From 80947e7c99c29ce3a78bdc1933b310468455a82f Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Mon, 18 May 2009 02:10:05 +0000 Subject: [PATCH] powerpc: Keep track of emulated instructions If CONFIG_PPC_EMULATED_STATS is enabled, make available counters for the various classes of emulated instructions under /sys/kernel/debug/powerpc/emulated_instructions/ (assumed debugfs is mounted on /sys/kernel/debug). Optionally (controlled by /sys/kernel/debug/powerpc/emulated_instructions/do_warn), rate-limited warnings can be printed to the console when instructions are emulated. Signed-off-by: Geert Uytterhoeven Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/Kconfig.debug | 13 ++++ arch/powerpc/include/asm/emulated_ops.h | 73 +++++++++++++++++++ arch/powerpc/kernel/align.c | 20 ++++-- arch/powerpc/kernel/traps.c | 96 ++++++++++++++++++++++++- 4 files changed, 196 insertions(+), 6 deletions(-) create mode 100644 arch/powerpc/include/asm/emulated_ops.h diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug index a1098e23221f..d79a902d155a 100644 --- a/arch/powerpc/Kconfig.debug +++ b/arch/powerpc/Kconfig.debug @@ -41,6 +41,19 @@ config HCALL_STATS This option will add a small amount of overhead to all hypervisor calls. +config PPC_EMULATED_STATS + bool "Emulated instructions tracking" + depends on DEBUG_FS + help + Adds code to keep track of the number of instructions that are + emulated by the in-kernel emulator. Counters for the various classes + of emulated instructions are available under + powerpc/emulated_instructions/ in the root of the debugfs file + system. Optionally (controlled by + powerpc/emulated_instructions/do_warn in debugfs), rate-limited + warnings can be printed to the console when instructions are + emulated. + config CODE_PATCHING_SELFTEST bool "Run self-tests of the code-patching code." depends on DEBUG_KERNEL diff --git a/arch/powerpc/include/asm/emulated_ops.h b/arch/powerpc/include/asm/emulated_ops.h new file mode 100644 index 000000000000..9154e8526732 --- /dev/null +++ b/arch/powerpc/include/asm/emulated_ops.h @@ -0,0 +1,73 @@ +/* + * Copyright 2007 Sony Corporation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. + * If not, see . + */ + +#ifndef _ASM_POWERPC_EMULATED_OPS_H +#define _ASM_POWERPC_EMULATED_OPS_H + +#include + + +#ifdef CONFIG_PPC_EMULATED_STATS + +struct ppc_emulated_entry { + const char *name; + atomic_t val; +}; + +extern struct ppc_emulated { +#ifdef CONFIG_ALTIVEC + struct ppc_emulated_entry altivec; +#endif + struct ppc_emulated_entry dcba; + struct ppc_emulated_entry dcbz; + struct ppc_emulated_entry fp_pair; + struct ppc_emulated_entry isel; + struct ppc_emulated_entry mcrxr; + struct ppc_emulated_entry mfpvr; + struct ppc_emulated_entry multiple; + struct ppc_emulated_entry popcntb; + struct ppc_emulated_entry spe; + struct ppc_emulated_entry string; + struct ppc_emulated_entry unaligned; +#ifdef CONFIG_MATH_EMULATION + struct ppc_emulated_entry math; +#elif defined(CONFIG_8XX_MINIMAL_FPEMU) + struct ppc_emulated_entry 8xx; +#endif +#ifdef CONFIG_VSX + struct ppc_emulated_entry vsx; +#endif +} ppc_emulated; + +extern u32 ppc_warn_emulated; + +extern void ppc_warn_emulated_print(const char *type); + +#define PPC_WARN_EMULATED(type) \ + do { \ + atomic_inc(&ppc_emulated.type.val); \ + if (ppc_warn_emulated) \ + ppc_warn_emulated_print(ppc_emulated.type.name); \ + } while (0) + +#else /* !CONFIG_PPC_EMULATED_STATS */ + +#define PPC_WARN_EMULATED(type) do { } while (0) + +#endif /* !CONFIG_PPC_EMULATED_STATS */ + +#endif /* _ASM_POWERPC_EMULATED_OPS_H */ diff --git a/arch/powerpc/kernel/align.c b/arch/powerpc/kernel/align.c index 5ffcfaa77d6a..a5b632e52fae 100644 --- a/arch/powerpc/kernel/align.c +++ b/arch/powerpc/kernel/align.c @@ -24,6 +24,7 @@ #include #include #include +#include struct aligninfo { unsigned char len; @@ -730,8 +731,10 @@ int fix_alignment(struct pt_regs *regs) areg = dsisr & 0x1f; /* register to update */ #ifdef CONFIG_SPE - if ((instr >> 26) == 0x4) + if ((instr >> 26) == 0x4) { + PPC_WARN_EMULATED(spe); return emulate_spe(regs, reg, instr); + } #endif instr = (dsisr >> 10) & 0x7f; @@ -783,23 +786,28 @@ int fix_alignment(struct pt_regs *regs) flags |= SPLT; nb = 8; } + PPC_WARN_EMULATED(vsx); return emulate_vsx(addr, reg, areg, regs, flags, nb); } #endif /* A size of 0 indicates an instruction we don't support, with * the exception of DCBZ which is handled as a special case here */ - if (instr == DCBZ) + if (instr == DCBZ) { + PPC_WARN_EMULATED(dcbz); return emulate_dcbz(regs, addr); + } if (unlikely(nb == 0)) return 0; /* Load/Store Multiple instructions are handled in their own * function */ - if (flags & M) + if (flags & M) { + PPC_WARN_EMULATED(multiple); return emulate_multiple(regs, addr, reg, nb, flags, instr, swiz); + } /* Verify the address of the operand */ if (unlikely(user_mode(regs) && @@ -816,8 +824,12 @@ int fix_alignment(struct pt_regs *regs) } /* Special case for 16-byte FP loads and stores */ - if (nb == 16) + if (nb == 16) { + PPC_WARN_EMULATED(fp_pair); return emulate_fp_pair(addr, reg, flags); + } + + PPC_WARN_EMULATED(unaligned); /* If we are loading, get the data from user space, else * get it from register values diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index 678fbff0d206..6a5b2b731f43 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -33,7 +33,9 @@ #include #include #include +#include +#include #include #include #include @@ -757,36 +759,44 @@ static int emulate_instruction(struct pt_regs *regs) /* Emulate the mfspr rD, PVR. */ if ((instword & PPC_INST_MFSPR_PVR_MASK) == PPC_INST_MFSPR_PVR) { + PPC_WARN_EMULATED(mfpvr); rd = (instword >> 21) & 0x1f; regs->gpr[rd] = mfspr(SPRN_PVR); return 0; } /* Emulating the dcba insn is just a no-op. */ - if ((instword & PPC_INST_DCBA_MASK) == PPC_INST_DCBA) + if ((instword & PPC_INST_DCBA_MASK) == PPC_INST_DCBA) { + PPC_WARN_EMULATED(dcba); return 0; + } /* Emulate the mcrxr insn. */ if ((instword & PPC_INST_MCRXR_MASK) == PPC_INST_MCRXR) { int shift = (instword >> 21) & 0x1c; unsigned long msk = 0xf0000000UL >> shift; + PPC_WARN_EMULATED(mcrxr); regs->ccr = (regs->ccr & ~msk) | ((regs->xer >> shift) & msk); regs->xer &= ~0xf0000000UL; return 