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-rw-r--r--target/linux/ramips/patches-3.10/0203-MIPS-Fix-accessing-to-per-cpu-data-when-flushing-the.patch84
1 files changed, 84 insertions, 0 deletions
diff --git a/target/linux/ramips/patches-3.10/0203-MIPS-Fix-accessing-to-per-cpu-data-when-flushing-the.patch b/target/linux/ramips/patches-3.10/0203-MIPS-Fix-accessing-to-per-cpu-data-when-flushing-the.patch
new file mode 100644
index 0000000000..fc853fa1bd
--- /dev/null
+++ b/target/linux/ramips/patches-3.10/0203-MIPS-Fix-accessing-to-per-cpu-data-when-flushing-the.patch
@@ -0,0 +1,84 @@
+From 871d1be8c3ce46b8ef395b56cd0e37cede10e76a Mon Sep 17 00:00:00 2001
+From: Ralf Baechle <ralf@linux-mips.org>
+Date: Tue, 17 Sep 2013 12:44:31 +0200
+Subject: [PATCH 203/215] MIPS: Fix accessing to per-cpu data when flushing
+ the cache
+
+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
+(cherry picked from commit ff522058bd717506b2fa066fa564657f2b86477e)
+---
+ arch/mips/mm/c-r4k.c | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+--- 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>
+@@ -601,6 +602,7 @@ static void r4k_dma_cache_wback_inv(unsi
+ /* Catch bad driver code */
+ BUG_ON(size == 0);
+
++ preempt_disable();
+ if (cpu_has_inclusive_pcaches) {
+ if (size >= scache_size)
+ r4k_blast_scache();
+@@ -621,6 +623,7 @@ static void r4k_dma_cache_wback_inv(unsi
+ R4600_HIT_CACHEOP_WAR_IMPL;
+ blast_dcache_range(addr, addr + size);
+ }
++ preempt_enable();
+
+ bc_wback_inv(addr, size);
+ __sync();
+@@ -631,6 +634,7 @@ static void r4k_dma_cache_inv(unsigned l
+ /* Catch bad driver code */
+ BUG_ON(size == 0);
+
++ preempt_disable();
+ if (cpu_has_inclusive_pcaches) {
+ if (size >= scache_size)
+ r4k_blast_scache();
+@@ -655,6 +659,7 @@ static void r4k_dma_cache_inv(unsigned l
+ R4600_HIT_CACHEOP_WAR_IMPL;
+ blast_inv_dcache_range(addr, addr + size);
+ }
++ preempt_enable();
+
+ bc_inv(addr, size);
+ __sync();