summaryrefslogtreecommitdiffstats
path: root/arch/x86/platform/efi/efi_64.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/platform/efi/efi_64.c')
-rw-r--r--arch/x86/platform/efi/efi_64.c1039
1 files changed, 1039 insertions, 0 deletions
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
new file mode 100644
index 000000000..77d05b560
--- /dev/null
+++ b/arch/x86/platform/efi/efi_64.c
@@ -0,0 +1,1039 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * x86_64 specific EFI support functions
+ * Based on Extensible Firmware Interface Specification version 1.0
+ *
+ * Copyright (C) 2005-2008 Intel Co.
+ * Fenghua Yu <fenghua.yu@intel.com>
+ * Bibo Mao <bibo.mao@intel.com>
+ * Chandramouli Narayanan <mouli@linux.intel.com>
+ * Huang Ying <ying.huang@intel.com>
+ *
+ * Code to convert EFI to E820 map has been implemented in elilo bootloader
+ * based on a EFI patch by Edgar Hucek. Based on the E820 map, the page table
+ * is setup appropriately for EFI runtime code.
+ * - mouli 06/14/2007.
+ *
+ */
+
+#define pr_fmt(fmt) "efi: " fmt
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/bootmem.h>
+#include <linux/ioport.h>
+#include <linux/mc146818rtc.h>
+#include <linux/efi.h>
+#include <linux/export.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+#include <linux/reboot.h>
+#include <linux/slab.h>
+#include <linux/ucs2_string.h>
+#include <linux/mem_encrypt.h>
+#include <linux/sched/task.h>
+
+#include <asm/setup.h>
+#include <asm/page.h>
+#include <asm/e820/api.h>
+#include <asm/pgtable.h>
+#include <asm/tlbflush.h>
+#include <asm/proto.h>
+#include <asm/efi.h>
+#include <asm/cacheflush.h>
+#include <asm/fixmap.h>
+#include <asm/realmode.h>
+#include <asm/time.h>
+#include <asm/pgalloc.h>
+
+/*
+ * We allocate runtime services regions top-down, starting from -4G, i.e.
+ * 0xffff_ffff_0000_0000 and limit EFI VA mapping space to 64G.
+ */
+static u64 efi_va = EFI_VA_START;
+
+struct efi_scratch efi_scratch;
+
+static void __init early_code_mapping_set_exec(int executable)
+{
+ efi_memory_desc_t *md;
+
+ if (!(__supported_pte_mask & _PAGE_NX))
+ return;
+
+ /* Make EFI service code area executable */
+ for_each_efi_memory_desc(md) {
+ if (md->type == EFI_RUNTIME_SERVICES_CODE ||
+ md->type == EFI_BOOT_SERVICES_CODE)
+ efi_set_executable(md, executable);
+ }
+}
+
+pgd_t * __init efi_call_phys_prolog(void)
+{
+ unsigned long vaddr, addr_pgd, addr_p4d, addr_pud;
+ pgd_t *save_pgd, *pgd_k, *pgd_efi;
+ p4d_t *p4d, *p4d_k, *p4d_efi;
+ pud_t *pud;
+
+ int pgd;
+ int n_pgds, i, j;
+
+ if (!efi_enabled(EFI_OLD_MEMMAP)) {
+ efi_switch_mm(&efi_mm);
+ return NULL;
+ }
+
+ early_code_mapping_set_exec(1);
+
+ n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT), PGDIR_SIZE);
+ save_pgd = kmalloc_array(n_pgds, sizeof(*save_pgd), GFP_KERNEL);
+
+ /*
+ * Build 1:1 identity mapping for efi=old_map usage. Note that
+ * PAGE_OFFSET is PGDIR_SIZE aligned when KASLR is disabled, while
+ * it is PUD_SIZE ALIGNED with KASLR enabled. So for a given physical
+ * address X, the pud_index(X) != pud_index(__va(X)), we can only copy
+ * PUD entry of __va(X) to fill in pud entry of X to build 1:1 mapping.
+ * This means here we can only reuse the PMD tables of the direct mapping.
