[PATCH v3 16/16] drm/msm/a5xx: Support per-instance pagetables

Jordan Crouse
2019-05-29T20:56:41Z

Add support for per-instance pagetables for 5XX targets. Create a support
buffer for preemption to hold the SMMU pagetable information for a
preempted ring, enable TTBR1 to support split pagetables and add the
necessary PM4 commands to trigger a pagetable switch at the beginning
of a user command.

Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
---

drivers/gpu/drm/msm/adreno/a5xx_gpu.c | 120 +++++++++++++++++++++++++++++-
drivers/gpu/drm/msm/adreno/a5xx_gpu.h | 19 +++++
drivers/gpu/drm/msm/adreno/a5xx_preempt.c | 70 +++++++++++++----
3 files changed, 192 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
index 2f87c3e..fedd470 100644
--- a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
@@ -111,6 +111,59 @@ static void a5xx_submit_in_rb(struct msm_gpu *gpu, struct msm_gem_submit *submit
msm_gpu_retire(gpu);
}

+static void a5xx_set_pagetable(struct msm_gpu *gpu, struct msm_ringbuffer *ring,
+ struct msm_file_private *ctx)
+{
+ u64 ttbr;
+ u32 asid;
+
+ if (!msm_iommu_get_ptinfo(ctx->aspace->mmu, &ttbr, &asid))
+ return;
+
+ ttbr = ttbr | ((u64) asid) << 48;
+
+ /* Turn off protected mode */
+ OUT_PKT7(ring, CP_SET_PROTECTED_MODE, 1);
+ OUT_RING(ring, 0);
+
+ /* Turn on APIV mode to access critical regions */
+ OUT_PKT4(ring, REG_A5XX_CP_CNTL, 1);
+ OUT_RING(ring, 1);
+
+ /* Make sure the ME is synchronized before staring the update */
+ OUT_PKT7(ring, CP_WAIT_FOR_ME, 0);
+
+ /* Execute the table update */
+ OUT_PKT7(ring, CP_SMMU_TABLE_UPDATE, 3);
+ OUT_RING(ring, lower_32_bits(ttbr));
+ OUT_RING(ring, upper_32_bits(ttbr));
+ OUT_RING(ring, 0);
+
+ /*
+ * Write the new TTBR0 to the preemption records - this will be used to
+ * reload the pagetable if the current ring gets preempted out.
+ */
+ OUT_PKT7(ring, CP_MEM_WRITE, 4);
+ OUT_RING(ring, lower_32_bits(rbmemptr(ring, ttbr0)));
+ OUT_RING(ring, upper_32_bits(rbmemptr(ring, ttbr0)));
+ OUT_RING(ring, lower_32_bits(ttbr));
+ OUT_RING(ring, upper_32_bits(ttbr));
+
+ /* Invalidate the draw state so we start off fresh */
+ OUT_PKT7(ring, CP_SET_DRAW_STATE, 3);
+ OUT_RING(ring, 0x40000);
+ OUT_RING(ring, 1);
+ OUT_RING(ring, 0);
+
+ /* Turn off APRIV */
+ OUT_PKT4(ring, REG_A5XX_CP_CNTL, 1);
+ OUT_RING(ring, 0);
+
+ /* Turn off protected mode */
+ OUT_PKT7(ring, CP_SET_PROTECTED_MODE, 1);
+ OUT_RING(ring, 1);
+}
+
static void a5xx_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit,
struct msm_file_private *ctx)
{
@@ -126,6 +179,8 @@ static void a5xx_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit,
return;
}

+ a5xx_set_pagetable(gpu, ring, ctx);
+
OUT_PKT7(ring, CP_PREEMPT_ENABLE_GLOBAL, 1);
OUT_RING(ring, 0x02);

@@ -1349,21 +1404,77 @@ static unsigned long a5xx_gpu_busy(struct msm_gpu *gpu)
return (unsigned long)busy_time;
}

