[PATCH AUTOSEL 4.19 010/237] powerpc: Fix signedness bug in update_flash_db()

[PATCH AUTOSEL 4.19 010/237] powerpc: Fix signedness bug in update_flash_db()

[Sasha Levin]

From: Dan Carpenter <dan.carpenter@oracle.com>

[ Upstream commit 014704e6f54189a203cc14c7c0bb411b940241bc ]

The "count < sizeof(struct os_area_db)" comparison is type promoted to
size_t so negative values of "count" are treated as very high values
and we accidentally return success instead of a negative error code.

This doesn't really change runtime much but it fixes a static checker
warning.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/platforms/ps3/os-area.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/ps3/os-area.c b/arch/powerpc/platforms/ps3/os-area.c
index cdbfc5cfd6f38..f5387ad822798 100644
--- a/arch/powerpc/platforms/ps3/os-area.c
+++ b/arch/powerpc/platforms/ps3/os-area.c
@@ -664,7 +664,7 @@ static int update_flash_db(void)
 	db_set_64(db, &os_area_db_id_rtc_diff, saved_params.rtc_diff);
 
 	count = os_area_flash_write(db, sizeof(struct os_area_db), pos);
-	if (count < sizeof(struct os_area_db)) {
+	if (count < 0 || count < sizeof(struct os_area_db)) {
 		pr_debug("%s: os_area_flash_write failed %zd\n", __func__,
 			 count);
 		error = count < 0 ? count : -EIO;
-- 
2.20.1

[PATCH AUTOSEL 4.19 011/237] powerpc/boot: Fix opal console in boot wrapper

[Sasha Levin]

From: Joel Stanley <joel@jms.id.au>

[ Upstream commit 1a855eaccf353f7ed1d51a3d4b3af727ccbd81ca ]

As of commit 10c77dba40ff ("powerpc/boot: Fix build failure in 32-bit
boot wrapper") the opal code is hidden behind CONFIG_PPC64_BOOT_WRAPPER,
but the boot wrapper avoids include/linux, so it does not get the normal
Kconfig flags.

We can drop the guard entirely as in commit f8e8e69cea49 ("powerpc/boot:
Only build OPAL code when necessary") the makefile only includes opal.c
in the build if CONFIG_PPC64_BOOT_WRAPPER is set.

Fixes: 10c77dba40ff ("powerpc/boot: Fix build failure in 32-bit boot wrapper")
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/boot/opal.c | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/arch/powerpc/boot/opal.c b/arch/powerpc/boot/opal.c
index 0272570d02de1..dfb199ef5b949 100644
--- a/arch/powerpc/boot/opal.c
+++ b/arch/powerpc/boot/opal.c
@@ -13,8 +13,6 @@
 #include <libfdt.h>
 #include "../include/asm/opal-api.h"
 
-#ifdef CONFIG_PPC64_BOOT_WRAPPER
-
 /* Global OPAL struct used by opal-call.S */
 struct opal {
 	u64 base;
@@ -101,9 +99,3 @@ int opal_console_init(void *devp, struct serial_console_data *scdp)
 
 	return 0;
 }
-#else
-int opal_console_init(void *devp, struct serial_console_data *scdp)
-{
-	return -1;
-}
-#endif /* __powerpc64__ */
-- 
2.20.1

[PATCH AUTOSEL 4.19 012/237] powerpc/boot: Disable vector instructions

[Sasha Levin]

From: Joel Stanley <joel@jms.id.au>

[ Upstream commit e8e132e6885962582784b6fa16a80d07ea739c0f ]

This will avoid auto-vectorisation when building with higher
optimisation levels.

We don't know if the machine can support VSX and even if it's present
it's probably not going to be enabled at this point in boot.

These flag were both added prior to GCC 4.6 which is the minimum
compiler version supported by upstream, thanks to Segher for the
details.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/boot/Makefile | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index 25e3184f11f78..7d5ddf53750ce 100644
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile
@@ -32,8 +32,8 @@ else
 endif
 
 BOOTCFLAGS    := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
-		 -fno-strict-aliasing -Os -msoft-float -pipe \
-		 -fomit-frame-pointer -fno-builtin -fPIC -nostdinc \
+		 -fno-strict-aliasing -Os -msoft-float -mno-altivec -mno-vsx \
+		 -pipe -fomit-frame-pointer -fno-builtin -fPIC -nostdinc \
 		 -D$(compress-y)
 
 ifdef CONFIG_PPC64_BOOT_WRAPPER
-- 
2.20.1

[PATCH AUTOSEL 4.19 013/237] powerpc/eeh: Fix null deref for devices removed during EEH

[Sasha Levin]

From: Sam Bobroff <sbobroff@linux.ibm.com>

[ Upstream commit bcbe3730531239abd45ab6c6af4a18078b37dd47 ]

If a device is removed during EEH processing (either by a driver's
handler or as part of recovery), it can lead to a null dereference
in eeh_pe_report_edev().

