4 files changed, 14 insertions, 18 deletions

diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
index c5bc4c2d33f5..084ef95274cd 100644
--- a/arch/x86/include/asm/msr.h
+++ b/arch/x86/include/asm/msr.h
@@ -148,8 +148,8 @@ static inline unsigned long long native_read_pmc(int counter)
 #define rdmsr(msr, val1, val2)                                  \
 do {                                                            \
         u64 __val = native_read_msr((msr));                     \
-        (val1) = (u32)__val;                                    \
-        (val2) = (u32)(__val >> 32);                            \
+        (void)((val1) = (u32)__val);                            \
+        (void)((val2) = (u32)(__val >> 32));                    \
 } while (0)
 
 static inline void wrmsr(unsigned msr, unsigned low, unsigned high)
diff --git a/arch/x86/include/asm/rwsem.h b/arch/x86/include/asm/rwsem.h
index 606ede126972..d1e41b0f9b60 100644
--- a/arch/x86/include/asm/rwsem.h
+++ b/arch/x86/include/asm/rwsem.h
@@ -118,7 +118,7 @@ static inline void __down_read(struct rw_semaphore *sem)
 {
         asm volatile("# beginning down_read\n\t"
                      LOCK_PREFIX _ASM_INC "(%1)\n\t"
-                     /* adds 0x00000001, returns the old value */
+                     /* adds 0x00000001 */
                      "  jns        1f\n"
                      "  call call_rwsem_down_read_failed\n"
                      "1:\n\t"
@@ -156,11 +156,9 @@ static inline int __down_read_trylock(struct rw_semaphore *sem)
 static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
 {
         rwsem_count_t tmp;
-
-        tmp = RWSEM_ACTIVE_WRITE_BIAS;
         asm volatile("# beginning down_write\n\t"
                      LOCK_PREFIX "  xadd      %1,(%2)\n\t"
-                     /* subtract 0x0000ffff, returns the old value */
+                     /* adds 0xffff0001, returns the old value */
                      "  test      %1,%1\n\t"
                      /* was the count 0 before? */
                      "  jz        1f\n"
@@ -168,7 +166,7 @@ static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
                      "1:\n"
                      "# ending down_write"
                      : "+m" (sem->count), "=d" (tmp)
-                     : "a" (sem), "1" (tmp)
+                     : "a" (sem), "1" (RWSEM_ACTIVE_WRITE_BIAS)
                      : "memory", "cc");
 }
 
@@ -195,16 +193,16 @@ static inline int __down_write_trylock(struct rw_semaphore *sem)
  */
 static inline void __up_read(struct rw_semaphore *sem)
 {
-        rwsem_count_t tmp = -RWSEM_ACTIVE_READ_BIAS;
+        rwsem_count_t tmp;
         asm volatile("# beginning __up_read\n\t"
                      LOCK_PREFIX "  xadd      %1,(%2)\n\t"
                      /* subtracts 1, returns the old value */
                      "  jns        1f\n\t"
-                     "  call call_rwsem_wake\n"
+                     "  call call_rwsem_wake\n" /* expects old value in %edx */
                      "1:\n"
                      "# ending __up_read\n"
                      : "+m" (sem->count), "=d" (tmp)
-                     : "a" (sem), "1" (tmp)
+                     : "a" (sem), "1" (-RWSEM_ACTIVE_READ_BIAS)
                      : "memory", "cc");
 }
 
@@ -216,10 +214,9 @@ static inline void __up_write(struct rw_semaphore *sem)
         rwsem_count_t tmp;
         asm volatile("# beginning __up_write\n\t"
                      LOCK_PREFIX "  xadd      %1,(%2)\n\t"
-                     /* tries to transition
-                        0xffff0001 -> 0x00000000 */
-                     "  jz       1f\n"
-                     "  call call_rwsem_wake\n"
+                     /* subtracts 0xffff0001, returns the old value */
+                     "  jns        1f\n\t"
+                     "  call call_rwsem_wake\n" /* expects old value in %edx */
                      "1:\n\t"
                      "# ending __up_write\n"
                      : "+m" (sem->count), "=d" (tmp)
diff --git a/arch/x86/kernel/aperture_64.c b/arch/x86/kernel/aperture_64.c
index b5d8b0bcf235..a2e0caf26e17 100644
--- a/arch/x86/kernel/aperture_64.c
+++ b/arch/x86/kernel/aperture_64.c
@@ -280,7 +280,7 @@ void __init early_gart_iommu_check(void)
          * or BIOS forget to put that in reserved.
          * try to update e820 to make that region as reserved.
          */
-        u32 agp_aper_base = 0, agp_aper_order = 0;
+        u32 agp_aper_order = 0;
         int i, fix, slot, valid_agp = 0;
         u32 ctl;
         u32 aper_size = 0, aper_order = 0, last_aper_order = 0;
@@ -291,7 +291,7 @@ void __init early_gart_iommu_check(void)
                 return;
 
         /* This is mostly duplicate of iommu_hole_init */
-        agp_aper_base = search_agp_bridge(&agp_aper_order, &valid_agp);
+        search_agp_bridge(&agp_aper_order, &valid_agp);
 
         fix = 0;
         for (i = 0; i < ARRAY_SIZE(bus_dev_ranges); i++) {
diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c
index fd31a441c61c..7d28d7d03885 100644
--- a/arch/x86/kernel/cpu/mtrr/generic.c
+++ b/arch/x86/kernel/cpu/mtrr/generic.c
@@ -433,13 +433,12 @@ static void generic_get_mtrr(unsigned int reg, unsigned long *base,
 {
         unsigned int mask_lo, mask_hi, base_lo, base_hi;
         unsigned int tmp, hi;
-        int cpu;
 
         /*
          * get_mtrr doesn't need to update mtrr_state, also it could be called
          * from any cpu, so try to print it out directly.
          */
-        cpu = get_cpu();
+        get_cpu();
 
         rdmsr(MTRRphysMask_MSR(reg), mask_lo, mask_hi);