1/* 2 * ESI call stub. 3 * 4 * Copyright (C) 2005 Hewlett-Packard Co 5 * Alex Williamson <alex.williamson@hp.com> 6 * 7 * Based on EFI call stub by David Mosberger. The stub is virtually 8 * identical to the one for EFI phys-mode calls, except that ESI 9 * calls may have up to 8 arguments, so they get passed to this routine 10 * through memory. 11 * 12 * This stub allows us to make ESI calls in physical mode with interrupts 13 * turned off. ESI calls may not support calling from virtual mode. 14 * 15 * Google for "Extensible SAL specification" for a document describing the 16 * ESI standard. 17 */ 18 19/* 20 * PSR settings as per SAL spec (Chapter 8 in the "IA-64 System 21 * Abstraction Layer Specification", revision 2.6e). Note that 22 * psr.dfl and psr.dfh MUST be cleared, despite what this manual says. 23 * Otherwise, SAL dies whenever it's trying to do an IA-32 BIOS call 24 * (the br.ia instruction fails unless psr.dfl and psr.dfh are 25 * cleared). Fortunately, SAL promises not to touch the floating 26 * point regs, so at least we don't have to save f2-f127. 27 */ 28#define PSR_BITS_TO_CLEAR \ 29 (IA64_PSR_I | IA64_PSR_IT | IA64_PSR_DT | IA64_PSR_RT | \ 30 IA64_PSR_DD | IA64_PSR_SS | IA64_PSR_RI | IA64_PSR_ED | \ 31 IA64_PSR_DFL | IA64_PSR_DFH) 32 33#define PSR_BITS_TO_SET \ 34 (IA64_PSR_BN) 35 36#include <asm/processor.h> 37#include <asm/asmmacro.h> 38#include <asm/export.h> 39 40/* 41 * Inputs: 42 * in0 = address of function descriptor of ESI routine to call 43 * in1 = address of array of ESI parameters 44 * 45 * Outputs: 46 * r8 = result returned by called function 47 */ 48GLOBAL_ENTRY(esi_call_phys) 49 .prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(2) 50 alloc loc1=ar.pfs,2,7,8,0 51 ld8 r2=[in0],8 // load ESI function's entry point 52 mov loc0=rp 53 .body 54 ;; 55 ld8 out0=[in1],8 // ESI params loaded from array 56 ;; // passing all as inputs doesn't work 57 ld8 out1=[in1],8 58 ;; 59 ld8 out2=[in1],8 60 ;; 61 ld8 out3=[in1],8 62 ;; 63 ld8 out4=[in1],8 64 ;; 65 ld8 out5=[in1],8 66 ;; 67 ld8 out6=[in1],8 68 ;; 69 ld8 out7=[in1] 70 mov loc2=gp // save global pointer 71 mov loc4=ar.rsc // save RSE configuration 72 mov ar.rsc=0 // put RSE in enforced lazy, LE mode 73 ;; 74 ld8 gp=[in0] // load ESI function's global pointer 75 movl r16=PSR_BITS_TO_CLEAR 76 mov loc3=psr // save processor status word 77 movl r17=PSR_BITS_TO_SET 78 ;; 79 or loc3=loc3,r17 80 mov b6=r2 81 ;; 82 andcm r16=loc3,r16 // get psr with IT, DT, and RT bits cleared 83 br.call.sptk.many rp=ia64_switch_mode_phys 84.ret0: mov loc5=r19 // old ar.bsp 85 mov loc6=r20 // old sp 86 br.call.sptk.many rp=b6 // call the ESI function 87.ret1: mov ar.rsc=0 // put RSE in enforced lazy, LE mode 88 mov r16=loc3 // save virtual mode psr 89 mov r19=loc5 // save virtual mode bspstore 90 mov r20=loc6 // save virtual mode sp 91 br.call.sptk.many rp=ia64_switch_mode_virt // return to virtual mode 92.ret2: mov ar.rsc=loc4 // restore RSE configuration 93 mov ar.pfs=loc1 94 mov rp=loc0 95 mov gp=loc2 96 br.ret.sptk.many rp 97END(esi_call_phys) 98EXPORT_SYMBOL_GPL(esi_call_phys) 99