powerpc: Rename and flesh out the facility unavailable exception handler

The exception at 0xf60 is not the TM (Transactional Memory) unavailable
exception, it is the "Facility Unavailable Exception", rename it as
such.

Flesh out the handler to acknowledge the fact that it can be called for
many reasons, one of which is TM being unavailable.

Use STD_EXCEPTION_COMMON() for the exception body, for some reason we
had it open-coded, I've checked the generated code is identical.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
CC: <stable@vger.kernel.org> [v3.10]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

2 files changed, 32 insertions, 22 deletions

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 89eba1fb5bbe..6ee74f8bae2f 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -341,10 +341,11 @@ vsx_unavailable_pSeries_1:
         EXCEPTION_PROLOG_0(PACA_EXGEN)
         b       vsx_unavailable_pSeries
 
+facility_unavailable_trampoline:
         . = 0xf60
         SET_SCRATCH0(r13)
         EXCEPTION_PROLOG_0(PACA_EXGEN)
-        b       tm_unavailable_pSeries
+        b       facility_unavailable_pSeries
 
 #ifdef CONFIG_CBE_RAS
         STD_EXCEPTION_HV(0x1200, 0x1202, cbe_system_error)
@@ -522,7 +523,7 @@ denorm_done:
         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)
+        STD_EXCEPTION_PSERIES_OOL(0xf60, facility_unavailable)
         KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0xf60)
 
 /*
@@ -829,11 +830,11 @@ vsx_unavailable_relon_pSeries_1:
         EXCEPTION_PROLOG_0(PACA_EXGEN)
         b       vsx_unavailable_relon_pSeries
 
-tm_unavailable_relon_pSeries_1:
+facility_unavailable_relon_trampoline:
         . = 0x4f60
         SET_SCRATCH0(r13)
         EXCEPTION_PROLOG_0(PACA_EXGEN)
-        b       tm_unavailable_relon_pSeries
+        b       facility_unavailable_relon_pSeries
 
         STD_RELON_EXCEPTION_PSERIES(0x5300, 0x1300, instruction_breakpoint)
 #ifdef CONFIG_PPC_DENORMALISATION
@@ -1159,15 +1160,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
         bl      .vsx_unavailable_exception
         b       .ret_from_except
 
-        .align  7
-        .globl tm_unavailable_common
-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
+        STD_EXCEPTION_COMMON(0xf60, facility_unavailable, .facility_unavailable_exception)
 
         .align  7
         .globl  __end_handlers
@@ -1180,7 +1173,7 @@ __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)
+        STD_RELON_EXCEPTION_PSERIES_OOL(0xf60, facility_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 300daf3e7ab0..11f448812dc1 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1286,25 +1286,42 @@ void vsx_unavailable_exception(struct pt_regs *regs)
         die("Unrecoverable VSX Unavailable Exception", regs, SIGABRT);
 }
 
-void tm_unavailable_exception(struct pt_regs *regs)
+void facility_unavailable_exception(struct pt_regs *regs)
 {
+        static char *facility_strings[] = {
+                "FPU",
+                "VMX/VSX",
+                "DSCR",
+                "PMU SPRs",
+                "BHRB",
+                "TM",
+                "AT",
+                "EBB",
+                "TAR",
+        };
+        char *facility;
+        u64 value;
+
+        value = mfspr(SPRN_FSCR) >> 56;
+
         /* 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 (value < ARRAY_SIZE(facility_strings))
+                facility = facility_strings[value];
+        else
+                facility = "unknown";
+
+        pr_err("Facility '%s' unavailable, exception at 0x%lx, MSR=%lx\n",
+                facility, regs->nip, regs->msr);
 
         if (user_mode(regs)) {
                 _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
                 return;
         }
 
-        die("Unexpected TM unavailable exception", regs, SIGABRT);
+        die("Unexpected facility unavailable exception", regs, SIGABRT);
 }
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM