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drm/i915/execlists: Split out CSB processing

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Pull the CSB event processing into its own routine so that we can reuse
it during reset to flush any missed interrupts/events.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michał Winiarski <michal.winiarski@intel.com>
CC: Michel Thierry <michel.thierry@intel.com>
Cc: Jeff McGee <jeff.mcgee@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180516183355.10553-6-chris@chris-wilson.co.uk
This commit is contained in:
Chris Wilson 2018-05-16 19:33:53 +01:00
parent 1329115c6c
commit 73377dbcc7
1 changed files with 52 additions and 39 deletions
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91
drivers/gpu/drm/i915/intel_lrc.c
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@ -958,34 +958,14 @@ static void execlists_cancel_requests(struct intel_engine_cs *engine)
local_irq_restore(flags);
}
/*
* Check the unread Context Status Buffers and manage the submission of new
* contexts to the ELSP accordingly.
*/
static void execlists_submission_tasklet(unsigned long data)
static void process_csb(struct intel_engine_cs *engine)
{
struct intel_engine_cs * const engine = (struct intel_engine_cs *)data;
struct intel_engine_execlists * const execlists = &engine->execlists;
struct execlist_port *port = execlists->port;
struct drm_i915_private *dev_priv = engine->i915;
struct drm_i915_private *i915 = engine->i915;
bool fw = false;
/*
* We can skip acquiring intel_runtime_pm_get() here as it was taken
* on our behalf by the request (see i915_gem_mark_busy()) and it will
* not be relinquished until the device is idle (see
* i915_gem_idle_work_handler()). As a precaution, we make sure
* that all ELSP are drained i.e. we have processed the CSB,
* before allowing ourselves to idle and calling intel_runtime_pm_put().
*/
GEM_BUG_ON(!dev_priv->gt.awake);
/*
* Prefer doing test_and_clear_bit() as a two stage operation to avoid
* imposing the cost of a locked atomic transaction when submitting a
* new request (outside of the context-switch interrupt).
*/
while (test_bit(ENGINE_IRQ_EXECLIST, &engine->irq_posted)) {
do {
/* The HWSP contains a (cacheable) mirror of the CSB */
const u32 *buf =
&engine->status_page.page_addr[I915_HWS_CSB_BUF0_INDEX];
@ -993,28 +973,27 @@ static void execlists_submission_tasklet(unsigned long data)
if (unlikely(execlists->csb_use_mmio)) {
buf = (u32 * __force)
(dev_priv->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_BUF_LO(engine, 0)));
execlists->csb_head = -1; /* force mmio read of CSB ptrs */
(i915->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_BUF_LO(engine, 0)));
execlists->csb_head = -1; /* force mmio read of CSB */
}
/* Clear before reading to catch new interrupts */
clear_bit(ENGINE_IRQ_EXECLIST, &engine->irq_posted);
smp_mb__after_atomic();
if (unlikely(execlists->csb_head == -1)) { /* following a reset */
if (unlikely(execlists->csb_head == -1)) { /* after a reset */
if (!fw) {
intel_uncore_forcewake_get(dev_priv,
execlists->fw_domains);
intel_uncore_forcewake_get(i915, execlists->fw_domains);
fw = true;
}
head = readl(dev_priv->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_PTR(engine)));
head = readl(i915->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_PTR(engine)));
tail = GEN8_CSB_WRITE_PTR(head);
head = GEN8_CSB_READ_PTR(head);
execlists->csb_head = head;
} else {
const int write_idx =
intel_hws_csb_write_index(dev_priv) -
intel_hws_csb_write_index(i915) -
I915_HWS_CSB_BUF0_INDEX;
head = execlists->csb_head;
@ -1023,8 +1002,8 @@ static void execlists_submission_tasklet(unsigned long data)
}
GEM_TRACE("%s cs-irq head=%d [%d%s], tail=%d [%d%s]\n",
engine->name,
head, GEN8_CSB_READ_PTR(readl(dev_priv->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_PTR(engine)))), fw ? "" : "?",
tail, GEN8_CSB_WRITE_PTR(readl(dev_priv->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_PTR(engine)))), fw ? "" : "?");
head, GEN8_CSB_READ_PTR(readl(i915->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_PTR(engine)))), fw ? "" : "?",
tail, GEN8_CSB_WRITE_PTR(readl(i915->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_PTR(engine)))), fw ? "" : "?");
while (head != tail) {
struct i915_request *rq;
@ -1034,7 +1013,8 @@ static void execlists_submission_tasklet(unsigned long data)
if (++head == GEN8_CSB_ENTRIES)
head = 0;
/* We are flying near dragons again.
/*
* We are flying near dragons again.
*
* We hold a reference to the request in execlist_port[]
* but no more than that. We are operating in softirq
@ -1143,16 +1123,49 @@ static void execlists_submission_tasklet(unsigned long data)
if (head != execlists->csb_head) {
execlists->csb_head = head;
writel(_MASKED_FIELD(GEN8_CSB_READ_PTR_MASK, head << 8),
dev_priv->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_PTR(engine)));
i915->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_PTR(engine)));
}
}
} while (test_bit(ENGINE_IRQ_EXECLIST, &engine->irq_posted));
if (!execlists_is_active(execlists, EXECLISTS_ACTIVE_PREEMPT))
if (unlikely(fw))
intel_uncore_forcewake_put(i915, execlists->fw_domains);
}
/*
* Check the unread Context Status Buffers and manage the submission of new
* contexts to the ELSP accordingly.
*/
static void execlists_submission_tasklet(unsigned long data)
{
struct intel_engine_cs * const engine = (struct intel_engine_cs *)data;
GEM_TRACE("%s awake?=%d, active=%x, irq-posted?=%d\n",
engine->name,
engine->i915->gt.awake,
engine->execlists.active,
test_bit(ENGINE_IRQ_EXECLIST, &engine->irq_posted));
/*
* We can skip acquiring intel_runtime_pm_get() here as it was taken
* on our behalf by the request (see i915_gem_mark_busy()) and it will
* not be relinquished until the device is idle (see
* i915_gem_idle_work_handler()). As a precaution, we make sure
* that all ELSP are drained i.e. we have processed the CSB,
* before allowing ourselves to idle and calling intel_runtime_pm_put().
*/
GEM_BUG_ON(!engine->i915->gt.awake);
/*
* Prefer doing test_and_clear_bit() as a two stage operation to avoid
* imposing the cost of a locked atomic transaction when submitting a
* new request (outside of the context-switch interrupt).
*/
if (test_bit(ENGINE_IRQ_EXECLIST, &engine->irq_posted))
process_csb(engine);
if (!execlists_is_active(&engine->execlists, EXECLISTS_ACTIVE_PREEMPT))
execlists_dequeue(engine);
if (fw)
intel_uncore_forcewake_put(dev_priv, execlists->fw_domains);
/* If the engine is now idle, so should be the flag; and vice versa. */
GEM_BUG_ON(execlists_is_active(&engine->execlists,
EXECLISTS_ACTIVE_USER) ==