drm/panfrost: Disable the AS on unhandled page faults

If we don't do that, we have to wait for the job timeout to expire
before the fault jobs gets killed.

v3:
* Make sure the AS is re-enabled when new jobs are submitted to the
  context

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210630062751.2832545-12-boris.brezillon@collabora.com

diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h b/drivers/gpu/drm/panfrost/panfrost_device.h
index d37bc09809e8f7e0b9653eabc05fcb3b3451edce..cb5aadf7ae90fc0167630926c24adc78ebf54cf3 100644 (file)
--- a/drivers/gpu/drm/panfrost/panfrost_device.h
+++ b/drivers/gpu/drm/panfrost/panfrost_device.h
@@ -97,6 +97,7 @@ struct panfrost_device {
        spinlock_t as_lock;
        unsigned long as_in_use_mask;
        unsigned long as_alloc_mask;
+       unsigned long as_faulty_mask;
        struct list_head as_lru_list;
 
        struct panfrost_job_slot *js;

diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
index 2a9bf30edc9d1ca80857c3d261adae3e91815c6e..959da770295cdab1fc101e8f5a469325419d5e65 100644 (file)
--- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
+++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
@@ -154,6 +154,7 @@ u32 panfrost_mmu_as_get(struct panfrost_device *pfdev, struct panfrost_mmu *mmu)
        as = mmu->as;
        if (as >= 0) {
                int en = atomic_inc_return(&mmu->as_count);
+               u32 mask = BIT(as) | BIT(16 + as);
 
                /*
                 * AS can be retained by active jobs or a perfcnt context,
@@ -162,6 +163,18 @@ u32 panfrost_mmu_as_get(struct panfrost_device *pfdev, struct panfrost_mmu *mmu)
                WARN_ON(en >= (NUM_JOB_SLOTS + 1));
 
                list_move(&mmu->list, &pfdev->as_lru_list);
+
+               if (pfdev->as_faulty_mask & mask) {
+                       /* Unhandled pagefault on this AS, the MMU was
+                        * disabled. We need to re-enable the MMU after
+                        * clearing+unmasking the AS interrupts.
+                        */
+                       mmu_write(pfdev, MMU_INT_CLEAR, mask);
+                       mmu_write(pfdev, MMU_INT_MASK, ~pfdev->as_faulty_mask);
+                       pfdev->as_faulty_mask &= ~mask;
+                       panfrost_mmu_enable(pfdev, mmu);
+               }
+
                goto out;
        }
 
@@ -211,6 +224,7 @@ void panfrost_mmu_reset(struct panfrost_device *pfdev)
        spin_lock(&pfdev->as_lock);
 
        pfdev->as_alloc_mask = 0;
+       pfdev->as_faulty_mask = 0;
 
        list_for_each_entry_safe(mmu, mmu_tmp, &pfdev->as_lru_list, list) {
                mmu->as = -1;
@@ -661,7 +675,7 @@ static irqreturn_t panfrost_mmu_irq_handler_thread(int irq, void *data)
                if ((status & mask) == BIT(as) && (exception_type & 0xF8) == 0xC0)
                        ret = panfrost_mmu_map_fault_addr(pfdev, as, addr);
 
-               if (ret)
+               if (ret) {
                        /* terminal fault, print info about the fault */
                        dev_err(pfdev->dev,
                                "Unhandled Page fault in AS%d at VA 0x%016llX\n"
@@ -679,14 +693,28 @@ static irqreturn_t panfrost_mmu_irq_handler_thread(int irq, void *data)
                                access_type, access_type_name(pfdev, fault_status),
                                source_id);
 
+                       spin_lock(&pfdev->as_lock);
+                       /* Ignore MMU interrupts on this AS until it's been
+                        * re-enabled.
+                        */
+                       pfdev->as_faulty_mask |= mask;
+
+                       /* Disable the MMU to kill jobs on this AS. */
+                       panfrost_mmu_disable(pfdev, as);
+                       spin_unlock(&pfdev->as_lock);
+               }
+
                status &= ~mask;
 
                /* If we received new MMU interrupts, process them before returning. */
                if (!status)
-                       status = mmu_read(pfdev, MMU_INT_RAWSTAT);
+                       status = mmu_read(pfdev, MMU_INT_RAWSTAT) & ~pfdev->as_faulty_mask;
        }
 
-       mmu_write(pfdev, MMU_INT_MASK, ~0);
+       spin_lock(&pfdev->as_lock);
+       mmu_write(pfdev, MMU_INT_MASK, ~pfdev->as_faulty_mask);
+       spin_unlock(&pfdev->as_lock);
+
        return IRQ_HANDLED;
 };