+ */
+ for (pgd = 0; pgd < n_pgds; pgd++) {
+ addr_pgd = (unsigned long)(pgd * PGDIR_SIZE);
+ vaddr = (unsigned long)__va(pgd * PGDIR_SIZE);
+ pgd_efi = pgd_offset_k(addr_pgd);
+ save_pgd[pgd] = *pgd_efi;
+
+ p4d = p4d_alloc(&init_mm, pgd_efi, addr_pgd);
+ if (!p4d) {
+ pr_err("Failed to allocate p4d table!\n");
+ goto out;
+ }
+
+ for (i = 0; i < PTRS_PER_P4D; i++) {
+ addr_p4d = addr_pgd + i * P4D_SIZE;
+ p4d_efi = p4d + p4d_index(addr_p4d);
+
+ pud = pud_alloc(&init_mm, p4d_efi, addr_p4d);
+ if (!pud) {
+ pr_err("Failed to allocate pud table!\n");
+ goto out;
+ }
+
+ for (j = 0; j < PTRS_PER_PUD; j++) {
+ addr_pud = addr_p4d + j * PUD_SIZE;
+
+ if (addr_pud > (max_pfn << PAGE_SHIFT))
+ break;
+
+ vaddr = (unsigned long)__va(addr_pud);
+
+ pgd_k = pgd_offset_k(vaddr);
+ p4d_k = p4d_offset(pgd_k, vaddr);
+ pud[j] = *pud_offset(p4d_k, vaddr);
+ }
+ }
+ pgd_offset_k(pgd * PGDIR_SIZE)->pgd &= ~_PAGE_NX;
+ }
+
+out:
+ __flush_tlb_all();
+
+ return save_pgd;
+}
+
+void __init efi_call_phys_epilog(pgd_t *save_pgd)
+{
+ /*
+ * After the lock is released, the original page table is restored.
+ */
+ int pgd_idx, i;
+ int nr_pgds;
+ pgd_t *pgd;
+ p4d_t *p4d;
+ pud_t *pud;
+
+ if (!efi_enabled(EFI_OLD_MEMMAP)) {
+ efi_switch_mm(efi_scratch.prev_mm);
+ return;
+ }
+
+ nr_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE);
+
+ for (pgd_idx = 0; pgd_idx < nr_pgds; pgd_idx++) {
+ pgd = pgd_offset_k(pgd_idx * PGDIR_SIZE);
+ set_pgd(pgd_offset_k(pgd_idx * PGDIR_SIZE), save_pgd[pgd_idx]);
+
+ if (!pgd_present(*pgd))
+ continue;
+
+ for (i = 0; i < PTRS_PER_P4D; i++) {
+ p4d = p4d_offset(pgd,
+ pgd_idx * PGDIR_SIZE + i * P4D_SIZE);
+
+ if (!p4d_present(*p4d))
+ continue;
+
+ pud = (pud_t *)p4d_page_vaddr(*p4d);
+ pud_free(&init_mm, pud);
+ }
+
+ p4d = (p4d_t *)pgd_page_vaddr(*pgd);
+ p4d_free(&init_mm, p4d);
+ }
+
+ kfree(save_pgd);
+
+ __flush_tlb_all();
+ early_code_mapping_set_exec(0);
+}
+
+EXPORT_SYMBOL_GPL(efi_mm);
+
+/*
+ * We need our own copy of the higher levels of the page tables
+ * because we want to avoid inserting EFI region mappings (EFI_VA_END
+ * to EFI_VA_START) into the standard kernel page tables. Everything
+ * else can be shared, see efi_sync_low_kernel_mappings().
+ *
+ * We don't want the pgd on the pgd_list and cannot use pgd_alloc() for the
+ * allocation.
+ */
+int __init efi_alloc_page_tables(void)
+{
+ pgd_t *pgd, *efi_pgd;
+ p4d_t *p4d;
+ pud_t *pud;
+ gfp_t gfp_mask;
+
+ if (efi_enabled(EFI_OLD_MEMMAP))
+ return 0;
+
+ gfp_mask = GFP_KERNEL | __GFP_ZERO;
+ efi_pgd = (pgd_t *)__get_free_pages(gfp_mask, PGD_ALLOCATION_ORDER);
+ if (!efi_pgd)
+ goto fail;
+
+ pgd = efi_pgd + pgd_index(EFI_VA_END);
+ p4d = p4d_alloc(&init_mm, pgd, EFI_VA_END);
+ if (!p4d)
+ goto free_pgd;
+
+ pud = pud_alloc(&init_mm, p4d, EFI_VA_END);
+ if (!pud)
+ goto free_p4d;
+
+ efi_mm.pgd = efi_pgd;
+ mm_init_cpumask(&efi_mm);
+ init_new_context(NULL, &efi_mm);
+
+ return 0;
+
+free_p4d:
+ if (pgtable_l5_enabled())
+ free_page((unsigned long)pgd_page_vaddr(*pgd));
+free_pgd:
+ free_pages((unsigned long)efi_pgd, PGD_ALLOCATION_ORDER);
+fail:
+ return -ENOMEM;
+}
+
+/*
+ * Add low kernel mappings for passing arguments to EFI functions.
