diff options
Diffstat (limited to 'arch/arm/kernel/efi.c')
-rw-r--r-- | arch/arm/kernel/efi.c | 446 |
1 files changed, 446 insertions, 0 deletions
diff --git a/arch/arm/kernel/efi.c b/arch/arm/kernel/efi.c new file mode 100644 index 000000000000..f9bfd64e5cc4 --- /dev/null +++ b/arch/arm/kernel/efi.c @@ -0,0 +1,446 @@ +/* + * Extensible Firmware Interface + * + * Based on Extensible Firmware Interface Specification version 2.3.1 + * + * Copyright (C) 2013 Linaro Ltd. + * + */ + +#include <linux/efi.h> +#include <linux/export.h> +#include <linux/memblock.h> +#include <linux/of.h> +#include <linux/of_fdt.h> +#include <linux/sched.h> +#include <linux/slab.h> + +#include <asm/cacheflush.h> +#include <asm/efi.h> +#include <asm/idmap.h> +#include <asm/tlbflush.h> + +struct efi_memory_map memmap; + +static efi_runtime_services_t *runtime; + +static phys_addr_t efi_system_table; +static phys_addr_t efi_boot_mmap; +static u32 efi_boot_mmap_size; +static u32 efi_mmap_desc_size; +static u32 efi_mmap_desc_ver; + +static unsigned long arm_efi_facility; + +/* Default memory map descriptor information */ +#define DESC_SIZE 48 +#define DESC_VER 1 + +/* If you're planning to wire up a debugger and debug the UEFI side ... */ +#undef KEEP_ALL_REGIONS +#define KEEP_BOOT_SERVICES_REGIONS + +/* + * Returns 1 if 'facility' is enabled, 0 otherwise. + */ +int efi_enabled(int facility) +{ + return test_bit(facility, &arm_efi_facility) != 0; +} +EXPORT_SYMBOL(efi_enabled); + +static int __initdata uefi_debug; +static int __init uefi_debug_setup(char *str) +{ + uefi_debug = 1; + + return 0; +} +early_param("uefi_debug", uefi_debug_setup); + +static int __init fdt_find_efi_params(unsigned long node, const char *uname, + int depth, void *data) +{ + unsigned long len; + __be32 *prop; + + if (depth != 1 || + (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0)) + return 0; + + pr_info("Getting EFI parameters from FDT.\n"); + + prop = of_get_flat_dt_prop(node, "efi-system-table", &len); + if (!prop) + return 0; + efi_system_table = of_read_ulong(prop, len/4); + + prop = of_get_flat_dt_prop(node, "efi-runtime-mmap", &len); + if (!prop) + return 0; + efi_boot_mmap = of_read_ulong(prop, len/4); + + prop = of_get_flat_dt_prop(node, "efi-runtime-mmap-size", &len); + if (!prop) + return 0; + efi_boot_mmap_size = of_read_ulong(prop, len/4); + + prop = of_get_flat_dt_prop(node, "efi-mmap-desc-size", &len); + if (prop) + efi_mmap_desc_size = of_read_ulong(prop, len/4); + else + efi_mmap_desc_size = DESC_SIZE; + + prop = of_get_flat_dt_prop(node, "efi-mmap-desc-ver", &len); + if (prop) + efi_mmap_desc_ver = of_read_ulong(prop, len/4); + else + efi_mmap_desc_ver = DESC_VER; + + if (uefi_debug) { + pr_info(" EFI system table @ 0x%08x\n", + (unsigned int) efi_system_table); + pr_info(" EFI mmap @ 0x%08x\n", + (unsigned int) efi_boot_mmap); + pr_info(" EFI mmap size = 0x%08x\n", + (unsigned int) efi_boot_mmap_size); + pr_info(" EFI mmap descriptor size = 0x%08x\n", + (unsigned int) efi_mmap_desc_size); + pr_info(" EFI mmap descriptor version = 0x%08x\n", + (unsigned int) efi_mmap_desc_ver); + } + + return 1; +} + +static int __init uefi_init(void) +{ + efi_char16_t *c16; + char vendor[100] = "unknown"; + int i, retval; + + efi.systab = early_ioremap(efi_system_table, + sizeof(efi_system_table_t)); + + /* + * Verify the EFI Table + */ + if (efi.systab == NULL) + panic("Whoa! Can't find EFI system table.\n"); + if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) + panic("Whoa! EFI system table signature incorrect\n"); + if ((efi.systab->hdr.revision >> 16) == 0) + pr_warn("Warning: EFI system table version %d.%02d, expected 1.00 or greater\n", + efi.systab->hdr.revision >> 16, + efi.systab->hdr.revision & 0xffff); + + /* Show what we know for posterity */ + c16 = (efi_char16_t *)early_ioremap(efi.systab->fw_vendor, + sizeof(vendor)); + if (c16) { + for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i) + vendor[i] = c16[i]; + vendor[i] = '\0'; + } + + pr_info("EFI v%u.