter Hurley
0 siblings, 1 reply; 17+ messages in thread
From: Aleksey Makarov @ 2016-03-03 11:59 UTC (permalink / raw)
To: linux-arm-kernel
On 03/01/2016 06:31 PM, Peter Hurley wrote:
> On 02/29/2016 04:02 AM, Aleksey Makarov wrote:
>> 'ARM Server Base Boot Requirements' [1] mentions SPCR (Serial Port
>> Console Redirection Table) [2] as a mandatory ACPI table that
>> specifies the configuration of serial console.
>>
>> Introduce a new function acpi_console_check(). At the uart port
>> registration, this function checks if the ACPI SPCR table specifies
>> its argument of type struct uart_port to be a console
>> and if so calls add_preferred_console().
>
> How will a user enable an earlycon on the same console as the SPCR
> console if there is no DBG2 table?
...
[ 0.000000] earlycon: pl11 at MMIO 0x0000000009000000 (options '')
[ 0.000000] bootconsole [pl11] enabled
...
[ 0.000000] Kernel command line: root=/dev/vda1 rw systemd.show_status=no acpi=force earlycon=pl011,0x9000000
...
[ 0.318248] ACPI: SPCR: adding preferred console [ttyAMA0]
[ 0.318736] ARMH0011:00: ttyAMA0 at MMIO 0x9000000 (irq = 5, base_baud = 0) is a SBSA
[ 0.319502] console [ttyAMA0] enabled
[ 0.319502] console [ttyAMA0] enabled
[ 0.319933] bootconsole [pl11] disabled
[ 0.319933] bootconsole [pl11] disabled
...
Why?
>
>
>> Use SPCR to tell if SBSA serial driver should use 32-bit access to registers.
>>
>> Based on the work by Leif Lindholm [3]
>>
>> Should be applied to next-20160229.
>>
>> Tested on QEMU. SPCR support is included in QEMU's ARM mach-virt
>> since 2.4 release.
>>
>> v4:
>> - drop patch "ACPI: change __init to __ref for early_acpi_os_unmap_memory()"
>> ACPI developers work on a new API and asked not to do that.
>> Instead, use acpi_get_table_with_size()/early_acpi_os_unmap_memory() once
>> and cache the result. (Lv Zheng)
>> - fix some style issues (Yury Norov)
>>
>> v3:
>> https://lkml.kernel.org/g/1455559532-8305-1-git-send-email-aleksey.makarov at linaro.org
>>
>> Greg Kroah-Hartman did not like v2 so I have rewritten this patchset:
>>
>> - drop acpi_match() member of struct console
>> - drop implementations of this member for pl011 and 8250
>> - drop the patch that renames some vars in printk.c as it is not needed anymore
>> - drop patch that introduces system wide acpi_table_parse2().
>> Instead introduce a custom acpi_table_parse_spcr() in spcr.c
>>
>> Instead of introducing a new match_acpi() member of struct console,
>> this patchset introduces a new function acpi_console_check().
>> This function is called when a new uart is registered at serial_core.c
>> the same way OF code checks for console. If the registered uart is the
>> console specified by SPCR table, this function calls add_preferred_console()
>>
>> The restrictions of this approach are:
>>
>> - only serial consoles can be set up
>> - only consoles specified by the memory/io address can be set up
>> (SPCR can specify devices by PCI id/PCI address)
>>
>> v2:
>> https://lkml.kernel.org/g/1455299022-11641-1-git-send-email-aleksey.makarov at linaro.org
>> - don't use SPCR if user specified console in command line
>> - fix initialization order of newcon->index = 0
>> - rename some variables at printk.c (Joe Perches, Peter Hurley)
>> - enable ACPI_SPCR_TABLE in a separate patch (Andy Shevchenko)
>> - remove the retry loop for console registering (Peter Hurley).
