diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/io.h | 5 | ||||
| -rw-r--r-- | arch/x86/mm/ioremap.c | 180 |
2 files changed, 185 insertions, 0 deletions
diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h index 7afb0e2f07f4..09c5557b1454 100644 --- a/arch/x86/include/asm/io.h +++ b/arch/x86/include/asm/io.h @@ -381,4 +381,9 @@ extern void arch_io_free_memtype_wc(resource_size_t start, resource_size_t size) #define arch_io_reserve_memtype_wc arch_io_reserve_memtype_wc #endif +extern bool arch_memremap_can_ram_remap(resource_size_t offset, + unsigned long size, + unsigned long flags); +#define arch_memremap_can_ram_remap arch_memremap_can_ram_remap + #endif /* _ASM_X86_IO_H */ diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 570201bbf442..8986b2868944 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -13,6 +13,8 @@ #include <linux/slab.h> #include <linux/vmalloc.h> #include <linux/mmiotrace.h> +#include <linux/mem_encrypt.h> +#include <linux/efi.h> #include <asm/set_memory.h> #include <asm/e820/api.h> @@ -21,6 +23,7 @@ #include <asm/tlbflush.h> #include <asm/pgalloc.h> #include <asm/pat.h> +#include <asm/setup.h> #include "physaddr.h" @@ -417,6 +420,183 @@ void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr) iounmap((void __iomem *)((unsigned long)addr & PAGE_MASK)); } +/* + * Examine the physical address to determine if it is an area of memory + * that should be mapped decrypted. If the memory is not part of the + * kernel usable area it was accessed and created decrypted, so these + * areas should be mapped decrypted. + */ +static bool memremap_should_map_decrypted(resource_size_t phys_addr, + unsigned long size) +{ + /* Check if the address is outside kernel usable area */ + switch (e820__get_entry_type(phys_addr, phys_addr + size - 1)) { + case E820_TYPE_RESERVED: + case E820_TYPE_ACPI: + case E820_TYPE_NVS: + case E820_TYPE_UNUSABLE: + return true; + default: + break; + } + + return false; +} + +/* + * Examine the physical address to determine if it is EFI data. Check + * it against the boot params structure and EFI tables and memory types. + */ +static bool memremap_is_efi_data(resource_size_t phys_addr, + unsigned long size) +{ + u64 paddr; + + /* Check if the address is part of EFI boot/runtime data */ + if (!efi_enabled(EFI_BOOT)) + return false; + + paddr = boot_params.efi_info.efi_memmap_hi; + paddr <<= 32; + paddr |= boot_params.efi_info.efi_memmap; + if (phys_addr == paddr) + return true; + + paddr = boot_params.efi_info.efi_systab_hi; + paddr <<= 32; + paddr |= boot_params.efi_info.efi_systab; + if (phys_addr == paddr) + return true; + + if (efi_is_table_address(phys_addr)) + return true; + + switch (efi_mem_type(phys_addr)) { + case EFI_BOOT_SERVICES_DATA: + case EFI_RUNTIME_SERVICES_DATA: + return true; + default: + break; + } + + return false; +} + +/* + * Examine the physical address to determine if it is boot data by checking + * it against the boot params setup_data chain. + */ +static bool memremap_is_setup_data(resource_size_t phys_addr, + unsigned long size) +{ + struct setup_data *data; + u64 paddr, paddr_next; + + paddr = boot_params.hdr.setup_data; + while (paddr) { + unsigned int len; + + if (phys_addr == paddr) + return true; + + data = memremap(paddr, sizeof(*data), + MEMREMAP_WB | MEMREMAP_DEC); + + paddr_next = data->next; + len = data->len; + + memunmap(data); + + if ((phys_addr > paddr) && (phys_addr < (paddr + len))) + return true; + + paddr = paddr_next; + } + + return false; +} + +/* + * Examine the physical address to determine if it is boot data by checking + * it against the boot params setup_data chain (early boot version). + */ +static bool __init early_memremap_is_setup_data(resource_size_t phys_addr, + unsigned long size) +{ + struct setup_data *data; + u64 paddr, paddr_next; + + paddr = boot_params.hdr.setup_data; + while (paddr) { + unsigned int len; + + if (phys_addr == paddr) + return true; + + data = early_memremap_decrypted(paddr, sizeof(*data)); + + paddr_next = data->next; + len = data->len; + + early_memunmap(data, sizeof(*data)); + + if ((phys_addr > paddr) && (phys_addr < (paddr + len))) + return true; + + paddr = paddr_next; + } + + return false; +} + +/* + * Architecture function to determine if RAM remap is allowed. By default, a + * RAM remap will map the data as encrypted. Determine if a RAM remap should + * not be done so that the data will be mapped decrypted. + */ +bool arch_memremap_can_ram_remap(resource_size_t phys_addr, unsigned long size, + unsigned long flags) +{ + if (!sme_active()) + return true; + + if (flags & MEMREMAP_ENC) + return true; + + if (flags & MEMREMAP_DEC) + return false; + + if (memremap_is_setup_data(phys_addr, size) || + memremap_is_efi_data(phys_addr, size) || + memremap_should_map_decrypted(phys_addr, size)) + return false; + + return true; +} + +/* + * Architecture override of __weak function to adjust the protection attributes + * used when remapping memory. By default, early_memremap() will map the data + * as encrypted. Determine if an encrypted mapping should not be done and set + * the appropriate protection attributes. + */ +pgprot_t __init early_memremap_pgprot_adjust(resource_size_t phys_addr, + unsigned long size, + pgprot_t prot) +{ + if (!sme_active()) + return prot; + + if (early_memremap_is_setup_data(phys_addr, size) || + memremap_is_efi_data(phys_addr, size) || + memremap_should_map_decrypted(phys_addr, size)) + prot = pgprot_decrypted(prot); + else + prot = pgprot_encrypted(prot); + + return prot; +} + #ifdef CONFIG_ARCH_USE_MEMREMAP_PROT /* Remap memory with encryption */ void __init *early_memremap_encrypted(resource_size_t phys_addr, |