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qemu/atomic.h: rename atomic_ to qatomic_

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clang's C11 atomic_fetch_*() functions only take a C11 atomic type
pointer argument. QEMU uses direct types (int, etc) and this causes a
compiler error when a QEMU code calls these functions in a source file
that also included <stdatomic.h> via a system header file:

  $ CC=clang CXX=clang++ ./configure ... && make
  ../util/async.c:79:17: error: address argument to atomic operation must be a pointer to _Atomic type ('unsigned int *' invalid)

Avoid using atomic_*() names in QEMU's atomic.h since that namespace is
used by <stdatomic.h>. Prefix QEMU's APIs with 'q' so that atomic.h
and <stdatomic.h> can co-exist. I checked /usr/include on my machine and
searched GitHub for existing "qatomic_" users but there seem to be none.

This patch was generated using:

  $ git grep -h -o '\<atomic\(64\)\?_[a-z0-9_]\+' include/qemu/atomic.h | \
    sort -u >/tmp/changed_identifiers
  $ for identifier in $(</tmp/changed_identifiers); do
        sed -i "s%\<$identifier\>%q$identifier%g" \
            $(git grep -I -l "\<$identifier\>")
    done

I manually fixed line-wrap issues and misaligned rST tables.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200923105646.47864-1-stefanha@redhat.com>
This commit is contained in:
Stefan Hajnoczi
2020-09-23 11:56:46 +01:00
parent ed7db34b5a
commit d73415a315
133 changed files with 1041 additions and 1018 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
accel/kvm/kvm-all.c
View File

@@ -2379,7 +2379,7 @@ static __thread bool have_sigbus_pending;
static void kvm_cpu_kick(CPUState *cpu)
{
atomic_set(&cpu->kvm_run->immediate_exit, 1);
qatomic_set(&cpu->kvm_run->immediate_exit, 1);
}
static void kvm_cpu_kick_self(void)
@@ -2400,7 +2400,7 @@ static void kvm_eat_signals(CPUState *cpu)
int r;
if (kvm_immediate_exit) {
atomic_set(&cpu->kvm_run->immediate_exit, 0);
qatomic_set(&cpu->kvm_run->immediate_exit, 0);
/* Write kvm_run->immediate_exit before the cpu->exit_request
* write in kvm_cpu_exec.
*/
@@ -2434,7 +2434,7 @@ int kvm_cpu_exec(CPUState *cpu)
DPRINTF("kvm_cpu_exec()\n");
if (kvm_arch_process_async_events(cpu)) {
atomic_set(&cpu->exit_request, 0);
qatomic_set(&cpu->exit_request, 0);
return EXCP_HLT;
}
@@ -2450,7 +2450,7 @@ int kvm_cpu_exec(CPUState *cpu)
}
kvm_arch_pre_run(cpu, run);
if (atomic_read(&cpu->exit_request)) {
if (qatomic_read(&cpu->exit_request)) {
DPRINTF("interrupt exit requested\n");
/*
* KVM requires us to reenter the kernel after IO exits to complete
@@ -2577,7 +2577,7 @@ int kvm_cpu_exec(CPUState *cpu)
vm_stop(RUN_STATE_INTERNAL_ERROR);
}
atomic_set(&cpu->exit_request, 0);
qatomic_set(&cpu->exit_request, 0);
return ret;
}
@@ -2994,7 +2994,7 @@ int kvm_on_sigbus_vcpu(CPUState *cpu, int code, void *addr)
have_sigbus_pending = true;
pending_sigbus_addr = addr;
pending_sigbus_code = code;
atomic_set(&cpu->exit_request, 1);
qatomic_set(&cpu->exit_request, 1);
return 0;
#else
return 1;

20
accel/tcg/atomic_template.h
View File

@@ -83,7 +83,7 @@ ABI_TYPE ATOMIC_NAME(cmpxchg)(CPUArchState *env, target_ulong addr,
#if DATA_SIZE == 16
ret = atomic16_cmpxchg(haddr, cmpv, newv);
#else
ret = atomic_cmpxchg__nocheck(haddr, cmpv, newv);
ret = qatomic_cmpxchg__nocheck(haddr, cmpv, newv);
#endif
ATOMIC_MMU_CLEANUP;
atomic_trace_rmw_post(env, addr, info);
@@ -131,7 +131,7 @@ ABI_TYPE ATOMIC_NAME(xchg)(CPUArchState *env, target_ulong addr,
ATOMIC_MMU_IDX);
atomic_trace_rmw_pre(env, addr, info);
ret = atomic_xchg__nocheck(haddr, val);
ret = qatomic_xchg__nocheck(haddr, val);
ATOMIC_MMU_CLEANUP;
atomic_trace_rmw_post(env, addr, info);
return ret;
@@ -147,7 +147,7 @@ ABI_TYPE ATOMIC_NAME(X)(CPUArchState *env, target_ulong addr, \
uint16_t info = trace_mem_build_info(SHIFT, false, 0, false, \
ATOMIC_MMU_IDX); \
atomic_trace_rmw_pre(env, addr, info); \
ret = atomic_##X(haddr, val); \
ret = qatomic_##X(haddr, val); \
ATOMIC_MMU_CLEANUP; \
atomic_trace_rmw_post(env, addr, info); \
return ret; \
@@ -182,10 +182,10 @@ ABI_TYPE ATOMIC_NAME(X)(CPUArchState *env, target_ulong addr, \
ATOMIC_MMU_IDX); \
atomic_trace_rmw_pre(env, addr, info); \
smp_mb(); \
cmp = atomic_read__nocheck(haddr); \
cmp = qatomic_read__nocheck(haddr); \
do { \
old = cmp; new = FN(old, val); \
cmp = atomic_cmpxchg__nocheck(haddr, old, new); \
cmp = qatomic_cmpxchg__nocheck(haddr, old, new); \
} while (cmp != old); \
ATOMIC_MMU_CLEANUP; \
atomic_trace_rmw_post(env, addr, info); \
@@ -230,7 +230,7 @@ ABI_TYPE ATOMIC_NAME(cmpxchg)(CPUArchState *env, target_ulong addr,
#if DATA_SIZE == 16
ret = atomic16_cmpxchg(haddr, BSWAP(cmpv), BSWAP(newv));
#else
ret = atomic_cmpxchg__nocheck(haddr, BSWAP(cmpv), BSWAP(newv));
ret = qatomic_cmpxchg__nocheck(haddr, BSWAP(cmpv), BSWAP(newv));
#endif
ATOMIC_MMU_CLEANUP;
atomic_trace_rmw_post(env, addr, info);
@@ -280,7 +280,7 @@ ABI_TYPE ATOMIC_NAME(xchg)(CPUArchState *env, target_ulong addr,
ATOMIC_MMU_IDX);
atomic_trace_rmw_pre(env, addr, info);
ret = atomic_xchg__nocheck(haddr, BSWAP(val));
ret = qatomic_xchg__nocheck(haddr, BSWAP(val));
ATOMIC_MMU_CLEANUP;
atomic_trace_rmw_post(env, addr, info);
return BSWAP(ret);
@@ -296,7 +296,7 @@ ABI_TYPE ATOMIC_NAME(X)(CPUArchState *env, target_ulong addr, \
uint16_t info = trace_mem_build_info(SHIFT, false, MO_BSWAP, \
false, ATOMIC_MMU_IDX); \
atomic_trace_rmw_pre(env, addr, info); \
ret = atomic_##X(haddr, BSWAP(val)); \
ret = qatomic_##X(haddr, BSWAP(val)); \
ATOMIC_MMU_CLEANUP; \
atomic_trace_rmw_post(env, addr, info); \
return BSWAP(ret); \
@@ -329,10 +329,10 @@ ABI_TYPE ATOMIC_NAME(X)(CPUArchState *env, target_ulong addr, \
false, ATOMIC_MMU_IDX); \
atomic_trace_rmw_pre(env, addr, info); \
smp_mb(); \
ldn = atomic_read__nocheck(haddr); \
ldn = qatomic_read__nocheck(haddr); \
do { \
ldo = ldn; old = BSWAP(ldo); new = FN(old, val); \
ldn = atomic_cmpxchg__nocheck(haddr, ldo, BSWAP(new)); \
ldn = qatomic_cmpxchg__nocheck(haddr, ldo, BSWAP(new)); \
} while (ldo != ldn); \
ATOMIC_MMU_CLEANUP; \
atomic_trace_rmw_post(env, addr, info); \

