diff options
Diffstat (limited to 'kernel/arch/x86/platform/efi/efi.c')
| -rw-r--r-- | kernel/arch/x86/platform/efi/efi.c | 956 |
1 files changed, 956 insertions, 0 deletions
diff --git a/kernel/arch/x86/platform/efi/efi.c b/kernel/arch/x86/platform/efi/efi.c new file mode 100644 index 000000000..02744df57 --- /dev/null +++ b/kernel/arch/x86/platform/efi/efi.c @@ -0,0 +1,956 @@ +/* + * Common EFI (Extensible Firmware Interface) support functions + * Based on Extensible Firmware Interface Specification version 1.0 + * + * Copyright (C) 1999 VA Linux Systems + * Copyright (C) 1999 Walt Drummond <drummond@valinux.com> + * Copyright (C) 1999-2002 Hewlett-Packard Co. + * David Mosberger-Tang <davidm@hpl.hp.com> + * Stephane Eranian <eranian@hpl.hp.com> + * 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> + * Copyright (C) 2013 SuSE Labs + * Borislav Petkov <bp@suse.de> - runtime services VA mapping + * + * Copied from efi_32.c to eliminate the duplicated code between EFI + * 32/64 support code. --ying 2007-10-26 + * + * All EFI Runtime Services are not implemented yet as EFI only + * supports physical mode addressing on SoftSDV. This is to be fixed + * in a future version. --drummond 1999-07-20 + * + * Implemented EFI runtime services and virtual mode calls. --davidm + * + * Goutham Rao: <goutham.rao@intel.com> + * Skip non-WB memory and ignore empty memory ranges. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/efi.h> +#include <linux/efi-bgrt.h> +#include <linux/export.h> +#include <linux/bootmem.h> +#include <linux/slab.h> +#include <linux/memblock.h> +#include <linux/spinlock.h> +#include <linux/uaccess.h> +#include <linux/time.h> +#include <linux/io.h> +#include <linux/reboot.h> +#include <linux/bcd.h> + +#include <asm/setup.h> +#include <asm/efi.h> +#include <asm/time.h> +#include <asm/cacheflush.h> +#include <asm/tlbflush.h> +#include <asm/x86_init.h> +#include <asm/rtc.h> +#include <asm/uv/uv.h> + +#define EFI_DEBUG + +struct efi_memory_map memmap; + +static struct efi efi_phys __initdata; +static efi_system_table_t efi_systab __initdata; + +static efi_config_table_type_t arch_tables[] __initdata = { +#ifdef CONFIG_X86_UV + {UV_SYSTEM_TABLE_GUID, "UVsystab", &efi.uv_systab}, +#endif + {NULL_GUID, NULL, NULL}, +}; + +u64 efi_setup; /* efi setup_data physical address */ + +static int add_efi_memmap __initdata; +static int __init setup_add_efi_memmap(char *arg) +{ + add_efi_memmap = 1; + return 0; +} +early_param("add_efi_memmap", setup_add_efi_memmap); + +static efi_status_t __init phys_efi_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; + pgd_t *save_pgd; + + save_pgd = efi_call_phys_prolog(); + + /* Disable interrupts around EFI calls: */ + local_irq_save(flags); + status = efi_call_phys(efi_phys.set_virtual_address_map, + memory_map_size, descriptor_size, + descriptor_version, virtual_map); + local_irq_restore(flags); + + efi_call_phys_epilog(save_pgd); + + return status; +} + +void efi_get_time(struct timespec *now) +{ + efi_status_t status; + efi_time_t eft; + efi_time_cap_t cap; + + status = efi.get_time(&eft, &cap); + if (status != EFI_SUCCESS) + pr_err("Oops: efitime: can't read time!