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Diffstat (limited to 'arch/arm64/kernel/efi.c')
-rw-r--r--arch/arm64/kernel/efi.c356
1 files changed, 113 insertions, 243 deletions
diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
index 2bb4347d0edf..b42c7b480e1e 100644
--- a/arch/arm64/kernel/efi.c
+++ b/arch/arm64/kernel/efi.c
@@ -11,27 +11,46 @@
*
*/
+#include <linux/atomic.h>
#include <linux/dmi.h>
#include <linux/efi.h>
#include <linux/export.h>
#include <linux/memblock.h>
+#include <linux/mm_types.h>
#include <linux/bootmem.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
+#include <linux/preempt.h>
+#include <linux/rbtree.h>
+#include <linux/rwsem.h>
#include <linux/sched.h>
#include <linux/slab.h>
+#include <linux/spinlock.h>
#include <asm/cacheflush.h>
#include <asm/efi.h>
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
+#include <asm/mmu.h>
+#include <asm/pgtable.h>
struct efi_memory_map memmap;
-static efi_runtime_services_t *runtime;
-
static u64 efi_system_table;
+static pgd_t efi_pgd[PTRS_PER_PGD] __page_aligned_bss;
+
+static struct mm_struct efi_mm = {
+ .mm_rb = RB_ROOT,
+ .pgd = efi_pgd,
+ .mm_users = ATOMIC_INIT(2),
+ .mm_count = ATOMIC_INIT(1),
+ .mmap_sem = __RWSEM_INITIALIZER(efi_mm.mmap_sem),
+ .page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
+ .mmlist = LIST_HEAD_INIT(efi_mm.mmlist),
+ INIT_MM_CONTEXT(efi_mm)
+};
+
static int uefi_debug __initdata;
static int __init uefi_debug_setup(char *str)
{
@@ -48,30 +67,33 @@ static int __init is_normal_ram(efi_memory_desc_t *md)
return 0;
}
-static void __init efi_setup_idmap(void)
+/*
+ * Translate a EFI virtual address into a physical address: this is necessary,
+ * as some data members of the EFI system table are virtually remapped after
+ * SetVirtualAddressMap() has been called.
+ */
+static phys_addr_t efi_to_phys(unsigned long addr)
{
- struct memblock_region *r;
efi_memory_desc_t *md;
- u64 paddr, npages, size;
- for_each_memblock(memory, r)
- create_id_mapping(r->base, r->size, 0);
-
- /* map runtime io spaces */
for_each_efi_memory_desc(&memmap, md) {
- if (!(md->attribute & EFI_MEMORY_RUNTIME) || is_normal_ram(md))
+ if (!(md->attribute & EFI_MEMORY_RUNTIME))
continue;
- paddr = md->phys_addr;
- npages = md->num_pages;
- memrange_efi_to_native(&paddr, &npages);
- size = npages << PAGE_SHIFT;
- create_id_mapping(paddr, size, 1);
+ if (md->virt_addr == 0)
+ /* no virtual mapping has been installed by the stub */
+ break;
+ if (md->virt_addr <= addr &&
+ (addr - md->virt_addr) < (md->num_pages << EFI_PAGE_SHIFT))
+ return md->phys_addr + addr - md->virt_addr;
}
+ return addr;
}
static int __init uefi_init(void)
{
efi_char16_t *c16;
+ void *config_tables;
+ u64 table_size;
char vendor[100] = "unknown";
int i, retval;
@@ -99,7 +121,7 @@ static int __init uefi_init(void)
efi.systab->hdr.revision & 0xffff);
/* Show what we know for posterity */
- c16 = early_memremap(efi.systab->fw_vendor,
+ c16 = early_memremap(efi_to_phys(efi.systab->fw_vendor),
sizeof(vendor));
if (c16) {
for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i)
@@ -112,8 +134,14 @@ static int __init uefi_init(void)
