mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-21 11:44:01 +08:00
87 lines
2.6 KiB
ArmAsm
87 lines
2.6 KiB
ArmAsm
/*
|
|
* EFI call stub.
|
|
*
|
|
* Copyright (C) 1999-2001 Hewlett-Packard Co
|
|
* David Mosberger <davidm@hpl.hp.com>
|
|
*
|
|
* This stub allows us to make EFI calls in physical mode with interrupts
|
|
* turned off. We need this because we can't call SetVirtualMap() until
|
|
* the kernel has booted far enough to allow allocation of struct vma_struct
|
|
* entries (which we would need to map stuff with memory attributes other
|
|
* than uncached or writeback...). Since the GetTime() service gets called
|
|
* earlier than that, we need to be able to make physical mode EFI calls from
|
|
* the kernel.
|
|
*/
|
|
|
|
/*
|
|
* PSR settings as per SAL spec (Chapter 8 in the "IA-64 System
|
|
* Abstraction Layer Specification", revision 2.6e). Note that
|
|
* psr.dfl and psr.dfh MUST be cleared, despite what this manual says.
|
|
* Otherwise, SAL dies whenever it's trying to do an IA-32 BIOS call
|
|
* (the br.ia instruction fails unless psr.dfl and psr.dfh are
|
|
* cleared). Fortunately, SAL promises not to touch the floating
|
|
* point regs, so at least we don't have to save f2-f127.
|
|
*/
|
|
#define PSR_BITS_TO_CLEAR \
|
|
(IA64_PSR_I | IA64_PSR_IT | IA64_PSR_DT | IA64_PSR_RT | \
|
|
IA64_PSR_DD | IA64_PSR_SS | IA64_PSR_RI | IA64_PSR_ED | \
|
|
IA64_PSR_DFL | IA64_PSR_DFH)
|
|
|
|
#define PSR_BITS_TO_SET \
|
|
(IA64_PSR_BN)
|
|
|
|
#include <asm/processor.h>
|
|
#include <asm/asmmacro.h>
|
|
|
|
/*
|
|
* Inputs:
|
|
* in0 = address of function descriptor of EFI routine to call
|
|
* in1..in7 = arguments to routine
|
|
*
|
|
* Outputs:
|
|
* r8 = EFI_STATUS returned by called function
|
|
*/
|
|
|
|
GLOBAL_ENTRY(efi_call_phys)
|
|
.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8)
|
|
alloc loc1=ar.pfs,8,7,7,0
|
|
ld8 r2=[in0],8 // load EFI function's entry point
|
|
mov loc0=rp
|
|
.body
|
|
;;
|
|
mov loc2=gp // save global pointer
|
|
mov loc4=ar.rsc // save RSE configuration
|
|
mov ar.rsc=0 // put RSE in enforced lazy, LE mode
|
|
;;
|
|
ld8 gp=[in0] // load EFI function's global pointer
|
|
movl r16=PSR_BITS_TO_CLEAR
|
|
mov loc3=psr // save processor status word
|
|
movl r17=PSR_BITS_TO_SET
|
|
;;
|
|
or loc3=loc3,r17
|
|
mov b6=r2
|
|
;;
|
|
andcm r16=loc3,r16 // get psr with IT, DT, and RT bits cleared
|
|
br.call.sptk.many rp=ia64_switch_mode_phys
|
|
.ret0: mov out4=in5
|
|
mov out0=in1
|
|
mov out1=in2
|
|
mov out2=in3
|
|
mov out3=in4
|
|
mov out5=in6
|
|
mov out6=in7
|
|
mov loc5=r19
|
|
mov loc6=r20
|
|
br.call.sptk.many rp=b6 // call the EFI function
|
|
.ret1: mov ar.rsc=0 // put RSE in enforced lazy, LE mode
|
|
mov r16=loc3
|
|
mov r19=loc5
|
|
mov r20=loc6
|
|
br.call.sptk.many rp=ia64_switch_mode_virt // return to virtual mode
|
|
.ret2: mov ar.rsc=loc4 // restore RSE configuration
|
|
mov ar.pfs=loc1
|
|
mov rp=loc0
|
|
mov gp=loc2
|
|
br.ret.sptk.many rp
|
|
END(efi_call_phys)
|