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authorDavid S. Miller <davem@davemloft.net>2008-11-16 00:33:25 +0300
committerDavid S. Miller <davem@davemloft.net>2008-12-04 20:16:47 +0300
commit293666b7a17cb7a389fc274980439212386a19c4 (patch)
tree075cc7661d2113cf04da7130b3383979d8024206 /arch/sparc64
parent64f2dde3f743c8a1ad8c0a1aa74166c1034afd92 (diff)
downloadlinux-293666b7a17cb7a389fc274980439212386a19c4.tar.xz
sparc64: Stop using memory barriers for atomics and locks.
The kernel always executes in the TSO memory model now, so none of this stuff is necessary any more. With helpful feedback from Nick Piggin. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc64')
-rw-r--r--arch/sparc64/kernel/smp.c11
-rw-r--r--arch/sparc64/kernel/trampoline.S4
-rw-r--r--arch/sparc64/kernel/traps.c1
-rw-r--r--arch/sparc64/kernel/tsb.S6
-rw-r--r--arch/sparc64/lib/atomic.S26
-rw-r--r--arch/sparc64/lib/bitops.S24
-rw-r--r--arch/sparc64/lib/rwsem.S7
-rw-r--r--arch/sparc64/mm/init.c2
-rw-r--r--arch/sparc64/mm/tsb.c4
-rw-r--r--arch/sparc64/mm/ultra.S2
10 files changed, 9 insertions, 78 deletions
diff --git a/arch/sparc64/kernel/smp.c b/arch/sparc64/kernel/smp.c
index f500b0618bb0..c6d06362728c 100644
--- a/arch/sparc64/kernel/smp.c
+++ b/arch/sparc64/kernel/smp.c
@@ -163,7 +163,7 @@ static inline long get_delta (long *rt, long *master)
for (i = 0; i < NUM_ITERS; i++) {
t0 = tick_ops->get_tick();
go[MASTER] = 1;
- membar_storeload();
+ membar_safe("#StoreLoad");
while (!(tm = go[SLAVE]))
rmb();
go[SLAVE] = 0;
@@ -257,7 +257,7 @@ static void smp_synchronize_one_tick(int cpu)
/* now let the client proceed into his loop */
go[MASTER] = 0;
- membar_storeload();
+ membar_safe("#StoreLoad");
spin_lock_irqsave(&itc_sync_lock, flags);
{
@@ -267,7 +267,7 @@ static void smp_synchronize_one_tick(int cpu)
go[MASTER] = 0;
wmb();
go[SLAVE] = tick_ops->get_tick();
- membar_storeload();
+ membar_safe("#StoreLoad");
}
}
spin_unlock_irqrestore(&itc_sync_lock, flags);
@@ -1122,7 +1122,6 @@ void smp_capture(void)
smp_processor_id());
#endif
penguins_are_doing_time = 1;
- membar_storestore_loadstore();
atomic_inc(&smp_capture_registry);
smp_cross_call(&xcall_capture, 0, 0, 0);
while (atomic_read(&smp_capture_registry) != ncpus)
@@ -1142,7 +1141,7 @@ void smp_release(void)
smp_processor_id());
#endif
penguins_are_doing_time = 0;
- membar_storeload_storestore();
+ membar_safe("#StoreLoad");
atomic_dec(&smp_capture_registry);
}
}
@@ -1161,7 +1160,7 @@ void smp_penguin_jailcell(int irq, struct pt_regs *regs)
__asm__ __volatile__("flushw");
prom_world(1);
atomic_inc(&smp_capture_registry);
- membar_storeload_storestore();
+ membar_safe("#StoreLoad");
while (penguins_are_doing_time)
rmb();
atomic_dec(&smp_capture_registry);
diff --git a/arch/sparc64/kernel/trampoline.S b/arch/sparc64/kernel/trampoline.S
index 83abd5ae88a4..da1b781b5e65 100644
--- a/arch/sparc64/kernel/trampoline.S
+++ b/arch/sparc64/kernel/trampoline.S