efi.systab->hdr.revision >> 16,
efi.systab->hdr.revision & 0xffff, vendor);
- retval = efi_config_init(NULL);
+ table_size = sizeof(efi_config_table_64_t) * efi.systab->nr_tables;
+ config_tables = early_memremap(efi_to_phys(efi.systab->tables),
+ table_size);
+ retval = efi_config_parse_tables(config_tables, efi.systab->nr_tables,
+ sizeof(efi_config_table_64_t), NULL);
+
+ early_memunmap(config_tables, table_size);
out:
early_memunmap(efi.systab, sizeof(efi_system_table_t));
return retval;
@@ -163,9 +191,7 @@ static __init void reserve_regions(void)
if (is_normal_ram(md))
early_init_dt_add_memory_arch(paddr, size);
- if (is_reserve_region(md) ||
- md->type == EFI_BOOT_SERVICES_CODE ||
- md->type == EFI_BOOT_SERVICES_DATA) {
+ if (is_reserve_region(md)) {
memblock_reserve(paddr, size);
if (uefi_debug)
pr_cont("*");
@@ -178,123 +204,6 @@ static __init void reserve_regions(void)
set_bit(EFI_MEMMAP, &efi.flags);
}
-
-static u64 __init free_one_region(u64 start, u64 end)
-{
- u64 size = end - start;
-
- if (uefi_debug)
- pr_info(" EFI freeing: 0x%012llx-0x%012llx\n", start, end - 1);
-
- free_bootmem_late(start, size);
- return size;
-}
-
-static u64 __init free_region(u64 start, u64 end)
-{
- u64 map_start, map_end, total = 0;
-
- if (end <= start)
- return total;
-
- map_start = (u64)memmap.phys_map;
- map_end = PAGE_ALIGN(map_start + (memmap.map_end - memmap.map));
- map_start &= PAGE_MASK;
-
- if (start < map_end && end > map_start) {
- /* region overlaps UEFI memmap */
- if (start < map_start)
- total += free_one_region(start, map_start);
-
- if (map_end < end)
- total += free_one_region(map_end, end);
- } else
- total += free_one_region(start, end);
-
- return total;
-}
-
-static void __init free_boot_services(void)
-{
- u64 total_freed = 0;
- u64 keep_end, free_start, free_end;
- efi_memory_desc_t *md;
-
- /*
- * If kernel uses larger pages than UEFI, we have to be careful
- * not to inadvertantly free memory we want to keep if there is
- * overlap at the kernel page size alignment. We do not want to
- * free is_reserve_region() memory nor the UEFI memmap itself.
- *
- * The memory map is sorted, so we keep track of the end of
- * any previous region we want to keep, remember any region
- * we want to free and defer freeing it until we encounter
- * the next region we want to keep. This way, before freeing
- * it, we can clip it as needed to avoid freeing memory we
- * want to keep for UEFI.
- */
-
- keep_end = 0;
- free_start = 0;
-
- for_each_efi_memory_desc(&memmap, md) {
- u64 paddr, npages, size;
-
- if (is_reserve_region(md)) {
- /*
- * We don't want to free any memory from this region.
- */
- if (free_start) {
- /* adjust free_end then free region */
- if (free_end > md->phys_addr)
- free_end -= PAGE_SIZE;
- total_freed += free_region(free_start, free_end);
- free_start = 0;
- }
- keep_end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT);
- continue;
- }
-
- if (md->type != EFI_BOOT_SERVICES_CODE &&
- md->type != EFI_BOOT_SERVICES_DATA) {
- /* no need to free this region */
- continue;
- }
-
- /*
- * We want to free memory from this region.