\n"); + + now->tv_sec = mktime(eft.year, eft.month, eft.day, eft.hour, + eft.minute, eft.second); + now->tv_nsec = 0; +} + +/* + * Tell the kernel about the EFI memory map. This might include + * more than the max 128 entries that can fit in the e820 legacy + * (zeropage) memory map. + */ + +static void __init do_add_efi_memmap(void) +{ + void *p; + + for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { + efi_memory_desc_t *md = p; + unsigned long long start = md->phys_addr; + unsigned long long size = md->num_pages << EFI_PAGE_SHIFT; + int e820_type; + + switch (md->type) { + case EFI_LOADER_CODE: + case EFI_LOADER_DATA: + case EFI_BOOT_SERVICES_CODE: + case EFI_BOOT_SERVICES_DATA: + case EFI_CONVENTIONAL_MEMORY: + if (md->attribute & EFI_MEMORY_WB) + e820_type = E820_RAM; + else + e820_type = E820_RESERVED; + break; + case EFI_ACPI_RECLAIM_MEMORY: + e820_type = E820_ACPI; + break; + case EFI_ACPI_MEMORY_NVS: + e820_type = E820_NVS; + break; + case EFI_UNUSABLE_MEMORY: + e820_type = E820_UNUSABLE; + break; + default: + /* + * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE + * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO + * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE + */ + e820_type = E820_RESERVED; + break; + } + e820_add_region(start, size, e820_type); + } + sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map); +} + +int __init efi_memblock_x86_reserve_range(void) +{ + struct efi_info *e = &boot_params.efi_info; + unsigned long pmap; + + if (efi_enabled(EFI_PARAVIRT)) + return 0; + +#ifdef CONFIG_X86_32 + /* Can't handle data above 4GB at this time */ + if (e->efi_memmap_hi) { + pr_err("Memory map is above 4GB, disabling EFI.\n"); + return -EINVAL; + } + pmap = e->efi_memmap; +#else + pmap = (e->efi_memmap | ((__u64)e->efi_memmap_hi << 32)); +#endif + memmap.phys_map = (void *)pmap; + memmap.nr_map = e->efi_memmap_size / + e->efi_memdesc_size; + memmap.desc_size = e->efi_memdesc_size; + memmap.desc_version = e->efi_memdesc_version; + + memblock_reserve(pmap, memmap.nr_map * memmap.desc_size); + + efi.memmap = &memmap; + + return 0; +} + +static void __init print_efi_memmap(void) +{ +#ifdef EFI_DEBUG + efi_memory_desc_t *md; + void *p; + int i; + + for (p = memmap.map, i = 0; + p < memmap.map_end; + p += memmap.desc_size, i++) { + char buf[64]; + + md = p; + pr_info("mem%02u: %s range=[0x%016llx-0x%016llx) (%lluMB)\n", + i, efi_md_typeattr_format(buf, sizeof(buf), md), + md->phys_addr, + md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT), + (md->num_pages >> (20 - EFI_PAGE_SHIFT))); + } +#endif /* EFI_DEBUG */ +} + +void __init efi_unmap_memmap(void) +{ + clear_bit(EFI_MEMMAP, &efi.flags); + if (memmap.map) { + early_memunmap(memmap.map, memmap.nr_map * memmap.desc_size); + memmap.map = NULL; + } +} + +static int __init efi_systab_init(void *phys) +{ + if (efi_enabled(EFI_64BIT)) { + efi_system_table_64_t *systab64; + struct efi_setup_data *data = NULL; + u64 tmp = 0; + + if (efi_setup) { + data = early_memremap(efi_setup, sizeof(*data)); + if (!data) + return -ENOMEM; + } + systab64 = early_memremap((unsigned long)phys, + sizeof(*systab64)); + if (systab64 == NULL) { + pr_err("Couldn't map the system table!\n"); + if (data) + early_memunmap(data, sizeof(*data)); + return -ENOMEM; + } + + efi_systab.hdr = systab64->hdr; + efi_systab.fw_vendor = data ? (unsigned long)data->fw_vendor : + systab64->fw_vendor; + tmp |= data ? data->fw_vendor : systab64->fw_vendor; + efi_systab.fw_revision = systab64->fw_revision; + efi_systab.con_in_handle = systab64->con_in_handle; + tmp |= systab64->con_in_handle; + efi_systab.con_in = systab64->con_in; + tmp |= systab64->con_in; + efi_systab.con_out_handle = systab64->con_out_handle; + tmp |= systab64->con_out_handle; + efi_systab.con_out = systab64->con_out; + tmp |= systab64->con_out; + efi_systab.stderr_handle = systab64->stderr_handle; + tmp |= systab64->stderr_handle; + efi_systab.stderr = systab64->stderr; + tmp |= systab64->stderr; + efi_systab.runtime = data ? + (void *)(unsigned long)data->runtime : + (void *)(unsigned long)systab64->runtime; + tmp |= data ? data->runtime : systab64->runtime; + efi_systab.boottime = (void *)(unsigned long)systab64->boottime; + tmp |= systab64->boottime; + efi_systab.nr_tables = systab64->nr_tables; + efi_systab.tables = data ? (unsigned long)data->tables : + systab64->tables; + tmp |= data ? data->tables : systab64->tables; + + early_memunmap(systab64, sizeof(*systab64)); + if (data) + early_memunmap(data, sizeof(*data)); +#ifdef CONFIG_X86_32 + if (tmp >> 32) { + pr_err("EFI data located above 4GB, disabling EFI.\n"); + return -EINVAL; + } +#endif + } else { + efi_system_table_32_t *systab32; + + systab32 = early_memremap((unsigned long)phys, + sizeof(*systab32)); + if (systab32 == NULL) { + pr_err("Couldn't map the system table!\n"); + return -ENOMEM; + } + + efi_systab.hdr = systab32->hdr; + efi_systab.fw_vendor = systab32->fw_vendor; + efi_systab.fw_revision = systab32->fw_revision; + efi_systab.con_in_handle = systab32->con_in_handle; + efi_systab.con_in = systab32->con_in; + efi_systab.con_out_handle = systab32->con_out_handle; + efi_systab.con_out = systab32->con_out; + efi_systab.stderr_handle = systab32->stderr_handle; + efi_systab.stderr = systab32->stderr; + efi_systab.runtime = (void *)(unsigned long)systab32->runtime; + efi_systab.boottime = (void *)(unsigned long)systab32->boottime; + efi_systab.nr_tables = systab32->nr_tables; + efi_systab.tables = systab32->tables; + + early_memunmap(systab32, sizeof(*systab32)); + } + + efi.systab = &efi_systab; + + /* + * Verify the EFI Table + */ + if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) { + pr_err("System table signature incorrect!\n"); + return -EINVAL; + } + if ((efi.systab->hdr.revision >> 16) == 0) + pr_err("Warning: System table version %d.%02d, expected 1.00 or greater!\n", + efi.systab->hdr.revision >> 16, + efi.systab->hdr.revision & 0xffff); + + set_bit(EFI_SYSTEM_TABLES, &efi.flags); + + return 0; +} + +static int __init efi_runtime_init32(void) +{ + efi_runtime_services_32_t *runtime; + + runtime = early_memremap((unsigned long)efi.systab->runtime, + sizeof(efi_runtime_services_32_t)); + if (!runtime) { + pr_err("Could not map the runtime service table!\n"); + return -ENOMEM; + } + + /* + * We will only need *early* access to the SetVirtualAddressMap + * EFI runtime service. All other runtime services will be called + * via the virtual mapping. + */ + efi_phys.set_virtual_address_map = + (efi_set_virtual_address_map_t *) + (unsigned long)runtime->set_virtual_address_map; + early_memunmap(runtime, sizeof(efi_runtime_services_32_t)); + + return 0; +} + +static int __init efi_runtime_init64(void) +{ + efi_runtime_services_64_t *runtime; + + runtime = early_memremap((unsigned long)efi.systab->runtime, + sizeof(efi_runtime_services_64_t)); + if (!runtime) { + pr_err("Could not map the runtime service table!\n"); + return -ENOMEM; + } + + /* + * We will only need *early* access to the SetVirtualAddressMap + * EFI runtime service. All other runtime services will be called + * via the virtual mapping. + */ + efi_phys.set_virtual_address_map = + (efi_set_virtual_address_map_t *) + (unsigned long)runtime->set_virtual_address_map; + early_memunmap(runtime, sizeof(efi_runtime_services_64_t)); + + return 0; +} + +static int __init efi_runtime_init(void) +{ + int rv; + + /* + * Check out the runtime services table. We need to map + * the runtime services table so that we can grab the physical + * address of several of the EFI runtime functions, needed to + * set the firmware into virtual mode. + * + * When EFI_PARAVIRT is in force then we could not map runtime + * service memory region because we do not have direct access to it. + * However, runtime services are available through proxy functions + * (e.g. in case of Xen dom0 EFI implementation they call special + * hypercall which executes relevant EFI functions) and that is why + * they are always enabled. + */ + + if (!efi_enabled(EFI_PARAVIRT)) { + if (efi_enabled(EFI_64BIT)) + rv = efi_runtime_init64(); + else + rv = efi_runtime_init32(); + + if (rv) + return rv; + } + + set_bit(EFI_RUNTIME_SERVICES, &efi.flags); + + return 0; +} + +static int __init efi_memmap_init(void) +{ + if (efi_enabled(EFI_PARAVIRT)) + return 0; + + /* Map the EFI memory map */ + memmap.map = early_memremap((unsigned long)memmap.phys_map, + memmap.nr_map * memmap.desc_size); + if (memmap.map == NULL) { + pr_err("Could not map the memory map!\n"); + return -ENOMEM; + } + memmap.map_end = memmap.map + (memmap.nr_map * memmap.desc_size); + + if (add_efi_memmap) + do_add_efi_memmap(); + + set_bit(EFI_MEMMAP, &efi.flags); + + return 0; +} + +void __init efi_init(void) +{ + efi_char16_t *c16; + char vendor[100] = "unknown"; + int i = 0; + void *tmp; + +#ifdef CONFIG_X86_32 + if (boot_params.efi_info.efi_systab_hi || + boot_params.efi_info.efi_memmap_hi) { + pr_info("Table located above 4GB, disabling EFI.\n"); + return; + } + efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab; +#else + efi_phys.systab = (efi_system_table_t *) + (boot_params.efi_info.efi_systab | + ((__u64)boot_params.efi_info.efi_systab_hi<<32)); +#endif + + if (efi_systab_init(efi_phys.systab)) + return; + + efi.config_table = (unsigned long)efi.systab->tables; + efi.fw_vendor = (unsigned long)efi.systab->fw_vendor; + efi.runtime = (unsigned long)efi.systab->runtime; + + /* + * Show what we know for posterity + */ + c16 = tmp = early_memremap(efi.systab->fw_vendor, 2); + if (c16) { + for (i = 0; i < sizeof(vendor) - 1 && *c16; ++i) + vendor[i] = *c16++; + vendor[i] = '\0'; + } else + pr_err("Could not map the firmware vendor!\n"); + early_memunmap(tmp, 2); + + pr_info("EFI v%u.%.02u by %s\n", + efi.systab->hdr.revision >> 16, + efi.systab->hdr.revision & 0xffff, vendor); + + if (efi_reuse_config(efi.systab->tables, efi.systab->nr_tables)) + return; + + if (efi_config_init(arch_tables)) + return; + + /* + * Note: We currently don't support runtime services on an EFI + * that doesn't match the kernel 32/64-bit mode. + */ + + if (!efi_runtime_supported()) + pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n"); + else { + if (efi_runtime_disabled() || efi_runtime_init()) + return; + } + if (efi_memmap_init()) + return; + + if (efi_enabled(EFI_DBG)) + print_efi_memmap(); +} + +void __init efi_late_init(void) +{ + efi_bgrt_init(); +} + +void __init efi_set_executable(efi_memory_desc_t *md, bool executable) +{ + u64 addr, npages; + + addr = md->virt_addr; + npages = md->num_pages; + + memrange_efi_to_native(&addr, &npages); + + if (executable) + set_memory_x(addr, npages); + else + set_memory_nx(addr, npages); +} + +void __init runtime_code_page_mkexec(void) +{ + efi_memory_desc_t *md; + void *p; + + /* Make EFI runtime service code