>> Instead, obtain SPCR with acpi_get_table(). That works after
>> call to acpi_early_init() i. e. in any *_initcall()
>> - describe design decision behind introducing acpi_match() (Peter Hurley)
>> - fix compilation for x86 + ACPI (Graeme Gregory)
>> - introduce DBG2 constants in a separate patch (Andy Shevchenko)
>> - fix a typo in DBG2 constants (Andy Shevchenko)
>> - add ACPI_DBG2_ARM_SBSA_32BIT constant (Christopher Covington)
>> - add support for ACPI_DBG2_ARM_SBSA_* consoles (Christopher Covington)
>> - add documentation for functions
>> - add a patch that uses SPCR to find if SBSA serial driver should use 32-bit
>> accessor functions (Christopher Covington)
>> - change __init to __ref for early_acpi_os_unmap_memory() in a separate patch
>> - introduce acpi_table_parse2() in a separate patch
>> - fix fetching the SPCR table early (Mark Salter)
>> - add a patch from Mark Salter that introduces support for matching 8250-based
>> consoles
>>
>> v1:
>> https://lkml.kernel.org/g/1453722324-22407-1-git-send-email-aleksey.makarov at linaro.org
>>
>> [1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.den0044a/index.html
>> [2] https://msdn.microsoft.com/en-us/library/windows/hardware/dn639132(v=vs.85).aspx
>> [3] https://lkml.kernel.org/g/1441716217-23786-1-git-send-email-leif.lindholm at linaro.org
>>
>> Aleksey Makarov (4):
>> ACPI: parse SPCR and enable matching console
>> ACPI: enable ACPI_SPCR_TABLE on ARM64
>> ACPI: add definitions of DBG2 subtypes
>> serial: pl011: use ACPI SPCR to setup 32-bit access
>>
>> arch/arm64/Kconfig | 1 +
>> drivers/acpi/Kconfig | 3 +
>> drivers/acpi/Makefile | 1 +
>> drivers/acpi/spcr.c | 138 +++++++++++++++++++++++++++++++++++++++
>> drivers/tty/serial/amba-pl011.c | 2 +
>> drivers/tty/serial/serial_core.c | 14 +++-
>> include/acpi/actbl2.h | 5 ++
>> include/linux/acpi.h | 15 +++++
>> 8 files changed, 177 insertions(+), 2 deletions(-)
>> create mode 100644 drivers/acpi/spcr.c
>>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 17+ messages in thread
* [PATCH v4 0/4] ACPI: parse the SPCR table
2016-03-03 11:59 ` Aleksey Makarov
@ 2016-03-03 15:35 ` Peter Hurley
2016-03-04 11:53 ` Aleksey Makarov
0 siblings, 1 reply; 17+ messages in thread
From: Peter Hurley @ 2016-03-03 15:35 UTC (permalink / raw)
To: linux-arm-kernel
On 03/03/2016 03:59 AM, Aleksey Makarov wrote:
>
>
> On 03/01/2016 06:31 PM, Peter Hurley wrote:
>> On 02/29/2016 04:02 AM, Aleksey Makarov wrote:
>>> 'ARM Server Base Boot Requirements' [1] mentions SPCR (Serial Port
>>> Console Redirection Table) [2] as a mandatory ACPI table that
>>> specifies the configuration of serial console.
>>>
>>> Introduce a new function acpi_console_check(). At the uart port
>>> registration, this function checks if the ACPI SPCR table specifies
>>> its argument of type struct uart_port to be a console
>>> and if so calls add_preferred_console().
>>
>> How will a user enable an earlycon on the same console as the SPCR
>> console if there is no DBG2 table?
>
> ...
> [ 0.000000] earlycon: pl11 at MMIO 0x0000000009000000 (options '')
> [ 0.000000] bootconsole [pl11] enabled
> ...
> [ 0.000000] Kernel command line: root=/dev/vda1 rw systemd.show_status=no acpi=force earlycon=pl011,0x9000000
> ...
> [ 0.318248] ACPI: SPCR: adding preferred console [ttyAMA0]
> [ 0.318736] ARMH0011:00: ttyAMA0 at MMIO 0x9000000 (irq = 5, base_baud = 0) is a SBSA
> [ 0.319502] console [ttyAMA0] enabled
> [ 0.319502] console [ttyAMA0] enabled
> [ 0.319933] bootconsole [pl11] disabled
> [ 0.319933] bootconsole [pl11] disabled
> ...