15
accel/tcg/cpu-exec.c
View File

@@ -367,7 +367,8 @@ static inline void tb_add_jump(TranslationBlock *tb, int n,
goto out_unlock_next;
}
/* Atomically claim the jump destination slot only if it was NULL */
old = atomic_cmpxchg(&tb->jmp_dest[n], (uintptr_t)NULL, (uintptr_t)tb_next);
old = qatomic_cmpxchg(&tb->jmp_dest[n], (uintptr_t)NULL,
(uintptr_t)tb_next);
if (old) {
goto out_unlock_next;
}
@@ -407,7 +408,7 @@ static inline TranslationBlock *tb_find(CPUState *cpu,
tb = tb_gen_code(cpu, pc, cs_base, flags, cf_mask);
mmap_unlock();
/* We add the TB in the virtual pc hash table for the fast lookup */
atomic_set(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)], tb);
qatomic_set(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)], tb);
}
#ifndef CONFIG_USER_ONLY
/* We don't take care of direct jumps when address mapping changes in
@@ -536,9 +537,9 @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
* Ensure zeroing happens before reading cpu->exit_request or
* cpu->interrupt_request (see also smp_wmb in cpu_exit())
*/
atomic_mb_set(&cpu_neg(cpu)->icount_decr.u16.high, 0);
qatomic_mb_set(&cpu_neg(cpu)->icount_decr.u16.high, 0);
if (unlikely(atomic_read(&cpu->interrupt_request))) {
if (unlikely(qatomic_read(&cpu->interrupt_request))) {
int interrupt_request;
qemu_mutex_lock_iothread();
interrupt_request = cpu->interrupt_request;
@@ -613,10 +614,10 @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
}
/* Finally, check if we need to exit to the main loop. */
if (unlikely(atomic_read(&cpu->exit_request))
if (unlikely(qatomic_read(&cpu->exit_request))
|| (use_icount
&& cpu_neg(cpu)->icount_decr.u16.low + cpu->icount_extra == 0)) {
atomic_set(&cpu->exit_request, 0);
qatomic_set(&cpu->exit_request, 0);
if (cpu->exception_index == -1) {
cpu->exception_index = EXCP_INTERRUPT;
}
@@ -642,7 +643,7 @@ static inline void cpu_loop_exec_tb(CPUState *cpu, TranslationBlock *tb,
}
*last_tb = NULL;
insns_left = atomic_read(&cpu_neg(cpu)->icount_decr.u32);
insns_left = qatomic_read(&cpu_neg(cpu)->icount_decr.u32);
if (insns_left < 0) {
/* Something asked us to stop executing chained TBs; just
* continue round the main loop. Whatever requested the exit

24
accel/tcg/cputlb.c
View File

@@ -312,9 +312,9 @@ void tlb_flush_counts(size_t *pfull, size_t *ppart, size_t *pelide)
CPU_FOREACH(cpu) {
CPUArchState *env = cpu->env_ptr;
full += atomic_read(&env_tlb(env)->c.full_flush_count);
part += atomic_read(&env_tlb(env)->c.part_flush_count);
elide += atomic_read(&env_tlb(env)->c.elide_flush_count);
full += qatomic_read(&env_tlb(env)->c.full_flush_count);
part += qatomic_read(&env_tlb(env)->c.part_flush_count);
elide += qatomic_read(&env_tlb(env)->c.elide_flush_count);
}
*pfull = full;
*ppart = part;
@@ -349,13 +349,13 @@ static void tlb_flush_by_mmuidx_async_work(CPUState *cpu, run_on_cpu_data data)
cpu_tb_jmp_cache_clear(cpu);
if (to_clean == ALL_MMUIDX_BITS) {
atomic_set(&env_tlb(env)->c.full_flush_count,
qatomic_set(&env_tlb(env)->c.full_flush_count,
env_tlb(env)->c.full_flush_count + 1);
} else {
atomic_set(&env_tlb(env)->c.part_flush_count,
qatomic_set(&env_tlb(env)->c.part_flush_count,
env_tlb(env)->c.part_flush_count + ctpop16(to_clean));
if (to_clean != asked) {
atomic_set(&env_tlb(env)->c.elide_flush_count,
qatomic_set(&env_tlb(env)->c.elide_flush_count,
env_tlb(env)->c.elide_flush_count +
ctpop16(asked & ~to_clean));
}
@@ -693,7 +693,7 @@ void tlb_unprotect_code(ram_addr_t ram_addr)
* generated code.
*
* Other vCPUs might be reading their TLBs during guest execution, so we update
* te->addr_write with atomic_set. We don't need to worry about this for
* te->addr_write with qatomic_set. We don't need to worry about this for
* oversized guests as MTTCG is disabled for them.
*
* Called with tlb_c.lock held.
@@ -711,7 +711,7 @@ static void tlb_reset_dirty_range_locked(CPUTLBEntry *tlb_entry,
#if TCG_OVERSIZED_GUEST
tlb_entry->addr_write |= TLB_NOTDIRTY;
#else
atomic_set(&tlb_entry->addr_write,
qatomic_set(&tlb_entry->addr_write,
tlb_entry->addr_write | TLB_NOTDIRTY);
#endif
}
@@ -1138,8 +1138,8 @@ static inline target_ulong tlb_read_ofs(CPUTLBEntry *entry, size_t ofs)
#if TCG_OVERSIZED_GUEST
return *(target_ulong *)((uintptr_t)entry + ofs);
#else
/* ofs might correspond to .addr_write, so use atomic_read */
return atomic_read((target_ulong *)((uintptr_t)entry + ofs));
/* ofs might correspond to .addr_write, so use qatomic_read */
return qatomic_read((target_ulong *)((uintptr_t)entry + ofs));
#endif
}
@@ -1155,11 +1155,11 @@ static bool victim_tlb_hit(CPUArchState *env, size_t mmu_idx, size_t index,
CPUTLBEntry *vtlb = &env_tlb(env)->d[mmu_idx].vtable[vidx];
target_ulong cmp;
/* elt_ofs might correspond to .addr_write, so use atomic_read */
/* elt_ofs might correspond to .addr_write, so use qatomic_read */
#if TCG_OVERSIZED_GUEST
cmp = *(target_ulong *)((uintptr_t)vtlb + elt_ofs);
#else
cmp = atomic_read((target_ulong *)((uintptr_t)vtlb + elt_ofs));
cmp = qatomic_read((target_ulong *)((uintptr_t)vtlb + elt_ofs));
#endif
if (cmp == page) {

2
accel/tcg/tcg-all.c
View File

@@ -65,7 +65,7 @@ static void tcg_handle_interrupt(CPUState *cpu, int mask)
if (!qemu_cpu_is_self(cpu)) {
qemu_cpu_kick(cpu);
} else {
atomic_set(&cpu_neg(cpu)->icount_decr.u16.high, -1);
qatomic_set(&cpu_neg(cpu)->icount_decr.u16.high, -1);
if (use_icount &&
!cpu->can_do_io
&& (mask & ~old_mask) != 0) {

55
accel/tcg/translate-all.c
View File

@@ -377,9 +377,9 @@ static int cpu_restore_state_from_tb(CPUState *cpu, TranslationBlock *tb,
restore_state_to_opc(env, tb, data);
#ifdef CONFIG_PROFILER
atomic_set(&prof->restore_time,
qatomic_set(&prof->restore_time,
prof->restore_time + profile_getclock() - ti);
atomic_set(&prof->restore_count, prof->restore_count + 1);
qatomic_set(&prof->restore_count, prof->restore_count + 1);
#endif
return 0;
}
@@ -509,7 +509,7 @@ static PageDesc *page_find_alloc(tb_page_addr_t index, int alloc)
/* Level 2..N-1. */
for (i = v_l2_levels; i > 0; i--) {
void **p = atomic_rcu_read(lp);
void **p = qatomic_rcu_read(lp);
if (p == NULL) {
void *existing;
@@ -518,7 +518,7 @@ static PageDesc *page_find_alloc(tb_page_addr_t index, int alloc)
return NULL;
}
p = g_new0(void *, V_L2_SIZE);
existing = atomic_cmpxchg(lp, NULL, p);
existing = qatomic_cmpxchg(lp, NULL, p);
if (unlikely(existing)) {
g_free(p);
p = existing;
@@ -528,7 +528,7 @@ static PageDesc *page_find_alloc(tb_page_addr_t index, int alloc)
lp = p + ((index >> (i * V_L2_BITS)) & (V_L2_SIZE - 1));
}
pd = atomic_rcu_read(lp);
pd = qatomic_rcu_read(lp);
if (pd == NULL) {
void *existing;
@@ -545,7 +545,7 @@ static PageDesc *page_find_alloc(tb_page_addr_t index, int alloc)
}
}
#endif
existing = atomic_cmpxchg(lp, NULL, pd);
existing = qatomic_cmpxchg(lp, NULL, pd);
if (unlikely(existing)) {
#ifndef CONFIG_USER_ONLY
{
@@ -1253,7 +1253,7 @@ static void do_tb_flush(CPUState *cpu, run_on_cpu_data tb_flush_count)
tcg_region_reset_all();
/* XXX: flush processor icache at this point if cache flush is
expensive */
atomic_mb_set(&tb_ctx.tb_flush_count, tb_ctx.tb_flush_count + 1);
qatomic_mb_set(&tb_ctx.tb_flush_count, tb_ctx.tb_flush_count + 1);
done:
mmap_unlock();
@@ -1265,7 +1265,7 @@ done:
void tb_flush(CPUState *cpu)
{
if (tcg_enabled()) {
unsigned tb_flush_count = atomic_mb_read(&tb_ctx.tb_flush_count);
unsigned tb_flush_count = qatomic_mb_read(&tb_ctx.tb_flush_count);
if (cpu_in_exclusive_context(cpu)) {
do_tb_flush(cpu, RUN_ON_CPU_HOST_INT(tb_flush_count));
@@ -1358,7 +1358,7 @@ static inline void tb_remove_from_jmp_list(TranslationBlock *orig, int n_orig)
int n;
/* mark the LSB of jmp_dest[] so that no further jumps can be inserted */
ptr = atomic_or_fetch(&orig->jmp_dest[n_orig], 1);
ptr = qatomic_or_fetch(&orig->jmp_dest[n_orig], 1);
dest = (TranslationBlock *)(ptr & ~1);
if (dest == NULL) {
return;
@@ -1369,7 +1369,7 @@ static inline void tb_remove_from_jmp_list(TranslationBlock *orig, int n_orig)
* While acquiring the lock, the jump might have been removed if the
* destination TB was invalidated; check again.
*/
ptr_locked = atomic_read(&orig->jmp_dest[n_orig]);
ptr_locked = qatomic_read(&orig->jmp_dest[n_orig]);
if (ptr_locked != ptr) {
qemu_spin_unlock(&dest->jmp_lock);
/*
@@ -1415,7 +1415,7 @@ static inline void tb_jmp_unlink(TranslationBlock *dest)
TB_FOR_EACH_JMP(dest, tb, n) {
tb_reset_jump(tb, n);
atomic_and(&tb->jmp_dest[n], (uintptr_t)NULL | 1);
qatomic_and(&tb->jmp_dest[n], (uintptr_t)NULL | 1);
/* No need to clear the list entry; setting the dest ptr is enough */
}
dest->jmp_list_head = (uintptr_t)NULL;
@@ -1439,7 +1439,7 @@ static void do_tb_phys_invalidate(TranslationBlock *tb, bool rm_from_page_list)
/* make sure no further incoming jumps will be chained to this TB */
qemu_spin_lock(&tb->jmp_lock);
atomic_set(&tb->cflags, tb->cflags | CF_INVALID);
qatomic_set(&tb->cflags, tb->cflags | CF_INVALID);
qemu_spin_unlock(&tb->jmp_lock);
/* remove the TB from the hash list */
@@ -1466,8 +1466,8 @@ static void do_tb_phys_invalidate(TranslationBlock *tb, bool rm_from_page_list)
/* remove the TB from the hash list */
h = tb_jmp_cache_hash_func(tb->pc);
CPU_FOREACH(cpu) {
if (atomic_read(&cpu->tb_jmp_cache[h]) == tb) {
atomic_set(&cpu->tb_jmp_cache[h], NULL);
if (qatomic_read(&cpu->tb_jmp_cache[h]) == tb) {
qatomic_set(&cpu->tb_jmp_cache[h], NULL);
}
}
@@ -1478,7 +1478,7 @@ static void do_tb_phys_invalidate(TranslationBlock *tb, bool rm_from_page_list)
/* suppress any remaining jumps to this TB */
tb_jmp_unlink(tb);
atomic_set(&tcg_ctx->tb_phys_invalidate_count,
qatomic_set(&tcg_ctx->tb_phys_invalidate_count,
tcg_ctx->tb_phys_invalidate_count + 1);
}
@@ -1733,7 +1733,7 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
#ifdef CONFIG_PROFILER
/* includes aborted translations because of exceptions */
atomic_set(&prof->tb_count1, prof->tb_count1 + 1);
qatomic_set(&prof->tb_count1, prof->tb_count1 + 1);
ti = profile_getclock();
#endif
@@ -1758,8 +1758,9 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
}
#ifdef CONFIG_PROFILER
atomic_set(&prof->tb_count, prof->tb_count + 1);
atomic_set(&prof->interm_time, prof->interm_time + profile_getclock() - ti);
qatomic_set(&prof->tb_count, prof->tb_count + 1);
qatomic_set(&prof->interm_time,
prof->interm_time + profile_getclock() - ti);
ti = profile_getclock();
#endif
@@ -1804,10 +1805,10 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
tb->tc.size = gen_code_size;
#ifdef CONFIG_PROFILER
atomic_set(&prof->code_time, prof->code_time + profile_getclock() - ti);
atomic_set(&prof->code_in_len, prof->code_in_len + tb->size);
atomic_set(&prof->code_out_len, prof->code_out_len + gen_code_size);
atomic_set(&prof->search_out_len, prof->search_out_len + search_size);
qatomic_set(&prof->code_time, prof->code_time + profile_getclock() - ti);
qatomic_set(&prof->code_in_len, prof->code_in_len + tb->size);
qatomic_set(&prof->code_out_len, prof->code_out_len + gen_code_size);
qatomic_set(&prof->search_out_len, prof->search_out_len + search_size);
#endif
#ifdef DEBUG_DISAS
@@ -1869,7 +1870,7 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
}
#endif
atomic_set(&tcg_ctx->code_gen_ptr, (void *)
qatomic_set(&tcg_ctx->code_gen_ptr, (void *)
ROUND_UP((uintptr_t)gen_code_buf + gen_code_size + search_size,
CODE_GEN_ALIGN));
@@ -1905,7 +1906,7 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
uintptr_t orig_aligned = (uintptr_t)gen_code_buf;
orig_aligned -= ROUND_UP(sizeof(*tb), qemu_icache_linesize);
atomic_set(&tcg_ctx->code_gen_ptr, (void *)orig_aligned);
qatomic_set(&tcg_ctx->code_gen_ptr, (void *)orig_aligned);
tb_destroy(tb);
return existing_tb;
}
@@ -2273,7 +2274,7 @@ static void tb_jmp_cache_clear_page(CPUState *cpu, target_ulong page_addr)
unsigned int i, i0 = tb_jmp_cache_hash_page(page_addr);
for (i = 0; i < TB_JMP_PAGE_SIZE; i++) {
atomic_set(&cpu->tb_jmp_cache[i0 + i], NULL);
qatomic_set(&cpu->tb_jmp_cache[i0 + i], NULL);
}
}
@@ -2393,7 +2394,7 @@ void dump_exec_info(void)
qemu_printf("\nStatistics:\n");
qemu_printf("TB flush count %u\n",
atomic_read(&tb_ctx.tb_flush_count));
qatomic_read(&tb_ctx.tb_flush_count));
qemu_printf("TB invalidate count %zu\n",
tcg_tb_phys_invalidate_count());
@@ -2415,7 +2416,7 @@ void cpu_interrupt(CPUState *cpu, int mask)
{
g_assert(qemu_mutex_iothread_locked());
cpu->interrupt_request |= mask;
atomic_set(&cpu_neg(cpu)->icount_decr.u16.high, -1);
qatomic_set(&cpu_neg(cpu)->icount_decr.u16.high, -1);
}
/*

