--- /dev/null
+From 1bbc21785b7336619fb6a67f1fff5afdaf229acc Mon Sep 17 00:00:00 2001
+From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+Date: Thu, 7 Apr 2022 11:51:20 +0100
+Subject: ACPI: sysfs: Fix BERT error region memory mapping
+
+From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+
+commit 1bbc21785b7336619fb6a67f1fff5afdaf229acc upstream.
+
+Currently the sysfs interface maps the BERT error region as "memory"
+(through acpi_os_map_memory()) in order to copy the error records into
+memory buffers through memory operations (eg memory_read_from_buffer()).
+
+The OS system cannot detect whether the BERT error region is part of
+system RAM or it is "device memory" (eg BMC memory) and therefore it
+cannot detect which memory attributes the bus to memory support (and
+corresponding kernel mapping, unless firmware provides the required
+information).
+
+The acpi_os_map_memory() arch backend implementation determines the
+mapping attributes. On arm64, if the BERT error region is not present in
+the EFI memory map, the error region is mapped as device-nGnRnE; this
+triggers alignment faults since memcpy unaligned accesses are not
+allowed in device-nGnRnE regions.
+
+The ACPI sysfs code cannot therefore map by default the BERT error
+region with memory semantics but should use a safer default.
+
+Change the sysfs code to map the BERT error region as MMIO (through
+acpi_os_map_iomem()) and use the memcpy_fromio() interface to read the
+error region into the kernel buffer.
+
+Link: https://lore.kernel.org/linux-arm-kernel/31ffe8fc-f5ee-2858-26c5-0fd8bdd68702@arm.com
+Link: https://lore.kernel.org/linux-acpi/CAJZ5v0g+OVbhuUUDrLUCfX_mVqY_e8ubgLTU98=jfjTeb4t+Pw@mail.gmail.com
+Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+Tested-by: Veronika Kabatova <vkabatov@redhat.com>
+Tested-by: Aristeu Rozanski <aris@redhat.com>
+Acked-by: Ard Biesheuvel <ardb@kernel.org>
+Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+Cc: dann frazier <dann.frazier@canonical.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/acpi/sysfs.c | 25 ++++++++++++++++++-------
+ 1 file changed, 18 insertions(+), 7 deletions(-)
+
+--- a/drivers/acpi/sysfs.c
++++ b/drivers/acpi/sysfs.c
+@@ -438,19 +438,30 @@ static ssize_t acpi_data_show(struct fil
+ loff_t offset, size_t count)
+ {
+ struct acpi_data_attr *data_attr;
+- void *base;
+- ssize_t rc;
++ void __iomem *base;
++ ssize_t size;
+
+ data_attr = container_of(bin_attr, struct acpi_data_attr, attr);
++ size = data_attr->attr.size;
+
+- base = acpi_os_map_memory(data_attr->addr, data_attr->attr.size);
++ if (offset < 0)
++ return -EINVAL;
++
++ if (offset >= size)
++ return 0;
++
++ if (count > size - offset)
++ count = size - offset;
++
++ base = acpi_os_map_iomem(data_attr->addr, size);
+ if (!base)
+ return -ENOMEM;
+- rc = memory_read_from_buffer(buf, count, &offset, base,
+- data_attr->attr.size);
+- acpi_os_unmap_memory(base, data_attr->attr.size);
+
+- return rc;
++ memcpy_fromio(buf, base + offset, count);
++
++ acpi_os_unmap_iomem(base, size);
++
++ return count;
+ }
+
+ static int acpi_bert_data_init(void *th, struct acpi_data_attr *data_attr)
--- /dev/null
+From bdd56d7d8931e842775d2e5b93d426a8d1940e33 Mon Sep 17 00:00:00 2001
+From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+Date: Wed, 16 Jun 2021 20:03:32 +0300
+Subject: ACPI: sysfs: Make sparse happy about address space in use
+
+From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+
+commit bdd56d7d8931e842775d2e5b93d426a8d1940e33 upstream.
+
+Sparse is not happy about address space in use in acpi_data_show():
+
+drivers/acpi/sysfs.c:428:14: warning: incorrect type in assignment (different address spaces)
+drivers/acpi/sysfs.c:428:14: expected void [noderef] __iomem *base
+drivers/acpi/sysfs.c:428:14: got void *
+drivers/acpi/sysfs.c:431:59: warning: incorrect type in argument 4 (different address spaces)
+drivers/acpi/sysfs.c:431:59: expected void const *from
+drivers/acpi/sysfs.c:431:59: got void [noderef] __iomem *base
+drivers/acpi/sysfs.c:433:30: warning: incorrect type in argument 1 (different address spaces)
+drivers/acpi/sysfs.c:433:30: expected void *logical_address
+drivers/acpi/sysfs.c:433:30: got void [noderef] __iomem *base
+
+Indeed, acpi_os_map_memory() returns a void pointer with dropped specific
+address space. Hence, we don't need to carry out __iomem in acpi_data_show().
+
+Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+Cc: dann frazier <dann.frazier@canonical.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/acpi/sysfs.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/acpi/sysfs.c
++++ b/drivers/acpi/sysfs.c
+@@ -438,7 +438,7 @@ static ssize_t acpi_data_show(struct fil
+ loff_t offset, size_t count)
+ {
+ struct acpi_data_attr *data_attr;
+- void __iomem *base;
++ void *base;
+ ssize_t rc;
+
+ data_attr = container_of(bin_attr, struct acpi_data_attr, attr);
projects / thirdparty / kernel / stable-queue.git / commitdiff