+ */
+void efi_sync_low_kernel_mappings(void)
+{
+ unsigned num_entries;
+ pgd_t *pgd_k, *pgd_efi;
+ p4d_t *p4d_k, *p4d_efi;
+ pud_t *pud_k, *pud_efi;
+ pgd_t *efi_pgd = efi_mm.pgd;
+
+ if (efi_enabled(EFI_OLD_MEMMAP))
+ return;
+
+ /*
+ * We can share all PGD entries apart from the one entry that
+ * covers the EFI runtime mapping space.
+ *
+ * Make sure the EFI runtime region mappings are guaranteed to
+ * only span a single PGD entry and that the entry also maps
+ * other important kernel regions.
+ */
+ MAYBE_BUILD_BUG_ON(pgd_index(EFI_VA_END) != pgd_index(MODULES_END));
+ MAYBE_BUILD_BUG_ON((EFI_VA_START & PGDIR_MASK) !=
+ (EFI_VA_END & PGDIR_MASK));
+
+ pgd_efi = efi_pgd + pgd_index(PAGE_OFFSET);
+ pgd_k = pgd_offset_k(PAGE_OFFSET);
+
+ num_entries = pgd_index(EFI_VA_END) - pgd_index(PAGE_OFFSET);
+ memcpy(pgd_efi, pgd_k, sizeof(pgd_t) * num_entries);
+
+ /*
+ * As with PGDs, we share all P4D entries apart from the one entry
+ * that covers the EFI runtime mapping space.
+ */
+ BUILD_BUG_ON(p4d_index(EFI_VA_END) != p4d_index(MODULES_END));
+ BUILD_BUG_ON((EFI_VA_START & P4D_MASK) != (EFI_VA_END & P4D_MASK));
+
+ pgd_efi = efi_pgd + pgd_index(EFI_VA_END);
+ pgd_k = pgd_offset_k(EFI_VA_END);
+ p4d_efi = p4d_offset(pgd_efi, 0);
+ p4d_k = p4d_offset(pgd_k, 0);
+
+ num_entries = p4d_index(EFI_VA_END);
+ memcpy(p4d_efi, p4d_k, sizeof(p4d_t) * num_entries);
+
+ /*
+ * We share all the PUD entries apart from those that map the
+ * EFI regions. Copy around them.
+ */
+ BUILD_BUG_ON((EFI_VA_START & ~PUD_MASK) != 0);
+ BUILD_BUG_ON((EFI_VA_END & ~PUD_MASK) != 0);
+
+ p4d_efi = p4d_offset(pgd_efi, EFI_VA_END);
+ p4d_k = p4d_offset(pgd_k, EFI_VA_END);
+ pud_efi = pud_offset(p4d_efi, 0);
+ pud_k = pud_offset(p4d_k, 0);
+
+ num_entries = pud_index(EFI_VA_END);
+ memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
+
+ pud_efi = pud_offset(p4d_efi, EFI_VA_START);
+ pud_k = pud_offset(p4d_k, EFI_VA_START);
+
+ num_entries = PTRS_PER_PUD - pud_index(EFI_VA_START);
+ memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
+}
+
+/*
+ * Wrapper for slow_virt_to_phys() that handles NULL addresses.
+ */
+static inline phys_addr_t
+virt_to_phys_or_null_size(void *va, unsigned long size)
+{
+ phys_addr_t pa;
+
+ if (!va)
+ return 0;
+
+ if (virt_addr_valid(va))
+ return virt_to_phys(va);
+
+ pa = slow_virt_to_phys(va);
+
+ /* check if the object crosses a page boundary */
+ if (WARN_ON((pa ^ (pa + size - 1)) & PAGE_MASK))
+ return 0;
+
+ return pa;
+}
+
+#define virt_to_phys_or_null(addr) \
+ virt_to_phys_or_null_size((addr), sizeof(*(addr)))
+
+int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
+{
+ unsigned long pfn, text, pf;
+ struct page *page;
+ unsigned npages;
+ pgd_t *pgd = efi_mm.pgd;
+
+ if (efi_enabled(EFI_OLD_MEMMAP))
+ return 0;
+
+ /*
+ * It can happen that the physical address of new_memmap lands in memory
+ * which is not mapped in the EFI page table. Therefore we need to go
+ * and ident-map those pages containing the map before calling
+ * phys_efi_set_virtual_address_map().
+ */
+ pfn = pa_memmap >> PAGE_SHIFT;
+ pf = _PAGE_NX | _PAGE_RW | _PAGE_ENC;
+ if (kernel_map_pages_in_pgd(pgd, pfn, pa_memmap, num_pages, pf)) {
+ pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap);
+ return 1;
+ }
+
+ /*
+ * Certain firmware versions are way too sentimential and still believe
+ * they are exclusive and unquestionable owners of the first physical page,
+ * even though they explicitly mark it as EFI_CONVENTIONAL_MEMORY
+ * (but then write-access it later during SetVirtualAddressMap()).
