summaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/efi_64.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kernel/efi_64.c')
-rw-r--r--arch/x86/kernel/efi_64.c134
1 files changed, 134 insertions, 0 deletions
diff --git a/arch/x86/kernel/efi_64.c b/arch/x86/kernel/efi_64.c
new file mode 100644
index 00000000000..4b73992c1e1
--- /dev/null
+++ b/arch/x86/kernel/efi_64.c
@@ -0,0 +1,134 @@
+/*
+ * 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.
+ *
+ */
+
+#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/module.h>
+#include <linux/efi.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+#include <linux/reboot.h>
+
+#include <asm/setup.h>
+#include <asm/page.h>
+#include <asm/e820.h>
+#include <asm/pgtable.h>
+#include <asm/tlbflush.h>
+#include <asm/proto.h>
+#include <asm/efi.h>
+
+static pgd_t save_pgd __initdata;
+static unsigned long efi_flags __initdata;
+
+static void __init early_mapping_set_exec(unsigned long start,
+ unsigned long end,
+ int executable)
+{
+ pte_t *kpte;
+ int level;
+
+ while (start < end) {
+ kpte = lookup_address((unsigned long)__va(start), &level);
+ BUG_ON(!kpte);
+ if (executable)
+ set_pte(kpte, pte_mkexec(*kpte));
+ else
+ set_pte(kpte, __pte((pte_val(*kpte) | _PAGE_NX) & \
+ __supported_pte_mask));
+ if (level == 4)
+ start = (start + PMD_SIZE) & PMD_MASK;
+ else
+ start = (start + PAGE_SIZE) & PAGE_MASK;
+ }
+}
+
+static void __init early_runtime_code_mapping_set_exec(int executable)
+{
+ efi_memory_desc_t *md;
+ void *p;
+
+ if (!(__supported_pte_mask & _PAGE_NX))
+ return;
+
+ /* 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) {
+ unsigned long end;
+ end = md->phys_addr + (md->num_pages << PAGE_SHIFT);
+ early_mapping_set_exec(md->phys_addr, end, executable);
+ }
+ }
+}
+
+void __init efi_call_phys_prelog(void)
+{
+ unsigned long vaddress;
+
+ local_irq_save(efi_flags);
+ early_runtime_code_mapping_set_exec(1);
+ vaddress = (unsigned long)__va(0x0UL);
+ save_pgd = *pgd_offset_k(0x0UL);
+ set_pgd(pgd_offset_k(0x0UL), *pgd_offset_k(vaddress));
+ __flush_tlb_all();
+}
+
+void __init efi_call_phys_epilog(void)
+{
+ /*
+ * After the lock is released, the original page table is restored.
+ */
+ set_pgd(pgd_offset_k(0x0UL), save_pgd);
+ early_runtime_code_mapping_set_exec(0);
+ __flush_tlb_all();
+ local_irq_restore(efi_flags);
+}
+
+void __init efi_reserve_bootmem(void)
+{
+ reserve_bootmem_generic((unsigned long)memmap.phys_map,
+ memmap.nr_map * memmap.desc_size);
+}
+
+void __iomem * __init efi_ioremap(unsigned long offset,
+ unsigned long size)
+{
+ static unsigned pages_mapped;
+ unsigned long last_addr;
+ unsigned i, pages;
+
+ last_addr = offset + size - 1;
+ offset &= PAGE_MASK;
+ pages = (PAGE_ALIGN(last_addr) - offset) >> PAGE_SHIFT;
+ if (pages_mapped + pages > MAX_EFI_IO_PAGES)
+ return NULL;
+
+ for (i = 0; i < pages; i++) {
+ __set_fixmap(FIX_EFI_IO_MAP_FIRST_PAGE - pages_mapped,
+ offset, PAGE_KERNEL_EXEC_NOCACHE);
+ offset += PAGE_SIZE;
+ pages_mapped++;
+ }
+
+ return (void __iomem *)__fix_to_virt(FIX_EFI_IO_MAP_FIRST_PAGE - \
+ (pages_mapped - pages));
+}