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authorMichael Neuling <mikey@neuling.org>2013-02-13 16:21:40 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2013-02-15 17:02:23 +1100
commitbc2a9408fa65195288b41751016c36fd00a75a85 (patch)
tree4261aaddc1382981e9d566699a2f03a816c89ae7 /arch/powerpc
parentf54db641b9bbca91b071128e4d71f0f6af9a3c25 (diff)
downloadlinux-bc2a9408fa65195288b41751016c36fd00a75a85.tar.bz2
powerpc: Hook in new transactional memory code
This hooks the new transactional memory code into context switching, FP/VMX/VMX unavailable and exception return. Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/kernel/exceptions-64s.S56
-rw-r--r--arch/powerpc/kernel/process.c15
-rw-r--r--arch/powerpc/kernel/traps.c32
-rw-r--r--arch/powerpc/mm/hash_utils_64.c16
4 files changed, 115 insertions, 4 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index c6b88c1f3ebd..a8a5361fb70c 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1176,9 +1176,26 @@ 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:
@@ -1186,8 +1203,25 @@ 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
@@ -1204,7 +1238,24 @@ 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
@@ -1219,6 +1270,7 @@ 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 48a987579e4f..59dd545fdde1 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 5c304697fe84..f9b751b29558 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 3a292be2e079..1b6e1271719f 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -55,6 +55,7 @@
#include <asm/code-patching.h>
#include <asm/fadump.h>
#include <asm/firmware.h>
+#include <asm/tm.h>
#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)