area executable */ + for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { + md = p; + + if (md->type != EFI_RUNTIME_SERVICES_CODE) + continue; + + efi_set_executable(md, true); + } +} + +void __init efi_memory_uc(u64 addr, unsigned long size) +{ + unsigned long page_shift = 1UL << EFI_PAGE_SHIFT; + u64 npages; + + npages = round_up(size, page_shift) / page_shift; + memrange_efi_to_native(&addr, &npages); + set_memory_uc(addr, npages); +} + +void __init old_map_region(efi_memory_desc_t *md) +{ + u64 start_pfn, end_pfn, end; + unsigned long size; + void *va; + + start_pfn = PFN_DOWN(md->phys_addr); + size = md->num_pages << PAGE_SHIFT; + end = md->phys_addr + size; + end_pfn = PFN_UP(end); + + if (pfn_range_is_mapped(start_pfn, end_pfn)) { + va = __va(md->phys_addr); + + if (!(md->attribute & EFI_MEMORY_WB)) + efi_memory_uc((u64)(unsigned long)va, size); + } else + va = efi_ioremap(md->phys_addr, size, + md->type, md->attribute); + + md->virt_addr = (u64) (unsigned long) va; + if (!va) + pr_err("ioremap of 0x%llX failed!\n", + (unsigned long long)md->phys_addr); +} + +/* Merge contiguous regions of the same type and attribute */ +static void __init efi_merge_regions(void) +{ + void *p; + efi_memory_desc_t *md, *prev_md = NULL; + + for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { + u64 prev_size; + md = p; + + if (!prev_md) { + prev_md = md; + continue; + } + + if (prev_md->type != md->type || + prev_md->attribute != md->attribute) { + prev_md = md; + continue; + } + + prev_size = prev_md->num_pages << EFI_PAGE_SHIFT; + + if (md->phys_addr == (prev_md->phys_addr + prev_size)) { + prev_md->num_pages += md->num_pages; + md->type = EFI_RESERVED_TYPE; + md->attribute = 0; + continue; + } + prev_md = md; + } +} + +static void __init get_systab_virt_addr(efi_memory_desc_t *md) +{ + unsigned long size; + u64 end, systab; + + size = md->num_pages << EFI_PAGE_SHIFT; + end = md->phys_addr + size; + systab = (u64)(unsigned long)efi_phys.systab; + if (md->phys_addr <= systab && systab < end) { + systab += md->virt_addr - md->phys_addr; + efi.systab = (efi_system_table_t *)(unsigned long)systab; + } +} + +static void __init save_runtime_map(void) +{ +#ifdef CONFIG_KEXEC + efi_memory_desc_t *md; + void *tmp, *p, *q = NULL; + int count = 0; + + if (efi_enabled(EFI_OLD_MEMMAP)) + return; + + for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { + md = p; + + if (!(md->attribute & EFI_MEMORY_RUNTIME) || + (md->type == EFI_BOOT_SERVICES_CODE) || + (md->type == EFI_BOOT_SERVICES_DATA)) + continue; + tmp = krealloc(q, (count + 1) * memmap.desc_size, GFP_KERNEL); + if (!tmp) + goto out; + q = tmp; + + memcpy(q + count * memmap.desc_size, md, memmap.desc_size); + count++; + } + + efi_runtime_map_setup(q, count, memmap.desc_size); + return; + +out: + kfree(q); + pr_err("Error saving runtime map, efi runtime on kexec non-functional!!\n"); +#endif +} + +static void *realloc_pages(void *old_memmap, int old_shift) +{ + void *ret; + + ret = (void *)__get_free_pages(GFP_KERNEL, old_shift + 1); + if (!ret) + goto out; + + /* + * A first-time allocation doesn't have anything to copy. + */ + if (!old_memmap) + return ret; + + memcpy(ret, old_memmap, PAGE_SIZE << old_shift); + +out: + free_pages((unsigned long)old_memmap, old_shift); + return ret; +} + +/* + * Map the efi memory ranges of the runtime services and update new_mmap with + * virtual addresses. + */ +static void * __init efi_map_regions(int *count, int *pg_shift) +{ + void *p, *new_memmap = NULL; + unsigned long left = 0; + efi_memory_desc_t *md; + + for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { + md = p; + if (!