x86: EFI runtime service support

This patch adds basic runtime services support for EFI x86_64 system.  The
main file of the patch is the addition of efi_64.c for x86_64.  This file is
modeled after the EFI IA32 avatar.  EFI runtime services initialization are
implemented in efi_64.c.  Some x86_64 specifics are worth noting here.  On
x86_64, parameters passed to EFI firmware services need to follow the EFI
calling convention.  For this purpose, a set of functions named efi_call<x>
(<x> is the number of parameters) are implemented.  EFI function calls are
wrapped before calling the firmware service.  The duplicated code between
efi_32.c and efi_64.c is placed in efi.c to remove them from efi_32.c.

Signed-off-by: Chandramouli Narayanan <mouli@linux.intel.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 164 insertions, 0 deletions

diff --git a/arch/x86/kernel/efi_64.c b/arch/x86/kernel/efi_64.c
new file mode 100644
index 000000000000..f2000dbc7195
--- /dev/null
+++ b/arch/x86/kernel/efi_64.c
@@ -0,0 +1,164 @@
+/*
+ * 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/cacheflush.h>
+#include <asm/proto.h>
+#include <asm/efi.h>
+
+static pgd_t save_pgd __initdata;
+static unsigned long efi_flags __initdata;
+
+static int __init setup_noefi(char *arg)
+{
+        efi_enabled = 0;
+        return 0;
+}
+early_param("noefi", setup_noefi);
+
+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 (pte_huge(*kpte))
+                        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;
+
+        /* 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);
+        pgd_val(save_pgd) = pgd_val(*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);
+}
+
+/*
+ * We need to map the EFI memory map again after init_memory_mapping().
+ */
+void __init efi_map_memmap(void)
+{
+        memmap.map = __va(memmap.phys_map);
+        memmap.map_end = memmap.map + (memmap.nr_map * memmap.desc_size);
+}
+
+void __init efi_reserve_bootmem(void)
+{
+        reserve_bootmem_generic((unsigned long)memmap.phys_map,
+                                memmap.nr_map * memmap.desc_size);
+}
+
+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)
+                        change_page_attr_addr(md->virt_addr,
+                                              md->num_pages,
+                                              PAGE_KERNEL_EXEC);
+        }
+        __flush_tlb_all();
+}
+
+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_nocache(FIX_EFI_IO_MAP_FIRST_PAGE - pages_mapped,
+                                   offset);
+                offset += PAGE_SIZE;
+                pages_mapped++;
+        }
+
+        return (void __iomem *)__fix_to_virt(FIX_EFI_IO_MAP_FIRST_PAGE - \
+                                             (pages_mapped - pages));
+}