powerpc: Add transactional memory unavaliable execption handler

These should never happen since we always turn on MSR TM when in userspace. We
don't do lazy TM.

Hence if we hit this, we barf and kill the task as something's gone horribly
wrong.

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>

2 files changed, 44 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index b9bcf21dbb11..c6b88c1f3ebd 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -336,6 +336,11 @@ vsx_unavailable_pSeries_1:
         EXCEPTION_PROLOG_0(PACA_EXGEN)
         b       vsx_unavailable_pSeries
 
+        . = 0xf60
+        SET_SCRATCH0(r13)
+        EXCEPTION_PROLOG_0(PACA_EXGEN)
+        b       tm_unavailable_pSeries
+
 #ifdef CONFIG_CBE_RAS
         STD_EXCEPTION_HV(0x1200, 0x1202, cbe_system_error)
         KVM_HANDLER_SKIP(PACA_EXGEN, EXC_HV, 0x1202)
@@ -550,6 +555,8 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_206)
         KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0xf20)
         STD_EXCEPTION_PSERIES_OOL(0xf40, vsx_unavailable)
         KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0xf40)
+        STD_EXCEPTION_PSERIES_OOL(0xf60, tm_unavailable)
+        KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0xf60)
 
 /*
  * An interrupt came in while soft-disabled. We set paca->irq_happened, then:
@@ -852,6 +859,12 @@ vsx_unavailable_relon_pSeries_1:
         EXCEPTION_PROLOG_0(PACA_EXGEN)
         b       vsx_unavailable_relon_pSeries
 
+tm_unavailable_relon_pSeries_1:
+        . = 0x4f60
+        SET_SCRATCH0(r13)
+        EXCEPTION_PROLOG_0(PACA_EXGEN)
+        b       tm_unavailable_relon_pSeries
+
         STD_RELON_EXCEPTION_PSERIES(0x5300, 0x1300, instruction_breakpoint)
 #ifdef CONFIG_PPC_DENORMALISATION
         . = 0x5500
@@ -1202,6 +1215,15 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
         b       .ret_from_except
 
         .align  7
+        .globl tm_unavailable_common
+tm_unavailable_common:
+        EXCEPTION_PROLOG_COMMON(0xf60, PACA_EXGEN)
+        bl      .save_nvgprs
+        addi    r3,r1,STACK_FRAME_OVERHEAD
+        bl      .tm_unavailable_exception
+        b       .ret_from_except
+
+        .align  7
         .globl  __end_handlers
 __end_handlers:
 
@@ -1220,6 +1242,7 @@ __end_handlers:
         STD_RELON_EXCEPTION_PSERIES_OOL(0xf00, performance_monitor)
         STD_RELON_EXCEPTION_PSERIES_OOL(0xf20, altivec_unavailable)
         STD_RELON_EXCEPTION_PSERIES_OOL(0xf40, vsx_unavailable)
+        STD_RELON_EXCEPTION_PSERIES_OOL(0xf60, tm_unavailable)
 
 #if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_PPC_POWERNV)
 /*
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index bd5de5deaf51..f829e05d8b1b 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1168,6 +1168,27 @@ void vsx_unavailable_exception(struct pt_regs *regs)
         die("Unrecoverable VSX Unavailable Exception", regs, SIGABRT);
 }
 
+void tm_unavailable_exception(struct pt_regs *regs)
+{
+        /* We restore the interrupt state now */
+        if (!arch_irq_disabled_regs(regs))
+                local_irq_enable();
+
+        /* Currently we never expect a TMU exception.  Catch
+         * this and kill the process!
+         */
+        printk(KERN_EMERG "Unexpected TM unavailable exception at %lx "
+               "(msr %lx)\n",
+               regs->nip, regs->msr);
+
+        if (user_mode(regs)) {
+                _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
+                return;
+        }
+
+        die("Unexpected TM unavailable exception", regs, SIGABRT);
+}
+
 void performance_monitor_exception(struct pt_regs *regs)
 {
         __get_cpu_var(irq_stat).pmu_irqs++;