>
> Why?
That's pretty disingenuous; via command line?
By that measure, none of your patches are required because a user
can already start both console and earlycon without them.
With the console location specified in the SPCR, earlycon should
be opt-in on the command-line simply with "earlycon" command-line
parameter.
^ permalink raw reply [flat|nested] 17+ messages in thread
* [PATCH v4 0/4] ACPI: parse the SPCR table
2016-03-03 15:35 ` Peter Hurley
@ 2016-03-04 11:53 ` Aleksey Makarov
2016-03-04 15:47 ` Peter Hurley
0 siblings, 1 reply; 17+ messages in thread
From: Aleksey Makarov @ 2016-03-04 11:53 UTC (permalink / raw)
To: linux-arm-kernel
On 03/03/2016 06:35 PM, Peter Hurley wrote:
> On 03/03/2016 03:59 AM, Aleksey Makarov wrote:
>>
>>
>> On 03/01/2016 06:31 PM, Peter Hurley wrote:
>>> On 02/29/2016 04:02 AM, Aleksey Makarov wrote:
>>>> 'ARM Server Base Boot Requirements' [1] mentions SPCR (Serial Port
>>>> Console Redirection Table) [2] as a mandatory ACPI table that
>>>> specifies the configuration of serial console.
>>>>
>>>> Introduce a new function acpi_console_check(). At the uart port
>>>> registration, this function checks if the ACPI SPCR table specifies
>>>> its argument of type struct uart_port to be a console
>>>> and if so calls add_preferred_console().
>>>
>>> How will a user enable an earlycon on the same console as the SPCR
>>> console if there is no DBG2 table?
>>
>> ...
>> [ 0.000000] earlycon: pl11 at MMIO 0x0000000009000000 (options '')
>> [ 0.000000] bootconsole [pl11] enabled
>> ...
>> [ 0.000000] Kernel command line: root=/dev/vda1 rw systemd.show_status=no acpi=force earlycon=pl011,0x9000000
>> ...
>> [ 0.318248] ACPI: SPCR: adding preferred console [ttyAMA0]
>> [ 0.318736] ARMH0011:00: ttyAMA0 at MMIO 0x9000000 (irq = 5, base_baud = 0) is a SBSA
>> [ 0.319502] console [ttyAMA0] enabled
>> [ 0.319502] console [ttyAMA0] enabled
>> [ 0.319933] bootconsole [pl11] disabled
>> [ 0.319933] bootconsole [pl11] disabled
>> ...
>>
>> Why?
>
> That's pretty disingenuous; via command line?
>
> By that measure, none of your patches are required because a user
> can already start both console and earlycon without them.
>
> With the console location specified in the SPCR, earlycon should
> be opt-in on the command-line simply with "earlycon" command-line
> parameter.
Yes. That's why we have SPCR *and* DBG2.
DBG2 specifies where we should run earlycon.
>>> How will a user enable an earlycon on the same console as the SPCR
>>> console if there is no DBG2 table?
In no way. You need DBG2 to run earlycon.
(If you don't want to specify it's address etc explicitly)
^ permalink raw reply [flat|nested] 17+ messages in thread
* [PATCH v4 0/4] ACPI: parse the SPCR table
2016-03-04 11:53 ` Aleksey Makarov
@ 2016-03-04 15:47 ` Peter Hurley
2016-03-11 16:25 ` Aleksey Makarov
0 siblings, 1 reply; 17+ messages in thread
From: Peter Hurley @ 2016-03-04 15:47 UTC (permalink / raw)
To: linux-arm-kernel
On 03/04/2016 03:53 AM, Aleksey Makarov wrote:
>
>
> On 03/03/2016 06:35 PM, Peter Hurley wrote:
>> On 03/03/2016 03:59 AM, Aleksey Makarov wrote:
>>>
>>>
>>> On 03/01/2016 06:31 PM, Peter Hurley wrote:
>>>> On 02/29/2016 04:02 AM, Aleksey Makarov wrote:
>>>>> 'ARM Server Base Boot Requirements' [1] mentions SPCR (Serial Port
>>>>> Console Redirection Table) [2] as a mandatory ACPI table that
>>>>> specifies the configuration of serial console.