To handle this, skip devices that have been removed.

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/kernel/eeh_driver.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c
index 110eba400de7c..af1f3d5f9a0f7 100644
--- a/arch/powerpc/kernel/eeh_driver.c
+++ b/arch/powerpc/kernel/eeh_driver.c
@@ -281,6 +281,10 @@ static void eeh_pe_report_edev(struct eeh_dev *edev, eeh_report_fn fn,
 	struct pci_driver *driver;
 	enum pci_ers_result new_result;
 
+	if (!edev->pdev) {
+		eeh_edev_info(edev, "no device");
+		return;
+	}
 	device_lock(&edev->pdev->dev);
 	if (eeh_edev_actionable(edev)) {
 		driver = eeh_pcid_get(edev->pdev);
-- 
2.20.1

[PATCH AUTOSEL 4.19 014/237] powerpc/eeh: Fix use of EEH_PE_KEEP on wrong field

[Sasha Levin]

From: Sam Bobroff <sbobroff@linux.ibm.com>

[ Upstream commit 473af09b56dc4be68e4af33220ceca6be67aa60d ]

eeh_add_to_parent_pe() sometimes removes the EEH_PE_KEEP flag, but it
incorrectly removes it from pe->type, instead of pe->state.

However, rather than clearing it from the correct field, remove it.
Inspection of the code shows that it can't ever have had any effect
(even if it had been cleared from the correct field), because the
field is never tested after it is cleared by the statement in
question.

The clear statement was added by commit 807a827d4e74 ("powerpc/eeh:
Keep PE during hotplug"), but it didn't explain why it was necessary.

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/kernel/eeh_pe.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/eeh_pe.c b/arch/powerpc/kernel/eeh_pe.c
index 1b238ecc553e2..210d239a93950 100644
--- a/arch/powerpc/kernel/eeh_pe.c
+++ b/arch/powerpc/kernel/eeh_pe.c
@@ -379,7 +379,7 @@ int eeh_add_to_parent_pe(struct eeh_dev *edev)
 		while (parent) {
 			if (!(parent->type & EEH_PE_INVALID))
 				break;
-			parent->type &= ~(EEH_PE_INVALID | EEH_PE_KEEP);
+			parent->type &= ~EEH_PE_INVALID;
 			parent = parent->parent;
 		}
 
-- 
2.20.1

[PATCH AUTOSEL 4.19 075/237] macintosh/windfarm_smu_sat: Fix debug output

[Sasha Levin]

From: Benjamin Herrenschmidt <benh@kernel.crashing.org>

[ Upstream commit fc0c8b36d379a046525eacb9c3323ca635283757 ]

There's some antiquated debug output that's trying
to do a hand-made hexdump and turning into horrible
1-byte-per-line output these days.

Use print_hex_dump() instead

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/macintosh/windfarm_smu_sat.c | 25 +++++++------------------
 1 file changed, 7 insertions(+), 18 deletions(-)

diff --git a/drivers/macintosh/windfarm_smu_sat.c b/drivers/macintosh/windfarm_smu_sat.c
index da7f4fc1a51d1..a0f61eb853c55 100644
--- a/drivers/macintosh/windfarm_smu_sat.c
+++ b/drivers/macintosh/windfarm_smu_sat.c
@@ -22,14 +22,6 @@
 
 #define VERSION "1.0"
 
-#define DEBUG
-
-#ifdef DEBUG
-#define DBG(args...)	printk(args)
-#else
-#define DBG(args...)	do { } while(0)
-#endif
-
 /* If the cache is older than 800ms we'll refetch it */
 #define MAX_AGE		msecs_to_jiffies(800)
 
@@ -106,13 +98,10 @@ struct smu_sdbp_header *smu_sat_get_sdb_partition(unsigned int sat_id, int id,
 		buf[i+2] = data[3];
 		buf[i+3] = data[2];
 	}
-#ifdef DEBUG
-	DBG(KERN_DEBUG "sat %d partition %x:", sat_id, id);
-	for (i = 0; i < len; ++i)
-		DBG(" %x", buf[i]);
-	DBG("\n");
-#endif
 
+	printk(KERN_DEBUG "sat %d partition %x:", sat_id, id);
+	print_hex_dump(KERN_DEBUG, "  ", DUMP_PREFIX_OFFSET,
+		       16, 1, buf, len, false);
 	if (size)
 		*size = len;
 	return (struct smu_sdbp_header *) buf;
@@ -132,13 +121,13 @@ static int wf_sat_read_cache(struct wf_sat *sat)
 	if (err < 0)
 		return err;
 	sat->last_read = jiffies;
+
 #ifdef LOTSA_DEBUG
 	{
 		int i;
-		DBG(KERN_DEBUG "wf_sat_get: data is");
-		for (i = 0; i < 16; ++i)
-			DBG(" %.2x", sat->cache[i]);
-		DBG("\n");
+		printk(KERN_DEBUG "wf_sat_get: data is");
+		print_hex_dump(KERN_DEBUG, "  ", DUMP_PREFIX_OFFSET,
+			       16, 1, sat->cache, 16, false);
 	}
 #endif
 	return 0;
-- 
2.20.1

