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authorMauro Carvalho Chehab <mchehab@redhat.com>2012-12-11 11:18:45 -0200
committerMauro Carvalho Chehab <mchehab@redhat.com>2012-12-11 11:18:45 -0200
commit9374020a78fce13a1cf2edf3d26f6dd7231b5c3d (patch)
tree50c8629e6c6222c5b9681506b52afbde818c5e56 /arch/sparc/include/asm/processor_64.h
parentd2a0db1ee01aea154ccc460e45a16857e32c4427 (diff)
parent29594404d7fe73cd80eaa4ee8c43dcc53970c60e (diff)
Merge tag 'v3.7' into v4l_for_linus
Linux 3.7 * tag 'v3.7': (1545 commits) Linux 3.7 Input: matrix-keymap - provide proper module license Revert "revert "Revert "mm: remove __GFP_NO_KSWAPD""" and associated damage ipv4: ip_check_defrag must not modify skb before unsharing Revert "mm: avoid waking kswapd for THP allocations when compaction is deferred or contended" inet_diag: validate port comparison byte code to prevent unsafe reads inet_diag: avoid unsafe and nonsensical prefix matches in inet_diag_bc_run() inet_diag: validate byte code to prevent oops in inet_diag_bc_run() inet_diag: fix oops for IPv4 AF_INET6 TCP SYN-RECV state mm: vmscan: fix inappropriate zone congestion clearing vfs: fix O_DIRECT read past end of block device net: gro: fix possible panic in skb_gro_receive() tcp: bug fix Fast Open client retransmission tmpfs: fix shared mempolicy leak mm: vmscan: do not keep kswapd looping forever due to individual uncompactable zones mm: compaction: validate pfn range passed to isolate_freepages_block mmc: sh-mmcif: avoid oops on spurious interrupts (second try) Revert misapplied "mmc: sh-mmcif: avoid oops on spurious interrupts" mmc: sdhci-s3c: fix missing clock for gpio card-detect lib/Makefile: Fix oid_registry build dependency ...
Diffstat (limited to 'arch/sparc/include/asm/processor_64.h')
-rw-r--r--arch/sparc/include/asm/processor_64.h17
1 files changed, 16 insertions, 1 deletions
diff --git a/arch/sparc/include/asm/processor_64.h b/arch/sparc/include/asm/processor_64.h
index 4e5a483122a..721e25f0e2e 100644
--- a/arch/sparc/include/asm/processor_64.h
+++ b/arch/sparc/include/asm/processor_64.h
@@ -196,7 +196,22 @@ extern unsigned long get_wchan(struct task_struct *task);
#define KSTK_EIP(tsk) (task_pt_regs(tsk)->tpc)
#define KSTK_ESP(tsk) (task_pt_regs(tsk)->u_regs[UREG_FP])
-#define cpu_relax() barrier()
+/* Please see the commentary in asm/backoff.h for a description of
+ * what these instructions are doing and how they have been choosen.
+ * To make a long story short, we are trying to yield the current cpu
+ * strand during busy loops.
+ */
+#define cpu_relax() asm volatile("\n99:\n\t" \
+ "rd %%ccr, %%g0\n\t" \
+ "rd %%ccr, %%g0\n\t" \
+ "rd %%ccr, %%g0\n\t" \
+ ".section .pause_3insn_patch,\"ax\"\n\t"\
+ ".word 99b\n\t" \
+ "wr %%g0, 128, %%asr27\n\t" \
+ "nop\n\t" \
+ "nop\n\t" \
+ ".previous" \
+ ::: "memory")
/* Prefetch support. This is tuned for UltraSPARC-III and later.
* UltraSPARC-I will treat these as nops, and UltraSPARC-II has