[PATCH AUTOSEL 5.1 043/141] powerpc/pseries/mobility: prevent cpu hotplug during DT update

[PATCH AUTOSEL 5.1 043/141] 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 88925f8ca8a0..edc1ec408589 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>
@@ -338,11 +339,19 @@ 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 5.1 058/141] 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 24191ea2d9a7..64ad92016b63 100644
--- a/arch/powerpc/kernel/pci_of_scan.c
+++ b/arch/powerpc/kernel/pci_of_scan.c
@@ -45,6 +45,8 @@ 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 5.1 069/141] powerpc/cacheflush: fix variable set but not used

[Sasha Levin]

From: Qian Cai <cai@lca.pw>

[ Upstream commit 04db3ede40ae4fc23a5c4237254c4a53bbe4c1f2 ]

The powerpc's flush_cache_vmap() is defined as a macro and never use
both of its arguments, so it will generate a compilation warning,

lib/ioremap.c: In function 'ioremap_page_range':
lib/ioremap.c:203:16: warning: variable 'start' set but not used
[-Wunused-but-set-variable]

Fix it by making it an inline function.

Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/include/asm/cacheflush.h | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/cacheflush.h b/arch/powerpc/include/asm/cacheflush.h
index d5a8d7bf0759..b189f7aee222 100644
--- a/arch/powerpc/include/asm/cacheflush.h
+++ b/arch/powerpc/include/asm/cacheflush.h
@@ -32,9 +32,12 @@
  * not expect this type of fault. flush_cache_vmap is not exactly the right
  * place to put this, but it seems to work well enough.
  */
-#define flush_cache_vmap(start, end)		do { asm volatile("ptesync" ::: "memory"); } while (0)
+static inline void flush_cache_vmap(unsigned long start, unsigned long end)
+{
+	asm volatile("ptesync" ::: "memory");
+}
 #else
-#define flush_cache_vmap(start, end)		do { } while (0)
+static inline void flush_cache_vmap(unsigned long start, unsigned long end) { }
 #endif
 
 #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
-- 
2.20.1

[PATCH AUTOSEL 5.1 070/141] powerpc/xmon: Fix disabling tracing while in xmon

[Sasha Levin]

From: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>

[ Upstream commit aaf06665f7ea3ee9f9754e16c1a507a89f1de5b1 ]

Commit ed49f7fd6438d ("powerpc/xmon: Disable tracing when entering
xmon") added code to disable recording trace entries while in xmon. The
commit introduced a variable 'tracing_enabled' to record if tracing was
enabled on xmon entry, and used this to conditionally enable tracing
during exit from xmon.

However, we are not checking the value of 'fromipi' variable in
xmon_core() when setting 'tracing_enabled'. Due to this, when secondary
cpus enter xmon, they will see tracing as being disabled already and
tracing won't be re-enabled on exit. Fix the same.

Fixes: ed49f7fd6438d ("powerpc/xmon: Disable tracing when entering xmon")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/xmon/xmon.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index a0f44f992360..c608e3fa6d3b 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -466,8 +466,10 @@ static int xmon_core(struct pt_regs *regs, int fromipi)
 	local_irq_save(flags);
 	hard_irq_disable();
 
-	tracing_enabled = tracing_is_on();
-	tracing_off();
+	if (!fromipi) {
+		tracing_enabled = tracing_is_on();
+		tracing_off();
+	}
 
 	bp = in_breakpoint_table(regs->nip, &offset);
 	if (bp != NULL) {
-- 
2.20.1

[PATCH AUTOSEL 5.1 071/141] powerpc/rtas: retry when cpu offline races with suspend/migration

[Sasha Levin]

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

[ Upstream commit 9fb603050ffd94f8127df99c699cca2f575eb6a0 ]

The protocol for suspending or migrating an LPAR requires all present
processor threads to enter H_JOIN. So if we have threads offline, we
have to temporarily bring them up. This can race with administrator
actions such as SMT state changes. As of dfd718a2ed1f ("powerpc/rtas:
Fix a potential race between CPU-Offline & Migration"),
rtas_ibm_suspend_me() accounts for this, but errors out with -EBUSY
for what almost certainly is a transient condition in any reasonable
scenario.

