[PATCH 3.13 031/162] sparc64: sun4v TLB error power off events
Kamal Mostafa
kamal at canonical.com
Thu Nov 6 22:34:55 UTC 2014
3.13.11.11 -stable review patch. If anyone has any objections, please let me know.
------------------
From: bob picco <bpicco at meloft.net>
[ Upstream commit 4ccb9272892c33ef1c19a783cfa87103b30c2784 ]
We've witnessed a few TLB events causing the machine to power off because
of prom_halt. In one case it was some nfs related area during rmmod. Another
was an mmapper of /dev/mem. A more recent one is an ITLB issue with
a bad pagesize which could be a hardware bug. Bugs happen but we should
attempt to not power off the machine and/or hang it when possible.
This is a DTLB error from an mmapper of /dev/mem:
[root at sparcie ~]# SUN4V-DTLB: Error at TPC[fffff80100903e6c], tl 1
SUN4V-DTLB: TPC<0xfffff80100903e6c>
SUN4V-DTLB: O7[fffff801081979d0]
SUN4V-DTLB: O7<0xfffff801081979d0>
SUN4V-DTLB: vaddr[fffff80100000000] ctx[1250] pte[98000000000f0610] error[2]
.
This is recent mainline for ITLB:
[ 3708.179864] SUN4V-ITLB: TPC<0xfffffc010071cefc>
[ 3708.188866] SUN4V-ITLB: O7[fffffc010071cee8]
[ 3708.197377] SUN4V-ITLB: O7<0xfffffc010071cee8>
[ 3708.206539] SUN4V-ITLB: vaddr[e0003] ctx[1a3c] pte[2900000dcc800eeb] error[4]
.
Normally sun4v_itlb_error_report() and sun4v_dtlb_error_report() would call
prom_halt() and drop us to OF command prompt "ok". This isn't the case for
LDOMs and the machine powers off.
For the HV reported error of HV_ENORADDR for HV HV_MMU_MAP_ADDR_TRAP we cause
a SIGBUS error by qualifying it within do_sparc64_fault() for fault code mask
of FAULT_CODE_BAD_RA. This is done when trap level (%tl) is less or equal
one("1"). Otherwise, for %tl > 1, we proceed eventually to die_if_kernel().
The logic of this patch was partially inspired by David Miller's feedback.
Power off of large sparc64 machines is painful. Plus die_if_kernel provides
more context. A reset sequence isn't a brief period on large sparc64 but
better than power-off/power-on sequence.
Cc: sparclinux at vger.kernel.org
Signed-off-by: Bob Picco <bob.picco at oracle.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
arch/sparc/include/asm/thread_info_64.h | 1 +
arch/sparc/kernel/sun4v_tlb_miss.S | 35 ++++++++++++++++++++-------------
arch/sparc/kernel/traps_64.c | 15 ++++++++------
arch/sparc/mm/fault_64.c | 3 +++
4 files changed, 34 insertions(+), 20 deletions(-)
diff --git a/arch/sparc/include/asm/thread_info_64.h b/arch/sparc/include/asm/thread_info_64.h
index a5f01ac..f85dc85 100644
--- a/arch/sparc/include/asm/thread_info_64.h
+++ b/arch/sparc/include/asm/thread_info_64.h
@@ -102,6 +102,7 @@ struct thread_info {
#define FAULT_CODE_ITLB 0x04 /* Miss happened in I-TLB */
#define FAULT_CODE_WINFIXUP 0x08 /* Miss happened during spill/fill */
#define FAULT_CODE_BLKCOMMIT 0x10 /* Use blk-commit ASI in copy_page */
+#define FAULT_CODE_BAD_RA 0x20 /* Bad RA for sun4v */
#if PAGE_SHIFT == 13
#define THREAD_SIZE (2*PAGE_SIZE)
diff --git a/arch/sparc/kernel/sun4v_tlb_miss.S b/arch/sparc/kernel/sun4v_tlb_miss.S
index e0c09bf8..6179e19 100644
--- a/arch/sparc/kernel/sun4v_tlb_miss.S
+++ b/arch/sparc/kernel/sun4v_tlb_miss.S
@@ -195,6 +195,11 @@ sun4v_tsb_miss_common:
ldx [%g2 + TRAP_PER_CPU_PGD_PADDR], %g7
sun4v_itlb_error:
+ rdpr %tl, %g1
+ cmp %g1, 1
+ ble,pt %icc, sun4v_bad_ra
+ or %g0, FAULT_CODE_BAD_RA | FAULT_CODE_ITLB, %g1
+
sethi %hi(sun4v_err_itlb_vaddr), %g1
