msm: kgsl: On pagefault stall GPU so that it hangs
Prevent the iommu fault handler from clearing the stalled status
of GPU on page fault. This will cause a GPU hang and print out
the snapshot that will help in fault analysis.
Change-Id: I9dcab83a098a988f86a0c03c46b0dbe6624de937
Signed-off-by: Shubhraprakash Das <sadas@codeaurora.org>
Signed-off-by: Rajeev Kulkarni <krajeev@codeaurora.org>
diff --git a/drivers/gpu/msm/kgsl_iommu.c b/drivers/gpu/msm/kgsl_iommu.c
index 87e8746..5eabc4d 100644
--- a/drivers/gpu/msm/kgsl_iommu.c
+++ b/drivers/gpu/msm/kgsl_iommu.c
@@ -34,6 +34,7 @@
{ 0x14, 0x0003FFFF, 14 }, /* TTBR1 */
{ 0x20, 0, 0 }, /* FSR */
{ 0x800, 0, 0 }, /* TLBIALL */
+ { 0x820, 0, 0 }, /* RESUME */
};
static struct kgsl_iommu_register_list kgsl_iommuv2_reg[KGSL_IOMMU_REG_MAX] = {
@@ -41,7 +42,8 @@
{ 0x20, 0x00FFFFFF, 14 }, /* TTBR0 */
{ 0x28, 0x00FFFFFF, 14 }, /* TTBR1 */
{ 0x58, 0, 0 }, /* FSR */
- { 0x618, 0, 0 } /* TLBIALL */
+ { 0x618, 0, 0 }, /* TLBIALL */
+ { 0x008, 0, 0 } /* RESUME */
};
static int get_iommu_unit(struct device *dev, struct kgsl_mmu **mmu_out,
@@ -124,9 +126,19 @@
KGSL_MEM_CRIT(iommu_dev->kgsldev, "context = %d FSR = %X\n",
iommu_dev->ctx_id, fsr);
+ mmu->fault = 1;
+ iommu_dev->fault = 1;
+
trace_kgsl_mmu_pagefault(iommu_dev->kgsldev, addr,
kgsl_mmu_get_ptname_from_ptbase(mmu, ptbase), 0);
+ /*
+ * We do not want the h/w to resume fetching data from an iommu unit
+ * that has faulted, this is better for debugging as it will stall
+ * the GPU and trigger a snapshot. To stall the transaction return
+ * EBUSY error.
+ */
+ ret = -EBUSY;
done:
return ret;
}
@@ -859,12 +871,13 @@
*/
for (i = 0; i < iommu->unit_count; i++) {
struct kgsl_iommu_unit *iommu_unit = &iommu->iommu_units[i];
- for (j = 0; j < iommu_unit->dev_count; j++)
+ for (j = 0; j < iommu_unit->dev_count; j++) {
iommu_unit->dev[j].pt_lsb = KGSL_IOMMMU_PT_LSB(iommu,
KGSL_IOMMU_GET_CTX_REG(iommu,
iommu_unit,
iommu_unit->dev[j].ctx_id,
TTBR0));
+ }
}
kgsl_iommu_disable_clk_on_ts(mmu, 0, false);
@@ -945,6 +958,7 @@
static void kgsl_iommu_stop(struct kgsl_mmu *mmu)
{
struct kgsl_iommu *iommu = mmu->priv;
+ int i, j;
/*
* stop device mmu
*
@@ -957,8 +971,25 @@
mmu->hwpagetable = NULL;
mmu->flags &= ~KGSL_FLAGS_STARTED;
- }
+ if (mmu->fault) {
+ for (i = 0; i < iommu->unit_count; i++) {
+ struct kgsl_iommu_unit *iommu_unit =
+ &iommu->iommu_units[i];
+ for (j = 0; j < iommu_unit->dev_count; j++) {
+ if (iommu_unit->dev[j].fault) {
+ kgsl_iommu_enable_clk(mmu, j);
+ KGSL_IOMMU_SET_CTX_REG(iommu,
+ iommu_unit,
+ iommu_unit->dev[j].ctx_id,
+ RESUME, 1);
+ iommu_unit->dev[j].fault = 0;
+ }
+ }
+ }
+ mmu->fault = 0;
+ }
+ }
/* switch off MMU clocks and cancel any events it has queued */
iommu->clk_event_queued = false;
kgsl_cancel_events(mmu->device, mmu);