- */
- paddr = md->phys_addr;
- npages = md->num_pages;
- memrange_efi_to_native(&paddr, &npages);
- size = npages << PAGE_SHIFT;
-
- if (free_start) {
- if (paddr <= free_end)
- free_end = paddr + size;
- else {
- total_freed += free_region(free_start, free_end);
- free_start = paddr;
- free_end = paddr + size;
- }
- } else {
- free_start = paddr;
- free_end = paddr + size;
- }
- if (free_start < keep_end) {
- free_start += PAGE_SIZE;
- if (free_start >= free_end)
- free_start = 0;
- }
- }
- if (free_start)
- total_freed += free_region(free_start, free_end);
-
- if (total_freed)
- pr_info("Freed 0x%llx bytes of EFI boot services memory",
- total_freed);
-}
-
void __init efi_init(void)
{
struct efi_fdt_params params;
@@ -317,159 +226,100 @@ void __init efi_init(void)
return;
reserve_regions();
+ early_memunmap(memmap.map, params.mmap_size);
}
-void __init efi_idmap_init(void)
+static bool __init efi_virtmap_init(void)
{
- if (!efi_enabled(EFI_BOOT))
- return;
-
- /* boot time idmap_pg_dir is incomplete, so fill in missing parts */
- efi_setup_idmap();
- early_memunmap(memmap.map, memmap.map_end - memmap.map);
-}
-
-static int __init remap_region(efi_memory_desc_t *md, void **new)
-{
- u64 paddr, vaddr, npages, size;
-
- paddr = md->phys_addr;
- npages = md->num_pages;
- memrange_efi_to_native(&paddr, &npages);
- size = npages << PAGE_SHIFT;
+ efi_memory_desc_t *md;
- if (is_normal_ram(md))
- vaddr = (__force u64)ioremap_cache(paddr, size);
- else
- vaddr = (__force u64)ioremap(paddr, size);
+ for_each_efi_memory_desc(&memmap, md) {
+ u64 paddr, npages, size;
+ pgprot_t prot;
- if (!vaddr) {
- pr_err("Unable to remap 0x%llx pages @ %p\n",
- npages, (void *)paddr);
- return 0;
- }
+ if (!(md->attribute & EFI_MEMORY_RUNTIME))
+ continue;
+ if (md->virt_addr == 0)
+ return false;
- /* adjust for any rounding when EFI and system pagesize differs */
- md->virt_addr = vaddr + (md->phys_addr - paddr);
+ paddr = md->phys_addr;
+ npages = md->num_pages;
+ memrange_efi_to_native(&paddr, &npages);
+ size = npages << PAGE_SHIFT;
- if (uefi_debug)
- pr_info(" EFI remap 0x%012llx => %p\n",
+ pr_info(" EFI remap 0x%016llx => %p\n",
md->phys_addr, (void *)md->virt_addr);
- memcpy(*new, md, memmap.desc_size);
- *new += memmap.desc_size;
-
- return 1;
+ /*
+ * Only regions of type EFI_RUNTIME_SERVICES_CODE need to be
+ * executable, everything else can be mapped with the XN bits
+ * set.
+ */
+ if (!is_normal_ram(md))
+ prot = __pgprot(PROT_DEVICE_nGnRE);
+ else if (md->type == EFI_RUNTIME_SERVICES_CODE)
+ prot = PAGE_KERNEL_EXEC;
+ else
+ prot = PAGE_KERNEL;
+
+ create_pgd_mapping(&efi_mm, paddr, md->virt_addr, size, prot);
+ }
+ return true;
}
/*
- * Switch UEFI from an identity map to a kernel virtual map
+ * Enable the UEFI Runtime Services if all prerequisites are in place, i.e.,
+ * non-early mapping of the UEFI system table and virtual mappings for all
+ * EFI_MEMORY_RUNTIME regions.
