[PATCH AUTOSEL 4.4 12/35] powerpc/pseries/mobility: prevent cpu hotplug during DT update

[PATCH AUTOSEL 4.4 12/35] powerpc/pseries/mobility: prevent cpu hotplug during DT update

[Sasha Levin]

From: Nathan Lynch <nathanl@linux.ibm.com>

[ Upstream commit e59a175faa8df9d674247946f2a5a9c29c835725 ]

CPU online/offline code paths are sensitive to parts of the device
tree (various cpu node properties, cache nodes) that can be changed as
a result of a migration.

Prevent CPU hotplug while the device tree potentially is inconsistent.

Fixes: 410bccf97881 ("powerpc/pseries: Partition migration in the kernel")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/platforms/pseries/mobility.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c
index c773396d0969..fcd1a32267c4 100644
--- a/arch/powerpc/platforms/pseries/mobility.c
+++ b/arch/powerpc/platforms/pseries/mobility.c
@@ -9,6 +9,7 @@
  * 2 as published by the Free Software Foundation.
  */
 
+#include <linux/cpu.h>
 #include <linux/kernel.h>
 #include <linux/kobject.h>
 #include <linux/smp.h>
@@ -309,11 +310,19 @@ void post_mobility_fixup(void)
 	if (rc)
 		printk(KERN_ERR "Post-mobility activate-fw failed: %d\n", rc);
 
+	/*
+	 * We don't want CPUs to go online/offline while the device
+	 * tree is being updated.
+	 */
+	cpus_read_lock();
+
 	rc = pseries_devicetree_update(MIGRATION_SCOPE);
 	if (rc)
 		printk(KERN_ERR "Post-mobility device tree update "
 			"failed: %d\n", rc);
 
+	cpus_read_unlock();
+
 	/* Possibly switch to a new RFI flush type */
 	pseries_setup_rfi_flush();
 
-- 
2.20.1

[PATCH AUTOSEL 4.4 13/35] powerpc/pseries/mobility: rebuild cacheinfo hierarchy post-migration

[Sasha Levin]

From: Nathan Lynch <nathanl@linux.ibm.com>

[ Upstream commit e610a466d16a086e321f0bd421e2fc75cff28605 ]

It's common for the platform to replace the cache device nodes after a
migration. Since the cacheinfo code is never informed about this, it
never drops its references to the source system's cache nodes, causing
it to wind up in an inconsistent state resulting in warnings and oopses
as soon as CPU online/offline occurs after the migration, e.g.

  cache for /cpus/l3-cache@3113(Unified) refers to cache for /cpus/l2-cache@200d(Unified)
  WARNING: CPU: 15 PID: 86 at arch/powerpc/kernel/cacheinfo.c:176 release_cache+0x1bc/0x1d0
  [...]
  NIP release_cache+0x1bc/0x1d0
  LR  release_cache+0x1b8/0x1d0
  Call Trace:
    release_cache+0x1b8/0x1d0 (unreliable)
    cacheinfo_cpu_offline+0x1c4/0x2c0
    unregister_cpu_online+0x1b8/0x260
    cpuhp_invoke_callback+0x114/0xf40
    cpuhp_thread_fun+0x270/0x310
    smpboot_thread_fn+0x2c8/0x390
    kthread+0x1b8/0x1c0
    ret_from_kernel_thread+0x5c/0x68

Using device tree notifiers won't work since we want to rebuild the
hierarchy only after all the removals and additions have occurred and
the device tree is in a consistent state. Call cacheinfo_teardown()
before processing device tree updates, and rebuild the hierarchy
afterward.