(md->attribute & EFI_MEMORY_RUNTIME)) { +#ifdef CONFIG_X86_64 + if (md->type != EFI_BOOT_SERVICES_CODE && + md->type != EFI_BOOT_SERVICES_DATA) +#endif + continue; + } + + efi_map_region(md); + get_systab_virt_addr(md); + + if (left < memmap.desc_size) { + new_memmap = realloc_pages(new_memmap, *pg_shift); + if (!new_memmap) + return NULL; + + left += PAGE_SIZE << *pg_shift; + (*pg_shift)++; + } + + memcpy(new_memmap + (*count * memmap.desc_size), md, + memmap.desc_size); + + left -= memmap.desc_size; + (*count)++; + } + + return new_memmap; +} + +static void __init kexec_enter_virtual_mode(void) +{ +#ifdef CONFIG_KEXEC + efi_memory_desc_t *md; + void *p; + + efi.systab = NULL; + + /* + * We don't do virtual mode, since we don't do runtime services, on + * non-native EFI + */ + if (!efi_is_native()) { + efi_unmap_memmap(); + clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); + return; + } + + /* + * Map efi regions which were passed via setup_data. The virt_addr is a + * fixed addr which was used in first kernel of a kexec boot. + */ + for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { + md = p; + efi_map_region_fixed(md); /* FIXME: add error handling */ + get_systab_virt_addr(md); + } + + save_runtime_map(); + + BUG_ON(!efi.systab); + + efi_sync_low_kernel_mappings(); + + /* + * Now that EFI is in virtual mode, update the function + * pointers in the runtime service table to the new virtual addresses. + * + * Call EFI services through wrapper functions. + */ + efi.runtime_version = efi_systab.hdr.revision; + + efi_native_runtime_setup(); + + efi.set_virtual_address_map = NULL; + + if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX)) + runtime_code_page_mkexec(); + + /* clean DUMMY object */ + efi_delete_dummy_variable(); +#endif +} + +/* + * This function will switch the EFI runtime services to virtual mode. + * Essentially, we look through the EFI memmap and map every region that + * has the runtime attribute bit set in its memory descriptor into the + * ->trampoline_pgd page table using a top-down VA allocation scheme. + * + * The old method which used to update that memory descriptor with the + * virtual address obtained from ioremap() is still supported when the + * kernel is booted with efi=old_map on its command line. Same old + * method enabled the runtime services to be called without having to + * thunk back into physical mode for every invocation. + * + * The new method does a pagetable switch in a preemption-safe manner + * so that we're in a different address space when calling a runtime + * function. For function arguments passing we do copy the PGDs of the + * kernel page table into ->trampoline_pgd prior to each call. + * + * Specially for kexec boot, efi runtime maps in previous kernel should + * be passed in via setup_data. In that case runtime ranges will be mapped + * to the same virtual addresses as the first kernel, see + * kexec_enter_virtual_mode(). + */ +static void __init __efi_enter_virtual_mode(void) +{ + int count = 0, pg_shift = 0; + void *new_memmap = NULL; + efi_status_t status; + + efi.systab = NULL; + + efi_merge_regions(); + new_memmap = efi_map_regions(&count, &pg_shift); + if (!new_memmap) { + pr_err("Error reallocating memory, EFI runtime non-functional!