From 4b086a750debcb4a5e1738c00a2f0e6c97c44a23 Mon Sep 17 00:00:00 2001 From: wolfgang Date: Tue, 11 Jan 2005 07:23:21 +0000 Subject: [PATCH] [project @ 2005-01-11 07:23:21 by wolfgang] Support foreign import "wrapper" with > 6 arguments on PowerPC Linux (32-bit). This calling convention looks deceptively simple at first, but it turns out to be hideously complex... --- ghc/rts/Adjustor.c | 288 ++++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 222 insertions(+), 66 deletions(-) diff --git a/ghc/rts/Adjustor.c b/ghc/rts/Adjustor.c index b798d86..387d792 100644 --- a/ghc/rts/Adjustor.c +++ b/ghc/rts/Adjustor.c @@ -55,6 +55,10 @@ Haskell side. typedef unsigned long my_uintptr_t; #endif +#if defined(powerpc_TARGET_ARCH) && defined(linux_TARGET_OS) +#include +#endif + /* Heavily arch-specific, I'm afraid.. */ /* @@ -134,6 +138,15 @@ stgAllocStable(size_t size_in_bytes, StgStablePtr *stable) } #endif +#if defined(powerpc_TARGET_ARCH) && defined(linux_TARGET_OS) +__asm__("obscure_ccall_ret_code:\n\t" + "lwz 1,0(1)\n\t" + "lwz 0,4(1)\n\t" + "mtlr 0\n\t" + "blr"); +extern void obscure_ccall_ret_code(void); +#endif + #if defined(powerpc_TARGET_ARCH) || defined(powerpc64_TARGET_ARCH) #if !(defined(powerpc_TARGET_ARCH) && defined(linux_TARGET_OS)) @@ -384,70 +397,213 @@ TODO: Depending on how much allocation overhead stgMallocBytes uses for __asm__ volatile("call_pal %0" : : "i" (PAL_imb)); } #elif defined(powerpc_TARGET_ARCH) && defined(linux_TARGET_OS) -/* - For PowerPC Linux, the following code is used: - - mr r10,r8 - mr r9,r7 - mr r8,r6 - mr r7,r5 - mr r6,r4 - mr r5,r3 - lis r0,0xDEAD ;hi(wptr) - lis r3,0xDEAF ;hi(hptr) - ori r0,r0,0xBEEF ; lo(wptr) - ori r3,r3,0xFACE ; lo(hptr) - mtctr r0 - bctr - - The arguments (passed in registers r3 - r10) are shuffled along by two to - make room for hptr and a dummy argument. As r9 and r10 are overwritten by - this code, it only works for up to 6 arguments (when floating point arguments - are involved, this may be more or less, depending on the exact situation). -*/ - adjustor = mallocBytesRWX(4*13); - { - unsigned long *const adj_code = (unsigned long *)adjustor; - - // make room for extra arguments - adj_code[0] = 0x7d0a4378; //mr r10,r8 - adj_code[1] = 0x7ce93b78; //mr r9,r7 - adj_code[2] = 0x7cc83378; //mr r8,r6 - adj_code[3] = 0x7ca72b78; //mr r7,r5 - adj_code[4] = 0x7c862378; //mr r6,r4 - adj_code[5] = 0x7c651b78; //mr r5,r3 - - adj_code[6] = 0x3c000000; //lis r0,hi(wptr) - adj_code[6] |= ((unsigned long)wptr) >> 16; - - adj_code[7] = 0x3c600000; //lis r3,hi(hptr) - adj_code[7] |= ((unsigned long)hptr) >> 16; - - adj_code[8] = 0x60000000; //ori r0,r0,lo(wptr) - adj_code[8] |= ((unsigned long)wptr) & 0xFFFF; - - adj_code[9] = 0x60630000; //ori r3,r3,lo(hptr) - adj_code[9] |= ((unsigned long)hptr) & 0xFFFF; - - adj_code[10] = 0x7c0903a6; //mtctr r0 - adj_code[11] = 0x4e800420; //bctr - adj_code[12] = (unsigned long)hptr; - - // Flush the Instruction