[PATCH AUTOSEL 4.19 091/237] powerpc/pseries: Export raw per-CPU VPA data via debugfs

[Sasha Levin]

From: Aravinda Prasad <aravinda@linux.vnet.ibm.com>

[ Upstream commit c6c26fb55e8e4b3fc376be5611685990a17de27a ]

This patch exports the raw per-CPU VPA data via debugfs.
A per-CPU file is created which exports the VPA data of
that CPU to help debug some of the VPA related issues or
to analyze the per-CPU VPA related statistics.

v3: Removed offline CPU check.

v2: Included offline CPU check and other review comments.

Signed-off-by: Aravinda Prasad <aravinda@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/lpar.c | 54 +++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index ea602f7f97ce1..49e3a88b6a0c1 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -48,6 +48,7 @@
 #include <asm/kexec.h>
 #include <asm/fadump.h>
 #include <asm/asm-prototypes.h>
+#include <asm/debugfs.h>
 
 #include "pseries.h"
 
@@ -1032,3 +1033,56 @@ static int __init reserve_vrma_context_id(void)
 	return 0;
 }
 machine_device_initcall(pseries, reserve_vrma_context_id);
+
+#ifdef CONFIG_DEBUG_FS
+/* debugfs file interface for vpa data */
+static ssize_t vpa_file_read(struct file *filp, char __user *buf, size_t len,
+			      loff_t *pos)
+{
+	int cpu = (long)filp->private_data;
+	struct lppaca *lppaca = &lppaca_of(cpu);
+
+	return simple_read_from_buffer(buf, len, pos, lppaca,
+				sizeof(struct lppaca));
+}
+
+static const struct file_operations vpa_fops = {
+	.open		= simple_open,
+	.read		= vpa_file_read,
+	.llseek		= default_llseek,
+};
+
+static int __init vpa_debugfs_init(void)
+{
+	char name[16];
+	long i;
+	static struct dentry *vpa_dir;
+
+	if (!firmware_has_feature(FW_FEATURE_SPLPAR))
+		return 0;
+
+	vpa_dir = debugfs_create_dir("vpa", powerpc_debugfs_root);
+	if (!vpa_dir) {
+		pr_warn("%s: can't create vpa root dir\n", __func__);
+		return -ENOMEM;
+	}
+
+	/* set up the per-cpu vpa file*/
+	for_each_possible_cpu(i) {
+		struct dentry *d;
+
+		sprintf(name, "cpu-%ld", i);
+
+		d = debugfs_create_file(name, 0400, vpa_dir, (void *)i,
+					&vpa_fops);
+		if (!d) {
+			pr_warn("%s: can't create per-cpu vpa file\n",
+					__func__);
+			return -ENOMEM;
+		}
+	}
+
+	return 0;
+}
+machine_arch_initcall(pseries, vpa_debugfs_init);
+#endif /* CONFIG_DEBUG_FS */
-- 
2.20.1

[PATCH AUTOSEL 4.19 092/237] powerpc/mm/radix: Fix off-by-one in split mapping logic

[Sasha Levin]

From: Michael Ellerman <mpe@ellerman.id.au>

[ Upstream commit 5c6499b7041b43807dfaeda28aa87fc0e62558f7 ]

When we have CONFIG_STRICT_KERNEL_RWX enabled, we try to split the
kernel linear (1:1) mapping so that the kernel text is in a separate
page to kernel data, so we can mark the former read-only.

We could achieve that just by always using 64K pages for the linear
mapping, but we try to be smarter. Instead we use huge pages when
possible, and only switch to smaller pages when necessary.

However we have an off-by-one bug in that logic, which causes us to
calculate the wrong boundary between text and data.

For example with the end of the kernel text at 16M we see:

  radix-mmu: Mapped 0x0000000000000000-0x0000000001200000 with 64.0 KiB pages
  radix-mmu: Mapped 0x0000000001200000-0x0000000040000000 with 2.00 MiB pages
  radix-mmu: Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages

ie. we mapped from 0 to 18M with 64K pages, even though the boundary
between text and data is at 16M.