+ *
+ * Create a 1:1 mapping for this page, to avoid triple faults during early
+ * boot with such firmware. We are free to hand this page to the BIOS,
+ * as trim_bios_range() will reserve the first page and isolate it away
+ * from memory allocators anyway.
+ */
+ pf = _PAGE_RW;
+ if (sev_active())
+ pf |= _PAGE_ENC;
+
+ if (kernel_map_pages_in_pgd(pgd, 0x0, 0x0, 1, pf)) {
+ pr_err("Failed to create 1:1 mapping for the first page!\n");
+ return 1;
+ }
+
+ /*
+ * When making calls to the firmware everything needs to be 1:1
+ * mapped and addressable with 32-bit pointers. Map the kernel
+ * text and allocate a new stack because we can't rely on the
+ * stack pointer being < 4GB.
+ */
+ if (!IS_ENABLED(CONFIG_EFI_MIXED) || efi_is_native())
+ return 0;
+
+ page = alloc_page(GFP_KERNEL|__GFP_DMA32);
+ if (!page) {
+ pr_err("Unable to allocate EFI runtime stack < 4GB\n");
+ return 1;
+ }
+
+ efi_scratch.phys_stack = page_to_phys(page + 1); /* stack grows down */
+
+ npages = (_etext - _text) >> PAGE_SHIFT;
+ text = __pa(_text);
+ pfn = text >> PAGE_SHIFT;
+
+ pf = _PAGE_RW | _PAGE_ENC;
+ if (kernel_map_pages_in_pgd(pgd, pfn, text, npages, pf)) {
+ pr_err("Failed to map kernel text 1:1\n");
+ return 1;
+ }
+
+ return 0;
+}
+
+static void __init __map_region(efi_memory_desc_t *md, u64 va)
+{
+ unsigned long flags = _PAGE_RW;
+ unsigned long pfn;
+ pgd_t *pgd = efi_mm.pgd;
+
+ if (!(md->attribute & EFI_MEMORY_WB))
+ flags |= _PAGE_PCD;
+
+ if (sev_active() && md->type != EFI_MEMORY_MAPPED_IO)
+ flags |= _PAGE_ENC;
+
+ pfn = md->phys_addr >> PAGE_SHIFT;
+ if (kernel_map_pages_in_pgd(pgd, pfn, va, md->num_pages, flags))
+ pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
+ md->phys_addr, va);
+}
+
+void __init efi_map_region(efi_memory_desc_t *md)
+{
+ unsigned long size = md->num_pages << PAGE_SHIFT;
+ u64 pa = md->phys_addr;
+
+ if (efi_enabled(EFI_OLD_MEMMAP))
+ return old_map_region(md);
+
+ /*
+ * Make sure the 1:1 mappings are present as a catch-all for b0rked
+ * firmware which doesn't update all internal pointers after switching
+ * to virtual mode and would otherwise crap on us.
+ */
+ __map_region(md, md->phys_addr);
+
+ /*
+ * Enforce the 1:1 mapping as the default virtual address when
+ * booting in EFI mixed mode, because even though we may be
+ * running a 64-bit kernel, the firmware may only be 32-bit.
+ */
+ if (!efi_is_native () && IS_ENABLED(CONFIG_EFI_MIXED)) {
+ md->virt_addr = md->phys_addr;
+ return;
+ }
+
+ efi_va -= size;
+
+ /* Is PA 2M-aligned? */
+ if (!(pa & (PMD_SIZE - 1))) {
+ efi_va &= PMD_MASK;
+ } else {
+ u64 pa_offset = pa & (PMD_SIZE - 1);
+ u64 prev_va = efi_va;
+
+ /* get us the same offset within this 2M page */
+ efi_va = (efi_va & PMD_MASK) + pa_offset;
+
+ if (efi_va > prev_va)
+ efi_va -= PMD_SIZE;
+ }
+
+ if (efi_va < EFI_VA_END) {
+ pr_warn(FW_WARN "VA address range overflow!\n");
+ return;
+ }
+
+ /* Do the VA map */
+ __map_region(md, efi_va);
+ md->virt_addr = efi_va;
+}
+
+/*
+ * kexec kernel will use efi_map_region_fixed to map efi runtime memory ranges.
+ * md->virt_addr is the original virtual address which had been mapped in kexec
+ * 1st kernel.