Fixes: 410bccf97881 ("powerpc/pseries: Partition migration in the kernel")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/platforms/pseries/mobility.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c
index fcd1a32267c4..e85767c74e81 100644
--- a/arch/powerpc/platforms/pseries/mobility.c
+++ b/arch/powerpc/platforms/pseries/mobility.c
@@ -22,6 +22,7 @@
 #include <asm/machdep.h>
 #include <asm/rtas.h>
 #include "pseries.h"
+#include "../../kernel/cacheinfo.h"
 
 static struct kobject *mobility_kobj;
 
@@ -316,11 +317,20 @@ void post_mobility_fixup(void)
 	 */
 	cpus_read_lock();
 
+	/*
+	 * It's common for the destination firmware to replace cache
+	 * nodes.  Release all of the cacheinfo hierarchy's references
+	 * before updating the device tree.
+	 */
+	cacheinfo_teardown();
+
 	rc = pseries_devicetree_update(MIGRATION_SCOPE);
 	if (rc)
 		printk(KERN_ERR "Post-mobility device tree update "
 			"failed: %d\n", rc);
 
+	cacheinfo_rebuild();
+
 	cpus_read_unlock();
 
 	/* Possibly switch to a new RFI flush type */
-- 
2.20.1

[PATCH AUTOSEL 4.4 15/35] powerpc/pci/of: Fix OF flags parsing for 64bit BARs

[Sasha Levin]

From: Alexey Kardashevskiy <aik@ozlabs.ru>

[ Upstream commit df5be5be8735ef2ae80d5ae1f2453cd81a035c4b ]

When the firmware does PCI BAR resource allocation, it passes the assigned
addresses and flags (prefetch/64bit/...) via the "reg" property of
a PCI device device tree node so the kernel does not need to do
resource allocation.

The flags are stored in resource::flags - the lower byte stores
PCI_BASE_ADDRESS_SPACE/etc bits and the other bytes are IORESOURCE_IO/etc.
Some flags from PCI_BASE_ADDRESS_xxx and IORESOURCE_xxx are duplicated,
such as PCI_BASE_ADDRESS_MEM_PREFETCH/PCI_BASE_ADDRESS_MEM_TYPE_64/etc.
When parsing the "reg" property, we copy the prefetch flag but we skip
on PCI_BASE_ADDRESS_MEM_TYPE_64 which leaves the flags out of sync.

The missing IORESOURCE_MEM_64 flag comes into play under 2 conditions:
1. we remove PCI_PROBE_ONLY for pseries (by hacking pSeries_setup_arch()
or by passing "/chosen/linux,pci-probe-only");
2. we request resource alignment (by passing pci=resource_alignment=
via the kernel cmd line to request PAGE_SIZE alignment or defining
ppc_md.pcibios_default_alignment which returns anything but 0). Note that
the alignment requests are ignored if PCI_PROBE_ONLY is enabled.

With 1) and 2), the generic PCI code in the kernel unconditionally
decides to:
- reassign the BARs in pci_specified_resource_alignment() (works fine)
- write new BARs to the device - this fails for 64bit BARs as the generic
code looks at IORESOURCE_MEM_64 (not set) and writes only lower 32bits
of the BAR and leaves the upper 32bit unmodified which breaks BAR mapping
in the hypervisor.

This fixes the issue by copying the flag. This is useful if we want to
enforce certain BAR alignment per platform as handling subpage sized BARs
is proven to cause problems with hotplug (SLOF already aligns BARs to 64k).

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Reviewed-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Shawn Anastasio <shawn@anastas.io>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/kernel/pci_of_scan.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/powerpc/kernel/pci_of_scan.c b/arch/powerpc/kernel/pci_of_scan.c
index 2e710c15893f..a38d7293460d 100644
--- a/arch/powerpc/kernel/pci_of_scan.c
+++ b/arch/powerpc/kernel/pci_of_scan.c
@@ -45,6 +45,8 @@ static unsigned int pci_parse_of_flags(u32 addr0, int bridge)
 	if (addr0 & 0x02000000) {
 		flags = IORESOURCE_MEM | PCI_BASE_ADDRESS_SPACE_MEMORY;
 		flags |= (addr0 >> 22) & PCI_BASE_ADDRESS_MEM_TYPE_64;
+		if (flags & PCI_BASE_ADDRESS_MEM_TYPE_64)
+			flags |= IORESOURCE_MEM_64;
 		flags |= (addr0 >> 28) & PCI_BASE_ADDRESS_MEM_TYPE_1M;
 		if (addr0 & 0x40000000)
 			flags |= IORESOURCE_PREFETCH
-- 
2.20.1