@@ -109,7 +109,6 @@ startup_continue:
*/
sethi %hi(prom_entry_lock), %g2
1: ldstub [%g2 + %lo(prom_entry_lock)], %g1
- membar #StoreLoad | #StoreStore
brnz,pn %g1, 1b
nop
@@ -214,7 +213,6 @@ startup_continue:
sethi %hi(prom_entry_lock), %g2
stb %g0, [%g2 + %lo(prom_entry_lock)]
- membar #StoreStore | #StoreLoad
ba,pt %xcc, after_lock_tlb
nop
@@ -330,7 +328,6 @@ after_lock_tlb:
sethi %hi(prom_entry_lock), %g2
1: ldstub [%g2 + %lo(prom_entry_lock)], %g1
- membar #StoreLoad | #StoreStore
brnz,pn %g1, 1b
nop
@@ -394,7 +391,6 @@ after_lock_tlb:
3: sethi %hi(prom_entry_lock), %g2
stb %g0, [%g2 + %lo(prom_entry_lock)]
- membar #StoreStore | #StoreLoad
ldx [%l0], %g6
ldx [%g6 + TI_TASK], %g4
diff --git a/arch/sparc64/kernel/traps.c b/arch/sparc64/kernel/traps.c
index 81ccd22e78d4..04994fc8700d 100644
--- a/arch/sparc64/kernel/traps.c
+++ b/arch/sparc64/kernel/traps.c
@@ -1371,7 +1371,6 @@ static int cheetah_fix_ce(unsigned long physaddr)
__asm__ __volatile__("ldxa [%0] %3, %%g0\n\t"
"ldxa [%1] %3, %%g0\n\t"
"casxa [%2] %3, %%g0, %%g0\n\t"
- "membar #StoreLoad | #StoreStore\n\t"
"ldxa [%0] %3, %%g0\n\t"
"ldxa [%1] %3, %%g0\n\t"
"membar #Sync"
diff --git a/arch/sparc64/kernel/tsb.S b/arch/sparc64/kernel/tsb.S
index c499214b501d..8c91d9b29a2f 100644
--- a/arch/sparc64/kernel/tsb.S
+++ b/arch/sparc64/kernel/tsb.S
@@ -317,7 +317,7 @@ tsb_flush:
srlx %g1, 32, %o3
andcc %o3, %g2, %g0
bne,pn %icc, 1b
- membar #LoadLoad
+ nop
cmp %g1, %o1
mov 1, %o3
bne,pt %xcc, 2f
@@ -327,7 +327,7 @@ tsb_flush:
bne,pn %xcc, 1b
nop
2: retl
- TSB_MEMBAR
+ nop
.size tsb_flush, .-tsb_flush
/* Reload MMU related context switch state at
@@ -478,7 +478,7 @@ copy_tsb: /* %o0=old_tsb_base, %o1=old_tsb_size
nop
retl
- TSB_MEMBAR
+ nop
.size copy_tsb, .-copy_tsb
/* Set the invalid bit in all TSB entries. */
diff --git a/arch/sparc64/lib/atomic.S b/arch/sparc64/lib/atomic.S
index 70ac4186f62b..0268210ca168 100644
--- a/arch/sparc64/lib/atomic.S
+++ b/arch/sparc64/lib/atomic.S
@@ -43,29 +43,10 @@ atomic_sub: /* %o0 = decrement, %o1 = atomic_ptr */
2: BACKOFF_SPIN(%o2, %o3, 1b)
.size atomic_sub, .-atomic_sub
- /* On SMP we need to use memory barriers to ensure
- * correct memory operation ordering, nop these out
- * for uniprocessor.
- */
-#ifdef CONFIG_SMP
-
-#define ATOMIC_PRE_BARRIER membar #StoreLoad | #LoadLoad;
-#define ATOMIC_POST_BARRIER \
- ba,pt %xcc, 80b; \
- membar #StoreLoad | #StoreStore
-
-80: retl
- nop
-#else
-#define ATOMIC_PRE_BARRIER
-#define ATOMIC_POST_BARRIER
-#endif
-
.globl atomic_add_ret
.type atomic_add_ret,#function
atomic_add_ret: /* %o0 = increment, %o1 = atomic_ptr */
BACKOFF_SETUP(%o2)
- ATOMIC_PRE_BARRIER
1: lduw [%o1], %g1
add %g1, %o0, %g7
cas [%o1], %g1, %g7
@@ -73,7 +54,6 @@ atomic_add_ret: /* %o0 = increment, %o1 = atomic_ptr */
bne,pn %icc, 2f
add %g7, %o0, %g7
sra %g7, 0, %o0
- ATOMIC_POST_BARRIER
retl
nop
2: BACKOFF_SPIN(%o2, %o3, 1b)
@@ -83,7 +63,6 @@ atomic_add_ret: /* %o0 = increment, %o1 = atomic_ptr */