With the fix we see we're correctly hitting the 16M boundary:

  radix-mmu: Mapped 0x0000000000000000-0x0000000001000000 with 64.0 KiB pages
  radix-mmu: Mapped 0x0000000001000000-0x0000000040000000 with 2.00 MiB pages
  radix-mmu: Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/mm/pgtable-radix.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index 3ea4c1f107d7e..24a2eadc8c21a 100644
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -294,14 +294,14 @@ static int __meminit create_physical_mapping(unsigned long start,
 		}
 
 		if (split_text_mapping && (mapping_size == PUD_SIZE) &&
-			(addr <= __pa_symbol(__init_begin)) &&
+			(addr < __pa_symbol(__init_begin)) &&
 			(addr + mapping_size) >= __pa_symbol(_stext)) {
 			max_mapping_size = PMD_SIZE;
 			goto retry;
 		}
 
 		if (split_text_mapping && (mapping_size == PMD_SIZE) &&
-		    (addr <= __pa_symbol(__init_begin)) &&
+		    (addr < __pa_symbol(__init_begin)) &&
 		    (addr + mapping_size) >= __pa_symbol(_stext)) {
 			mapping_size = PAGE_SIZE;
 			psize = mmu_virtual_psize;
-- 
2.20.1

[PATCH AUTOSEL 4.19 093/237] powerpc/mm/radix: Fix overuse of small pages in splitting logic

[Sasha Levin]

From: Michael Ellerman <mpe@ellerman.id.au>

[ Upstream commit 3b5657ed5b4e27ccf593a41ff3c5aa27dae8df18 ]

When we have CONFIG_STRICT_KERNEL_RWX enabled, we want to split the
linear mapping at the text/data boundary so we can map the kernel text
read only.

But the current logic uses small pages for the entire text section,
regardless of whether a larger page size would fit. eg. with the
boundary at 16M we could use 2M pages, but instead we use 64K pages up
to the 16M boundary:

  Mapped 0x0000000000000000-0x0000000001000000 with 64.0 KiB pages
  Mapped 0x0000000001000000-0x0000000040000000 with 2.00 MiB pages
  Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages

This is because the test is checking if addr is < __init_begin
and addr + mapping_size is >= _stext. But that is true for all pages
between _stext and __init_begin.

Instead what we want to check is if we are crossing the text/data
boundary, which is at __init_begin. With that fixed we see:

  Mapped 0x0000000000000000-0x0000000000e00000 with 2.00 MiB pages
  Mapped 0x0000000000e00000-0x0000000001000000 with 64.0 KiB pages
  Mapped 0x0000000001000000-0x0000000040000000 with 2.00 MiB pages
  Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages

ie. we're correctly using 2MB pages below __init_begin, but we still
drop down to 64K pages unnecessarily at the boundary.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/mm/pgtable-radix.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index 24a2eadc8c21a..b387c7b917b7e 100644
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -295,14 +295,14 @@ static int __meminit create_physical_mapping(unsigned long start,
 
 		if (split_text_mapping && (mapping_size == PUD_SIZE) &&
 			(addr < __pa_symbol(__init_begin)) &&
-			(addr + mapping_size) >= __pa_symbol(_stext)) {
+			(addr + mapping_size) >= __pa_symbol(__init_begin)) {
 			max_mapping_size = PMD_SIZE;
 			goto retry;
 		}
 
 		if (split_text_mapping && (mapping_size == PMD_SIZE) &&
 		    (addr < __pa_symbol(__init_begin)) &&
-		    (addr + mapping_size) >= __pa_symbol(_stext)) {
+		    (addr + mapping_size) >= __pa_symbol(__init_begin)) {
 			mapping_size = PAGE_SIZE;
 			psize = mmu_virtual_psize;
 		}
-- 
2.20.1

[PATCH AUTOSEL 4.19 094/237] powerpc/mm/radix: Fix small page at boundary when splitting

[Sasha Levin]

From: Michael Ellerman <mpe@ellerman.id.au>

[ Upstream commit 81d1b54dec95209ab5e5be2cf37182885f998753 ]

When we have CONFIG_STRICT_KERNEL_RWX enabled, we want to split the
linear mapping at the text/data boundary so we can map the kernel
text read only.

Currently we always use a small page at the text/data boundary, even
when that's not necessary:

  Mapped 0x0000000000000000-0x0000000000e00000 with 2.00 MiB pages
  Mapped 0x0000000000e00000-0x0000000001000000 with 64.0 KiB pages
  Mapped 0x0000000001000000-0x0000000040000000 with 2.00 MiB pages

This is because the check that the mapping crosses the __init_begin
boundary is too strict, it also returns true when we map exactly up to
the boundary.

So fix it to check that the mapping would actually map past
__init_begin, and with that we see:

  Mapped 0x0000000000000000-0x0000000040000000 with 2.00 MiB pages
  Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/mm/pgtable-radix.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index b387c7b917b7e..69caeb5bccb21 100644
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -295,14 +295,14 @@ static int __meminit create_physical_mapping(unsigned long start,
 
 		if (split_text_mapping && (mapping_size == PUD_SIZE) &&
 			(addr < __pa_symbol(__init_begin)) &&
-			(addr + mapping_size) >= __pa_symbol(__init_begin)) {
+			(addr + mapping_size) > __pa_symbol(__init_begin)) {
 			max_mapping_size = PMD_SIZE;
 			goto retry;
 		}
 
 		if (split_text_mapping && (mapping_size == PMD_SIZE) &&
 		    (addr < __pa_symbol(__init_begin)) &&
-		    (addr + mapping_size) >= __pa_symbol(__init_begin)) {
+		    (addr + mapping_size) > __pa_symbol(__init_begin)) {
 			mapping_size = PAGE_SIZE;
 			psize = mmu_virtual_psize;
 		}
-- 
2.20.1