+static struct msm_gem_address_space *a5xx_new_address_space(struct msm_gpu *gpu)
+{
+ struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
+ struct a5xx_gpu *a5xx_gpu = to_a5xx_gpu(adreno_gpu);
+ struct msm_gem_address_space *aspace;
+ int ret;
+
+ /* Return the default pagetable if per instance tables don't work */
+ if (!a5xx_gpu->per_instance_tables)
+ return gpu->aspace;
+
+ aspace = msm_gem_address_space_create_instance(&gpu->pdev->dev,
+ "gpu", 0x100000000ULL, 0x1ffffffffULL);
+ if (IS_ERR(aspace))
+ return aspace;
+
+ ret = aspace->mmu->funcs->attach(aspace->mmu, NULL, 0);
+ if (ret) {
+ /* -ENODEV means that aux domains aren't supported */
+ if (ret == -ENODEV)
+ return gpu->aspace;
+
+ return ERR_PTR(ret);
+ }
+
+ return aspace;
+}
+
static struct msm_gem_address_space *
a5xx_create_address_space(struct msm_gpu *gpu)
{
+ struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
+ struct a5xx_gpu *a5xx_gpu = to_a5xx_gpu(adreno_gpu);
+ struct device *dev = &gpu->pdev->dev;
struct msm_gem_address_space *aspace;
struct iommu_domain *iommu;
- int ret;
+ int ret, val = 1;
+
+ a5xx_gpu->per_instance_tables = false;

iommu = iommu_domain_alloc(&platform_bus_type);
if (!iommu)
return ERR_PTR(-ENXIO);

- iommu->geometry.aperture_start = 0x100000000ULL;
- iommu->geometry.aperture_end = 0x1ffffffffULL;
+ /* Try to enable split pagetables */
+ if (iommu_domain_set_attr(iommu, DOMAIN_ATTR_SPLIT_TABLES, &val)) {
+ /*
+ * If split pagetables aren't available we won't be able to do
+ * per-instance pagetables so set up the global va space at our
+ * susual location
+ */
+ iommu->geometry.aperture_start = 0x100000000ULL;
+ iommu->geometry.aperture_end = 0x1ffffffffULL;
+ } else {
+ /*
+ * If split pagetables are available then we might be able to do
+ * per-instance pagetables. Put the default va-space in TTBR1 to
+ * prepare
+ */
+ iommu->geometry.aperture_start = 0xfffffff100000000ULL;
+ iommu->geometry.aperture_end = 0xfffffff1ffffffffULL;
+
+ /*
+ * If both split pagetables and aux domains are supported we can
+ * do per_instance pagetables
+ */
+ a5xx_gpu->per_instance_tables =
+ iommu_dev_has_feature(dev, IOMMU_DEV_FEAT_AUX);
+ }

- aspace = msm_gem_address_space_create(&gpu->pdev->dev, iommu, "gpu");
+ aspace = msm_gem_address_space_create(dev, iommu, "gpu");
if (IS_ERR(aspace)) {
iommu_domain_free(iommu);
DRM_DEV_ERROR(gpu->dev->dev, "failed to init mmu: %ld\n",
@@ -1403,6 +1514,7 @@ static const struct adreno_gpu_funcs funcs = {
.gpu_state_get = a5xx_gpu_state_get,
.gpu_state_put = a5xx_gpu_state_put,
.create_address_space = a5xx_create_address_space,
+ .new_address_space = a5xx_new_address_space,
},
.get_timestamp = a5xx_get_timestamp,
};
diff --git a/drivers/gpu/drm/msm/adreno/a5xx_gpu.h b/drivers/gpu/drm/msm/adreno/a5xx_gpu.h
index 7d71860..82ceb9b 100644
--- a/drivers/gpu/drm/msm/adreno/a5xx_gpu.h
+++ b/drivers/gpu/drm/msm/adreno/a5xx_gpu.h
@@ -45,6 +45,11 @@ struct a5xx_gpu {

atomic_t preempt_state;
struct timer_list preempt_timer;
+ struct a5xx_smmu_info *smmu_info;
+ struct drm_gem_object *smmu_info_bo;
+ uint64_t smmu_info_iova;
+
+ bool per_instance_tables;
};

#define to_a5xx_gpu(x) container_of(x, struct a5xx_gpu, base)
@@ -132,6 +137,20 @@ struct a5xx_preempt_record {
*/
#define A5XX_PREEMPT_COUNTER_SIZE (16 * 4)

+/*
+ * This is a global structure that the preemption code uses to switch in the
+ * pagetable for the preempted process - the code switches in whatever we
+ * after preempting in a new ring.
+ */
+struct a5xx_smmu_info {
+ uint32_t magic;
+ uint32_t _pad4;
+ uint64_t ttbr0;
+ uint32_t asid;
+ uint32_t contextidr;
+};
+
+#define A5XX_SMMU_INFO_MAGIC 0x3618CDA3UL

int a5xx_power_init(struct msm_gpu *gpu);
void a5xx_gpmu_ucode_init(struct msm_gpu *gpu);
diff --git a/drivers/gpu/drm/msm/adreno/a5xx_preempt.c b/drivers/gpu/drm/msm/adreno/a5xx_preempt.c
index 3d62310..1050409 100644
--- a/drivers/gpu/drm/msm/adreno/a5xx_preempt.c
+++ b/drivers/gpu/drm/msm/adreno/a5xx_preempt.c
@@ -12,6 +12,7 @@
*/