18
audio/jackaudio.c
View File

@@ -104,7 +104,7 @@ static void qjack_buffer_create(QJackBuffer *buffer, int channels, int frames)
static void qjack_buffer_clear(QJackBuffer *buffer)
{
assert(buffer->data);
atomic_store_release(&buffer->used, 0);
qatomic_store_release(&buffer->used, 0);
buffer->rptr = 0;
buffer->wptr = 0;
}
@@ -129,7 +129,7 @@ static int qjack_buffer_write(QJackBuffer *buffer, float *data, int size)
assert(buffer->data);
const int samples = size / sizeof(float);
int frames = samples / buffer->channels;
const int avail = buffer->frames - atomic_load_acquire(&buffer->used);
const int avail = buffer->frames - qatomic_load_acquire(&buffer->used);
if (frames > avail) {
frames = avail;
@@ -153,7 +153,7 @@ static int qjack_buffer_write(QJackBuffer *buffer, float *data, int size)
buffer->wptr = wptr;
atomic_add(&buffer->used, frames);
qatomic_add(&buffer->used, frames);
return frames * buffer->channels * sizeof(float);
};
@@ -161,7 +161,7 @@ static int qjack_buffer_write(QJackBuffer *buffer, float *data, int size)
static int qjack_buffer_write_l(QJackBuffer *buffer, float **dest, int frames)
{
assert(buffer->data);
const int avail = buffer->frames - atomic_load_acquire(&buffer->used);
const int avail = buffer->frames - qatomic_load_acquire(&buffer->used);
int wptr = buffer->wptr;
if (frames > avail) {
@@ -185,7 +185,7 @@ static int qjack_buffer_write_l(QJackBuffer *buffer, float **dest, int frames)
}
buffer->wptr = wptr;
atomic_add(&buffer->used, frames);
qatomic_add(&buffer->used, frames);
return frames;
}
@@ -195,7 +195,7 @@ static int qjack_buffer_read(QJackBuffer *buffer, float *dest, int size)
assert(buffer->data);
const int samples = size / sizeof(float);
int frames = samples / buffer->channels;
const int avail = atomic_load_acquire(&buffer->used);
const int avail = qatomic_load_acquire(&buffer->used);
if (frames > avail) {
frames = avail;
@@ -219,7 +219,7 @@ static int qjack_buffer_read(QJackBuffer *buffer, float *dest, int size)
buffer->rptr = rptr;
atomic_sub(&buffer->used, frames);
qatomic_sub(&buffer->used, frames);
return frames * buffer->channels * sizeof(float);
}
@@ -228,7 +228,7 @@ static int qjack_buffer_read_l(QJackBuffer *buffer, float **dest, int frames)
{
assert(buffer->data);
int copy = frames;
const int used = atomic_load_acquire(&buffer->used);
const int used = qatomic_load_acquire(&buffer->used);
int rptr = buffer->rptr;
if (copy > used) {
@@ -252,7 +252,7 @@ static int qjack_buffer_read_l(QJackBuffer *buffer, float **dest, int frames)
}
buffer->rptr = rptr;
atomic_sub(&buffer->used, copy);
qatomic_sub(&buffer->used, copy);
return copy;
}

4
block.c
View File

@@ -1694,7 +1694,7 @@ static int bdrv_open_common(BlockDriverState *bs, BlockBackend *file,
}
/* bdrv_new() and bdrv_close() make it so */
assert(atomic_read(&bs->copy_on_read) == 0);
assert(qatomic_read(&bs->copy_on_read) == 0);
if (bs->open_flags & BDRV_O_COPY_ON_READ) {
if (!bs->read_only) {
@@ -4436,7 +4436,7 @@ static void bdrv_close(BlockDriverState *bs)
bs->file = NULL;
g_free(bs->opaque);
bs->opaque = NULL;
atomic_set(&bs->copy_on_read, 0);
qatomic_set(&bs->copy_on_read, 0);
bs->backing_file[0] = '\0';
bs->backing_format[0] = '\0';
bs->total_sectors = 0;

15
block/block-backend.c
View File

@@ -1353,12 +1353,12 @@ int blk_make_zero(BlockBackend *blk, BdrvRequestFlags flags)
void blk_inc_in_flight(BlockBackend *blk)
{
atomic_inc(&blk->in_flight);
qatomic_inc(&blk->in_flight);
}
void blk_dec_in_flight(BlockBackend *blk)
{
atomic_dec(&blk->in_flight);
qatomic_dec(&blk->in_flight);
aio_wait_kick();
}
@@ -1720,7 +1720,7 @@ void blk_drain(BlockBackend *blk)
/* We may have -ENOMEDIUM completions in flight */
AIO_WAIT_WHILE(blk_get_aio_context(blk),
atomic_mb_read(&blk->in_flight) > 0);
qatomic_mb_read(&blk->in_flight) > 0);
if (bs) {
bdrv_drained_end(bs);
@@ -1739,7 +1739,7 @@ void blk_drain_all(void)
aio_context_acquire(ctx);
/* We may have -ENOMEDIUM completions in flight */
AIO_WAIT_WHILE(ctx, atomic_mb_read(&blk->in_flight) > 0);
AIO_WAIT_WHILE(ctx, qatomic_mb_read(&blk->in_flight) > 0);
aio_context_release(ctx);
}
@@ -2346,6 +2346,7 @@ void blk_io_limits_update_group(BlockBackend *blk, const char *group)
static void blk_root_drained_begin(BdrvChild *child)
{
BlockBackend *blk = child->opaque;
ThrottleGroupMember *tgm = &blk->public.throttle_group_member;
if (++blk->quiesce_counter == 1) {
if (blk->dev_ops && blk->dev_ops->drained_begin) {
@@ -2356,8 +2357,8 @@ static void blk_root_drained_begin(BdrvChild *child)
/* Note that blk->root may not be accessible here yet if we are just
* attaching to a BlockDriverState that is drained. Use child instead. */
if (atomic_fetch_inc(&blk->public.throttle_group_member.io_limits_disabled) == 0) {
throttle_group_restart_tgm(&blk->public.throttle_group_member);
if (qatomic_fetch_inc(&tgm->io_limits_disabled) == 0) {
throttle_group_restart_tgm(tgm);
}
}
@@ -2374,7 +2375,7 @@ static void blk_root_drained_end(BdrvChild *child, int *drained_end_counter)
assert(blk->quiesce_counter);
assert(blk->public.throttle_group_member.io_limits_disabled);
atomic_dec(&blk->public.throttle_group_member.io_limits_disabled);
qatomic_dec(&blk->public.throttle_group_member.io_limits_disabled);
if (--blk->quiesce_counter == 0) {
if (blk->dev_ops && blk->dev_ops->drained_end) {