>>>>>
>>>>> Introduce a new function acpi_console_check(). At the uart port
>>>>> registration, this function checks if the ACPI SPCR table specifies
>>>>> its argument of type struct uart_port to be a console
>>>>> and if so calls add_preferred_console().
>>>>
>>>> How will a user enable an earlycon on the same console as the SPCR
>>>> console if there is no DBG2 table?
>>>
>>> ...
>>> [ 0.000000] earlycon: pl11 at MMIO 0x0000000009000000 (options '')
>>> [ 0.000000] bootconsole [pl11] enabled
>>> ...
>>> [ 0.000000] Kernel command line: root=/dev/vda1 rw systemd.show_status=no acpi=force earlycon=pl011,0x9000000
>>> ...
>>> [ 0.318248] ACPI: SPCR: adding preferred console [ttyAMA0]
>>> [ 0.318736] ARMH0011:00: ttyAMA0 at MMIO 0x9000000 (irq = 5, base_baud = 0) is a SBSA
>>> [ 0.319502] console [ttyAMA0] enabled
>>> [ 0.319502] console [ttyAMA0] enabled
>>> [ 0.319933] bootconsole [pl11] disabled
>>> [ 0.319933] bootconsole [pl11] disabled
>>> ...
>>>
>>> Why?
>>
>> That's pretty disingenuous; via command line?
>>
>> By that measure, none of your patches are required because a user
>> can already start both console and earlycon without them.
>>
>> With the console location specified in the SPCR, earlycon should
>> be opt-in on the command-line simply with "earlycon" command-line
>> parameter.
>
> Yes. That's why we have SPCR *and* DBG2.
> DBG2 specifies where we should run earlycon.
>
>>>> How will a user enable an earlycon on the same console as the SPCR
>>>> console if there is no DBG2 table?
>
> In no way. You need DBG2 to run earlycon.
And that's an entirely arbitrary decision being made by you.
Which I think is unnecessarily limited.
> (If you don't want to specify it's address etc explicitly)
^ permalink raw reply [flat|nested] 17+ messages in thread
* [PATCH v4 0/4] ACPI: parse the SPCR table
2016-03-04 15:47 ` Peter Hurley
@ 2016-03-11 16:25 ` Aleksey Makarov
0 siblings, 0 replies; 17+ messages in thread
From: Aleksey Makarov @ 2016-03-11 16:25 UTC (permalink / raw)
To: linux-arm-kernel
Hi Peter,
You are right, SPCR console should support earlycon.
I will send next version that will try to follow your recommendations in
a week, after I return from vacations.
As we discussed with Christopher, "serial: pl011: use SPCR to setup
32-bit access" will be dropped.
Thank you
Aleksey Makarov
On 04.03.2016 22:47, Peter Hurley wrote:
> On 03/04/2016 03:53 AM, Aleksey Makarov wrote:
>>
>>
>> On 03/03/2016 06:35 PM, Peter Hurley wrote:
>>> On 03/03/2016 03:59 AM, Aleksey Makarov wrote:
>>>>
>>>>
>>>> On 03/01/2016 06:31 PM, Peter Hurley wrote:
>>>>> On 02/29/2016 04:02 AM, Aleksey Makarov wrote:
>>>>>> 'ARM Server Base Boot Requirements' [1] mentions SPCR (Serial Port
>>>>>> Console Redirection Table) [2] as a mandatory ACPI table that
>>>>>> specifies the configuration of serial console.
>>>>>>
>>>>>> Introduce a new function acpi_console_check(). At the uart port
>>>>>> registration, this function checks if the ACPI SPCR table specifies
>>>>>> its argument of type struct uart_port to be a console
>>>>>> and if so calls add_preferred_console().
>>>>>
>>>>> How will a user enable an earlycon on the same console as the SPCR
>>>>> console if there is no DBG2 table?
>>>>
>>>> ...
>>>> [ 0.000000] earlycon: pl11 at MMIO 0x0000000009000000 (options '')
>>>> [ 0.000000] bootconsole [pl11] enabled
>>>> ...