%.02u by %s\n", + efi.systab->hdr.revision >> 16, + efi.systab->hdr.revision & 0xffff, vendor); + + retval = efi_config_init(NULL); + + early_iounmap(c16, sizeof(vendor)); + early_iounmap(efi.systab, sizeof(efi_system_table_t)); + + return retval; +} + +static __init int is_discardable_region(efi_memory_desc_t *md) +{ +#ifdef KEEP_ALL_REGIONS + return 0; +#endif + + if (md->attribute & EFI_MEMORY_RUNTIME) + return 0; + + switch (md->type) { +#ifdef KEEP_BOOT_SERVICES_REGIONS + case EFI_BOOT_SERVICES_CODE: + case EFI_BOOT_SERVICES_DATA: +#endif + /* Keep tables around for any future kexec operations */ + case EFI_ACPI_RECLAIM_MEMORY: + return 0; + } + + return 1; +} + +static __initdata struct { + u32 type; + const char *name; +} memory_type_name_map[] = { + {EFI_RESERVED_TYPE, "EFI reserved"}, + {EFI_LOADER_CODE, "EFI loader code"}, + {EFI_LOADER_DATA, "EFI loader data"}, + {EFI_BOOT_SERVICES_CODE, "EFI boot services code"}, + {EFI_BOOT_SERVICES_DATA, "EFI boot services data"}, + {EFI_RUNTIME_SERVICES_CODE, "EFI runtime services code"}, + {EFI_RUNTIME_SERVICES_DATA, "EFI runtime services data"}, + {EFI_CONVENTIONAL_MEMORY, "EFI conventional memory"}, + {EFI_UNUSABLE_MEMORY, "EFI unusable memory"}, + {EFI_ACPI_RECLAIM_MEMORY, "EFI ACPI reclaim memory"}, + {EFI_ACPI_MEMORY_NVS, "EFI ACPI memory nvs"}, + {EFI_MEMORY_MAPPED_IO, "EFI memory mapped I/O"}, + {EFI_MEMORY_MAPPED_IO_PORT_SPACE, "EFI memory mapped I/O port space"}, + {EFI_PAL_CODE, "EFI pal code"}, + {EFI_MAX_MEMORY_TYPE, NULL}, +}; + +static __init void remove_sections(phys_addr_t addr, unsigned long size) +{ + unsigned long section_offset; + unsigned long num_sections; + + section_offset = addr - (addr & SECTION_MASK); + num_sections = size / SECTION_SIZE; + if (size % SECTION_SIZE) + num_sections++; + + memblock_remove(addr - section_offset, num_sections * SECTION_SIZE); +} + +static __init int remove_regions(void) +{ + efi_memory_desc_t *md; + int count = 0; + + void *p; + + memmap.phys_map = early_ioremap(efi_boot_mmap, efi_boot_mmap_size); + + memmap.desc_size = efi_mmap_desc_size; + memmap.desc_version = efi_mmap_desc_ver; + memmap.map_end = (void *) memmap.phys_map + efi_boot_mmap_size; + memmap.nr_map = 0; + + if (uefi_debug) + pr_info("Processing EFI memory map:\n"); + + for (p = memmap.phys_map; p < memmap.map_end; p += memmap.desc_size) { + md = p; + if (is_discardable_region(md)) + continue; + + if (uefi_debug) + pr_info(" %8llu pages @ %016llx (%s)\n", + md->num_pages, md->phys_addr, + memory_type_name_map[md->type].name); + + if (md->type != EFI_MEMORY_MAPPED_IO) { + remove_sections(md->phys_addr, + md->num_pages * PAGE_SIZE); + count++; + } + memmap.nr_map++; + } + + if (uefi_debug) + pr_info("%d regions preserved.\n", memmap.nr_map); + + early_iounmap(memmap.phys_map, efi_boot_mmap_size); + + return 0; +} + +int __init efi_memblock_arm_reserve_range(void) +{ + /* Grab system table location out of FDT (or ACPI) */ + of_scan_flat_dt(fdt_find_efi_params, NULL); + + if (!efi_system_table || !efi_boot_mmap || !efi_boot_mmap_size) + return 0; + + set_bit(EFI_BOOT, &arm_efi_facility); + + uefi_init(); + + remove_regions(); + + return 0; +} + +/* + * Disable instrrupts, enable idmap and disable caches. + */ +static void __init phys_call_prologue(void) +{ + local_irq_disable(); + + /* Take out a flat memory mapping. */ + setup_mm_for_reboot(); + + /* Clean and invalidate caches */ + flush_cache_all(); + + /* Turn off caching */ + cpu_proc_fin(); + + /* Push out any further dirty data, and ensure cache is empty */ + flush_cache_all(); +} + +/* + * Restore original memory map and re-enable interrupts. + */ +static void __init phys_call_epilogue(void) +{ + static