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authorRalf Baechle <ralf@linux-mips.org>2013-09-17 12:44:31 +0200
committerBen Hutchings <ben@decadent.org.uk>2014-09-13 23:41:48 +0100
commit2ce277620ead681c615c46b89de352893f3d3dd5 (patch)
tree55ef6bba3400cb80427e8f9ff695868465e9b3c7
parent588ca81b421339a30b3328e8f7e8f00fd0c9afdf (diff)
MIPS: Fix accessing to per-cpu data when flushing the cache
commit ff522058bd717506b2fa066fa564657f2b86477e upstream. This fixes the following issue BUG: using smp_processor_id() in preemptible [00000000] code: kjournald/1761 caller is blast_dcache32+0x30/0x254 Call Trace: [<8047f02c>] dump_stack+0x8/0x34 [<802e7e40>] debug_smp_processor_id+0xe0/0xf0 [<80114d94>] blast_dcache32+0x30/0x254 [<80118484>] r4k_dma_cache_wback_inv+0x200/0x288 [<80110ff0>] mips_dma_map_sg+0x108/0x180 [<80355098>] ide_dma_prepare+0xf0/0x1b8 [<8034eaa4>] do_rw_taskfile+0x1e8/0x33c [<8035951c>] ide_do_rw_disk+0x298/0x3e4 [<8034a3c4>] do_ide_request+0x2e0/0x704 [<802bb0dc>] __blk_run_queue+0x44/0x64 [<802be000>] queue_unplugged.isra.36+0x1c/0x54 [<802beb94>] blk_flush_plug_list+0x18c/0x24c [<802bec6c>] blk_finish_plug+0x18/0x48 [<8026554c>] journal_commit_transaction+0x3b8/0x151c [<80269648>] kjournald+0xec/0x238 [<8014ac00>] kthread+0xb8/0xc0 [<8010268c>] ret_from_kernel_thread+0x14/0x1c Caches in most systems are identical - but not always, so we can't avoid the use of smp_call_function() by just looking at the boot CPU's data, have to fiddle with preemption instead. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/5835 Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r--arch/mips/mm/c-r4k.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c
index 7d5ac0b3ed8b..fe425bbef623 100644
--- a/arch/mips/mm/c-r4k.c
+++ b/arch/mips/mm/c-r4k.c
@@ -12,6 +12,7 @@
#include <linux/highmem.h>
#include <linux/kernel.h>
#include <linux/linkage.h>
+#include <linux/preempt.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/mm.h>
@@ -599,6 +600,7 @@ static void r4k_dma_cache_wback_inv(unsigned long addr, unsigned long size)
/* Catch bad driver code */
BUG_ON(size == 0);
+ preempt_disable();
if (cpu_has_inclusive_pcaches) {
if (size >= scache_size)
r4k_blast_scache();
@@ -619,6 +621,7 @@ static void r4k_dma_cache_wback_inv(unsigned long addr, unsigned long size)
R4600_HIT_CACHEOP_WAR_IMPL;
blast_dcache_range(addr, addr + size);
}
+ preempt_enable();
bc_wback_inv(addr, size);
__sync();
@@ -629,6 +632,7 @@ static void r4k_dma_cache_inv(unsigned long addr, unsigned long size)
/* Catch bad driver code */
BUG_ON(size == 0);
+ preempt_disable();
if (cpu_has_inclusive_pcaches) {
if (size >= scache_size)
r4k_blast_scache();
@@ -653,6 +657,7 @@ static void r4k_dma_cache_inv(unsigned long addr, unsigned long size)
R4600_HIT_CACHEOP_WAR_IMPL;
blast_inv_dcache_range(addr, addr + size);
}
+ preempt_enable();
bc_inv(addr, size);
__sync();