[PATCH AUTOSEL 4.4 23/35] powerpc/4xx/uic: clear pending interrupt after irq type/pol change

[Sasha Levin]

From: Christian Lamparter <chunkeey@gmail.com>

[ Upstream commit 3ab3a0689e74e6aa5b41360bc18861040ddef5b1 ]

When testing out gpio-keys with a button, a spurious
interrupt (and therefore a key press or release event)
gets triggered as soon as the driver enables the irq
line for the first time.

This patch clears any potential bogus generated interrupt
that was caused by the switching of the associated irq's
type and polarity.

Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/sysdev/uic.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/sysdev/uic.c b/arch/powerpc/sysdev/uic.c
index 6893d8f236df..225346dda151 100644
--- a/arch/powerpc/sysdev/uic.c
+++ b/arch/powerpc/sysdev/uic.c
@@ -158,6 +158,7 @@ static int uic_set_irq_type(struct irq_data *d, unsigned int flow_type)
 
 	mtdcr(uic->dcrbase + UIC_PR, pr);
 	mtdcr(uic->dcrbase + UIC_TR, tr);
+	mtdcr(uic->dcrbase + UIC_SR, ~mask);
 
 	raw_spin_unlock_irqrestore(&uic->lock, flags);
 
-- 
2.20.1

[PATCH AUTOSEL 4.4 30/35] powerpc/eeh: Handle hugepages in ioremap space

[Sasha Levin]

From: Oliver O'Halloran <oohall@gmail.com>

[ Upstream commit 33439620680be5225c1b8806579a291e0d761ca0 ]

In commit 4a7b06c157a2 ("powerpc/eeh: Handle hugepages in ioremap
space") support for using hugepages in the vmalloc and ioremap areas was
enabled for radix. Unfortunately this broke EEH MMIO error checking.

Detection works by inserting a hook which checks the results of the
ioreadXX() set of functions.  When a read returns a 0xFFs response we
need to check for an error which we do by mapping the (virtual) MMIO
address back to a physical address, then mapping physical address to a
PCI device via an interval tree.

When translating virt -> phys we currently assume the ioremap space is
only populated by PAGE_SIZE mappings. If a hugepage mapping is found we
emit a WARN_ON(), but otherwise handles the check as though a normal
page was found. In pathalogical cases such as copying a buffer
containing a lot of 0xFFs from BAR memory this can result in the system
not booting because it's too busy printing WARN_ON()s.

There's no real reason to assume huge pages can't be present and we're
prefectly capable of handling them, so do that.

Fixes: 4a7b06c157a2 ("powerpc/eeh: Handle hugepages in ioremap space")
Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190710150517.27114-1-oohall@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/kernel/eeh.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index 6696c1986844..16193d7b0635 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c
@@ -363,10 +363,19 @@ static inline unsigned long eeh_token_to_phys(unsigned long token)
 					   NULL, &hugepage_shift);
 	if (!ptep)
 		return token;
-	WARN_ON(hugepage_shift);
-	pa = pte_pfn(*ptep) << PAGE_SHIFT;
 
-	return pa | (token & (PAGE_SIZE-1));
+	pa = pte_pfn(*ptep);
+
+	/* On radix we can do hugepage mappings for io, so handle that */
+	if (hugepage_shift) {
+		pa <<= hugepage_shift;
+		pa |= token & ((1ul << hugepage_shift) - 1);
+	} else {
+		pa <<= PAGE_SHIFT;
+		pa |= token & (PAGE_SIZE - 1);
+	}
+
+	return pa;
 }
 
 /*
-- 
2.20.1