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Diffstat (limited to 'arch/x86/platform/efi/efi_64.c')
-rw-r--r--arch/x86/platform/efi/efi_64.c120
1 files changed, 120 insertions, 0 deletions
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index 39a0e7f1f0a3..6284f158a47d 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -38,10 +38,28 @@
#include <asm/efi.h>
#include <asm/cacheflush.h>
#include <asm/fixmap.h>
+#include <asm/realmode.h>
static pgd_t *save_pgd __initdata;
static unsigned long efi_flags __initdata;
+/*
+ * We allocate runtime services regions bottom-up, starting from -4G, i.e.
+ * 0xffff_ffff_0000_0000 and limit EFI VA mapping space to 64G.
+ */
+static u64 efi_va = -4 * (1UL << 30);
+#define EFI_VA_END (-68 * (1UL << 30))
+
+/*
+ * Scratch space used for switching the pagetable in the EFI stub
+ */
+struct efi_scratch {
+ u64 r15;
+ u64 prev_cr3;
+ pgd_t *efi_pgt;
+ bool use_pgd;
+};
+
static void __init early_code_mapping_set_exec(int executable)
{
efi_memory_desc_t *md;
@@ -65,6 +83,9 @@ void __init efi_call_phys_prelog(void)
int pgd;
int n_pgds;
+ if (!efi_enabled(EFI_OLD_MEMMAP))
+ return;
+
early_code_mapping_set_exec(1);
local_irq_save(efi_flags);
@@ -86,6 +107,10 @@ void __init efi_call_phys_epilog(void)
*/
int pgd;
int n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE);
+
+ if (!efi_enabled(EFI_OLD_MEMMAP))
+ return;
+
for (pgd = 0; pgd < n_pgds; pgd++)
set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), save_pgd[pgd]);
kfree(save_pgd);
@@ -94,6 +119,96 @@ void __init efi_call_phys_epilog(void)
early_code_mapping_set_exec(0);
}
+/*
+ * Add low kernel mappings for passing arguments to EFI functions.
+ */
+void efi_sync_low_kernel_mappings(void)
+{
+ unsigned num_pgds;
+ pgd_t *pgd = (pgd_t *)__va(real_mode_header->trampoline_pgd);
+
+ if (efi_enabled(EFI_OLD_MEMMAP))
+ return;
+
+ num_pgds = pgd_index(MODULES_END - 1) - pgd_index(PAGE_OFFSET);
+
+ memcpy(pgd + pgd_index(PAGE_OFFSET),
+ init_mm.pgd + pgd_index(PAGE_OFFSET),
+ sizeof(pgd_t) * num_pgds);
+}
+
+void efi_setup_page_tables(void)
+{
+ efi_scratch.efi_pgt = (pgd_t *)(unsigned long)real_mode_header->trampoline_pgd;
+
+ if (!efi_enabled(EFI_OLD_MEMMAP))
+ efi_scratch.use_pgd = true;
+}
+
+static void __init __map_region(efi_memory_desc_t *md, u64 va)
+{
+ pgd_t *pgd = (pgd_t *)__va(real_mode_header->trampoline_pgd);
+ unsigned long pf = 0;
+
+ if (!(md->attribute & EFI_MEMORY_WB))
+ pf |= _PAGE_PCD;
+
+ if (kernel_map_pages_in_pgd(pgd, md->phys_addr, va, md->num_pages, pf))
+ 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);
+
+ 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->virt_addr);
+}
+
void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size,
u32 type, u64 attribute)
{
@@ -113,3 +228,8 @@ void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long 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);
+}