[PATCH AUTOSEL 4.19 095/237] powerpc/64s/radix: Fix radix__flush_tlb_collapsed_pmd double flushing pmd

[Sasha Levin]

From: Nicholas Piggin <npiggin@gmail.com>

[ Upstream commit dd76ff5af35350fd6d5bb5b069e73b6017f66893 ]

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/mm/tlb-radix.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/powerpc/mm/tlb-radix.c b/arch/powerpc/mm/tlb-radix.c
index 62be0e5732b70..02bc3ae8522f4 100644
--- a/arch/powerpc/mm/tlb-radix.c
+++ b/arch/powerpc/mm/tlb-radix.c
@@ -1071,7 +1071,6 @@ void radix__flush_tlb_collapsed_pmd(struct mm_struct *mm, unsigned long addr)
 			goto local;
 		}
 		_tlbie_va_range(addr, end, pid, PAGE_SIZE, mmu_virtual_psize, true);
-		goto local;
 	} else {
 local:
 		_tlbiel_va_range(addr, end, pid, PAGE_SIZE, mmu_virtual_psize, true);
-- 
2.20.1

[PATCH AUTOSEL 4.19 126/237] powerpc/process: Fix flush_all_to_thread for SPE

[Sasha Levin]

From: Felipe Rechia <felipe.rechia@datacom.com.br>

[ Upstream commit e901378578c62202594cba0f6c076f3df365ec91 ]

Fix a bug introduced by the creation of flush_all_to_thread() for
processors that have SPE (Signal Processing Engine) and use it to
compute floating-point operations.

>From userspace perspective, the problem was seen in attempts of
computing floating-point operations which should generate exceptions.
For example:

  fork();
  float x = 0.0 / 0.0;
  isnan(x);           // forked process returns False (should be True)

The operation above also should always cause the SPEFSCR FINV bit to
be set. However, the SPE floating-point exceptions were turned off
after a fork().

Kernel versions prior to the bug used flush_spe_to_thread(), which
first saves SPEFSCR register values in tsk->thread and then calls
giveup_spe(tsk).

After commit 579e633e764e, the save_all() function was called first
to giveup_spe(), and then the SPEFSCR register values were saved in
tsk->thread. This would save the SPEFSCR register values after
disabling SPE for that thread, causing the bug described above.

Fixes 579e633e764e ("powerpc: create flush_all_to_thread()")
Signed-off-by: Felipe Rechia <felipe.rechia@datacom.com.br>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/kernel/process.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 909c9407e392a..02b69a68139cc 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -575,12 +575,11 @@ void flush_all_to_thread(struct task_struct *tsk)
 	if (tsk->thread.regs) {
 		preempt_disable();
 		BUG_ON(tsk != current);
-		save_all(tsk);
-
 #ifdef CONFIG_SPE
 		if (tsk->thread.regs->msr & MSR_SPE)
 			tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
 #endif
+		save_all(tsk);
 
 		preempt_enable();
 	}
-- 
2.20.1

[PATCH AUTOSEL 4.19 143/237] powerpc/xmon: Relax frame size for clang

[Sasha Levin]

From: Joel Stanley <joel@jms.id.au>

[ Upstream commit 9c87156cce5a63735d1218f0096a65c50a7a32aa ]

When building with clang (8 trunk, 7.0 release) the frame size limit is
hit:

 arch/powerpc/xmon/xmon.c:452:12: warning: stack frame size of 2576
 bytes in function 'xmon_core' [-Wframe-larger-than=]

Some investigation by Naveen indicates this is due to clang saving the
addresses to printf format strings on the stack.

While this issue is investigated, bump up the frame size limit for xmon
when building with clang.

Link: https://github.com/ClangBuiltLinux/linux/issues/252
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/xmon/Makefile | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/powerpc/xmon/Makefile b/arch/powerpc/xmon/Makefile
index 9d7d8e6d705c4..9ba44e190e5e4 100644
--- a/arch/powerpc/xmon/Makefile
+++ b/arch/powerpc/xmon/Makefile
@@ -13,6 +13,12 @@ UBSAN_SANITIZE := n
 ORIG_CFLAGS := $(KBUILD_CFLAGS)
 KBUILD_CFLAGS = $(subst $(CC_FLAGS_FTRACE),,$(ORIG_CFLAGS))
 
+ifdef CONFIG_CC_IS_CLANG
+# clang stores addresses on the stack causing the frame size to blow
+# out. See https://github.com/ClangBuiltLinux/linux/issues/252
+KBUILD_CFLAGS += -Wframe-larger-than=4096
+endif
+
 ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC)
 
 obj-y			+= xmon.o nonstdio.o spr_access.o
-- 
2.20.1

[PATCH AUTOSEL 4.19 144/237] selftests/powerpc/ptrace: Fix out-of-tree build

[Sasha Levin]

From: Joel Stanley <joel@jms.id.au>

[ Upstream commit c39b79082a38a4f8c801790edecbbb4d62ed2992 ]

We should use TEST_GEN_PROGS, not TEST_PROGS. That tells the selftests
makefile (lib.mk) that those tests are generated (built), and so it
adds the $(OUTPUT) prefix for us, making the out-of-tree build work
correctly.

