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Diffstat (limited to 'arch/x86/mm/ioremap.c')
-rw-r--r--arch/x86/mm/ioremap.c287
1 files changed, 269 insertions, 18 deletions
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 4c1b5fd0c7ad..34f0e1847dd6 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"
@@ -106,12 +109,6 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr,
}
/*
- * Don't remap the low PCI/ISA area, it's always mapped..
- */
- if (is_ISA_range(phys_addr, last_addr))
- return (__force void __iomem *)phys_to_virt(phys_addr);
-
- /*
* Don't allow anybody to remap normal RAM that we're using..
*/
pfn = phys_addr >> PAGE_SHIFT;
@@ -340,13 +337,17 @@ void iounmap(volatile void __iomem *addr)
return;
/*
- * __ioremap special-cases the PCI/ISA range by not instantiating a
- * vm_area and by simply returning an address into the kernel mapping
- * of ISA space. So handle that here.
+ * The PCI/ISA range special-casing was removed from __ioremap()
+ * so this check, in theory, can be removed. However, there are
+ * cases where iounmap() is called for addresses not obtained via
+ * ioremap() (vga16fb for example). Add a warning so that these
+ * cases can be caught and fixed.
*/
if ((void __force *)addr >= phys_to_virt(ISA_START_ADDRESS) &&
- (void __force *)addr < phys_to_virt(ISA_END_ADDRESS))
+ (void __force *)addr < phys_to_virt(ISA_END_ADDRESS)) {
+ WARN(1, "iounmap() called for ISA range not obtained using ioremap()\n");
return;
+ }
addr = (volatile void __iomem *)
(PAGE_MASK & (unsigned long __force)addr);
@@ -399,12 +400,10 @@ void *xlate_dev_mem_ptr(phys_addr_t phys)
unsigned long offset = phys & ~PAGE_MASK;
void *vaddr;
- /* If page is RAM, we can use __va. Otherwise ioremap and unmap. */
- if (page_is_ram(start >> PAGE_SHIFT))
- return __va(phys);
+ /* memremap() maps if RAM, otherwise falls back to ioremap() */
+ vaddr = memremap(start, PAGE_SIZE, MEMREMAP_WB);
- vaddr = ioremap_cache(start, PAGE_SIZE);
- /* Only add the offset on success and return NULL if the ioremap() failed: */
+ /* Only add the offset on success and return NULL if memremap() failed */
if (vaddr)
vaddr += offset;
@@ -413,11 +412,263 @@ void *xlate_dev_mem_ptr(phys_addr_t phys)
void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr)
{
- if (page_is_ram(phys >> PAGE_SHIFT))
- return;
+ memunmap((void *)((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. And since the encryption key can
+ * change across reboots, persistent memory should also be mapped
+ * decrypted.
+ */
+static bool memremap_should_map_decrypted(resource_size_t phys_addr,
+ unsigned long size)
+{
+ int is_pmem;
+
+ /*
+ * Check if the address is part of a persistent memory region.
+ * This check covers areas added by E820, EFI and ACPI.
+ */
+ is_pmem = region_intersects(phys_addr, size, IORESOURCE_MEM,
+ IORES_DESC_PERSISTENT_MEMORY);
+ if (is_pmem != REGION_DISJOINT)
+ return true;
+
+ /*
+ * Check if the non-volatile attribute is set for an EFI
+ * reserved area.
+ */
+ if (efi_enabled(EFI_BOOT)) {
+ switch (efi_mem_type(phys_addr)) {
+ case EFI_RESERVED_TYPE:
+ if (efi_mem_attributes(phys_addr) & EFI_MEMORY_NV)
+ return true;
+ break;
+ default:
+ break;
+ }
+ }
+
+ /* 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:
+ case E820_TYPE_PRAM:
+ 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;
+}
+
+bool phys_mem_access_encrypted(unsigned long phys_addr, unsigned long size)
+{
+ return arch_memremap_can_ram_remap(phys_addr, size, 0);
+}
+
+#ifdef CONFIG_ARCH_USE_MEMREMAP_PROT
+/* Remap memory with encryption */
+void __init *early_memremap_encrypted(resource_size_t phys_addr,
+ unsigned long size)
+{
+ return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_ENC);
+}
+
+/*
+ * Remap memory with encryption and write-protected - cannot be called
+ * before pat_init() is called
+ */
+void __init *early_memremap_encrypted_wp(resource_size_t phys_addr,
+ unsigned long size)
+{
+ /* Be sure the write-protect PAT entry is set for write-protect */
+ if (__pte2cachemode_tbl[_PAGE_CACHE_MODE_WP] != _PAGE_CACHE_MODE_WP)
+ return NULL;
+
+ return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_ENC_WP);
+}
+
+/* Remap memory without encryption */
+void __init *early_memremap_decrypted(resource_size_t phys_addr,
+ unsigned long size)
+{
+ return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_NOENC);
+}
+
+/*
+ * Remap memory without encryption and write-protected - cannot be called
+ * before pat_init() is called
+ */
+void __init *early_memremap_decrypted_wp(resource_size_t phys_addr,
+ unsigned long size)
+{
+ /* Be sure the write-protect PAT entry is set for write-protect */
+ if (__pte2cachemode_tbl[_PAGE_CACHE_MODE_WP] != _PAGE_CACHE_MODE_WP)
+ return NULL;
- iounmap((void __iomem *)((unsigned long)addr & PAGE_MASK));
+ return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_NOENC_WP);
}
+#endif /* CONFIG_ARCH_USE_MEMREMAP_PROT */
static pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)] __page_aligned_bss;