48
block/io.c
View File

@@ -69,7 +69,7 @@ void bdrv_parent_drained_end_single(BdrvChild *c)
{
int drained_end_counter = 0;
bdrv_parent_drained_end_single_no_poll(c, &drained_end_counter);
BDRV_POLL_WHILE(c->bs, atomic_read(&drained_end_counter) > 0);
BDRV_POLL_WHILE(c->bs, qatomic_read(&drained_end_counter) > 0);
}
static void bdrv_parent_drained_end(BlockDriverState *bs, BdrvChild *ignore,
@@ -186,12 +186,12 @@ void bdrv_refresh_limits(BlockDriverState *bs, Error **errp)
*/
void bdrv_enable_copy_on_read(BlockDriverState *bs)
{
atomic_inc(&bs->copy_on_read);
qatomic_inc(&bs->copy_on_read);
}
void bdrv_disable_copy_on_read(BlockDriverState *bs)
{
int old = atomic_fetch_dec(&bs->copy_on_read);
int old = qatomic_fetch_dec(&bs->copy_on_read);
assert(old >= 1);
}
@@ -219,9 +219,9 @@ static void coroutine_fn bdrv_drain_invoke_entry(void *opaque)
}
/* Set data->done and decrement drained_end_counter before bdrv_wakeup() */
atomic_mb_set(&data->done, true);
qatomic_mb_set(&data->done, true);
if (!data->begin) {
atomic_dec(data->drained_end_counter);
qatomic_dec(data->drained_end_counter);
}
bdrv_dec_in_flight(bs);
@@ -248,7 +248,7 @@ static void bdrv_drain_invoke(BlockDriverState *bs, bool begin,
};
if (!begin) {
atomic_inc(drained_end_counter);
qatomic_inc(drained_end_counter);
}
/* Make sure the driver callback completes during the polling phase for
@@ -268,7 +268,7 @@ bool bdrv_drain_poll(BlockDriverState *bs, bool recursive,
return true;
}
if (atomic_read(&bs->in_flight)) {
if (qatomic_read(&bs->in_flight)) {
return true;
}
@@ -382,7 +382,7 @@ void bdrv_do_drained_begin_quiesce(BlockDriverState *bs,
assert(!qemu_in_coroutine());
/* Stop things in parent-to-child order */
if (atomic_fetch_inc(&bs->quiesce_counter) == 0) {
if (qatomic_fetch_inc(&bs->quiesce_counter) == 0) {
aio_disable_external(bdrv_get_aio_context(bs));
}
@@ -473,7 +473,7 @@ static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive,
bdrv_parent_drained_end(bs, parent, ignore_bds_parents,
drained_end_counter);
old_quiesce_counter = atomic_fetch_dec(&bs->quiesce_counter);
old_quiesce_counter = qatomic_fetch_dec(&bs->quiesce_counter);
if (old_quiesce_counter == 1) {
aio_enable_external(bdrv_get_aio_context(bs));
}
@@ -492,7 +492,7 @@ void bdrv_drained_end(BlockDriverState *bs)
{
int drained_end_counter = 0;
bdrv_do_drained_end(bs, false, NULL, false, &drained_end_counter);
BDRV_POLL_WHILE(bs, atomic_read(&drained_end_counter) > 0);
BDRV_POLL_WHILE(bs, qatomic_read(&drained_end_counter) > 0);
}
void bdrv_drained_end_no_poll(BlockDriverState *bs, int *drained_end_counter)
@@ -504,7 +504,7 @@ void bdrv_subtree_drained_end(BlockDriverState *bs)
{
int drained_end_counter = 0;
bdrv_do_drained_end(bs, true, NULL, false, &drained_end_counter);
BDRV_POLL_WHILE(bs, atomic_read(&drained_end_counter) > 0);
BDRV_POLL_WHILE(bs, qatomic_read(&drained_end_counter) > 0);
}
void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent)
@@ -526,7 +526,7 @@ void bdrv_unapply_subtree_drain(BdrvChild *child, BlockDriverState *old_parent)
&drained_end_counter);
}
BDRV_POLL_WHILE(child->bs, atomic_read(&drained_end_counter) > 0);
BDRV_POLL_WHILE(child->bs, qatomic_read(&drained_end_counter) > 0);
}
/*
@@ -553,7 +553,7 @@ static void bdrv_drain_assert_idle(BlockDriverState *bs)
{
BdrvChild *child, *next;
assert(atomic_read(&bs->in_flight) == 0);
assert(qatomic_read(&bs->in_flight) == 0);
QLIST_FOREACH_SAFE(child, &bs->children, next, next) {
bdrv_drain_assert_idle(child->bs);
}
@@ -655,7 +655,7 @@ void bdrv_drain_all_end(void)
}
assert(qemu_get_current_aio_context() == qemu_get_aio_context());
AIO_WAIT_WHILE(NULL, atomic_read(&drained_end_counter) > 0);
AIO_WAIT_WHILE(NULL, qatomic_read(&drained_end_counter) > 0);
assert(bdrv_drain_all_count > 0);
bdrv_drain_all_count--;
@@ -675,7 +675,7 @@ void bdrv_drain_all(void)
static void tracked_request_end(BdrvTrackedRequest *req)
{
if (req->serialising) {
atomic_dec(&req->bs->serialising_in_flight);
qatomic_dec(&req->bs->serialising_in_flight);
}
qemu_co_mutex_lock(&req->bs->reqs_lock);
@@ -777,7 +777,7 @@ bool bdrv_mark_request_serialising(BdrvTrackedRequest *req, uint64_t align)
qemu_co_mutex_lock(&bs->reqs_lock);
if (!req->serialising) {
atomic_inc(&req->bs->serialising_in_flight);
qatomic_inc(&req->bs->serialising_in_flight);
req->serialising = true;
}
@@ -841,7 +841,7 @@ static int bdrv_get_cluster_size(BlockDriverState *bs)
void bdrv_inc_in_flight(BlockDriverState *bs)
{
atomic_inc(&bs->in_flight);
qatomic_inc(&bs->in_flight);
}
void bdrv_wakeup(BlockDriverState *bs)
@@ -851,7 +851,7 @@ void bdrv_wakeup(BlockDriverState *bs)
void bdrv_dec_in_flight(BlockDriverState *bs)
{
atomic_dec(&bs->in_flight);
qatomic_dec(&bs->in_flight);
bdrv_wakeup(bs);
}
@@ -860,7 +860,7 @@ static bool coroutine_fn bdrv_wait_serialising_requests(BdrvTrackedRequest *self
BlockDriverState *bs = self->bs;
bool waited = false;
if (!atomic_read(&bs->serialising_in_flight)) {
if (!qatomic_read(&bs->serialising_in_flight)) {
return false;
}
@@ -1747,7 +1747,7 @@ int coroutine_fn bdrv_co_preadv_part(BdrvChild *child,
bdrv_inc_in_flight(bs);
/* Don't do copy-on-read if we read data before write operation */
if (atomic_read(&bs->copy_on_read)) {
if (qatomic_read(&bs->copy_on_read)) {
flags |= BDRV_REQ_COPY_ON_READ;
}
@@ -1935,7 +1935,7 @@ bdrv_co_write_req_finish(BdrvChild *child, int64_t offset, uint64_t bytes,
int64_t end_sector = DIV_ROUND_UP(offset + bytes, BDRV_SECTOR_SIZE);
BlockDriverState *bs = child->bs;
atomic_inc(&bs->write_gen);
qatomic_inc(&bs->write_gen);
/*
* Discard cannot extend the image, but in error handling cases, such as
@@ -2768,7 +2768,7 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
}
qemu_co_mutex_lock(&bs->reqs_lock);
current_gen = atomic_read(&bs->write_gen);
current_gen = qatomic_read(&bs->write_gen);
/* Wait until any previous flushes are completed */
while (bs->active_flush_req) {
@@ -3116,7 +3116,7 @@ void bdrv_io_plug(BlockDriverState *bs)
bdrv_io_plug(child->bs);
}
if (atomic_fetch_inc(&bs->io_plugged) == 0) {
if (qatomic_fetch_inc(&bs->io_plugged) == 0) {
BlockDriver *drv = bs->drv;
if (drv && drv->bdrv_io_plug) {
drv->bdrv_io_plug(bs);
@@ -3129,7 +3129,7 @@ void bdrv_io_unplug(BlockDriverState *bs)
BdrvChild *child;
assert(bs->io_plugged);
if (atomic_fetch_dec(&bs->io_plugged) == 1) {
if (qatomic_fetch_dec(&bs->io_plugged) == 1) {
BlockDriver *drv = bs->drv;
if (drv && drv->bdrv_io_unplug) {
drv->bdrv_io_unplug(bs);

2
block/nfs.c
View File

@@ -721,7 +721,7 @@ nfs_get_allocated_file_size_cb(int ret, struct nfs_context *nfs, void *data,
}
/* Set task->complete before reading bs->wakeup. */
atomic_mb_set(&task->complete, 1);
qatomic_mb_set(&task->complete, 1);
bdrv_wakeup(task->bs);
}

2
block/sheepdog.c
View File

@@ -665,7 +665,7 @@ out:
srco->co = NULL;
srco->ret = ret;
/* Set srco->finished before reading bs->wakeup. */
atomic_mb_set(&srco->finished, true);
qatomic_mb_set(&srco->finished, true);
if (srco->bs) {
bdrv_wakeup(srco->bs);
}

