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1da177e4 LT |
1 | /* |
2 | * EFI call stub. | |
3 | * | |
4 | * Copyright (C) 1999-2001 Hewlett-Packard Co | |
5 | * David Mosberger <davidm@hpl.hp.com> | |
6 | * | |
7 | * This stub allows us to make EFI calls in physical mode with interrupts | |
8 | * turned off. We need this because we can't call SetVirtualMap() until | |
9 | * the kernel has booted far enough to allow allocation of struct vma_struct | |
10 | * entries (which we would need to map stuff with memory attributes other | |
11 | * than uncached or writeback...). Since the GetTime() service gets called | |
12 | * earlier than that, we need to be able to make physical mode EFI calls from | |
13 | * the kernel. | |
14 | */ | |
15 | ||
16 | /* | |
17 | * PSR settings as per SAL spec (Chapter 8 in the "IA-64 System | |
18 | * Abstraction Layer Specification", revision 2.6e). Note that | |
19 | * psr.dfl and psr.dfh MUST be cleared, despite what this manual says. | |
20 | * Otherwise, SAL dies whenever it's trying to do an IA-32 BIOS call | |
21 | * (the br.ia instruction fails unless psr.dfl and psr.dfh are | |
22 | * cleared). Fortunately, SAL promises not to touch the floating | |
23 | * point regs, so at least we don't have to save f2-f127. | |
24 | */ | |
25 | #define PSR_BITS_TO_CLEAR \ | |
26 | (IA64_PSR_I | IA64_PSR_IT | IA64_PSR_DT | IA64_PSR_RT | \ | |
27 | IA64_PSR_DD | IA64_PSR_SS | IA64_PSR_RI | IA64_PSR_ED | \ | |
28 | IA64_PSR_DFL | IA64_PSR_DFH) | |
29 | ||
30 | #define PSR_BITS_TO_SET \ | |
31 | (IA64_PSR_BN) | |
32 | ||
33 | #include <asm/processor.h> | |
34 | #include <asm/asmmacro.h> | |
35 | ||
36 | /* | |
37 | * Inputs: | |
38 | * in0 = address of function descriptor of EFI routine to call | |
39 | * in1..in7 = arguments to routine | |
40 | * | |
41 | * Outputs: | |
42 | * r8 = EFI_STATUS returned by called function | |
43 | */ | |
44 | ||
45 | GLOBAL_ENTRY(efi_call_phys) | |
46 | .prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8) | |
47 | alloc loc1=ar.pfs,8,7,7,0 | |
48 | ld8 r2=[in0],8 // load EFI function's entry point | |
49 | mov loc0=rp | |
50 | .body | |
51 | ;; | |
52 | mov loc2=gp // save global pointer | |
53 | mov loc4=ar.rsc // save RSE configuration | |
54 | mov ar.rsc=0 // put RSE in enforced lazy, LE mode | |
55 | ;; | |
56 | ld8 gp=[in0] // load EFI function's global pointer | |
57 | movl r16=PSR_BITS_TO_CLEAR | |
58 | mov loc3=psr // save processor status word | |
59 | movl r17=PSR_BITS_TO_SET | |
60 | ;; | |
61 | or loc3=loc3,r17 | |
62 | mov b6=r2 | |
63 | ;; | |
65884734 | 64 | andcm r16=loc3,r16 // get psr with IT, DT, and RT bits cleared |
1da177e4 LT |
65 | br.call.sptk.many rp=ia64_switch_mode_phys |
66 | .ret0: mov out4=in5 | |
67 | mov out0=in1 | |
68 | mov out1=in2 | |
69 | mov out2=in3 | |
70 | mov out3=in4 | |
71 | mov out5=in6 | |
72 | mov out6=in7 | |
73 | mov loc5=r19 | |
74 | mov loc6=r20 | |
75 | br.call.sptk.many rp=b6 // call the EFI function | |
76 | .ret1: mov ar.rsc=0 // put RSE in enforced lazy, LE mode | |
77 | mov r16=loc3 | |
78 | mov r19=loc5 | |
79 | mov r20=loc6 | |
80 | br.call.sptk.many rp=ia64_switch_mode_virt // return to virtual mode | |
81 | .ret2: mov ar.rsc=loc4 // restore RSE configuration | |
82 | mov ar.pfs=loc1 | |
83 | mov rp=loc0 | |
84 | mov gp=loc2 | |
85 | br.ret.sptk.many rp | |
86 | END(efi_call_phys) |