Callers of rtas_ibm_suspend_me() already retry when -EAGAIN is
returned, and it is typical during a migration for that to happen
repeatedly for several minutes polling the H_VASI_STATE hcall result
before proceeding to the next stage.

So return -EAGAIN instead of -EBUSY when this race is
encountered. Additionally: logging this event is still appropriate but
use pr_info instead of pr_err; and remove use of unlikely() while here
as this is not a hot path at all.

Fixes: dfd718a2ed1f ("powerpc/rtas: Fix a potential race between CPU-Offline & Migration")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/kernel/rtas.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index fbc676160adf..9b4d2a2ffb4f 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -984,10 +984,9 @@ int rtas_ibm_suspend_me(u64 handle)
 	cpu_hotplug_disable();
 
 	/* Check if we raced with a CPU-Offline Operation */
-	if (unlikely(!cpumask_equal(cpu_present_mask, cpu_online_mask))) {
-		pr_err("%s: Raced against a concurrent CPU-Offline\n",
-		       __func__);
-		atomic_set(&data.error, -EBUSY);
+	if (!cpumask_equal(cpu_present_mask, cpu_online_mask)) {
+		pr_info("%s: Raced against a concurrent CPU-Offline\n", __func__);
+		atomic_set(&data.error, -EAGAIN);
 		goto out_hotplug_enable;
 	}
 
-- 
2.20.1

[PATCH AUTOSEL 5.1 081/141] 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/platforms/4xx/uic.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/platforms/4xx/uic.c b/arch/powerpc/platforms/4xx/uic.c
index 8b4dd0da0839..9e27cfe27026 100644
--- a/arch/powerpc/platforms/4xx/uic.c
+++ b/arch/powerpc/platforms/4xx/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 5.1 086/141] powerpc/mm: Handle page table allocation failures

[Sasha Levin]

From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>

[ Upstream commit 2230ebf6e6dd0b7751e2921b40f6cfe34f09bb16 ]

This fixes kernel crash that arises due to not handling page table allocation
failures while allocating hugetlb page table.

Fixes: e2b3d202d1db ("powerpc: Switch 16GB and 16MB explicit hugepages to a different page table format")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/mm/hugetlbpage.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 9e732bb2c84a..88888e098a08 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -154,6 +154,8 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz
 	} else {
 		pdshift = PUD_SHIFT;
 		pu = pud_alloc(mm, pg, addr);
+		if (!pu)
+			return NULL;
 		if (pshift == PUD_SHIFT)
 			return (pte_t *)pu;
 		else if (pshift > PMD_SHIFT) {
@@ -162,6 +164,8 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz
 		} else {
 			pdshift = PMD_SHIFT;
 			pm = pmd_alloc(mm, pu, addr);
+			if (!pm)
+				return NULL;
 			if (pshift == PMD_SHIFT)
 				/* 16MB hugepage */
 				return (pte_t *)pm;
@@ -178,12 +182,16 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz
 	} else {
 		pdshift = PUD_SHIFT;
 		pu = pud_alloc(mm, pg, addr);
+		if (!pu)
+			return NULL;
 		if (pshift >= PUD_SHIFT) {
 			ptl = pud_lockptr(mm, pu);
 			hpdp = (hugepd_t *)pu;
 		} else {
 			pdshift = PMD_SHIFT;
 			pm = pmd_alloc(mm, pu, addr);
+			if (!pm)
+				return NULL;
 			ptl = pmd_lockptr(mm, pm);
 			hpdp = (hugepd_t *)pm;
 		}
-- 
2.20.1

[PATCH AUTOSEL 5.1 112/141] powerpc/boot: add {get, put}_unaligned_be32 to xz_config.h

