From 4eb0c00b6221f28b8988df37c9cb1bc5a2b91b39 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Thu, 5 Nov 2009 20:24:33 -0800 Subject: [PATCH 1/3] sparc64: Add a comment about why we only use certain memory barriers these days. Based upon feedback from Mathieu Desnoyers. Signed-off-by: David S. Miller --- arch/sparc/include/asm/system_64.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/sparc/include/asm/system_64.h b/arch/sparc/include/asm/system_64.h index 25e848f0cad7..d47a98e66972 100644 --- a/arch/sparc/include/asm/system_64.h +++ b/arch/sparc/include/asm/system_64.h @@ -63,6 +63,10 @@ do { __asm__ __volatile__("ba,pt %%xcc, 1f\n\t" \ : : : "memory"); \ } while (0) +/* The kernel always executes in TSO memory model these days, + * and furthermore most sparc64 chips implement more stringent + * memory ordering than required by the specifications. + */ #define mb() membar_safe("#StoreLoad") #define rmb() __asm__ __volatile__("":::"memory") #define wmb() __asm__ __volatile__("":::"memory") From 88b938e63e68fd35e603421f722be0f35dde1016 Mon Sep 17 00:00:00 2001 From: Roel Kluin Date: Sun, 8 Nov 2009 00:26:56 -0800 Subject: [PATCH 2/3] sparc64: replace parentheses in pmul() `>>' has a higher precedence than `?' so src2 evaluated to either 16 or 0 dependent on the bits set in rs2. Signed-off-by: Roel Kluin Signed-off-by: David S. Miller --- arch/sparc/kernel/visemul.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/sparc/kernel/visemul.c b/arch/sparc/kernel/visemul.c index b956fd71c131..d231cbd5c526 100644 --- a/arch/sparc/kernel/visemul.c +++ b/arch/sparc/kernel/visemul.c @@ -617,7 +617,7 @@ static void pmul(struct pt_regs *regs, unsigned int insn, unsigned int opf) rs2 = fps_regval(f, RS2(insn)); rd_val = 0; - src2 = (rs2 >> (opf == FMUL8x16AU_OPF) ? 16 : 0); + src2 = rs2 >> (opf == FMUL8x16AU_OPF ? 16 : 0); for (byte = 0; byte < 4; byte++) { u16 src1 = (rs1 >> (byte * 8)) & 0x00ff; u32 prod = src1 * src2; From 1c9d80ddc60f8ac26344ec3db9830e5f8016c16d Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Sun, 8 Nov 2009 17:41:20 -0800 Subject: [PATCH 3/3] sparc: Move of_set_property_mutex acquisition outside of devtree_lock grab. Otherwise we try to sleep with preemption disabled, etc. Noticed by Thomas Gleixner. Signed-off-by: David S. Miller --- arch/sparc/kernel/prom_common.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/sparc/kernel/prom_common.c b/arch/sparc/kernel/prom_common.c index 138910c67206..d80a65d9e893 100644 --- a/arch/sparc/kernel/prom_common.c +++ b/arch/sparc/kernel/prom_common.c @@ -79,6 +79,7 @@ int of_set_property(struct device_node *dp, const char *name, void *val, int len err = -ENODEV; + mutex_lock(&of_set_property_mutex); write_lock(&devtree_lock); prevp = &dp->properties; while (*prevp) { @@ -88,9 +89,7 @@ int of_set_property(struct device_node *dp, const char *name, void *val, int len void *old_val = prop->value; int ret; - mutex_lock(&of_set_property_mutex); ret = prom_setprop(dp->node, name, val, len); - mutex_unlock(&of_set_property_mutex); err = -EINVAL; if (ret >= 0) { @@ -109,6 +108,7 @@ int of_set_property(struct device_node *dp, const char *name, void *val, int len prevp = &(*prevp)->next; } write_unlock(&devtree_lock); + mutex_unlock(&of_set_property_mutex); /* XXX Upate procfs if necessary... */