cache: - // MakeDataExecutable(adjustor,4*13); - /* This would require us to link with CoreServices.framework */ - { /* this should do the same: */ - int n = 13; - unsigned long *p = adj_code; - while(n--) - { - __asm__ volatile ("dcbf 0,%0\n\tsync\n\ticbi 0,%0" - : : "r" (p)); - p++; - } - __asm__ volatile ("sync\n\tisync"); - } - } + +#define OP_LO(op,lo) ((((unsigned)(op)) << 16) | (((unsigned)(lo)) & 0xFFFF)) +#define OP_HI(op,hi) ((((unsigned)(op)) << 16) | (((unsigned)(hi)) >> 16)) + { + /* The PowerPC Linux (32-bit) calling convention is annoyingly complex. + We need to calculate all the details of the stack frame layout, + taking into account the types of all the arguments, and then + generate code on the fly. */ + + int src_gpr = 3, dst_gpr = 5; + int fpr = 3; + int src_offset = 0, dst_offset = 0; + int n = strlen(typeString),i; + int src_locs[n], dst_locs[n]; + int frameSize; + unsigned *code; + + /* Step 1: + Calculate where the arguments should go. + src_locs[] will contain the locations of the arguments in the + original stack frame passed to the adjustor. + dst_locs[] will contain the locations of the arguments after the + adjustor runs, on entry to the wrapper proc pointed to by wptr. + + This algorithm is based on the one described on page 3-19 of the + System V ABI PowerPC Processor Supplement. + */ + for(i=0;typeString[i];i++) + { + char t = typeString[i]; + if((t == 'f' || t == 'd') && fpr <= 8) + src_locs[i] = dst_locs[i] = -32-(fpr++); + else + { + if(t == 'l' && src_gpr <= 9) + { + if((src_gpr & 1) == 0) + src_gpr++; + src_locs[i] = -src_gpr; + src_gpr += 2; + } + else if(t == 'i' && src_gpr <= 10) + { + src_locs[i] = -(src_gpr++); + } + else + { + if(t == 'l' || t == 'd') + { + if(src_offset % 8) + src_offset += 4; + } + src_locs[i] = src_offset; + src_offset += (t == 'l' || t == 'd') ? 8 : 4; + } + + if(t == 'l' && dst_gpr <= 9) + { + if((dst_gpr & 1) == 0) + dst_gpr++; + dst_locs[i] = -dst_gpr; + dst_gpr += 2; + } + else if(t == 'i' && dst_gpr <= 10) + { + dst_locs[i] = -(dst_gpr++); + } + else + { + if(t == 'l' || t == 'd') + { + if(dst_offset % 8) + dst_offset += 4; + } + dst_locs[i] = dst_offset; + dst_offset += (t == 'l' || t == 'd') ? 8 : 4; + } + } + } + + frameSize = dst_offset + 8; + frameSize = (frameSize+15) & ~0xF; + + /* Step 2: + Build the adjustor. + */ + // allocate space for at most 4 insns per parameter + // plus 14 more instructions. + adjustor = mallocBytesRWX(4 * (4*n + 14)); + code = (unsigned*)adjustor; + + *code++ = 0x48000008; // b *+8 + // * Put the hptr in a place where freeHaskellFunctionPtr + // can get at it. + *code++ = (unsigned) hptr; + + // * save the link register + *code++ = 0x7c0802a6; // mflr r0; + *code++ = 0x90010004; // stw r0, 4(r1); + // * and build a new stack frame + *code++ = OP_LO(0x9421, -frameSize); // stwu r1, -frameSize(r1) + + // * now generate instructions to copy arguments + // from the old stack frame into