ACPI: Add memory semantics to acpi_os_map_memory()

The memory attributes attached to memory regions depend on architecture
specific mappings.

For some memory regions, the attributes specified by firmware (eg
uncached) are not sufficient to determine how a memory region should be
mapped by an OS (for instance a region that is define as uncached in
firmware can be mapped as Normal or Device memory on arm64) and
therefore the OS must be given control on how to map the region to match
the expected mapping behaviour (eg if a mapping is requested with memory
semantics, it must allow unaligned accesses).

Rework acpi_os_map_memory() and acpi_os_ioremap() back-end to split
them into two separate code paths:

acpi_os_memmap() -> memory semantics
acpi_os_ioremap() -> MMIO semantics

The split allows the architectural implementation back-ends to detect
the default memory attributes required by the mapping in question
(ie the mapping API defines the semantics memory vs MMIO) and map the
memory accordingly.

Link: https://lore.kernel.org/linux-arm-kernel/31ffe8fc-f5ee-2858-26c5-0fd8bdd68702@arm.com
Tested-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
index bd68e1b7f29f34552b9e4decd2c430a6d3916c43..7535dc7cc5aa18ddd4e05b5f325406c19ce0cf06 100644 (file)
--- 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 f3851724fe35611eb9d113e9e4aec6ee395b456f..1c9c2f7a1c04d40642698afccdaf36d2a86a0f46 100644 (file)
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c
@@ -273,7 +273,8 @@ 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;
@@ -299,9 +300,11 @@ void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size)
         * It is fine for AML to remap regions that are not represented in the
         * EFI memory map at all, as it only describes normal memory, and MMIO
         * regions that require a virtual mapping to make them accessible to
-        * the EFI runtime services.
+        * the EFI runtime services. Determine the region default
+        * attributes by checking the requested memory semantics.
         */
-       prot = __pgprot(PROT_DEVICE_nGnRnE);
+       prot = memory ? __pgprot(PROT_NORMAL_NC) :
+                       __pgprot(PROT_DEVICE_nGnRnE);
        if (region) {
                switch (region->type) {
                case EFI_LOADER_CODE:
@@ -361,6 +364,16 @@ 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 45c5c0e45e3327a3c6a1fe1acf81f2b7c709f379..a43f1521efe6d967f73e25c4c950a7c598834c8d 100644 (file)
--- 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 @@ out:
        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 027faa8883aab6804aa2b18480b8df2a4e4c68bb..a0212e67d6f44d29fd11fcddd6ba5a5c351f431f 100644 (file)
--- 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