From patchwork Wed Feb 13 04:31:30 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Neuling X-Patchwork-Id: 220036 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [IPv6:::1]) by ozlabs.org (Postfix) with ESMTP id 42C912C0FF5 for ; Wed, 13 Feb 2013 15:39:08 +1100 (EST) Received: from localhost.localdomain (localhost [127.0.0.1]) by ozlabs.org (Postfix) with ESMTP id 232E32C0302; Wed, 13 Feb 2013 15:31:57 +1100 (EST) Received: by localhost.localdomain (Postfix, from userid 1000) id 29469D44C66; Wed, 13 Feb 2013 15:31:57 +1100 (EST) From: Michael Neuling To: Benjamin Herrenschmidt Subject: [PATCH 12/17] powerpc: Hook in new transactional memory code Date: Wed, 13 Feb 2013 15:31:30 +1100 Message-Id: <1360729895-304-13-git-send-email-mikey@neuling.org> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1360729895-304-1-git-send-email-mikey@neuling.org> References: <1360729895-304-1-git-send-email-mikey@neuling.org> Cc: Michael Neuling , linuxppc-dev@lists.ozlabs.org, Matt Evans X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" This hooks the new transactional memory code into context switching, FP/VMX/VMX unavailable and exception return. Signed-off-by: Matt Evans Signed-off-by: Michael Neuling --- arch/powerpc/kernel/exceptions-64s.S | 56 ++++++++++++++++++++++++++++++++-- arch/powerpc/kernel/process.c | 15 +++++++-- arch/powerpc/kernel/traps.c | 32 +++++++++++++++++++ arch/powerpc/mm/hash_utils_64.c | 16 ++++++++++ 4 files changed, 115 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index d0cc657..85b923c 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -1147,9 +1147,26 @@ fp_unavailable_common: addi r3,r1,STACK_FRAME_OVERHEAD bl .kernel_fp_unavailable_exception BUG_OPCODE -1: bl .load_up_fpu +1: +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM +BEGIN_FTR_SECTION + /* Test if 2 TM state bits are zero. If non-zero (ie. userspace was in + * transaction), go do TM stuff + */ + rldicl. r0, r12, (64-MSR_TS_LG), (64-2) + bne- 2f +END_FTR_SECTION_IFSET(CPU_FTR_TM) +#endif + bl .load_up_fpu b fast_exception_return - +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM +2: /* User process was in a transaction */ + bl .save_nvgprs + DISABLE_INTS + addi r3,r1,STACK_FRAME_OVERHEAD + bl .fp_unavailable_tm + b .ret_from_except +#endif .align 7 .globl altivec_unavailable_common altivec_unavailable_common: @@ -1157,8 +1174,25 @@ altivec_unavailable_common: #ifdef CONFIG_ALTIVEC BEGIN_FTR_SECTION beq 1f +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + BEGIN_FTR_SECTION_NESTED(69) + /* Test if 2 TM state bits are zero. If non-zero (ie. userspace was in + * transaction), go do TM stuff + */ + rldicl. r0, r12, (64-MSR_TS_LG), (64-2) + bne- 2f + END_FTR_SECTION_NESTED(CPU_FTR_TM, CPU_FTR_TM, 69) +#endif bl .load_up_altivec b fast_exception_return +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM +2: /* User process was in a transaction */ + bl .save_nvgprs + DISABLE_INTS + addi r3,r1,STACK_FRAME_OVERHEAD + bl .altivec_unavailable_tm + b .ret_from_except +#endif 1: END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) #endif @@ -1175,7 +1209,24 @@ vsx_unavailable_common: #ifdef CONFIG_VSX BEGIN_FTR_SECTION beq 1f +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + BEGIN_FTR_SECTION_NESTED(69) + /* Test if 2 TM state bits are zero. If non-zero (ie. userspace was in + * transaction), go do TM stuff + */ + rldicl. r0, r12, (64-MSR_TS_LG), (64-2) + bne- 2f + END_FTR_SECTION_NESTED(CPU_FTR_TM, CPU_FTR_TM, 69) +#endif b .load_up_vsx +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM +2: /* User process was in a transaction */ + bl .save_nvgprs + DISABLE_INTS + addi r3,r1,STACK_FRAME_OVERHEAD + bl .vsx_unavailable_tm + b .ret_from_except +#endif 1: END_FTR_SECTION_IFSET(CPU_FTR_VSX) #endif @@ -1190,6 +1241,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX) tm_unavailable_common: EXCEPTION_PROLOG_COMMON(0xf60, PACA_EXGEN) bl .save_nvgprs + DISABLE_INTS addi r3,r1,STACK_FRAME_OVERHEAD bl .tm_unavailable_exception b .ret_from_except diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 48a9875..59dd545 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -515,7 +515,7 @@ out_and_saveregs: tm_save_sprs(thr); } -static inline void __maybe_unused tm_recheckpoint_new_task(struct task_struct *new) +static inline void tm_recheckpoint_new_task(struct task_struct *new) { unsigned long msr; @@ -590,6 +590,8 @@ struct task_struct *__switch_to(struct task_struct *prev, struct ppc64_tlb_batch *batch; #endif + __switch_to_tm(prev); + #ifdef CONFIG_SMP /* avoid complexity of lazy save/restore of fpu * by just saving it every time we switch out if @@ -705,6 +707,9 @@ struct task_struct *__switch_to(struct task_struct *prev, * of sync. Hard disable here. */ hard_irq_disable(); + + tm_recheckpoint_new_task(new); + last = _switch(old_thread, new_thread); #ifdef CONFIG_PPC_BOOK3S_64 @@ -1080,7 +1085,6 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp) regs->msr = MSR_USER32; } #endif - discard_lazy_cpu_state(); #ifdef CONFIG_VSX current->thread.used_vsr = 0; @@ -1100,6 +1104,13 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp) current->thread.spefscr = 0; current->thread.used_spe = 0; #endif /* CONFIG_SPE */ +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + if (cpu_has_feature(CPU_FTR_TM)) + regs->msr |= MSR_TM; + current->thread.tm_tfhar = 0; + current->thread.tm_texasr = 0; + current->thread.tm_tfiar = 0; +#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ } #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \ diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index 5c30469..f9b751b 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -1029,6 +1029,38 @@ void __kprobes program_check_exception(struct pt_regs *regs) _exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip); return; } +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + if (reason & REASON_TM) { + /* This is a TM "Bad Thing Exception" program check. + * This occurs when: + * - An rfid/hrfid/mtmsrd attempts to cause an illegal + * transition in TM states. + * - A trechkpt is attempted when transactional. + * - A treclaim is attempted when non transactional. + * - A tend is illegally attempted. + * - writing a TM SPR when transactional. + */ + if (!user_mode(regs) && + report_bug(regs->nip, regs) == BUG_TRAP_TYPE_WARN) { + regs->nip += 4; + return; + } + /* If usermode caused this, it's done something illegal and + * gets a SIGILL slap on the wrist. We call it an illegal + * operand to distinguish from the instruction just being bad + * (e.g. executing a 'tend' on a CPU without TM!); it's an + * illegal /placement/ of a valid instruction. + */ + if (user_mode(regs)) { + _exception(SIGILL, regs, ILL_ILLOPN, regs->nip); + return; + } else { + printk(KERN_EMERG "Unexpected TM Bad Thing exception " + "at %lx (msr 0x%x)\n", regs->nip, reason); + die("Unrecoverable exception", regs, SIGABRT); + } + } +#endif /* We restore the interrupt state now */ if (!arch_irq_disabled_regs(regs)) diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c index 3a292be..1b6e127 100644 --- a/arch/powerpc/mm/hash_utils_64.c +++ b/arch/powerpc/mm/hash_utils_64.c @@ -55,6 +55,7 @@ #include #include #include +#include #ifdef DEBUG #define DBG(fmt...) udbg_printf(fmt) @@ -1171,6 +1172,21 @@ void flush_hash_page(unsigned long vpn, real_pte_t pte, int psize, int ssize, DBG_LOW(" sub %ld: hash=%lx, hidx=%lx\n", index, slot, hidx); ppc_md.hpte_invalidate(slot, vpn, psize, ssize, local); } pte_iterate_hashed_end(); + +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + /* Transactions are not aborted by tlbiel, only tlbie. + * Without, syncing a page back to a block device w/ PIO could pick up + * transactional data (bad!) so we force an abort here. Before the + * sync the page will be made read-only, which will flush_hash_page. + * BIG ISSUE here: if the kernel uses a page from userspace without + * unmapping it first, it may see the speculated version. + */ + if (local && cpu_has_feature(CPU_FTR_TM) && + MSR_TM_ACTIVE(current->thread.regs->msr)) { + tm_enable(); + tm_abort(TM_CAUSE_TLBI); + } +#endif } void flush_hash_range(unsigned long number, int local)