[Sasha Levin]

From: Masahiro Yamada <yamada.masahiro@socionext.com>

[ Upstream commit 9e005b761e7ad153dcf40a6cba1d681fe0830ac6 ]

The next commit will make the way of passing CONFIG options more robust.
Unfortunately, it would uncover another hidden issue; without this
commit, skiroot_defconfig would be broken like this:

|   WRAP    arch/powerpc/boot/zImage.pseries
| arch/powerpc/boot/wrapper.a(decompress.o): In function `bcj_powerpc.isra.10':
| decompress.c:(.text+0x720): undefined reference to `get_unaligned_be32'
| decompress.c:(.text+0x7a8): undefined reference to `put_unaligned_be32'
| make[1]: *** [arch/powerpc/boot/Makefile;383: arch/powerpc/boot/zImage.pseries] Error 1
| make: *** [arch/powerpc/Makefile;295: zImage] Error 2

skiroot_defconfig is the only defconfig that enables CONFIG_KERNEL_XZ
for ppc, which has never been correctly built before.

I figured out the root cause in lib/decompress_unxz.c:

| #ifdef CONFIG_PPC
| #      define XZ_DEC_POWERPC
| #endif

CONFIG_PPC is undefined here in the ppc bootwrapper because autoconf.h
is not included except by arch/powerpc/boot/serial.c

XZ_DEC_POWERPC is not defined, therefore, bcj_powerpc() is not compiled
for the bootwrapper.

With the next commit passing CONFIG_PPC correctly, we would realize that
{get,put}_unaligned_be32 was missing.

Unlike the other decompressors, the ppc bootwrapper duplicates all the
necessary helpers in arch/powerpc/boot/.

The other architectures define __KERNEL__ and pull in helpers for
building the decompressors.

If ppc bootwrapper had defined __KERNEL__, lib/xz/xz_private.h would
have included <asm/unaligned.h>:

| #ifdef __KERNEL__
| #       include <linux/xz.h>
| #       include <linux/kernel.h>
| #       include <asm/unaligned.h>

However, doing so would cause tons of definition conflicts since the
bootwrapper has duplicated everything.

I just added copies of {get,put}_unaligned_be32, following the
bootwrapper coding convention.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190705100144.28785-1-yamada.masahiro@socionext.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/boot/xz_config.h | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/arch/powerpc/boot/xz_config.h b/arch/powerpc/boot/xz_config.h
index e22e5b3770dd..ebfadd39e192 100644
--- a/arch/powerpc/boot/xz_config.h
+++ b/arch/powerpc/boot/xz_config.h
@@ -20,10 +20,30 @@ static inline uint32_t swab32p(void *p)
 
 #ifdef __LITTLE_ENDIAN__
 #define get_le32(p) (*((uint32_t *) (p)))
+#define cpu_to_be32(x) swab32(x)
+static inline u32 be32_to_cpup(const u32 *p)
+{
+	return swab32p((u32 *)p);
+}
 #else
 #define get_le32(p) swab32p(p)
+#define cpu_to_be32(x) (x)
+static inline u32 be32_to_cpup(const u32 *p)
+{
+	return *p;
+}
 #endif
 
+static inline uint32_t get_unaligned_be32(const void *p)
+{
+	return be32_to_cpup(p);
+}
+
+static inline void put_unaligned_be32(u32 val, void *p)
+{
+	*((u32 *)p) = cpu_to_be32(val);
+}
+
 #define memeq(a, b, size) (memcmp(a, b, size) == 0)
 #define memzero(buf, size) memset(buf, 0, size)
 
-- 
2.20.1

[PATCH AUTOSEL 5.1 119/141] 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 289c0b37d845..0dc1865c84ce 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c
@@ -367,10 +367,19 @@ static inline unsigned long eeh_token_to_phys(unsigned long token)
 	ptep = find_init_mm_pte(token, &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