/**
* radeon_fence_process - process a fence
*
* @rdev: radeon_device pointer
* @ring: ring index the fence is associated with
*
* Checks the current fence value and wakes the fence queue
* if the sequence number has increased (all asics).
*/
void radeon_fence_process(struct radeon_device *rdev, int ring)
{
uint64_t seq, last_seq, last_emitted;
unsigned count_loop = 0;
bool wake = false;
/* Note there is a scenario here for an infinite loop but it's
* very unlikely to happen. For it to happen, the current polling
* process need to be interrupted by another process and another
* process needs to update the last_seq btw the atomic read and
* xchg of the current process.
*
* More over for this to go in infinite loop there need to be
* continuously new fence signaled ie radeon_fence_read needs
* to return a different value each time for both the currently
* polling process and the other process that xchg the last_seq
* btw atomic read and xchg of the current process. And the
* value the other process set as last seq must be higher than
* the seq value we just read. Which means that current process
* need to be interrupted after radeon_fence_read and before
* atomic xchg.
*
* To be even more safe we count the number of time we loop and
* we bail after 10 loop just accepting the fact that we might
* have temporarly set the last_seq not to the true real last
* seq but to an older one.
*/
last_seq = atomic64_read(&rdev->fence_drv[ring].last_seq);
do {
last_emitted = rdev->fence_drv[ring].sync_seq[ring];
seq = radeon_fence_read(rdev, ring);
seq |= last_seq & 0xffffffff00000000LL;
if (seq < last_seq) {
seq &= 0xffffffff;
seq |= last_emitted & 0xffffffff00000000LL;
}
if (seq <= last_seq || seq > last_emitted) {
break;
}
/* If we loop over we don't want to return without
* checking if a fence is signaled as it means that the
* seq we just read is different from the previous on.
*/
wake = true;
last_seq = seq;
if ((count_loop++) > 10) {
/* We looped over too many time leave with the
* fact that we might have set an older fence
* seq then the current real last seq as signaled
* by the hw.
*/
break;
}
} while (atomic64_xchg(&rdev->fence_drv[ring].last_seq, seq) > seq);
if (wake)
wake_up_all(&rdev->fence_queue);
}
static __init int test_atomic64(void)
{
long long v0 = 0xaaa31337c001d00dLL;
long long v1 = 0xdeadbeefdeafcafeLL;
long long v2 = 0xfaceabadf00df001LL;
long long onestwos = 0x1111111122222222LL;
long long one = 1LL;
atomic64_t v = ATOMIC64_INIT(v0);
long long r = v0;
BUG_ON(v.counter != r);
atomic64_set(&v, v1);
r = v1;
BUG_ON(v.counter != r);
BUG_ON(atomic64_read(&v) != r);
INIT(v0);
atomic64_add(onestwos, &v);
r += onestwos;
BUG_ON(v.counter != r);
INIT(v0);
atomic64_add(-one, &v);
r += -one;
BUG_ON(v.counter != r);
INIT(v0);
r += onestwos;
BUG_ON(atomic64_add_return(onestwos, &v) != r);
BUG_ON(v.counter != r);
INIT(v0);
r += -one;
BUG_ON(atomic64_add_return(-one, &v) != r);
BUG_ON(v.counter != r);
INIT(v0);
atomic64_sub(onestwos, &v);
r -= onestwos;
BUG_ON(v.counter != r);
INIT(v0);
atomic64_sub(-one, &v);
r -= -one;
BUG_ON(v.counter != r);
INIT(v0);
r -= onestwos;
BUG_ON(atomic64_sub_return(onestwos, &v) != r);
BUG_ON(v.counter != r);
INIT(v0);
r -= -one;
BUG_ON(atomic64_sub_return(-one, &v) != r);
BUG_ON(v.counter != r);
INIT(v0);
atomic64_inc(&v);
r += one;
BUG_ON(v.counter != r);
INIT(v0);
r += one;
BUG_ON(atomic64_inc_return(&v) != r);
BUG_ON(v.counter != r);
INIT(v0);
atomic64_dec(&v);
r -= one;
BUG_ON(v.counter != r);
INIT(v0);
r -= one;
BUG_ON(atomic64_dec_return(&v) != r);
BUG_ON(v.counter != r);
INIT(v0);
BUG_ON(atomic64_xchg(&v, v1) != v0);
r = v1;
BUG_ON(v.counter != r);
INIT(v0);
BUG_ON(atomic64_cmpxchg(&v, v0, v1) != v0);
r = v1;
BUG_ON(v.counter != r);
INIT(v0);
BUG_ON(atomic64_cmpxchg(&v, v2, v1) != v0);
BUG_ON(v.counter != r);
INIT(v0);
BUG_ON(atomic64_add_unless(&v, one, v0));
BUG_ON(v.counter != r);
INIT(v0);
BUG_ON(!atomic64_add_unless(&v, one, v1));
r += one;
BUG_ON(v.counter != r);
