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authorThomas Gleixner <tglx@linutronix.de>2010-10-16 10:19:54 +0200
committerThomas Gleixner <tglx@linutronix.de>2010-10-27 14:30:01 +0200
commitb17ed48040d9e8b6ae35bc492015bf0fe1c8bae4 (patch)
tree64c31f66a0fc65268d02b2cee14e7abd760121e9 /arch/x86/platform/efi/efi_32.c
parent937f961a6539b0ac5ebf31472b90810bc1f02200 (diff)
x86: Move efi to platform
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Huang Ying <ying.huang@intel.com>
Diffstat (limited to 'arch/x86/platform/efi/efi_32.c')
-rw-r--r--arch/x86/platform/efi/efi_32.c112
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 000000000000..5cab48ee61a4
--- /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);
+}

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