It also means we don't need our own clean rule, lib.mk does it.

We also have to update the ptrace-pkey and core-pkey rules to use
$(OUTPUT).

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/powerpc/ptrace/Makefile | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/tools/testing/selftests/powerpc/ptrace/Makefile b/tools/testing/selftests/powerpc/ptrace/Makefile
index 923d531265f8c..9f9423430059e 100644
--- a/tools/testing/selftests/powerpc/ptrace/Makefile
+++ b/tools/testing/selftests/powerpc/ptrace/Makefile
@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
-TEST_PROGS := ptrace-gpr ptrace-tm-gpr ptrace-tm-spd-gpr \
+TEST_GEN_PROGS := ptrace-gpr ptrace-tm-gpr ptrace-tm-spd-gpr \
               ptrace-tar ptrace-tm-tar ptrace-tm-spd-tar ptrace-vsx ptrace-tm-vsx \
               ptrace-tm-spd-vsx ptrace-tm-spr ptrace-hwbreak ptrace-pkey core-pkey \
               perf-hwbreak
@@ -7,14 +7,9 @@ TEST_PROGS := ptrace-gpr ptrace-tm-gpr ptrace-tm-spd-gpr \
 top_srcdir = ../../../../..
 include ../../lib.mk
 
-all: $(TEST_PROGS)
-
 CFLAGS += -m64 -I../../../../../usr/include -I../tm -mhtm -fno-pie
 
-ptrace-pkey core-pkey: child.h
-ptrace-pkey core-pkey: LDLIBS += -pthread
-
-$(TEST_PROGS): ../harness.c ../utils.c ../lib/reg.S ptrace.h
+$(OUTPUT)/ptrace-pkey $(OUTPUT)/core-pkey: child.h
+$(OUTPUT)/ptrace-pkey $(OUTPUT)/core-pkey: LDLIBS += -pthread
 
-clean:
-	rm -f $(TEST_PROGS) *.o
+$(TEST_GEN_PROGS): ../harness.c ../utils.c ../lib/reg.S ptrace.h
-- 
2.20.1

[PATCH AUTOSEL 4.19 145/237] selftests/powerpc/signal: Fix out-of-tree build

[Sasha Levin]

From: Joel Stanley <joel@jms.id.au>

[ Upstream commit 27825349d7b238533a47e3d98b8bb0efd886b752 ]

We should use TEST_GEN_PROGS, not TEST_PROGS. That tells the selftests
makefile (lib.mk) that those tests are generated (built), and so it
adds the $(OUTPUT) prefix for us, making the out-of-tree build work
correctly.

It also means we don't need our own clean rule, lib.mk does it.

We also have to update the signal_tm rule to use $(OUTPUT).

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/powerpc/signal/Makefile | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/powerpc/signal/Makefile b/tools/testing/selftests/powerpc/signal/Makefile
index 1fca25c6ace06..209a958dca127 100644
--- a/tools/testing/selftests/powerpc/signal/Makefile
+++ b/tools/testing/selftests/powerpc/signal/Makefile
@@ -1,15 +1,10 @@
 # SPDX-License-Identifier: GPL-2.0
-TEST_PROGS := signal signal_tm
-
-all: $(TEST_PROGS)
-
-$(TEST_PROGS): ../harness.c ../utils.c signal.S
+TEST_GEN_PROGS := signal signal_tm
 
 CFLAGS += -maltivec
-signal_tm: CFLAGS += -mhtm
+$(OUTPUT)/signal_tm: CFLAGS += -mhtm
 
 top_srcdir = ../../../../..
 include ../../lib.mk
 
-clean:
-	rm -f $(TEST_PROGS) *.o
+$(TEST_GEN_PROGS): ../harness.c ../utils.c signal.S
-- 
2.20.1

[PATCH AUTOSEL 4.19 146/237] selftests/powerpc/switch_endian: Fix out-of-tree build

[Sasha Levin]

From: Michael Ellerman <mpe@ellerman.id.au>

[ Upstream commit 266bac361d5677e61a6815bd29abeb3bdced2b07 ]

For the out-of-tree build to work we need to tell switch_endian_test
to look for check-reversed.S in $(OUTPUT).