#ifdef CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
INIT(onestwos);
BUG_ON(atomic64_dec_if_positive(&v) != (onestwos - 1));
r -= one;
BUG_ON(v.counter != r);
INIT(0);
BUG_ON(atomic64_dec_if_positive(&v) != -one);
BUG_ON(v.counter != r);
INIT(-one);
BUG_ON(atomic64_dec_if_positive(&v) != (-one - one));
BUG_ON(v.counter != r);
#else
#warning Please implement atomic64_dec_if_positive for your architecture and select the above Kconfig symbol
#endif
INIT(onestwos);
BUG_ON(!atomic64_inc_not_zero(&v));
r += one;
BUG_ON(v.counter != r);
INIT(0);
BUG_ON(atomic64_inc_not_zero(&v));
BUG_ON(v.counter != r);
INIT(-one);
BUG_ON(!atomic64_inc_not_zero(&v));
r += one;
BUG_ON(v.counter != r);
#ifdef CONFIG_X86
pr_info("passed for %s platform %s CX8 and %s SSE\n",
#ifdef CONFIG_X86_64
"x86-64",
#elif defined(CONFIG_X86_CMPXCHG64)
"i586+",
#else
"i386+",
#endif
boot_cpu_has(X86_FEATURE_CX8) ? "with" : "without",
boot_cpu_has(X86_FEATURE_XMM) ? "with" : "without");
#else
pr_info("passed\n");
#endif
return 0;
}
static __init int test_atomic64(void)
{
long long v0 = 0xaaa31337c001d00dLL;
long long v1 = 0xdeadbeefdeafcafeLL;
long long v2 = 0xfaceabadf00df001LL;
long long onestwos = 0x1111111122222222LL;
long long one = 1LL;
atomic64_t v = ATOMIC64_INIT(v0);
long long r = v0;
BUG_ON(v.counter != r);
atomic64_set(&v, v1);
r = v1;
BUG_ON(v.counter != r);
BUG_ON(atomic64_read(&v) != r);
INIT(v0);
atomic64_add(onestwos, &v);
r += onestwos;
BUG_ON(v.counter != r);
INIT(v0);
atomic64_add(-one, &v);
r += -one;
BUG_ON(v.counter != r);
INIT(v0);
r += onestwos;
BUG_ON(atomic64_add_return(onestwos, &v) != r);
BUG_ON(v.counter != r);
INIT(v0);
r += -one;
BUG_ON(atomic64_add_return(-one, &v) != r);
BUG_ON(v.counter != r);
INIT(v0);
atomic64_sub(onestwos, &v);
r -= onestwos;
BUG_ON(v.counter != r);
INIT(v0);
atomic64_sub(-one, &v);
r -= -one;
BUG_ON(v.counter != r);
INIT(v0);
r -= onestwos;
BUG_ON(atomic64_sub_return(onestwos, &v) != r);
BUG_ON(v.counter != r);
INIT(v0);
r -= -one;
BUG_ON(atomic64_sub_return(-one, &v) != r);
BUG_ON(v.counter != r);
INIT(v0);
atomic64_inc(&v);
r += one;
BUG_ON(v.counter != r);
INIT(v0);
r += one;
BUG_ON(atomic64_inc_return(&v) != r);
BUG_ON(v.counter != r);
INIT(v0);
atomic64_dec(&v);
r -= one;
BUG_ON(v.counter != r);
INIT(v0);
r -= one;
BUG_ON(atomic64_dec_return(&v) != r);
BUG_ON(v.counter != r);
INIT(v0);
BUG_ON(atomic64_xchg(&v, v1) != v0);
r = v1;
BUG_ON(v.counter != r);
INIT(v0);
BUG_ON(atomic64_cmpxchg(&v, v0, v1) != v0);
r = v1;
BUG_ON(v.counter != r);
INIT(v0);
BUG_ON(atomic64_cmpxchg(&v, v2, v1) != v0);
BUG_ON(v.counter != r);
INIT(v0);
BUG_ON(atomic64_add_unless(&v, one, v0));
BUG_ON(v.counter != r);
INIT(v0);
BUG_ON(!atomic64_add_unless(&v, one, v1));
r += one;
BUG_ON(v.counter != r);
#if defined(CONFIG_X86) || defined(CONFIG_MIPS) || defined(CONFIG_PPC) || \
defined(CONFIG_S390) || defined(_ASM_GENERIC_ATOMIC64_H) || defined(CONFIG_ARM)
INIT(onestwos);
BUG_ON(atomic64_dec_if_positive(&v) != (onestwos - 1));
r -= one;
BUG_ON(v.counter != r);
INIT(0);
BUG_ON(atomic64_dec_if_positive(&v) != -one);
BUG_ON(v.counter != r);
INIT(-one);
BUG_ON(atomic64_dec_if_positive(&v) != (-one - one));
BUG_ON(v.counter != r);
#else
#warning Please implement atomic64_dec_if_positive for your architecture, and add it to the IF above
#endif
INIT(onestwos);
BUG_ON(!atomic64_inc_not_zero(&v));
r += one;
BUG_ON(v.counter != r);
INIT(0);
BUG_ON(atomic64_inc_not_zero(&v));
BUG_ON(v.counter != r);
INIT(-one);
BUG_ON(!atomic64_inc_not_zero(&v));
r += one;
BUG_ON(v.counter != r);
#ifdef CONFIG_X86
#ifdef CONFIG_DEBUG_PRINTK
printk(KERN_INFO "atomic64 test passed for %s platform %s CX8 and %s SSE\n",
#ifdef CONFIG_X86_64
"x86-64",
#elif defined(CONFIG_X86_CMPXCHG64)
"i586+",
#else
"i386+",
#endif
boot_cpu_has(X86_FEATURE_CX8) ? "with" : "without",
boot_cpu_has(X86_FEATURE_XMM) ? "with" : "without");
#else
;
#endif
#else
#ifdef CONFIG_DEBUG_PRINTK
printk(KERN_INFO "atomic64 test passed\n");
#else
;
#endif
#endif
return 0;
}