.type atomic_sub_ret,#function
atomic_sub_ret: /* %o0 = decrement, %o1 = atomic_ptr */
BACKOFF_SETUP(%o2)
- ATOMIC_PRE_BARRIER
1: lduw [%o1], %g1
sub %g1, %o0, %g7
cas [%o1], %g1, %g7
@@ -91,7 +70,6 @@ atomic_sub_ret: /* %o0 = decrement, %o1 = atomic_ptr */
bne,pn %icc, 2f
sub %g7, %o0, %g7
sra %g7, 0, %o0
- ATOMIC_POST_BARRIER
retl
nop
2: BACKOFF_SPIN(%o2, %o3, 1b)
@@ -131,7 +109,6 @@ atomic64_sub: /* %o0 = decrement, %o1 = atomic_ptr */
.type atomic64_add_ret,#function
atomic64_add_ret: /* %o0 = increment, %o1 = atomic_ptr */
BACKOFF_SETUP(%o2)
- ATOMIC_PRE_BARRIER
1: ldx [%o1], %g1
add %g1, %o0, %g7
casx [%o1], %g1, %g7
@@ -139,7 +116,6 @@ atomic64_add_ret: /* %o0 = increment, %o1 = atomic_ptr */
bne,pn %xcc, 2f
add %g7, %o0, %g7
mov %g7, %o0
- ATOMIC_POST_BARRIER
retl
nop
2: BACKOFF_SPIN(%o2, %o3, 1b)
@@ -149,7 +125,6 @@ atomic64_add_ret: /* %o0 = increment, %o1 = atomic_ptr */
.type atomic64_sub_ret,#function
atomic64_sub_ret: /* %o0 = decrement, %o1 = atomic_ptr */
BACKOFF_SETUP(%o2)
- ATOMIC_PRE_BARRIER
1: ldx [%o1], %g1
sub %g1, %o0, %g7
casx [%o1], %g1, %g7
@@ -157,7 +132,6 @@ atomic64_sub_ret: /* %o0 = decrement, %o1 = atomic_ptr */
bne,pn %xcc, 2f
sub %g7, %o0, %g7
mov %g7, %o0
- ATOMIC_POST_BARRIER
retl
nop
2: BACKOFF_SPIN(%o2, %o3, 1b)
diff --git a/arch/sparc64/lib/bitops.S b/arch/sparc64/lib/bitops.S
index 6b015a6eefb5..2b7228cb8c22 100644
--- a/arch/sparc64/lib/bitops.S
+++ b/arch/sparc64/lib/bitops.S
@@ -8,29 +8,10 @@
.text
- /* On SMP we need to use memory barriers to ensure
- * correct memory operation ordering, nop these out
- * for uniprocessor.
- */
-
-#ifdef CONFIG_SMP
-#define BITOP_PRE_BARRIER membar #StoreLoad | #LoadLoad
-#define BITOP_POST_BARRIER \
- ba,pt %xcc, 80b; \
- membar #StoreLoad | #StoreStore
-
-80: retl
- nop
-#else
-#define BITOP_PRE_BARRIER
-#define BITOP_POST_BARRIER
-#endif
-
.globl test_and_set_bit
.type test_and_set_bit,#function
test_and_set_bit: /* %o0=nr, %o1=addr */
BACKOFF_SETUP(%o3)
- BITOP_PRE_BARRIER
srlx %o0, 6, %g1
mov 1, %o2
sllx %g1, 3, %g3
@@ -45,7 +26,6 @@ test_and_set_bit: /* %o0=nr, %o1=addr */
and %g7, %o2, %g2
clr %o0
movrne %g2, 1, %o0
- BITOP_POST_BARRIER
retl
nop
2: BACKOFF_SPIN(%o3, %o4, 1b)
@@ -55,7 +35,6 @@ test_and_set_bit: /* %o0=nr, %o1=addr */
.type test_and_clear_bit,#function
test_and_clear_bit: /* %o0=nr, %o1=addr */
BACKOFF_SETUP(%o3)
- BITOP_PRE_BARRIER
srlx %o0, 6, %g1
mov 1, %o2
sllx %g1, 3, %g3
@@ -70,7 +49,6 @@ test_and_clear_bit: /* %o0=nr, %o1=addr */
and %g7, %o2, %g2
clr %o0
movrne %g2, 1, %o0
- BITOP_POST_BARRIER
retl
nop
2: BACKOFF_SPIN(%o3, %o4, 1b)
@@ -80,7 +58,6 @@ test_and_clear_bit: /* %o0=nr, %o1=addr */
.type test_and_change_bit,#function
test_and_change_bit: /* %o0=nr, %o1=addr */
BACKOFF_SETUP(%o3)
- BITOP_PRE_BARRIER
srlx %o0, 6, %g1
mov 1, %o2
sllx %g1, 3, %g3
@@ -95,7 +72,6 @@ test_and_change_bit: /* %o0=nr, %o1=addr */
and %g7, %o2, %g2
clr %o0
movrne %g2, 1, %o0
- BITOP_POST_BARRIER