\n"); + clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); + return; + } + + save_runtime_map(); + + BUG_ON(!efi.systab); + + if (efi_setup_page_tables(__pa(new_memmap), 1 << pg_shift)) { + clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); + return; + } + + efi_sync_low_kernel_mappings(); + efi_dump_pagetable(); + + if (efi_is_native()) { + status = phys_efi_set_virtual_address_map( + memmap.desc_size * count, + memmap.desc_size, + memmap.desc_version, + (efi_memory_desc_t *)__pa(new_memmap)); + } else { + status = efi_thunk_set_virtual_address_map( + efi_phys.set_virtual_address_map, + memmap.desc_size * count, + memmap.desc_size, + memmap.desc_version, + (efi_memory_desc_t *)__pa(new_memmap)); + } + + if (status != EFI_SUCCESS) { + pr_alert("Unable to switch EFI into virtual mode (status=%lx)!\n", + status); + panic("EFI call to SetVirtualAddressMap() failed!"); + } + + /* + * Now that EFI is in virtual mode, update the function + * pointers in the runtime service table to the new virtual addresses. + * + * Call EFI services through wrapper functions. + */ + efi.runtime_version = efi_systab.hdr.revision; + + if (efi_is_native()) + efi_native_runtime_setup(); + else + efi_thunk_runtime_setup(); + + efi.set_virtual_address_map = NULL; + + efi_runtime_mkexec(); + + /* + * We mapped the descriptor array into the EFI pagetable above but we're + * not unmapping it here. Here's why: + * + * We're copying select PGDs from the kernel page table to the EFI page + * table and when we do so and make changes to those PGDs like unmapping + * stuff from them, those changes appear in the kernel page table and we + * go boom. + * + * From setup_real_mode(): + * + * ... + * trampoline_pgd[0] = init_level4_pgt[pgd_index(__PAGE_OFFSET)].pgd; + * + * In this particular case, our allocation is in PGD 0 of the EFI page + * table but we've copied that PGD from PGD[272] of the EFI page table: + * + * pgd_index(__PAGE_OFFSET = 0xffff880000000000) = 272 + * + * where the direct memory mapping in kernel space is. + * + * new_memmap's VA comes from that direct mapping and thus clearing it, + * it would get cleared in the kernel page table too. + * + * efi_cleanup_page_tables(__pa(new_memmap), 1 << pg_shift); + */ + free_pages((unsigned long)new_memmap, pg_shift); + + /* clean DUMMY object */ + efi_delete_dummy_variable(); +} + +void __init efi_enter_virtual_mode(void) +{ + if (efi_enabled(EFI_PARAVIRT)) + return; + + if (efi_setup) + kexec_enter_virtual_mode(); + else + __efi_enter_virtual_mode(); +} + +/* + * Convenience functions to obtain memory types and attributes + */ +u32 efi_mem_type(unsigned long phys_addr) +{ + efi_memory_desc_t *md; + void *p; + + if (!efi_enabled(EFI_MEMMAP)) + return 0; + + for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { + md = p; + if ((md->phys_addr <= phys_addr) && + (phys_addr < (md->phys_addr + + (md->num_pages << EFI_PAGE_SHIFT)))) + return md->type; + } + return 0; +} + +u64 efi_mem_attributes(unsigned long phys_addr) +{ + efi_memory_desc_t *md; + void *p; + + if (!efi_enabled(EFI_MEMMAP)) + return 0; + + for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { + md = p; + if ((md->phys_addr <= phys_addr) && + (phys_addr < (md->phys_addr + + (md->num_pages << EFI_PAGE_SHIFT)))) + return md->attribute; + } + return 0; +} + +static int __init arch_parse_efi_cmdline(char *str) +{ + if (parse_option_str(str, "old_map")) + set_bit(EFI_OLD_MEMMAP, &efi.flags); + if (parse_option_str(str, "debug")) + set_bit(EFI_DBG, &efi.flags); + + return 0; +} +early_param("efi", arch_parse_efi_cmdline); |