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 0000000..f2000db
--- /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));
+}