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/powerpc/switch_endian/Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/powerpc/switch_endian/Makefile b/tools/testing/selftests/powerpc/switch_endian/Makefile
index fcd2dcb8972ba..bdc081afedb0f 100644
--- a/tools/testing/selftests/powerpc/switch_endian/Makefile
+++ b/tools/testing/selftests/powerpc/switch_endian/Makefile
@@ -8,6 +8,7 @@ EXTRA_CLEAN = $(OUTPUT)/*.o $(OUTPUT)/check-reversed.S
 top_srcdir = ../../../../..
 include ../../lib.mk
 
+$(OUTPUT)/switch_endian_test: ASFLAGS += -I $(OUTPUT)
 $(OUTPUT)/switch_endian_test: $(OUTPUT)/check-reversed.S
 
 $(OUTPUT)/check-reversed.o: $(OUTPUT)/check.o
-- 
2.20.1

[PATCH AUTOSEL 4.19 147/237] selftests/powerpc/cache_shape: Fix out-of-tree build

[Sasha Levin]

From: Michael Ellerman <mpe@ellerman.id.au>

[ Upstream commit 69f8117f17b332a68cd8f4bf8c2d0d3d5b84efc5 ]

Use TEST_GEN_PROGS and don't redefine all, this makes the out-of-tree
build work. We need to move the extra dependencies below the include
of lib.mk, because it adds the $(OUTPUT) prefix if it's defined.

We can also drop the clean rule, lib.mk does it for us.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/powerpc/cache_shape/Makefile | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/powerpc/cache_shape/Makefile b/tools/testing/selftests/powerpc/cache_shape/Makefile
index ede4d3dae7505..689f6c8ebcd8d 100644
--- a/tools/testing/selftests/powerpc/cache_shape/Makefile
+++ b/tools/testing/selftests/powerpc/cache_shape/Makefile
@@ -1,12 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
-TEST_PROGS := cache_shape
-
-all: $(TEST_PROGS)
-
-$(TEST_PROGS): ../harness.c ../utils.c
+TEST_GEN_PROGS := cache_shape
 
 top_srcdir = ../../../../..
 include ../../lib.mk
 
-clean:
-	rm -f $(TEST_PROGS) *.o
+$(TEST_GEN_PROGS): ../harness.c ../utils.c
-- 
2.20.1

[PATCH AUTOSEL 4.19 163/237] mm/memory_hotplug: make add_memory() take the device_hotplug_lock

[Sasha Levin]

From: David Hildenbrand <david@redhat.com>

[ Upstream commit 8df1d0e4a265f25dc1e7e7624ccdbcb4a6630c89 ]

add_memory() currently does not take the device_hotplug_lock, however
is aleady called under the lock from
	arch/powerpc/platforms/pseries/hotplug-memory.c
	drivers/acpi/acpi_memhotplug.c
to synchronize against CPU hot-remove and similar.

In general, we should hold the device_hotplug_lock when adding memory to
synchronize against online/offline request (e.g.  from user space) - which
already resulted in lock inversions due to device_lock() and
mem_hotplug_lock - see 30467e0b3be ("mm, hotplug: fix concurrent memory
hot-add deadlock").  add_memory()/add_memory_resource() will create memory
block devices, so this really feels like the right thing to do.

Holding the device_hotplug_lock makes sure that a memory block device
can really only be accessed (e.g. via .online/.state) from user space,
once the memory has been fully added to the system.

The lock is not held yet in
	drivers/xen/balloon.c
	arch/powerpc/platforms/powernv/memtrace.c
	drivers/s390/char/sclp_cmd.c
	drivers/hv/hv_balloon.c
So, let's either use the locked variants or take the lock.

Don't export add_memory_resource(), as it once was exported to be used by
XEN, which is never built as a module.  If somebody requires it, we also
have to export a locked variant (as device_hotplug_lock is never
exported).

Link: http://lkml.kernel.org/r/20180925091457.28651-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Rashmica Gupta <rashmica.g@gmail.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Cc: John Allen <jallen@linux.vnet.ibm.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: YASUAKI ISHIMATSU <yasu.isimatu@gmail.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 .../platforms/pseries/hotplug-memory.c        |  2 +-
 drivers/acpi/acpi_memhotplug.c                |  2 +-
 drivers/base/memory.c                         |  9 ++++++--
 drivers/xen/balloon.c                         |  3 +++
 include/linux/memory_hotplug.h                |  1 +
 mm/memory_hotplug.c                           | 22 ++++++++++++++++---
 6 files changed, 32 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
index f99cd31b6fd1a..7d61da2fe5226 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -705,7 +705,7 @@ static int dlpar_add_lmb(struct drmem_lmb *lmb)
 	nid = memory_add_physaddr_to_nid(lmb->base_addr);
 
 	/* Add the memory */
-	rc = add_memory(nid, lmb->base_addr, block_sz);
+	rc = __add_memory(nid, lmb->base_addr, block_sz);
 	if (rc) {
 		dlpar_remove_device_tree_lmb(lmb);
 		return rc;
diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index 6b0d3ef7309cb..2ccfbb61ca899 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -228,7 +228,7 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 		if (node < 0)
 			node = memory_add_physaddr_to_nid(info->start_addr);
 
