On Wed, Jun 30, 2021 at 08:18:22PM +0200, Ard Biesheuvel wrote:
[...]
> > In current code, even if the BERT were mapped with acpi_os_map_iomem()
> > this would change nothing since it's acpi_os_ioremap() that runs the
> > rule (backed up by EFI memory map region info).
> >
>
> Indeed. So the fact that acpi_os_map_memory() is backed by
> acpi_os_ioremap() is something we should fix. So they should both
> consult the EFI memory map, but have different fallback defaults if
> the region is not annotated correctly.
Put together patch below even though I am not really satisfied, a tad
intrusive and duplicate code in generic/arch backends, compile tested
only; overall this IO vs memory mapping distinction is a bit too fuzzy
for my taste - there is legacy unfortunately to consider though.
-- >8 --
Subject: [PATCH] ACPI: Add memory semantics to acpi_os_map_memory()
Some platforms require memory semantics requested by the mapping function
to be translated into architectural specific memory attributes so that
the mapping is effectively implementing what is expected from it in
terms of allowed access patterns (eg unaligned access).
Rework acpi_os_map_memory() and acpi_os_ioremap() back-end to split
them into two separate code paths that allow the architectural
back-end to detect the default memory attributes required by
the mapping in question.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
---
arch/arm64/include/asm/acpi.h | 3 +++
arch/arm64/kernel/acpi.c | 16 ++++++++++++++--
drivers/acpi/osl.c | 23 ++++++++++++++++-------
include/acpi/acpi_io.h | 8 ++++++++
4 files changed, 41 insertions(+), 9 deletions(-)
diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
index bd68e1b7f29f..7535dc7cc5aa 100644
--- a/arch/arm64/include/asm/acpi.h
+++ b/arch/arm64/include/asm/acpi.h
@@ -50,6 +50,9 @@ pgprot_t __acpi_get_mem_attribute(phys_addr_t addr);
void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size);
#define acpi_os_ioremap acpi_os_ioremap
+void __iomem *acpi_os_memmap(acpi_physical_address phys, acpi_size size);
+#define acpi_os_memmap acpi_os_memmap
+
typedef u64 phys_cpuid_t;
#define PHYS_CPUID_INVALID INVALID_HWID
diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
index cada0b816c8a..4c04fb40dc86 100644
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c
@@ -261,7 +261,8 @@ pgprot_t __acpi_get_mem_attribute(phys_addr_t addr)
return __pgprot(PROT_DEVICE_nGnRnE);
}
-void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size)
+static void __iomem *__acpi_os_ioremap(acpi_physical_address phys,
+ acpi_size size, bool memory)
{
efi_memory_desc_t *md, *region = NULL;
pgprot_t prot;
@@ -289,7 +290,8 @@ void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size)
* regions that require a virtual mapping to make them accessible to
* the EFI runtime services.
*/
- prot = __pgprot(PROT_DEVICE_nGnRnE);
+ prot = memory ? __pgprot(PROT_NORMAL_NC) :
+ __pgprot(PROT_DEVICE_nGnRnE);
if (region) {
switch (region->type) {
case EFI_LOADER_CODE:
@@ -349,6 +351,16 @@ void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size)
return __ioremap(phys, size, prot);
}
+void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size)
+{
+ return __acpi_os_ioremap(phys, size, false);
+}
+
+void __iomem *acpi_os_memmap(acpi_physical_address phys, acpi_size size)
+{
+ return __acpi_os_ioremap(phys, size, true);
+}
+
/*
* Claim Synchronous External Aborts as a firmware first notification.
*
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 327e1b4eb6b0..01dd115689bf 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -284,7 +284,8 @@ acpi_map_lookup_virt(void __iomem *virt, acpi_size size)
#define should_use_kmap(pfn) page_is_ram(pfn)
#endif
-static void __iomem *acpi_map(acpi_physical_address pg_off, unsigned long pg_sz)
+static void __iomem *acpi_map(acpi_physical_address pg_off, unsigned long pg_sz,
+ bool memory)
{
unsigned long pfn;
@@ -294,7 +295,8 @@ static void __iomem *acpi_map(acpi_physical_address pg_off, unsigned long pg_sz)
return NULL;
return (void __iomem __force *)kmap(pfn_to_page(pfn));
} else
- return acpi_os_ioremap(pg_off, pg_sz);
+ return memory ? acpi_os_memmap(pg_off, pg_sz) :
+ acpi_os_ioremap(pg_off, pg_sz);
}
static void acpi_unmap(acpi_physical_address pg_off, void __iomem *vaddr)
@@ -309,9 +311,10 @@ static void acpi_unmap(acpi_physical_address pg_off, void __iomem *vaddr)
}
/**
- * acpi_os_map_iomem - Get a virtual address for a given physical address range.
+ * __acpi_os_map_iomem - Get a virtual address for a given physical address range.
* @phys: Start of the physical address range to map.
* @size: Size of the physical address range to map.
+ * @memory: true if remapping memory, false if IO
*
* Look up the given physical address range in the list of existing ACPI memory
* mappings. If found, get a reference to it and return a pointer to it (its
@@ -321,8 +324,8 @@ static void acpi_unmap(acpi_physical_address pg_off, void __iomem *vaddr)
* During early init (when acpi_permanent_mmap has not been set yet) this
* routine simply calls __acpi_map_table() to get the job done.
*/
-void __iomem __ref
-*acpi_os_map_iomem(acpi_physical_address phys, acpi_size size)
+static void __iomem __ref
+*__acpi_os_map_iomem(acpi_physical_address phys, acpi_size size, bool memory)
{
struct acpi_ioremap *map;
void __iomem *virt;
@@ -353,7 +356,7 @@ void __iomem __ref
pg_off = round_down(phys, PAGE_SIZE);
pg_sz = round_up(phys + size, PAGE_SIZE) - pg_off;
- virt = acpi_map(phys, size);
+ virt = acpi_map(phys, size, memory);
if (!virt) {
mutex_unlock(&acpi_ioremap_lock);
kfree(map);
@@ -372,11 +375,17 @@ void __iomem __ref
mutex_unlock(&acpi_ioremap_lock);
return map->virt + (phys - map->phys);
}
+
+void __iomem __ref
+*acpi_os_map_iomem(acpi_physical_address phys, acpi_size size)
+{
+ return __acpi_os_map_iomem(phys, size, false);
+}
EXPORT_SYMBOL_GPL(acpi_os_map_iomem);
void *__ref acpi_os_map_memory(acpi_physical_address phys, acpi_size size)
{
- return (void *)acpi_os_map_iomem(phys, size);
+ return (void *)__acpi_os_map_iomem(phys, size, true);
}
EXPORT_SYMBOL_GPL(acpi_os_map_memory);
diff --git a/include/acpi/acpi_io.h b/include/acpi/acpi_io.h
index 027faa8883aa..a0212e67d6f4 100644
--- a/include/acpi/acpi_io.h
+++ b/include/acpi/acpi_io.h
@@ -14,6 +14,14 @@ static inline void __iomem *acpi_os_ioremap(acpi_physical_address phys,
}
#endif
+#ifndef acpi_os_memmap
+static inline void __iomem *acpi_os_memmap(acpi_physical_address phys,
+ acpi_size size)
+{
+ return ioremap_cache(phys, size);
+}
+#endif
+
extern bool acpi_permanent_mmap;
void __iomem __ref
--
2.29.1