+ */
+void __init efi_map_region_fixed(efi_memory_desc_t *md)
+{
+ __map_region(md, md->phys_addr);
+ __map_region(md, md->virt_addr);
+}
+
+void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size,
+ u32 type, u64 attribute)
+{
+ unsigned long last_map_pfn;
+
+ if (type == EFI_MEMORY_MAPPED_IO)
+ return ioremap(phys_addr, size);
+
+ last_map_pfn = init_memory_mapping(phys_addr, phys_addr + size);
+ if ((last_map_pfn << PAGE_SHIFT) < phys_addr + size) {
+ unsigned long top = last_map_pfn << PAGE_SHIFT;
+ efi_ioremap(top, size - (top - phys_addr), type, attribute);
+ }
+
+ if (!(attribute & EFI_MEMORY_WB))
+ efi_memory_uc((u64)(unsigned long)__va(phys_addr), size);
+
+ return (void __iomem *)__va(phys_addr);
+}
+
+void __init parse_efi_setup(u64 phys_addr, u32 data_len)
+{
+ efi_setup = phys_addr + sizeof(struct setup_data);
+}
+
+static int __init efi_update_mappings(efi_memory_desc_t *md, unsigned long pf)
+{
+ unsigned long pfn;
+ pgd_t *pgd = efi_mm.pgd;
+ int err1, err2;
+
+ /* Update the 1:1 mapping */
+ pfn = md->phys_addr >> PAGE_SHIFT;
+ err1 = kernel_map_pages_in_pgd(pgd, pfn, md->phys_addr, md->num_pages, pf);
+ if (err1) {
+ pr_err("Error while updating 1:1 mapping PA 0x%llx -> VA 0x%llx!\n",
+ md->phys_addr, md->virt_addr);
+ }
+
+ err2 = kernel_map_pages_in_pgd(pgd, pfn, md->virt_addr, md->num_pages, pf);
+ if (err2) {
+ pr_err("Error while updating VA mapping PA 0x%llx -> VA 0x%llx!\n",
+ md->phys_addr, md->virt_addr);
+ }
+
+ return err1 || err2;
+}
+
+static int __init efi_update_mem_attr(struct mm_struct *mm, efi_memory_desc_t *md)
+{
+ unsigned long pf = 0;
+
+ if (md->attribute & EFI_MEMORY_XP)
+ pf |= _PAGE_NX;
+
+ if (!(md->attribute & EFI_MEMORY_RO))
+ pf |= _PAGE_RW;
+
+ if (sev_active())
+ pf |= _PAGE_ENC;
+
+ return efi_update_mappings(md, pf);
+}
+
+void __init efi_runtime_update_mappings(void)
+{
+ efi_memory_desc_t *md;
+
+ if (efi_enabled(EFI_OLD_MEMMAP)) {
+ if (__supported_pte_mask & _PAGE_NX)
+ runtime_code_page_mkexec();
+ return;
+ }
+
+ /*
+ * Use the EFI Memory Attribute Table for mapping permissions if it
+ * exists, since it is intended to supersede EFI_PROPERTIES_TABLE.
+ */
+ if (efi_enabled(EFI_MEM_ATTR)) {
+ efi_memattr_apply_permissions(NULL, efi_update_mem_attr);
+ return;
+ }
+
+ /*
+ * EFI_MEMORY_ATTRIBUTES_TABLE is intended to replace
+ * EFI_PROPERTIES_TABLE. So, use EFI_PROPERTIES_TABLE to update
+ * permissions only if EFI_MEMORY_ATTRIBUTES_TABLE is not
+ * published by the firmware. Even if we find a buggy implementation of
+ * EFI_MEMORY_ATTRIBUTES_TABLE, don't fall back to
+ * EFI_PROPERTIES_TABLE, because of the same reason.
+ */
+
+ if (!efi_enabled(EFI_NX_PE_DATA))
+ return;
+
+ for_each_efi_memory_desc(md) {
+ unsigned long pf = 0;
+
+ if (!(md->attribute & EFI_MEMORY_RUNTIME))
+ continue;
+
+ if (!(md->attribute & EFI_MEMORY_WB))
+ pf |= _PAGE_PCD;
+
+ if ((md->attribute & EFI_MEMORY_XP) ||
+ (md->type == EFI_RUNTIME_SERVICES_DATA))
+ pf |= _PAGE_NX;
+
+ if (!(md->attribute & EFI_MEMORY_RO) &&
+ (md->type != EFI_RUNTIME_SERVICES_CODE))
+ pf |= _PAGE_RW;
+
+ if (sev_active())
+ pf |= _PAGE_ENC;
+
+ efi_update_mappings(md, pf);
+ }
+}
+
+void __init efi_dump_pagetable(void)
+{
+#ifdef CONFIG_EFI_PGT_DUMP
+ if (efi_enabled(EFI_OLD_MEMMAP))
+ ptdump_walk_pgd_level(NULL, swapper_pg_dir);
+ else
+ ptdump_walk_pgd_level(NULL, efi_mm.pgd);
+#endif
+}
+
+/*
+ * Makes the calling thread switch to/from efi_mm context. Can be used
+ * for SetVirtualAddressMap() i.e. current->active_mm == init_mm as well
+ * as during efi runtime calls i.e current->active_mm == current_mm.