12
block/throttle-groups.c
View File

@@ -228,7 +228,7 @@ static ThrottleGroupMember *next_throttle_token(ThrottleGroupMember *tgm,
* immediately if it has pending requests. Otherwise we could be
* forcing it to wait for other member's throttled requests. */
if (tgm_has_pending_reqs(tgm, is_write) &&
atomic_read(&tgm->io_limits_disabled)) {
qatomic_read(&tgm->io_limits_disabled)) {
return tgm;
}
@@ -272,7 +272,7 @@ static bool throttle_group_schedule_timer(ThrottleGroupMember *tgm,
ThrottleTimers *tt = &tgm->throttle_timers;
bool must_wait;
if (atomic_read(&tgm->io_limits_disabled)) {
if (qatomic_read(&tgm->io_limits_disabled)) {
return false;
}
@@ -417,7 +417,7 @@ static void coroutine_fn throttle_group_restart_queue_entry(void *opaque)
g_free(data);
atomic_dec(&tgm->restart_pending);
qatomic_dec(&tgm->restart_pending);
aio_wait_kick();
}
@@ -434,7 +434,7 @@ static void throttle_group_restart_queue(ThrottleGroupMember *tgm, bool is_write
* be no timer pending on this tgm at this point */
assert(!timer_pending(tgm->throttle_timers.timers[is_write]));
atomic_inc(&tgm->restart_pending);
qatomic_inc(&tgm->restart_pending);
co = qemu_coroutine_create(throttle_group_restart_queue_entry, rd);
aio_co_enter(tgm->aio_context, co);
@@ -544,7 +544,7 @@ void throttle_group_register_tgm(ThrottleGroupMember *tgm,
tgm->throttle_state = ts;
tgm->aio_context = ctx;
atomic_set(&tgm->restart_pending, 0);
qatomic_set(&tgm->restart_pending, 0);
qemu_mutex_lock(&tg->lock);
/* If the ThrottleGroup is new set this ThrottleGroupMember as the token */
@@ -592,7 +592,7 @@ void throttle_group_unregister_tgm(ThrottleGroupMember *tgm)
}
/* Wait for throttle_group_restart_queue_entry() coroutines to finish */
AIO_WAIT_WHILE(tgm->aio_context, atomic_read(&tgm->restart_pending) > 0);
AIO_WAIT_WHILE(tgm->aio_context, qatomic_read(&tgm->restart_pending) > 0);
qemu_mutex_lock(&tg->lock);
for (i = 0; i < 2; i++) {

4
block/throttle.c
View File

@@ -217,7 +217,7 @@ static void throttle_reopen_abort(BDRVReopenState *reopen_state)
static void coroutine_fn throttle_co_drain_begin(BlockDriverState *bs)
{
ThrottleGroupMember *tgm = bs->opaque;
if (atomic_fetch_inc(&tgm->io_limits_disabled) == 0) {
if (qatomic_fetch_inc(&tgm->io_limits_disabled) == 0) {
throttle_group_restart_tgm(tgm);
}
}
@@ -226,7 +226,7 @@ static void coroutine_fn throttle_co_drain_end(BlockDriverState *bs)
{
ThrottleGroupMember *tgm = bs->opaque;
assert(tgm->io_limits_disabled);
atomic_dec(&tgm->io_limits_disabled);
qatomic_dec(&tgm->io_limits_disabled);
}
static const char *const throttle_strong_runtime_opts[] = {

2
blockdev.c
View File

@@ -1604,7 +1604,7 @@ static void external_snapshot_commit(BlkActionState *common)
/* We don't need (or want) to use the transactional
* bdrv_reopen_multiple() across all the entries at once, because we
* don't want to abort all of them if one of them fails the reopen */
if (!atomic_read(&state->old_bs->copy_on_read)) {
if (!qatomic_read(&state->old_bs->copy_on_read)) {
bdrv_reopen_set_read_only(state->old_bs, true, NULL);
}

2
blockjob.c
View File

@@ -298,7 +298,7 @@ BlockJobInfo *block_job_query(BlockJob *job, Error **errp)
info = g_new0(BlockJobInfo, 1);
info->type = g_strdup(job_type_str(&job->job));
info->device = g_strdup(job->job.id);
info->busy = atomic_read(&job->job.busy);
info->busy = qatomic_read(&job->job.busy);
info->paused = job->job.pause_count > 0;
info->offset = job->job.progress.current;
info->len = job->job.progress.total;

2
contrib/libvhost-user/libvhost-user.c
View File

@@ -449,7 +449,7 @@ static void
vu_log_page(uint8_t *log_table, uint64_t page)
{
DPRINT("Logged dirty guest page: %"PRId64"\n", page);
atomic_or(&log_table[page / 8], 1 << (page % 8));
qatomic_or(&log_table[page / 8], 1 << (page % 8));
}
static void

26
cpus-common.c
View File

@@ -148,7 +148,7 @@ void do_run_on_cpu(CPUState *cpu, run_on_cpu_func func, run_on_cpu_data data,
wi.exclusive = false;
queue_work_on_cpu(cpu, &wi);
while (!atomic_mb_read(&wi.done)) {
while (!qatomic_mb_read(&wi.done)) {
CPUState *self_cpu = current_cpu;
qemu_cond_wait(&qemu_work_cond, mutex);
@@ -188,20 +188,20 @@ void start_exclusive(void)
exclusive_idle();
/* Make all other cpus stop executing. */
atomic_set(&pending_cpus, 1);
qatomic_set(&pending_cpus, 1);
/* Write pending_cpus before reading other_cpu->running. */
smp_mb();
running_cpus = 0;
CPU_FOREACH(other_cpu) {
if (atomic_read(&other_cpu->running)) {
if (qatomic_read(&other_cpu->running)) {
other_cpu->has_waiter = true;
running_cpus++;
qemu_cpu_kick(other_cpu);
}
}
atomic_set(&pending_cpus, running_cpus + 1);
qatomic_set(&pending_cpus, running_cpus + 1);
while (pending_cpus > 1) {
qemu_cond_wait(&exclusive_cond, &qemu_cpu_list_lock);
}
@@ -220,7 +220,7 @@ void end_exclusive(void)
current_cpu->in_exclusive_context = false;
qemu_mutex_lock(&qemu_cpu_list_lock);
atomic_set(&pending_cpus, 0);
qatomic_set(&pending_cpus, 0);
qemu_cond_broadcast(&exclusive_resume);
qemu_mutex_unlock(&qemu_cpu_list_lock);
}
@@ -228,7 +228,7 @@ void end_exclusive(void)
/* Wait for exclusive ops to finish, and begin cpu execution. */
void cpu_exec_start(CPUState *cpu)
{
atomic_set(&cpu->running, true);
qatomic_set(&cpu->running, true);
/* Write cpu->running before reading pending_cpus. */
smp_mb();
@@ -246,17 +246,17 @@ void cpu_exec_start(CPUState *cpu)
* 3. pending_cpus == 0. Then start_exclusive is definitely going to
* see cpu->running == true, and it will kick the CPU.
*/
if (unlikely(atomic_read(&pending_cpus))) {
if (unlikely(qatomic_read(&pending_cpus))) {
QEMU_LOCK_GUARD(&qemu_cpu_list_lock);
if (!cpu->has_waiter) {
/* Not counted in pending_cpus, let the exclusive item
* run. Since we have the lock, just set cpu->running to true
* while holding it; no need to check pending_cpus again.
*/
atomic_set(&cpu->running, false);
qatomic_set(&cpu->running, false);
exclusive_idle();
/* Now pending_cpus is zero. */
atomic_set(&cpu->running, true);
qatomic_set(&cpu->running, true);
} else {
/* Counted in pending_cpus, go ahead and release the
* waiter at cpu_exec_end.
@@ -268,7 +268,7 @@ void cpu_exec_start(CPUState *cpu)
/* Mark cpu as not executing, and release pending exclusive ops. */
void cpu_exec_end(CPUState *cpu)
{
atomic_set(&cpu->running, false);
qatomic_set(&cpu->running, false);
/* Write cpu->running before reading pending_cpus. */
smp_mb();
@@ -288,11 +288,11 @@ void cpu_exec_end(CPUState *cpu)
* see cpu->running == false, and it can ignore this CPU until the
* next cpu_exec_start.
*/
if (unlikely(atomic_read(&pending_cpus))) {
if (unlikely(qatomic_read(&pending_cpus))) {
QEMU_LOCK_GUARD(&qemu_cpu_list_lock);
if (cpu->has_waiter) {
cpu->has_waiter = false;
atomic_set(&pending_cpus, pending_cpus - 1);
qatomic_set(&pending_cpus, pending_cpus - 1);
if (pending_cpus == 1) {
qemu_cond_signal(&exclusive_cond);
}
@@ -346,7 +346,7 @@ void process_queued_cpu_work(CPUState *cpu)
if (wi->free) {
g_free(wi);
} else {
atomic_mb_set(&wi->done, true);
qatomic_mb_set(&wi->done, true);
}
}
qemu_mutex_unlock(&cpu->work_mutex);