*/
-static int __init arm64_enter_virtual_mode(void)
+static int __init arm64_enable_runtime_services(void)
{
- efi_memory_desc_t *md;
- phys_addr_t virtmap_phys;
- void *virtmap, *virt_md;
- efi_status_t status;
u64 mapsize;
- int count = 0;
- unsigned long flags;
if (!efi_enabled(EFI_BOOT)) {
pr_info("EFI services will not be available.\n");
return -1;
}
- mapsize = memmap.map_end - memmap.map;
-
if (efi_runtime_disabled()) {
pr_info("EFI runtime services will be disabled.\n");
return -1;
}
pr_info("Remapping and enabling EFI services.\n");
- /* replace early memmap mapping with permanent mapping */
+
+ mapsize = memmap.map_end - memmap.map;
memmap.map = (__force void *)ioremap_cache((phys_addr_t)memmap.phys_map,
mapsize);
- memmap.map_end = memmap.map + mapsize;
-
- efi.memmap = &memmap;
-
- /* Map the runtime regions */
- virtmap = kmalloc(mapsize, GFP_KERNEL);
- if (!virtmap) {
- pr_err("Failed to allocate EFI virtual memmap\n");
+ if (!memmap.map) {
+ pr_err("Failed to remap EFI memory map\n");
return -1;
}
- virtmap_phys = virt_to_phys(virtmap);
- virt_md = virtmap;
-
- for_each_efi_memory_desc(&memmap, md) {
- if (!(md->attribute & EFI_MEMORY_RUNTIME))
- continue;
- if (!remap_region(md, &virt_md))
- goto err_unmap;
- ++count;
- }
+ memmap.map_end = memmap.map + mapsize;
+ efi.memmap = &memmap;
- efi.systab = (__force void *)efi_lookup_mapped_addr(efi_system_table);
+ efi.systab = (__force void *)ioremap_cache(efi_system_table,
+ sizeof(efi_system_table_t));
if (!efi.systab) {
- /*
- * If we have no virtual mapping for the System Table at this
- * point, the memory map doesn't cover the physical offset where
- * it resides. This means the System Table will be inaccessible
- * to Runtime Services themselves once the virtual mapping is
- * installed.
- */
- pr_err("Failed to remap EFI System Table -- buggy firmware?\n");
- goto err_unmap;
+ pr_err("Failed to remap EFI System Table\n");
+ return -1;
}
set_bit(EFI_SYSTEM_TABLES, &efi.flags);
- local_irq_save(flags);
- cpu_switch_mm(idmap_pg_dir, &init_mm);
-
- /* Call SetVirtualAddressMap with the physical address of the map */
- runtime = efi.systab->runtime;
- efi.set_virtual_address_map = runtime->set_virtual_address_map;
-
- status = efi.set_virtual_address_map(count * memmap.desc_size,
- memmap.desc_size,
- memmap.desc_version,
- (efi_memory_desc_t *)virtmap_phys);
- cpu_set_reserved_ttbr0();
- flush_tlb_all();
- local_irq_restore(flags);
-
- kfree(virtmap);
-
- free_boot_services();
-
- if (status != EFI_SUCCESS) {
- pr_err("Failed to set EFI virtual address map! [%lx]\n",
- status);
+ if (!efi_virtmap_init()) {
+ pr_err("No UEFI virtual mapping was installed -- runtime services will not be available\n");
return -1;
}
/* Set up runtime services function pointers */
- runtime = efi.systab->runtime;
efi_native_runtime_setup();
set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
efi.runtime_version = efi.systab->hdr.revision;
return 0;
-
-err_unmap:
- /* unmap all mappings that succeeded: there are 'count' of those */
- for (virt_md = virtmap; count--; virt_md += memmap.desc_size) {
- md = virt_md;
- iounmap((__force void __iomem *)md->virt_addr);
- }
- kfree(virtmap);
- return -1;
}
-early_initcall(arm64_enter_virtual_mode);
+early_initcall(arm64_enable_runtime_services);
static int __init arm64_dmi_init(void)
{
@@ -484,3 +334,23 @@ static int __init arm64_dmi_init(void)
return 0;
}
core_initcall(arm64_dmi_init);
+
+static void efi_set_pgd(struct mm_struct *mm)
+{
+ cpu_switch_mm(mm->pgd, mm);
+ flush_tlb_all();
+ if (icache_is_aivivt())
+ __flush_icache_all();
+}
+
+void efi_virtmap_load(void)
+{
+ preempt_disable();
+ efi_set_pgd(&efi_mm);
+}
+
+void efi_virtmap_unload(void)
+{
+ efi_set_pgd(current->active_mm);
+ preempt_enable();
+}