+ * We are not mm_dropping()/mm_grabbing() any mm, because we are not
+ * losing/creating any references.
+ */
+void efi_switch_mm(struct mm_struct *mm)
+{
+ task_lock(current);
+ efi_scratch.prev_mm = current->active_mm;
+ current->active_mm = mm;
+ switch_mm(efi_scratch.prev_mm, mm, NULL);
+ task_unlock(current);
+}
+
+#ifdef CONFIG_EFI_MIXED
+extern efi_status_t efi64_thunk(u32, ...);
+
+static DEFINE_SPINLOCK(efi_runtime_lock);
+
+#define runtime_service32(func) \
+({ \
+ u32 table = (u32)(unsigned long)efi.systab; \
+ u32 *rt, *___f; \
+ \
+ rt = (u32 *)(table + offsetof(efi_system_table_32_t, runtime)); \
+ ___f = (u32 *)(*rt + offsetof(efi_runtime_services_32_t, func)); \
+ *___f; \
+})
+
+/*
+ * Switch to the EFI page tables early so that we can access the 1:1
+ * runtime services mappings which are not mapped in any other page
+ * tables. This function must be called before runtime_service32().
+ *
+ * Also, disable interrupts because the IDT points to 64-bit handlers,
+ * which aren't going to function correctly when we switch to 32-bit.
+ */
+#define efi_thunk(f, ...) \
+({ \
+ efi_status_t __s; \
+ u32 __func; \
+ \
+ arch_efi_call_virt_setup(); \
+ \
+ __func = runtime_service32(f); \
+ __s = efi64_thunk(__func, __VA_ARGS__); \
+ \
+ arch_efi_call_virt_teardown(); \
+ \
+ __s; \
+})
+
+efi_status_t efi_thunk_set_virtual_address_map(
+ void *phys_set_virtual_address_map,
+ unsigned long memory_map_size,
+ unsigned long descriptor_size,
+ u32 descriptor_version,
+ efi_memory_desc_t *virtual_map)
+{
+ efi_status_t status;
+ unsigned long flags;
+ u32 func;
+
+ efi_sync_low_kernel_mappings();
+ local_irq_save(flags);
+
+ efi_switch_mm(&efi_mm);
+
+ func = (u32)(unsigned long)phys_set_virtual_address_map;
+ status = efi64_thunk(func, memory_map_size, descriptor_size,
+ descriptor_version, virtual_map);
+
+ efi_switch_mm(efi_scratch.prev_mm);
+ local_irq_restore(flags);
+
+ return status;
+}
+
+static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc)
+{
+ efi_status_t status;
+ u32 phys_tm, phys_tc;
+ unsigned long flags;
+
+ spin_lock(&rtc_lock);
+ spin_lock_irqsave(&efi_runtime_lock, flags);
+
+ phys_tm = virt_to_phys_or_null(tm);
+ phys_tc = virt_to_phys_or_null(tc);
+
+ status = efi_thunk(get_time, phys_tm, phys_tc);
+
+ spin_unlock_irqrestore(&efi_runtime_lock, flags);
+ spin_unlock(&rtc_lock);
+
+ return status;
+}
+
+static efi_status_t efi_thunk_set_time(efi_time_t *tm)
+{
+ efi_status_t status;
+ u32 phys_tm;
+ unsigned long flags;
+
+ spin_lock(&rtc_lock);
+ spin_lock_irqsave(&efi_runtime_lock, flags);
+
+ phys_tm = virt_to_phys_or_null(tm);
+
+ status = efi_thunk(set_time, phys_tm);
+
+ spin_unlock_irqrestore(&efi_runtime_lock, flags);
+ spin_unlock(&rtc_lock);
+
+ return status;
+}
+
+static efi_status_t
+efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending,
+ efi_time_t *tm)
+{
+ efi_status_t status;
+ u32 phys_enabled, phys_pending, phys_tm;
+ unsigned long flags;
+
+ spin_lock(&rtc_lock);
+ spin_lock_irqsave(&efi_runtime_lock, flags);
+
+ phys_enabled = virt_to_phys_or_null(enabled);
+ phys_pending = virt_to_phys_or_null(pending);
+ phys_tm = virt_to_phys_or_null(tm);
+
+ status = efi_thunk(get_wakeup_time, phys_enabled,
+ phys_pending, phys_tm);
+
+ spin_unlock_irqrestore(&efi_runtime_lock, flags);
+ spin_unlock(&rtc_lock);
+
+ return status;
+}
+
+static efi_status_t
+efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
+{
+ efi_status_t status;
+ u32 phys_tm;
+ unsigned long flags;
+
+ spin_lock(&rtc_lock);
+ spin_lock_irqsave(&efi_runtime_lock, flags);
+
+ phys_tm = virt_to_phys_or_null(tm);
+
+ status = efi_thunk(set_wakeup_time, enabled, phys_tm);
+
+ spin_unlock_irqrestore(&efi_runtime_lock, flags);
+ spin_unlock(&rtc_lock);
+
+ return status;
+}
+
+static unsigned long efi_name_size(efi_char16_t *name)
+{
+ return ucs2_strsize(name, EFI_VAR_NAME_LEN) + 1;
+}
+
+static efi_status_t
+efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor,
+ u32 *attr, unsigned long *data_size, void *data)
+{
+ u8 buf[24] __aligned(8);
+ efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
+ efi_status_t status;