0; } /* Emulate load/store string insn. */ - if ((instword & PPC_INST_STRING_GEN_MASK) == PPC_INST_STRING) + if ((instword & PPC_INST_STRING_GEN_MASK) == PPC_INST_STRING) { + PPC_WARN_EMULATED(string); return emulate_string_inst(regs, instword); + } /* Emulate the popcntb (Population Count Bytes) instruction. */ if ((instword & PPC_INST_POPCNTB_MASK) == PPC_INST_POPCNTB) { + PPC_WARN_EMULATED(popcntb); return emulate_popcntb_inst(regs, instword); } /* Emulate isel (Integer Select) instruction */ if ((instword & PPC_INST_ISEL_MASK) == PPC_INST_ISEL) { + PPC_WARN_EMULATED(isel); return emulate_isel(regs, instword); } @@ -984,6 +994,8 @@ void SoftwareEmulation(struct pt_regs *regs) #ifdef CONFIG_MATH_EMULATION errcode = do_mathemu(regs); + if (errcode >= 0) + PPC_WARN_EMULATED(math); switch (errcode) { case 0: @@ -1005,6 +1017,9 @@ void SoftwareEmulation(struct pt_regs *regs) #elif defined(CONFIG_8XX_MINIMAL_FPEMU) errcode = Soft_emulate_8xx(regs); + if (errcode >= 0) + PPC_WARN_EMULATED(8xx); + switch (errcode) { case 0: emulate_single_step(regs); @@ -1088,6 +1103,7 @@ void altivec_assist_exception(struct pt_regs *regs) flush_altivec_to_thread(current); + PPC_WARN_EMULATED(altivec); err = emulate_altivec(regs); if (err == 0) { regs->nip += 4; /* skip emulated instruction */ @@ -1286,3 +1302,79 @@ void kernel_bad_stack(struct pt_regs *regs) void __init trap_init(void) { } + + +#ifdef CONFIG_PPC_EMULATED_STATS + +#define WARN_EMULATED_SETUP(type) .type = { .name = #type } + +struct ppc_emulated ppc_emulated = { +#ifdef CONFIG_ALTIVEC + WARN_EMULATED_SETUP(altivec), +#endif + WARN_EMULATED_SETUP(dcba), + WARN_EMULATED_SETUP(dcbz), + WARN_EMULATED_SETUP(fp_pair), + WARN_EMULATED_SETUP(isel), + WARN_EMULATED_SETUP(mcrxr), + WARN_EMULATED_SETUP(mfpvr), + WARN_EMULATED_SETUP(multiple), + WARN_EMULATED_SETUP(popcntb), + WARN_EMULATED_SETUP(spe), + WARN_EMULATED_SETUP(string), + WARN_EMULATED_SETUP(unaligned), +#ifdef CONFIG_MATH_EMULATION + WARN_EMULATED_SETUP(math), +#elif defined(CONFIG_8XX_MINIMAL_FPEMU) + WARN_EMULATED_SETUP(8xx), +#endif +#ifdef CONFIG_VSX + WARN_EMULATED_SETUP(vsx), +#endif +}; + +u32 ppc_warn_emulated; + +void ppc_warn_emulated_print(const char *type) +{ + if (printk_ratelimit()) + pr_warning("%s used emulated %s instruction\n", current->comm, + type); +} + +static int __init ppc_warn_emulated_init(void) +{ + struct dentry *dir, *d; + unsigned int i; + struct ppc_emulated_entry *entries = (void *)&ppc_emulated; + + if (!powerpc_debugfs_root) + return -ENODEV; + + dir = debugfs_create_dir("emulated_instructions", + powerpc_debugfs_root); + if (!dir) + return -ENOMEM; + + d = debugfs_create_u32("do_warn", S_IRUGO | S_IWUSR, dir, + &ppc_warn_emulated); + if (!d) + goto fail; + + for (i = 0; i < sizeof(ppc_emulated)/sizeof(*entries); i++) { + d = debugfs_create_u32(entries[i].name, S_IRUGO | S_IWUSR, dir, + (u32 *)&entries[i].val.counter); + if (!d) + goto fail; + } + + return 0; + +fail: + debugfs_remove_recursive(dir); + return -ENOMEM; +} + +device_initcall(ppc_warn_emulated_init); + +#endif /* CONFIG_PPC_EMULATED_STATS */