stx %g4, [%g1 + %lo(sun4v_err_itlb_vaddr)]
sethi %hi(sun4v_err_itlb_ctx), %g1
@@ -206,15 +211,10 @@ sun4v_itlb_error:
sethi %hi(sun4v_err_itlb_error), %g1
stx %o0, [%g1 + %lo(sun4v_err_itlb_error)]
+ sethi %hi(1f), %g7
rdpr %tl, %g4
- cmp %g4, 1
- ble,pt %icc, 1f
- sethi %hi(2f), %g7
ba,pt %xcc, etraptl1
- or %g7, %lo(2f), %g7
-
-1: ba,pt %xcc, etrap
-2: or %g7, %lo(2b), %g7
+1: or %g7, %lo(1f), %g7
mov %l4, %o1
call sun4v_itlb_error_report
add %sp, PTREGS_OFF, %o0
@@ -222,6 +222,11 @@ sun4v_itlb_error:
/* NOTREACHED */
sun4v_dtlb_error:
+ rdpr %tl, %g1
+ cmp %g1, 1
+ ble,pt %icc, sun4v_bad_ra
+ or %g0, FAULT_CODE_BAD_RA | FAULT_CODE_DTLB, %g1
+
sethi %hi(sun4v_err_dtlb_vaddr), %g1
stx %g4, [%g1 + %lo(sun4v_err_dtlb_vaddr)]
sethi %hi(sun4v_err_dtlb_ctx), %g1
@@ -233,21 +238,23 @@ sun4v_dtlb_error:
sethi %hi(sun4v_err_dtlb_error), %g1
stx %o0, [%g1 + %lo(sun4v_err_dtlb_error)]
+ sethi %hi(1f), %g7
rdpr %tl, %g4
- cmp %g4, 1
- ble,pt %icc, 1f
- sethi %hi(2f), %g7
ba,pt %xcc, etraptl1
- or %g7, %lo(2f), %g7
-
-1: ba,pt %xcc, etrap
-2: or %g7, %lo(2b), %g7
+1: or %g7, %lo(1f), %g7
mov %l4, %o1
call sun4v_dtlb_error_report
add %sp, PTREGS_OFF, %o0
/* NOTREACHED */
+sun4v_bad_ra:
+ or %g0, %g4, %g5
+ ba,pt %xcc, sparc64_realfault_common
+ or %g1, %g0, %g4
+
+ /* NOTREACHED */
+
/* Instruction Access Exception, tl0. */
sun4v_iacc:
ldxa [%g0] ASI_SCRATCHPAD, %g2
diff --git a/arch/sparc/kernel/traps_64.c b/arch/sparc/kernel/traps_64.c
index 4ced92f..25d0c7e 100644
--- a/arch/sparc/kernel/traps_64.c
+++ b/arch/sparc/kernel/traps_64.c
@@ -2102,6 +2102,11 @@ void sun4v_nonresum_overflow(struct pt_regs *regs)
atomic_inc(&sun4v_nonresum_oflow_cnt);
}
+static void sun4v_tlb_error(struct pt_regs *regs)
+{
+ die_if_kernel("TLB/TSB error", regs);
+}
+
unsigned long sun4v_err_itlb_vaddr;
unsigned long sun4v_err_itlb_ctx;
unsigned long sun4v_err_itlb_pte;
@@ -2109,8 +2114,7 @@ unsigned long sun4v_err_itlb_error;
void sun4v_itlb_error_report(struct pt_regs *regs, int tl)
{
- if (tl > 1)
- dump_tl1_traplog((struct tl1_traplog *)(regs + 1));
+ dump_tl1_traplog((struct tl1_traplog *)(regs + 1));
printk(KERN_EMERG "SUN4V-ITLB: Error at TPC[%lx], tl %d\n",
regs->tpc, tl);
@@ -2123,7 +2127,7 @@ void sun4v_itlb_error_report(struct pt_regs *regs, int tl)
sun4v_err_itlb_vaddr, sun4v_err_itlb_ctx,
sun4v_err_itlb_pte, sun4v_err_itlb_error);
- prom_halt();
+ sun4v_tlb_error(regs);
}
unsigned long sun4v_err_dtlb_vaddr;
@@ -2133,8 +2137,7 @@ unsigned long sun4v_err_dtlb_error;
void sun4v_dtlb_error_report(struct pt_regs *regs, int tl)
{
- if (tl > 1)
- dump_tl1_traplog((struct tl1_traplog *)(regs + 1));
+ dump_tl1_traplog((struct tl1_traplog *)(regs + 1));
printk(KERN_EMERG "SUN4V-DTLB: Error at TPC[%lx], tl %d\n",
regs->tpc, tl);
@@ -2147,7 +2150,7 @@ void sun4v_dtlb_error_report(struct pt_regs *regs, int tl)
sun4v_err_dtlb_vaddr, sun4v_err_dtlb_ctx,
sun4v_err_dtlb_pte, sun4v_err_dtlb_error);
- prom_halt();
+ sun4v_tlb_error(regs);
}
void hypervisor_tlbop_error(unsigned long err, unsigned long op)
diff --git a/arch/sparc/mm/fault_64.c b/arch/sparc/mm/fault_64.c
index 4ced3fc..45a413e 100644
--- a/arch/sparc/mm/fault_64.c
+++ b/arch/sparc/mm/fault_64.c
@@ -348,6 +348,9 @@ retry:
down_read(&mm->mmap_sem);
}
+ if (fault_code & FAULT_CODE_BAD_RA)
+ goto do_sigbus;
+
vma = find_vma(mm, address);
if (!vma)
goto bad_area;
--
1.9.1
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