+ u32 phys_name, phys_vendor, phys_attr;
+ u32 phys_data_size, phys_data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&efi_runtime_lock, flags);
+
+ *vnd = *vendor;
+
+ phys_data_size = virt_to_phys_or_null(data_size);
+ phys_vendor = virt_to_phys_or_null(vnd);
+ phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
+ phys_attr = virt_to_phys_or_null(attr);
+ phys_data = virt_to_phys_or_null_size(data, *data_size);
+
+ if (!phys_name || (data && !phys_data))
+ status = EFI_INVALID_PARAMETER;
+ else
+ status = efi_thunk(get_variable, phys_name, phys_vendor,
+ phys_attr, phys_data_size, phys_data);
+
+ spin_unlock_irqrestore(&efi_runtime_lock, flags);
+
+ return status;
+}
+
+static efi_status_t
+efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor,
+ u32 attr, unsigned long data_size, void *data)
+{
+ u8 buf[24] __aligned(8);
+ efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
+ u32 phys_name, phys_vendor, phys_data;
+ efi_status_t status;
+ unsigned long flags;
+
+ spin_lock_irqsave(&efi_runtime_lock, flags);
+
+ *vnd = *vendor;
+
+ phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
+ phys_vendor = virt_to_phys_or_null(vnd);
+ phys_data = virt_to_phys_or_null_size(data, data_size);
+
+ if (!phys_name || (data && !phys_data))
+ status = EFI_INVALID_PARAMETER;
+ else
+ status = efi_thunk(set_variable, phys_name, phys_vendor,
+ attr, data_size, phys_data);
+
+ spin_unlock_irqrestore(&efi_runtime_lock, flags);
+
+ return status;
+}
+
+static efi_status_t
+efi_thunk_set_variable_nonblocking(efi_char16_t *name, efi_guid_t *vendor,
+ u32 attr, unsigned long data_size,
+ void *data)
+{
+ u8 buf[24] __aligned(8);
+ efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
+ u32 phys_name, phys_vendor, phys_data;
+ efi_status_t status;
+ unsigned long flags;
+
+ if (!spin_trylock_irqsave(&efi_runtime_lock, flags))
+ return EFI_NOT_READY;
+
+ *vnd = *vendor;
+
+ phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
+ phys_vendor = virt_to_phys_or_null(vnd);
+ phys_data = virt_to_phys_or_null_size(data, data_size);
+
+ if (!phys_name || (data && !phys_data))
+ status = EFI_INVALID_PARAMETER;
+ else
+ status = efi_thunk(set_variable, phys_name, phys_vendor,
+ attr, data_size, phys_data);
+
+ spin_unlock_irqrestore(&efi_runtime_lock, flags);
+
+ return status;
+}
+
+static efi_status_t
+efi_thunk_get_next_variable(unsigned long *name_size,
+ efi_char16_t *name,
+ efi_guid_t *vendor)
+{
+ u8 buf[24] __aligned(8);
+ efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
+ efi_status_t status;
+ u32 phys_name_size, phys_name, phys_vendor;
+ unsigned long flags;
+
+ spin_lock_irqsave(&efi_runtime_lock, flags);
+
+ *vnd = *vendor;
+
+ phys_name_size = virt_to_phys_or_null(name_size);
+ phys_vendor = virt_to_phys_or_null(vnd);
+ phys_name = virt_to_phys_or_null_size(name, *name_size);
+
+ if (!phys_name)
+ status = EFI_INVALID_PARAMETER;
+ else
+ status = efi_thunk(get_next_variable, phys_name_size,
+ phys_name, phys_vendor);
+
+ spin_unlock_irqrestore(&efi_runtime_lock, flags);
+
+ *vendor = *vnd;
+ return status;
+}
+
+static efi_status_t
+efi_thunk_get_next_high_mono_count(u32 *count)
+{
+ efi_status_t status;
+ u32 phys_count;
+ unsigned long flags;
+
+ spin_lock_irqsave(&efi_runtime_lock, flags);
+
+ phys_count = virt_to_phys_or_null(count);
+ status = efi_thunk(get_next_high_mono_count, phys_count);
+
+ spin_unlock_irqrestore(&efi_runtime_lock, flags);
+
+ return status;
+}
+
+static void
+efi_thunk_reset_system(int reset_type, efi_status_t status,
+ unsigned long data_size, efi_char16_t *data)
+{
+ u32 phys_data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&efi_runtime_lock, flags);
+
+ phys_data = virt_to_phys_or_null_size(data, data_size);
+
+ efi_thunk(reset_system, reset_type, status, data_size, phys_data);
+
+ spin_unlock_irqrestore(&efi_runtime_lock, flags);
+}
+
+static efi_status_t
+efi_thunk_update_capsule(efi_capsule_header_t **capsules,
+ unsigned long count, unsigned long sg_list)
+{
+ /*
+ * To properly support this function we would need to repackage
+ * 'capsules' because the firmware doesn't understand 64-bit
+ * pointers.