retl
nop
2: BACKOFF_SPIN(%o3, %o4, 1b)
diff --git a/arch/sparc64/lib/rwsem.S b/arch/sparc64/lib/rwsem.S
index 1a4cc5654de4..91a7d29a79d5 100644
--- a/arch/sparc64/lib/rwsem.S
+++ b/arch/sparc64/lib/rwsem.S
@@ -17,7 +17,6 @@ __down_read:
bne,pn %icc, 1b
add %g7, 1, %g7
cmp %g7, 0
- membar #StoreLoad | #StoreStore
bl,pn %icc, 3f
nop
2:
@@ -42,7 +41,6 @@ __down_read_trylock:
cmp %g1, %g7
bne,pn %icc, 1b
mov 1, %o1
- membar #StoreLoad | #StoreStore
2: retl
mov %o1, %o0
.size __down_read_trylock, .-__down_read_trylock
@@ -58,7 +56,6 @@ __down_write:
cmp %g3, %g7
bne,pn %icc, 1b
cmp %g7, 0
- membar #StoreLoad | #StoreStore
bne,pn %icc, 3f
nop
2: retl
@@ -85,7 +82,6 @@ __down_write_trylock:
cmp %g3, %g7
bne,pn %icc, 1b
mov 1, %o1
- membar #StoreLoad | #StoreStore
2: retl
mov %o1, %o0
.size __down_write_trylock, .-__down_write_trylock
@@ -99,7 +95,6 @@ __up_read:
cmp %g1, %g7
bne,pn %icc, 1b
cmp %g7, 0
- membar #StoreLoad | #StoreStore
bl,pn %icc, 3f
nop
2: retl
@@ -129,7 +124,6 @@ __up_write:
bne,pn %icc, 1b
sub %g7, %g1, %g7
cmp %g7, 0
- membar #StoreLoad | #StoreStore
bl,pn %icc, 3f
nop
2:
@@ -155,7 +149,6 @@ __downgrade_write:
bne,pn %icc, 1b
sub %g7, %g1, %g7
cmp %g7, 0
- membar #StoreLoad | #StoreStore
bl,pn %icc, 3f
nop
2:
diff --git a/arch/sparc64/mm/init.c b/arch/sparc64/mm/init.c
index 185f34679110..4bd63968400d 100644
--- a/arch/sparc64/mm/init.c
+++ b/arch/sparc64/mm/init.c
@@ -214,7 +214,6 @@ static inline void set_dcache_dirty(struct page *page, int this_cpu)
"or %%g1, %0, %%g1\n\t"
"casx [%2], %%g7, %%g1\n\t"
"cmp %%g7, %%g1\n\t"
- "membar #StoreLoad | #StoreStore\n\t"
"bne,pn %%xcc, 1b\n\t"
" nop"
: /* no outputs */
@@ -236,7 +235,6 @@ static inline void clear_dcache_dirty_cpu(struct page *page, unsigned long cpu)
" andn %%g7, %1, %%g1\n\t"
"casx [%2], %%g7, %%g1\n\t"
"cmp %%g7, %%g1\n\t"
- "membar #StoreLoad | #StoreStore\n\t"
"bne,pn %%xcc, 1b\n\t"
" nop\n"
"2:"
diff --git a/arch/sparc64/mm/tsb.c b/arch/sparc64/mm/tsb.c
index 587f8efb2e05..f0282fad632a 100644
--- a/arch/sparc64/mm/tsb.c
+++ b/arch/sparc64/mm/tsb.c
@@ -41,10 +41,8 @@ void flush_tsb_kernel_range(unsigned long start, unsigned long end)
KERNEL_TSB_NENTRIES);
struct tsb *ent = &swapper_tsb[hash];
- if (tag_compare(ent->tag, v)) {
+ if (tag_compare(ent->tag, v))
ent->tag = (1UL << TSB_TAG_INVALID_BIT);
- membar_storeload_storestore();
- }
}
}
diff --git a/arch/sparc64/mm/ultra.S b/arch/sparc64/mm/ultra.S
index 86773e89dc1b..e4c146f7c7e9 100644
--- a/arch/sparc64/mm/ultra.S
+++ b/arch/sparc64/mm/ultra.S
@@ -125,7 +125,6 @@ __spitfire_flush_tlb_mm_slow:
.align 32
.globl __flush_icache_page
__flush_icache_page: /* %o0 = phys_page */
- membar #StoreStore
srlx %o0, PAGE_SHIFT, %o0
sethi %uhi(PAGE_OFFSET), %g1
sllx %o0, PAGE_SHIFT, %o0
@@ -507,7 +506,6 @@ xcall_fetch_glob_regs:
sllx %g2, TRAP_BLOCK_SZ_SHIFT, %g2
add %g7, %g2, %g7
ldx [%g7 + TRAP_PER_CPU_THREAD], %g3
- membar #StoreStore
stx %g3, [%g1 + GR_SNAP_THREAD]
retry