-		result = add_memory(node, info->start_addr, info->length);
+		result = __add_memory(node, info->start_addr, info->length);
 
 		/*
 		 * If the memory block has been used by the kernel, add_memory()
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 85ee64d0a44e9..07901cacfec63 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -519,15 +519,20 @@ memory_probe_store(struct device *dev, struct device_attribute *attr,
 	if (phys_addr & ((pages_per_block << PAGE_SHIFT) - 1))
 		return -EINVAL;
 
+	ret = lock_device_hotplug_sysfs();
+	if (ret)
+		goto out;
+
 	nid = memory_add_physaddr_to_nid(phys_addr);
-	ret = add_memory(nid, phys_addr,
-			 MIN_MEMORY_BLOCK_SIZE * sections_per_block);
+	ret = __add_memory(nid, phys_addr,
+			   MIN_MEMORY_BLOCK_SIZE * sections_per_block);
 
 	if (ret)
 		goto out;
 
 	ret = count;
 out:
+	unlock_device_hotplug();
 	return ret;
 }
 
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index d4e8b717ce2b2..747a15acbce37 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -350,7 +350,10 @@ static enum bp_state reserve_additional_memory(void)
 	 * callers drop the mutex before trying again.
 	 */
 	mutex_unlock(&balloon_mutex);
+	/* add_memory_resource() requires the device_hotplug lock */
+	lock_device_hotplug();
 	rc = add_memory_resource(nid, resource, memhp_auto_online);
+	unlock_device_hotplug();
 	mutex_lock(&balloon_mutex);
 
 	if (rc) {
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 34a28227068dc..16487052017d5 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -322,6 +322,7 @@ static inline void remove_memory(int nid, u64 start, u64 size) {}
 extern void __ref free_area_init_core_hotplug(int nid);
 extern int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,
 		void *arg, int (*func)(struct memory_block *, void *));
+extern int __add_memory(int nid, u64 start, u64 size);
 extern int add_memory(int nid, u64 start, u64 size);
 extern int add_memory_resource(int nid, struct resource *resource, bool online);
 extern int arch_add_memory(int nid, u64 start, u64 size,
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index af67355622159..1992b416661fe 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1114,7 +1114,12 @@ static int online_memory_block(struct memory_block *mem, void *arg)
 	return device_online(&mem->dev);
 }
 
-/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
+/*
+ * NOTE: The caller must call lock_device_hotplug() to serialize hotplug
+ * and online/offline operations (triggered e.g. by sysfs).
+ *
+ * we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG
+ */
 int __ref add_memory_resource(int nid, struct resource *res, bool online)
 {
 	u64 start, size;
@@ -1183,9 +1188,9 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online)
 	mem_hotplug_done();
 	return ret;
 }
-EXPORT_SYMBOL_GPL(add_memory_resource);
 
-int __ref add_memory(int nid, u64 start, u64 size)
+/* requires device_hotplug_lock, see add_memory_resource() */
+int __ref __add_memory(int nid, u64 start, u64 size)
 {
 	struct resource *res;
 	int ret;
@@ -1199,6 +1204,17 @@ int __ref add_memory(int nid, u64 start, u64 size)
 		release_memory_resource(res);
 	return ret;
 }
+
+int add_memory(int nid, u64 start, u64 size)
+{
+	int rc;
+
+	lock_device_hotplug();
+	rc = __add_memory(nid, start, size);
+	unlock_device_hotplug();
+
+	return rc;
+}
 EXPORT_SYMBOL_GPL(add_memory);
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
-- 
2.20.1

[PATCH AUTOSEL 4.19 165/237] powerpc/powernv: hold device_hotplug_lock when calling device_online()

[Sasha Levin]

From: David Hildenbrand <david@redhat.com>

[ Upstream commit cec1680591d6d5b10ecc10f370210089416e98af ]

device_online() should be called with device_hotplug_lock() held.

Link: http://lkml.kernel.org/r/20180925091457.28651-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com>
Reviewed-by: Rashmica Gupta <rashmica.g@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Rashmica Gupta <rashmica.g@gmail.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: John Allen <jallen@linux.vnet.ibm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: YASUAKI ISHIMATSU <yasu.isimatu@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/platforms/powernv/memtrace.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/powerpc/platforms/powernv/memtrace.c b/arch/powerpc/platforms/powernv/memtrace.c
index 232bf5987f91d..dd3cc4632b9ae 100644
--- a/arch/powerpc/platforms/powernv/memtrace.c
+++ b/arch/powerpc/platforms/powernv/memtrace.c
@@ -244,9 +244,11 @@ static int memtrace_online(void)
 		 * we need to online the memory ourselves.
 		 */
 		if (!memhp_auto_online) {
+			lock_device_hotplug();
 			walk_memory_range(PFN_DOWN(ent->start),
 					  PFN_UP(ent->start + ent->size - 1),
 					  NULL, online_mem_block);
+			unlock_device_hotplug();
 		}
 
 		/*
-- 
2.20.1