struct mm_struct *mm = &init_mm; + + /* Restore original memory mapping */ + cpu_switch_mm(mm->pgd, mm); + + /* Flush branch predictor and TLBs */ + local_flush_bp_all(); +#ifdef CONFIG_CPU_HAS_ASID + local_flush_tlb_all(); +#endif + + local_irq_enable(); +} + +/* + * This function switches the EFI runtime services to virtual mode. + * This operation must be performed only once in the system's lifetime, + * including any kecec calls. + * + * This must be done with a 1:1 mapping. The current implementation + * resolves this by disabling the MMU. + */ +efi_status_t __init phys_set_virtual_address_map(u32 memory_map_size, + u32 descriptor_size, + u32 descriptor_version, + efi_memory_desc_t *dsc) +{ + efi_phys_call_t *phys_set_map; + efi_status_t status; + + phys_call_prologue(); + + phys_set_map = (void *)(unsigned long)virt_to_phys(efi_phys_call); + + /* Called with caches disabled, returns with caches enabled */ + status = phys_set_map(memory_map_size, descriptor_size, + descriptor_version, dsc, + efi.set_virtual_address_map); + + phys_call_epilogue(); + + return status; +} + +static int __init remap_region(efi_memory_desc_t *md, efi_memory_desc_t *entry) +{ + u64 va; + u64 paddr; + u64 size; + + *entry = *md; + paddr = entry->phys_addr; + size = entry->num_pages << EFI_PAGE_SHIFT; + + /* + * Map everything writeback-capable as coherent memory, + * anything else as device. + */ + if (md->attribute & EFI_MEMORY_WB) + va = (u64)((u32)efi_remap(paddr, size) & 0xffffffffUL); + else + va = (u64)((u32)efi_ioremap(paddr, size) & 0xffffffffUL); + if (!va) + return 0; + entry->virt_addr = va; + + if (uefi_debug) + pr_info(" %016llx-%016llx => 0x%08x : (%s)\n", + paddr, paddr + size - 1, (u32)va, + md->attribute & EFI_MEMORY_WB ? "WB" : "I/O"); + + return 1; +} + +static void __init remap_regions(void) +{ + void *p, *next; + efi_memory_desc_t *md; + + memmap.phys_map = efi_remap(efi_boot_mmap, efi_boot_mmap_size); + memmap.map_end = (void *)memmap.phys_map + efi_boot_mmap_size; + + /* Allocate space for the physical region map */ + memmap.map = kzalloc(memmap.nr_map * memmap.desc_size, GFP_KERNEL); + if (!memmap.map) + return; + + next = memmap.map; + for (p = memmap.phys_map; p < memmap.map_end; p += memmap.desc_size) { + md = p; + if (is_discardable_region(md)) + continue; + + if (remap_region(p, next)) + next += memmap.desc_size; + } + + memmap.map_end = next; + + efi_unmap(memmap.phys_map); + + efi.systab = efi_lookup_mapped_addr(efi_system_table); + set_bit(EFI_SYSTEM_TABLES, &arm_efi_facility); + /* + * efi.systab->runtime is a 32-bit pointer to something guaranteed by + * the UEFI specification to be 1:1 mapped in a 4GB address space. + */ + runtime = efi_lookup_mapped_addr((u32)efi.systab->runtime); +} + + +/* + * Called explicitly from init/mm.c + */ +void __init efi_enter_virtual_mode(void) +{ + efi_status_t status; + + if (!efi_enabled(EFI_BOOT)) { + pr_info("EFI services will not be available.\n"); + return; + } else { + pr_info("Remapping and enabling EFI services.\n"); + } + + /* Map the regions we memblock_remove:d earlier into kernel + address space */ + remap_regions(); + + /* Call SetVirtualAddressMap with the physical address of the map */ + efi.set_virtual_address_map = + (efi_set_virtual_address_map_t *) + runtime->set_virtual_address_map; + memmap.phys_map = + (efi_memory_desc_t *)(u32) __virt_to_phys((u32)memmap.map); + + status = phys_set_virtual_address_map(memmap.nr_map * memmap.desc_size, + memmap.desc_size, + memmap.desc_version, + memmap.phys_map); + + /* Set up function pointers for efivars */ + efi.get_variable = (efi_get_variable_t *)runtime->get_variable; + efi.get_next_variable = + (efi_get_next_variable_t *)runtime->get_next_variable; + efi.set_variable = (efi_set_variable_t *)runtime->set_variable; + set_bit(EFI_RUNTIME_SERVICES, &arm_efi_facility); +} |