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Diffstat (limited to 'arch/x86/platform/efi/efi_32.c')
-rw-r--r--arch/x86/platform/efi/efi_32.c69
1 files changed, 69 insertions, 0 deletions
diff --git a/arch/x86/platform/efi/efi_32.c b/arch/x86/platform/efi/efi_32.c
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+++ b/arch/x86/platform/efi/efi_32.c
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+/*
+ * 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/desc.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;
+
+void efi_call_phys_prelog(void)
+{
+ struct desc_ptr gdt_descr;
+
+ local_irq_save(efi_rt_eflags);
+
+ load_cr3(initial_page_table);
+ __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)
+{
+ 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);
+
+ load_cr3(swapper_pg_dir);
+ __flush_tlb_all();
+
+ local_irq_restore(efi_rt_eflags);
+}