This is a note to let you know that I have just added a patch titled
sparc64: sun4v TLB error power off events
to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree
which can be found at:
http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue
This patch is scheduled to be released in version 3.13.11.11.
If you, or anyone else, feels it should not be added to this tree, please
reply to this email.
For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
Thanks.
-Kamal
------
>From 5aa329df7153ef6985ff76745863e16058e7bbd9 Mon Sep 17 00:00:00 2001
From: bob picco <bpicco@xxxxxxxxxx>
Date: Tue, 16 Sep 2014 09:26:47 -0400
Subject: sparc64: sun4v TLB error power off events
[ 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@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@xxxxxxxxxxxxxxx
Signed-off-by: Bob Picco <bob.picco@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
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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