the new stack frame. + for(i=n-1;i>=0;i--) + { + if(src_locs[i] < -32) + ASSERT(dst_locs[i] == src_locs[i]); + else if(src_locs[i] < 0) + { + // source in GPR. + ASSERT(typeString[i] != 'f' && typeString[i] != 'd'); + if(dst_locs[i] < 0) + { + ASSERT(dst_locs[i] > -32); + // dst is in GPR, too. + + if(typeString[i] == 'l') + { + // mr dst+1, src+1 + *code++ = 0x7c000378 + | ((-dst_locs[i]+1) << 16) + | ((-src_locs[i]+1) << 11) + | ((-src_locs[i]+1) << 21); + } + // mr dst, src + *code++ = 0x7c000378 + | ((-dst_locs[i]) << 16) + | ((-src_locs[i]) << 11) + | ((-src_locs[i]) << 21); + } + else + { + if(typeString[i] == 'l') + { + // stw src+1, dst_offset+4(r1) + *code++ = 0x90010000 + | ((-src_locs[i]+1) << 21) + | (dst_locs[i] + 4); + } + + // stw src, dst_offset(r1) + *code++ = 0x90010000 + | ((-src_locs[i]) << 21) + | (dst_locs[i] + 8); + } + } + else + { + ASSERT(dst_locs[i] >= 0); + ASSERT(typeString[i] != 'f' && typeString[i] != 'd'); + + if(typeString[i] == 'l') + { + // lwz r0, src_offset(r1) + *code++ = 0x80010000 + | (src_locs[i] + frameSize + 8 + 4); + // stw r0, dst_offset(r1) + *code++ = 0x90010000 + | (dst_locs[i] + 8 + 4); + } + // lwz r0, src_offset(r1) + *code++ = 0x80010000 + | (src_locs[i] + frameSize + 8); + // stw r0, dst_offset(r1) + *code++ = 0x90010000 + | (dst_locs[i] + 8); + } + } + + // * hptr will be the new first argument. + // lis r3, hi(hptr) + *code++ = OP_HI(0x3c60, hptr); + // ori r3,r3,lo(hptr) + *code++ = OP_LO(0x6063, hptr); + + // * we need to return to a piece of code + // which will tear down the stack frame. + // lis r11,hi(obscure_ccall_ret_code) + *code++ = OP_HI(0x3d60, obscure_ccall_ret_code); + // ori r11,r11,lo(obscure_ccall_ret_code) + *code++ = OP_LO(0x616b, obscure_ccall_ret_code); + // mtlr r11 + *code++ = 0x7d6803a6; + + // * jump to wptr + // lis r11,hi(wptr) + *code++ = OP_HI(0x3d60, wptr); + // ori r11,r11,lo(wptr) + *code++ = OP_LO(0x616b, wptr); + // mtctr r11 + *code++ = 0x7d6903a6; + // bctr + *code++ = 0x4e800420; + + // Flush the Instruction cache: + { + unsigned *p = adjustor; + while(p < code) + { + __asm__ volatile ("dcbf 0,%0\n\tsync\n\ticbi 0,%0" + : : "r" (p)); + p++; + } + __asm__ volatile ("sync\n\tisync"); + } + } #elif defined(powerpc_TARGET_ARCH) || defined(powerpc64_TARGET_ARCH) @@ -672,11 +828,11 @@ freeHaskellFunctionPtr(void* ptr) /* Free the stable pointer first..*/ freeStablePtr(*((StgStablePtr*)((unsigned char*)ptr + 0x10))); #elif defined(powerpc_TARGET_ARCH) && defined(linux_TARGET_OS) - if ( *(StgWord*)ptr != 0x7d0a4378 ) { + if ( *(StgWord*)ptr != 0x48000008 ) { errorBelch("freeHaskellFunctionPtr: not for me, guv! %p\n", ptr); return; } - freeStablePtr(*((StgStablePtr*)((unsigned char*)ptr + 4*12))); + freeStablePtr(((StgStablePtr*)ptr)[1]); #elif defined(powerpc_TARGET_ARCH) || defined(powerpc64_TARGET_ARCH) extern void* adjustorCode; if ( ((AdjustorStub*)ptr)->code != (StgFunPtr) &adjustorCode ) { -- 1.7.10.4