134
docs/devel/atomics.rst
View File

@@ -23,9 +23,9 @@ provides macros that fall in three camps:
- compiler barriers: ``barrier()``;
- weak atomic access and manual memory barriers: ``atomic_read()``,
``atomic_set()``, ``smp_rmb()``, ``smp_wmb()``, ``smp_mb()``, ``smp_mb_acquire()``,
``smp_mb_release()``, ``smp_read_barrier_depends()``;
- weak atomic access and manual memory barriers: ``qatomic_read()``,
``qatomic_set()``, ``smp_rmb()``, ``smp_wmb()``, ``smp_mb()``,
``smp_mb_acquire()``, ``smp_mb_release()``, ``smp_read_barrier_depends()``;
- sequentially consistent atomic access: everything else.
@@ -67,23 +67,23 @@ in the order specified by its program".
``qemu/atomic.h`` provides the following set of atomic read-modify-write
operations::
void atomic_inc(ptr)
void atomic_dec(ptr)
void atomic_add(ptr, val)
void atomic_sub(ptr, val)
void atomic_and(ptr, val)
void atomic_or(ptr, val)
void qatomic_inc(ptr)
void qatomic_dec(ptr)
void qatomic_add(ptr, val)
void qatomic_sub(ptr, val)
void qatomic_and(ptr, val)
void qatomic_or(ptr, val)
typeof(*ptr) atomic_fetch_inc(ptr)
typeof(*ptr) atomic_fetch_dec(ptr)
typeof(*ptr) atomic_fetch_add(ptr, val)
typeof(*ptr) atomic_fetch_sub(ptr, val)
typeof(*ptr) atomic_fetch_and(ptr, val)
typeof(*ptr) atomic_fetch_or(ptr, val)
typeof(*ptr) atomic_fetch_xor(ptr, val)
typeof(*ptr) atomic_fetch_inc_nonzero(ptr)
typeof(*ptr) atomic_xchg(ptr, val)
typeof(*ptr) atomic_cmpxchg(ptr, old, new)
typeof(*ptr) qatomic_fetch_inc(ptr)
typeof(*ptr) qatomic_fetch_dec(ptr)
typeof(*ptr) qatomic_fetch_add(ptr, val)
typeof(*ptr) qatomic_fetch_sub(ptr, val)
typeof(*ptr) qatomic_fetch_and(ptr, val)
typeof(*ptr) qatomic_fetch_or(ptr, val)
typeof(*ptr) qatomic_fetch_xor(ptr, val)
typeof(*ptr) qatomic_fetch_inc_nonzero(ptr)
typeof(*ptr) qatomic_xchg(ptr, val)
typeof(*ptr) qatomic_cmpxchg(ptr, old, new)
all of which return the old value of ``*ptr``. These operations are
polymorphic; they operate on any type that is as wide as a pointer or
@@ -91,19 +91,19 @@ smaller.
Similar operations return the new value of ``*ptr``::
typeof(*ptr) atomic_inc_fetch(ptr)
typeof(*ptr) atomic_dec_fetch(ptr)
typeof(*ptr) atomic_add_fetch(ptr, val)
typeof(*ptr) atomic_sub_fetch(ptr, val)
typeof(*ptr) atomic_and_fetch(ptr, val)
typeof(*ptr) atomic_or_fetch(ptr, val)
typeof(*ptr) atomic_xor_fetch(ptr, val)
typeof(*ptr) qatomic_inc_fetch(ptr)
typeof(*ptr) qatomic_dec_fetch(ptr)
typeof(*ptr) qatomic_add_fetch(ptr, val)
typeof(*ptr) qatomic_sub_fetch(ptr, val)
typeof(*ptr) qatomic_and_fetch(ptr, val)
typeof(*ptr) qatomic_or_fetch(ptr, val)
typeof(*ptr) qatomic_xor_fetch(ptr, val)
``qemu/atomic.h`` also provides loads and stores that cannot be reordered
with each other::
typeof(*ptr) atomic_mb_read(ptr)
void atomic_mb_set(ptr, val)
typeof(*ptr) qatomic_mb_read(ptr)
void qatomic_mb_set(ptr, val)
However these do not provide sequential consistency and, in particular,
they do not participate in the total ordering enforced by
@@ -115,11 +115,11 @@ easiest to hardest):
- lightweight synchronization primitives such as ``QemuEvent``
- RCU operations (``atomic_rcu_read``, ``atomic_rcu_set``) when publishing
- RCU operations (``qatomic_rcu_read``, ``qatomic_rcu_set``) when publishing
or accessing a new version of a data structure
- other atomic accesses: ``atomic_read`` and ``atomic_load_acquire`` for
loads, ``atomic_set`` and ``atomic_store_release`` for stores, ``smp_mb``
- other atomic accesses: ``qatomic_read`` and ``qatomic_load_acquire`` for
loads, ``qatomic_set`` and ``qatomic_store_release`` for stores, ``smp_mb``
to forbid reordering subsequent loads before a store.
@@ -149,22 +149,22 @@ The only guarantees that you can rely upon in this case are:
When using this model, variables are accessed with:
- ``atomic_read()`` and ``atomic_set()``; these prevent the compiler from
- ``qatomic_read()`` and ``qatomic_set()``; these prevent the compiler from
optimizing accesses out of existence and creating unsolicited
accesses, but do not otherwise impose any ordering on loads and
stores: both the compiler and the processor are free to reorder
them.
- ``atomic_load_acquire()``, which guarantees the LOAD to appear to
- ``qatomic_load_acquire()``, which guarantees the LOAD to appear to
happen, with respect to the other components of the system,
before all the LOAD or STORE operations specified afterwards.
Operations coming before ``atomic_load_acquire()`` can still be
Operations coming before ``qatomic_load_acquire()`` can still be
reordered after it.
- ``atomic_store_release()``, which guarantees the STORE to appear to
- ``qatomic_store_release()``, which guarantees the STORE to appear to
happen, with respect to the other components of the system,
after all the LOAD or STORE operations specified before.
Operations coming after ``atomic_store_release()`` can still be
Operations coming after ``qatomic_store_release()`` can still be
reordered before it.
Restrictions to the ordering of accesses can also be specified
@@ -229,7 +229,7 @@ They come in six kinds:
dependency and a full read barrier or better is required.
Memory barriers and ``atomic_load_acquire``/``atomic_store_release`` are
Memory barriers and ``qatomic_load_acquire``/``qatomic_store_release`` are
mostly used when a data structure has one thread that is always a writer
and one thread that is always a reader:
@@ -238,8 +238,8 @@ and one thread that is always a reader:
+==================================+==================================+
| :: | :: |
| | |
| atomic_store_release(&a, x); | y = atomic_load_acquire(&b); |
| atomic_store_release(&b, y); | x = atomic_load_acquire(&a); |
| qatomic_store_release(&a, x); | y = qatomic_load_acquire(&b); |
| qatomic_store_release(&b, y); | x = qatomic_load_acquire(&a); |
+----------------------------------+----------------------------------+
In this case, correctness is easy to check for using the "pairing"
@@ -258,14 +258,14 @@ outside a loop. For example:
| | |
| n = 0; | n = 0; |
| for (i = 0; i < 10; i++) | for (i = 0; i < 10; i++) |
| n += atomic_load_acquire(&a[i]); | n += atomic_read(&a[i]); |
| n += qatomic_load_acquire(&a[i]); | n += qatomic_read(&a[i]); |
| | smp_mb_acquire(); |
+------------------------------------------+----------------------------------+
| :: | :: |
| | |
| | smp_mb_release(); |
| for (i = 0; i < 10; i++) | for (i = 0; i < 10; i++) |
| atomic_store_release(&a[i], false); | atomic_set(&a[i], false); |
| qatomic_store_release(&a[i], false); | qatomic_set(&a[i], false); |
+------------------------------------------+----------------------------------+
Splitting a loop can also be useful to reduce the number of barriers:
@@ -277,11 +277,11 @@ Splitting a loop can also be useful to reduce the number of barriers:
| | |
| n = 0; | smp_mb_release(); |
| for (i = 0; i < 10; i++) { | for (i = 0; i < 10; i++) |
| atomic_store_release(&a[i], false); | atomic_set(&a[i], false); |
| qatomic_store_release(&a[i], false); | qatomic_set(&a[i], false); |
| smp_mb(); | smb_mb(); |
| n += atomic_read(&b[i]); | n = 0; |
| n += qatomic_read(&b[i]); | n = 0; |
| } | for (i = 0; i < 10; i++) |
| | n += atomic_read(&b[i]); |
| | n += qatomic_read(&b[i]); |
+------------------------------------------+----------------------------------+
In this case, a ``smp_mb_release()`` is also replaced with a (possibly cheaper, and clearer
@@ -294,10 +294,10 @@ as well) ``smp_wmb()``:
| | |
| | smp_mb_release(); |
| for (i = 0; i < 10; i++) { | for (i = 0; i < 10; i++) |
| atomic_store_release(&a[i], false); | atomic_set(&a[i], false); |
| atomic_store_release(&b[i], false); | smb_wmb(); |
| qatomic_store_release(&a[i], false); | qatomic_set(&a[i], false); |
| qatomic_store_release(&b[i], false); | smb_wmb(); |
| } | for (i = 0; i < 10; i++) |
| | atomic_set(&b[i], false); |
| | qatomic_set(&b[i], false); |
+------------------------------------------+----------------------------------+
@@ -306,7 +306,7 @@ as well) ``smp_wmb()``:
Acquire/release pairing and the *synchronizes-with* relation
------------------------------------------------------------
Atomic operations other than ``atomic_set()`` and ``atomic_read()`` have
Atomic operations other than ``qatomic_set()`` and ``qatomic_read()`` have
either *acquire* or *release* semantics [#rmw]_. This has two effects:
.. [#rmw] Read-modify-write operations can have both---acquire applies to the
@@ -357,16 +357,16 @@ thread 2 is relying on the *synchronizes-with* relation between ``pthread_exit``
Synchronization between threads basically descends from this pairing of
a release operation and an acquire operation. Therefore, atomic operations
other than ``atomic_set()`` and ``atomic_read()`` will almost always be
other than ``qatomic_set()`` and ``qatomic_read()`` will almost always be
paired with another operation of the opposite kind: an acquire operation
will pair with a release operation and vice versa. This rule of thumb is
extremely useful; in the case of QEMU, however, note that the other
operation may actually be in a driver that runs in the guest!
``smp_read_barrier_depends()``, ``smp_rmb()``, ``smp_mb_acquire()``,
``atomic_load_acquire()`` and ``atomic_rcu_read()`` all count
``qatomic_load_acquire()`` and ``qatomic_rcu_read()`` all count
as acquire operations. ``smp_wmb()``, ``smp_mb_release()``,
``atomic_store_release()`` and ``atomic_rcu_set()`` all count as release
``qatomic_store_release()`` and ``qatomic_rcu_set()`` all count as release
operations. ``smp_mb()`` counts as both acquire and release, therefore
it can pair with any other atomic operation. Here is an example:
@@ -375,11 +375,11 @@ it can pair with any other atomic operation. Here is an example:
+======================+==============================+
| :: | :: |
| | |
| atomic_set(&a, 1); | |
| qatomic_set(&a, 1);| |
| smp_wmb(); | |
| atomic_set(&b, 2); | x = atomic_read(&b); |
| qatomic_set(&b, 2);| x = qatomic_read(&b); |
| | smp_rmb(); |
| | y = atomic_read(&a); |
| | y = qatomic_read(&a); |
+----------------------+------------------------------+
Note that a load-store pair only counts if the two operations access the
@@ -393,9 +393,9 @@ correct synchronization:
+================================+================================+
| :: | :: |
| | |
| atomic_set(&a, 1); | |
| atomic_store_release(&b, 2); | x = atomic_load_acquire(&b); |
| | y = atomic_read(&a); |
| qatomic_set(&a, 1); | |
| qatomic_store_release(&b, 2);| x = qatomic_load_acquire(&b);|
| | y = qatomic_read(&a); |
+--------------------------------+--------------------------------+
Acquire and release semantics of higher-level primitives can also be
@@ -421,7 +421,7 @@ cannot be a data race:
| smp_wmb(); | |
| x->i = 2; | |
| smp_wmb(); | |
| atomic_set(&a, x); | x = atomic_read(&a); |
| qatomic_set(&a, x);| x = qatomic_read(&a); |
| | smp_read_barrier_depends(); |
| | y = x->i; |
| | smp_read_barrier_depends(); |
@@ -442,7 +442,7 @@ and memory barriers, and the equivalents in QEMU:
at all. Linux 4.1 updated them to implement volatile
semantics via ``ACCESS_ONCE`` (or the more recent ``READ``/``WRITE_ONCE``).
QEMU's ``atomic_read`` and ``atomic_set`` implement C11 atomic relaxed
QEMU's ``qatomic_read`` and ``qatomic_set`` implement C11 atomic relaxed
semantics if the compiler supports it, and volatile semantics otherwise.
Both semantics prevent the compiler from doing certain transformations;
the difference is that atomic accesses are guaranteed to be atomic,
@@ -451,8 +451,8 @@ and memory barriers, and the equivalents in QEMU:
since we assume the variables passed are machine-word sized and
properly aligned.
No barriers are implied by ``atomic_read`` and ``atomic_set`` in either Linux
or QEMU.
No barriers are implied by ``qatomic_read`` and ``qatomic_set`` in either
Linux or QEMU.
- atomic read-modify-write operations in Linux are of three kinds:
@@ -469,7 +469,7 @@ and memory barriers, and the equivalents in QEMU:
a different set of memory barriers; in QEMU, all of them enforce
sequential consistency.
- in QEMU, ``atomic_read()`` and ``atomic_set()`` do not participate in
- in QEMU, ``qatomic_read()`` and ``qatomic_set()`` do not participate in
the total ordering enforced by sequentially-consistent operations.
This is because QEMU uses the C11 memory model. The following example
is correct in Linux but not in QEMU:
@@ -479,8 +479,8 @@ and memory barriers, and the equivalents in QEMU:
+==================================+================================+
| :: | :: |
| | |
| a = atomic_fetch_add(&x, 2); | a = atomic_fetch_add(&x, 2); |
| b = READ_ONCE(&y); | b = atomic_read(&y); |
| a = atomic_fetch_add(&x, 2); | a = qatomic_fetch_add(&x, 2);|
| b = READ_ONCE(&y); | b = qatomic_read(&y); |
+----------------------------------+--------------------------------+
because the read of ``y`` can be moved (by either the processor or the
@@ -495,10 +495,10 @@ and memory barriers, and the equivalents in QEMU:
+================================+
| :: |
| |
| a = atomic_read(&x); |
| atomic_set(&x, a + 2); |
| a = qatomic_read(&x); |
| qatomic_set(&x, a + 2); |
| smp_mb(); |
| b = atomic_read(&y); |
| b = qatomic_read(&y); |
+--------------------------------+
Sources

