1 files changed, 112 insertions, 0 deletions
diff --git a/arch/x86/platform/efi/efi_32.c b/arch/x86/platform/efi/efi_32.c
new file mode 100644
index 0000000..5cab48e
--- /dev/null
+++ b/arch/x86/platform/efi/efi_32.c
@@ -0,0 +1,112 @@
+/*
+ * Extensible Firmware Interface
+ *
+ * Based on Extensible Firmware Interface Specification version 1.0
+ *
+ * Copyright (C) 1999 VA Linux Systems
+ * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
+ * Copyright (C) 1999-2002 Hewlett-Packard Co.
+ *	David Mosberger-Tang <davidm@hpl.hp.com>
+ *	Stephane Eranian <eranian@hpl.hp.com>
+ *
+ * All EFI Runtime Services are not implemented yet as EFI only
+ * supports physical mode addressing on SoftSDV. This is to be fixed
+ * in a future version.  --drummond 1999-07-20
+ *
+ * Implemented EFI runtime services and virtual mode calls.  --davidm
+ *
+ * Goutham Rao: <goutham.rao@intel.com>
+ *	Skip non-WB memory and ignore empty memory ranges.
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/ioport.h>
+#include <linux/efi.h>
+
+#include <asm/io.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/tlbflush.h>
+#include <asm/efi.h>
+
+/*
+ * To make EFI call EFI runtime service in physical addressing mode we need
+ * prelog/epilog before/after the invocation to disable interrupt, to
+ * claim EFI runtime service handler exclusively and to duplicate a memory in
+ * low memory space say 0 - 3G.
+ */
+
+static unsigned long efi_rt_eflags;
+static pgd_t efi_bak_pg_dir_pointer[2];
+
+void efi_call_phys_prelog(void)
+{
+	unsigned long cr4;
+	unsigned long temp;
+	struct desc_ptr gdt_descr;
+
+	local_irq_save(efi_rt_eflags);
+
+	/*
+	 * If I don't have PAE, I should just duplicate two entries in page
+	 * directory. If I have PAE, I just need to duplicate one entry in
+	 * page directory.
+	 */
+	cr4 = read_cr4_safe();
+
+	if (cr4 & X86_CR4_PAE) {
+		efi_bak_pg_dir_pointer[0].pgd =
+		    swapper_pg_dir[pgd_index(0)].pgd;
+		swapper_pg_dir[0].pgd =
+		    swapper_pg_dir[pgd_index(PAGE_OFFSET)].pgd;
+	} else {
+		efi_bak_pg_dir_pointer[0].pgd =
+		    swapper_pg_dir[pgd_index(0)].pgd;
+		efi_bak_pg_dir_pointer[1].pgd =
+		    swapper_pg_dir[pgd_index(0x400000)].pgd;
+		swapper_pg_dir[pgd_index(0)].pgd =
+		    swapper_pg_dir[pgd_index(PAGE_OFFSET)].pgd;
+		temp = PAGE_OFFSET + 0x400000;
+		swapper_pg_dir[pgd_index(0x400000)].pgd =
+		    swapper_pg_dir[pgd_index(temp)].pgd;
+	}
+
+	/*
+	 * After the lock is released, the original page table is restored.
+	 */
+	__flush_tlb_all();
+
+	gdt_descr.address = __pa(get_cpu_gdt_table(0));
+	gdt_descr.size = GDT_SIZE - 1;
+	load_gdt(&gdt_descr);
+}
+
+void efi_call_phys_epilog(void)
+{
+	unsigned long cr4;
+	struct desc_ptr gdt_descr;
+
+	gdt_descr.address = (unsigned long)get_cpu_gdt_table(0);
+	gdt_descr.size = GDT_SIZE - 1;
+	load_gdt(&gdt_descr);
+
+	cr4 = read_cr4_safe();
+
+	if (cr4 & X86_CR4_PAE) {
+		swapper_pg_dir[pgd_index(0)].pgd =
+		    efi_bak_pg_dir_pointer[0].pgd;
+	} else {
+		swapper_pg_dir[pgd_index(0)].pgd =
+		    efi_bak_pg_dir_pointer[0].pgd;
+		swapper_pg_dir[pgd_index(0x400000)].pgd =
+		    efi_bak_pg_dir_pointer[1].pgd;
+	}
+
+	/*
+	 * After the lock is released, the original page table is restored.
+	 */
+	__flush_tlb_all();
+
+	local_irq_restore(efi_rt_eflags);
+}