diff options
Diffstat (limited to 'arch/x86/platform/efi/efi_32.c')
-rw-r--r-- | arch/x86/platform/efi/efi_32.c | 69 |
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 new file mode 100644 index 00000000..40e44694 --- /dev/null +++ b/arch/x86/platform/efi/efi_32.c @@ -0,0 +1,69 @@ +/* + * 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); +} |