diff options
Diffstat (limited to 'arch/arm64/kernel/acpi.c')
| -rw-r--r-- | arch/arm64/kernel/acpi.c | 24 |
1 files changed, 21 insertions, 3 deletions
diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c index 455966401102..cada0b816c8a 100644 --- a/arch/arm64/kernel/acpi.c +++ b/arch/arm64/kernel/acpi.c @@ -298,8 +298,21 @@ void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size) case EFI_BOOT_SERVICES_DATA: case EFI_CONVENTIONAL_MEMORY: case EFI_PERSISTENT_MEMORY: - pr_warn(FW_BUG "requested region covers kernel memory @ %pa\n", &phys); - return NULL; + if (memblock_is_map_memory(phys) || + !memblock_is_region_memory(phys, size)) { + pr_warn(FW_BUG "requested region covers kernel memory @ %pa\n", &phys); + return NULL; + } + /* + * Mapping kernel memory is permitted if the region in + * question is covered by a single memblock with the + * NOMAP attribute set: this enables the use of ACPI + * table overrides passed via initramfs, which are + * reserved in memory using arch_reserve_mem_area() + * below. As this particular use case only requires + * read access, fall through to the R/O mapping case. + */ + fallthrough; case EFI_RUNTIME_SERVICES_CODE: /* @@ -322,7 +335,7 @@ void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size) */ if (memblock_is_map_memory(phys)) return (void __iomem *)__phys_to_virt(phys); - /* fall through */ + fallthrough; default: if (region->attribute & EFI_MEMORY_WB) @@ -388,3 +401,8 @@ int apei_claim_sea(struct pt_regs *regs) return err; } + +void arch_reserve_mem_area(acpi_physical_address addr, size_t size) +{ + memblock_mark_nomap(addr, size); +} |