+ */
+ return EFI_UNSUPPORTED;
+}
+
+static efi_status_t
+efi_thunk_query_variable_info(u32 attr, u64 *storage_space,
+ u64 *remaining_space,
+ u64 *max_variable_size)
+{
+ efi_status_t status;
+ u32 phys_storage, phys_remaining, phys_max;
+ unsigned long flags;
+
+ if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
+ return EFI_UNSUPPORTED;
+
+ spin_lock_irqsave(&efi_runtime_lock, flags);
+
+ phys_storage = virt_to_phys_or_null(storage_space);
+ phys_remaining = virt_to_phys_or_null(remaining_space);
+ phys_max = virt_to_phys_or_null(max_variable_size);
+
+ status = efi_thunk(query_variable_info, attr, phys_storage,
+ phys_remaining, phys_max);
+
+ spin_unlock_irqrestore(&efi_runtime_lock, flags);
+
+ return status;
+}
+
+static efi_status_t
+efi_thunk_query_variable_info_nonblocking(u32 attr, u64 *storage_space,
+ u64 *remaining_space,
+ u64 *max_variable_size)
+{
+ efi_status_t status;
+ u32 phys_storage, phys_remaining, phys_max;
+ unsigned long flags;
+
+ if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
+ return EFI_UNSUPPORTED;
+
+ if (!spin_trylock_irqsave(&efi_runtime_lock, flags))
+ return EFI_NOT_READY;
+
+ phys_storage = virt_to_phys_or_null(storage_space);
+ phys_remaining = virt_to_phys_or_null(remaining_space);
+ phys_max = virt_to_phys_or_null(max_variable_size);
+
+ status = efi_thunk(query_variable_info, attr, phys_storage,
+ phys_remaining, phys_max);
+
+ spin_unlock_irqrestore(&efi_runtime_lock, flags);
+
+ return status;
+}
+
+static efi_status_t
+efi_thunk_query_capsule_caps(efi_capsule_header_t **capsules,
+ unsigned long count, u64 *max_size,
+ int *reset_type)
+{
+ /*
+ * To properly support this function we would need to repackage
+ * 'capsules' because the firmware doesn't understand 64-bit
+ * pointers.
+ */
+ return EFI_UNSUPPORTED;
+}
+
+void efi_thunk_runtime_setup(void)
+{
+ efi.get_time = efi_thunk_get_time;
+ efi.set_time = efi_thunk_set_time;
+ efi.get_wakeup_time = efi_thunk_get_wakeup_time;
+ efi.set_wakeup_time = efi_thunk_set_wakeup_time;
+ efi.get_variable = efi_thunk_get_variable;
+ efi.get_next_variable = efi_thunk_get_next_variable;
+ efi.set_variable = efi_thunk_set_variable;
+ efi.set_variable_nonblocking = efi_thunk_set_variable_nonblocking;
+ efi.get_next_high_mono_count = efi_thunk_get_next_high_mono_count;
+ efi.reset_system = efi_thunk_reset_system;
+ efi.query_variable_info = efi_thunk_query_variable_info;
+ efi.query_variable_info_nonblocking = efi_thunk_query_variable_info_nonblocking;
+ efi.update_capsule = efi_thunk_update_capsule;
+ efi.query_capsule_caps = efi_thunk_query_capsule_caps;
+}
+#endif /* CONFIG_EFI_MIXED */