>>>> [ 0.000000] Kernel command line: root=/dev/vda1 rw systemd.show_status=no acpi=force earlycon=pl011,0x9000000
>>>> ...
>>>> [ 0.318248] ACPI: SPCR: adding preferred console [ttyAMA0]
>>>> [ 0.318736] ARMH0011:00: ttyAMA0 at MMIO 0x9000000 (irq = 5, base_baud = 0) is a SBSA
>>>> [ 0.319502] console [ttyAMA0] enabled
>>>> [ 0.319502] console [ttyAMA0] enabled
>>>> [ 0.319933] bootconsole [pl11] disabled
>>>> [ 0.319933] bootconsole [pl11] disabled
>>>> ...
>>>>
>>>> Why?
>>>
>>> That's pretty disingenuous; via command line?
>>>
>>> By that measure, none of your patches are required because a user
>>> can already start both console and earlycon without them.
>>>
>>> With the console location specified in the SPCR, earlycon should
>>> be opt-in on the command-line simply with "earlycon" command-line
>>> parameter.
>>
>> Yes. That's why we have SPCR *and* DBG2.
>> DBG2 specifies where we should run earlycon.
>>
>>>>> How will a user enable an earlycon on the same console as the SPCR
>>>>> console if there is no DBG2 table?
>>
>> In no way. You need DBG2 to run earlycon.
>
> And that's an entirely arbitrary decision being made by you.
> Which I think is unnecessarily limited.
>
>
>> (If you don't want to specify it's address etc explicitly)
>
>
^ permalink raw reply [flat|nested] 17+ messages in thread
* [PATCH v4 2/4] ACPI: enable ACPI_SPCR_TABLE on ARM64
2016-02-29 12:02 ` [PATCH v4 2/4] ACPI: enable ACPI_SPCR_TABLE on ARM64 Aleksey Makarov
2016-03-01 15:27 ` Peter Hurley
@ 2016-03-17 17:20 ` Timur Tabi
1 sibling, 0 replies; 17+ messages in thread
From: Timur Tabi @ 2016-03-17 17:20 UTC (permalink / raw)
To: linux-arm-kernel
On Mon, Feb 29, 2016 at 6:02 AM, Aleksey Makarov
<aleksey.makarov@linaro.org> wrote:
> SBBR mentions SPCR as a mandatory ACPI table.
> So enable it for ARM64
>
> Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
Tested-by: Timur Tabi <timur@codeaurora.org>
I know another version of patch is coming, but I tested this version
and it works.
^ permalink raw reply [flat|nested] 17+ messages in thread
end of thread, other threads:[~2016-03-17 17:20 UTC | newest]
Thread overview: 17+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-02-29 12:02 [PATCH v4 0/4] ACPI: parse the SPCR table Aleksey Makarov
2016-02-29 12:02 ` [PATCH v4 1/4] ACPI: parse SPCR and enable matching console Aleksey Makarov
2016-02-29 13:29 ` Andy Shevchenko
2016-02-29 13:47 ` Aleksey Makarov
2016-02-29 12:02 ` [PATCH v4 2/4] ACPI: enable ACPI_SPCR_TABLE on ARM64 Aleksey Makarov
2016-03-01 15:27 ` Peter Hurley
2016-03-01 17:35 ` Aleksey Makarov
2016-03-17 17:20 ` Timur Tabi
2016-02-29 12:02 ` [PATCH v4 3/4] ACPI: add definitions of DBG2 subtypes Aleksey Makarov
2016-02-29 12:02 ` [PATCH v4 4/4] serial: pl011: use ACPI SPCR to setup 32-bit access Aleksey Makarov
2016-03-01 15:27 ` [PATCH v4 0/4] ACPI: parse the SPCR table Peter Hurley
2016-03-01 15:31 ` Peter Hurley
2016-03-03 11:59 ` Aleksey Makarov
2016-03-03 15:35 ` Peter Hurley
2016-03-04 11:53 ` Aleksey Makarov
2016-03-04 15:47 ` Peter Hurley
2016-03-11 16:25 ` Aleksey Makarov
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