8
docs/devel/lockcnt.txt
View File

@@ -95,7 +95,7 @@ not just frees, though there could be cases where this is not necessary.
Reads, instead, can be done without taking the mutex, as long as the
readers and writers use the same macros that are used for RCU, for
example atomic_rcu_read, atomic_rcu_set, QLIST_FOREACH_RCU, etc. This is
example qatomic_rcu_read, qatomic_rcu_set, QLIST_FOREACH_RCU, etc. This is
because the reads are done outside a lock and a set or QLIST_INSERT_HEAD
can happen concurrently with the read. The RCU API ensures that the
processor and the compiler see all required memory barriers.
@@ -189,7 +189,7 @@ qemu_lockcnt_lock and qemu_lockcnt_unlock:
if (!xyz) {
new_xyz = g_new(XYZ, 1);
...
atomic_rcu_set(&xyz, new_xyz);
qatomic_rcu_set(&xyz, new_xyz);
}
qemu_lockcnt_unlock(&xyz_lockcnt);
@@ -198,7 +198,7 @@ qemu_lockcnt_dec:
qemu_lockcnt_inc(&xyz_lockcnt);
if (xyz) {
XYZ *p = atomic_rcu_read(&xyz);
XYZ *p = qatomic_rcu_read(&xyz);
...
/* Accesses can now be done through "p". */
}
@@ -222,7 +222,7 @@ the decrement, the locking and the check on count as follows:
qemu_lockcnt_inc(&xyz_lockcnt);
if (xyz) {
XYZ *p = atomic_rcu_read(&xyz);
XYZ *p = qatomic_rcu_read(&xyz);
...
/* Accesses can now be done through "p". */
}

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