#include "msm_gem.h"
+#include "msm_mmu.h"
#include "a5xx_gpu.h"

/*
@@ -145,6 +146,15 @@ void a5xx_preempt_trigger(struct msm_gpu *gpu)
a5xx_gpu->preempt[ring->id]->wptr = get_wptr(ring);
spin_unlock_irqrestore(&ring->lock, flags);

+ /* Do read barrier to make sure we have updated pagetable info */
+ rmb();
+
+ /* Set the SMMU info for the preemption */
+ if (a5xx_gpu->smmu_info) {
+ a5xx_gpu->smmu_info->ttbr0 = ring->memptrs->ttbr0;
+ a5xx_gpu->smmu_info->contextidr = 0;
+ }
+
/* Set the address of the incoming preemption record */
gpu_write64(gpu, REG_A5XX_CP_CONTEXT_SWITCH_RESTORE_ADDR_LO,
REG_A5XX_CP_CONTEXT_SWITCH_RESTORE_ADDR_HI,
@@ -221,9 +231,10 @@ void a5xx_preempt_hw_init(struct msm_gpu *gpu)
a5xx_gpu->preempt[i]->rbase = gpu->rb[i]->iova;
}

- /* Write a 0 to signal that we aren't switching pagetables */
+ /* Tell the CP where to find the smmu_info buffer*/
gpu_write64(gpu, REG_A5XX_CP_CONTEXT_SWITCH_SMMU_INFO_LO,
- REG_A5XX_CP_CONTEXT_SWITCH_SMMU_INFO_HI, 0);
+ REG_A5XX_CP_CONTEXT_SWITCH_SMMU_INFO_HI,
+ a5xx_gpu->smmu_info_iova);

/* Reset the preemption state */
set_preempt_state(a5xx_gpu, PREEMPT_NONE);
@@ -271,6 +282,34 @@ void a5xx_preempt_fini(struct msm_gpu *gpu)

for (i = 0; i < gpu->nr_rings; i++)
msm_gem_kernel_put(a5xx_gpu->preempt_bo[i], gpu->aspace, true);
+
+ msm_gem_kernel_put(a5xx_gpu->smmu_info_bo, gpu->aspace, true);
+}
+
+static int a5xx_smmu_info_init(struct msm_gpu *gpu)
+{
+ struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
+ struct a5xx_gpu *a5xx_gpu = to_a5xx_gpu(adreno_gpu);
+ struct a5xx_smmu_info *ptr;
+ struct drm_gem_object *bo;
+ u64 iova;
+
+ if (!a5xx_gpu->per_instance_tables)
+ return 0;
+
+ ptr = msm_gem_kernel_new(gpu->dev, sizeof(struct a5xx_smmu_info),
+ MSM_BO_UNCACHED, gpu->aspace, &bo, &iova);
+
+ if (IS_ERR(ptr))
+ return PTR_ERR(ptr);
+
+ ptr->magic = A5XX_SMMU_INFO_MAGIC;
+
+ a5xx_gpu->smmu_info_bo = bo;
+ a5xx_gpu->smmu_info_iova = iova;
+ a5xx_gpu->smmu_info = ptr;
+
+ return 0;
}

void a5xx_preempt_init(struct msm_gpu *gpu)
@@ -284,17 +323,22 @@ void a5xx_preempt_init(struct msm_gpu *gpu)
return;

for (i = 0; i < gpu->nr_rings; i++) {
- if (preempt_init_ring(a5xx_gpu, gpu->rb[i])) {
- /*
- * On any failure our adventure is over. Clean up and
- * set nr_rings to 1 to force preemption off
- */
- a5xx_preempt_fini(gpu);
- gpu->nr_rings = 1;
-
- return;
- }
+ if (preempt_init_ring(a5xx_gpu, gpu->rb[i]))
+ goto fail;
}

- timer_setup(&a5xx_gpu->preempt_timer, a5xx_preempt_timer, 0);
+ if (a5xx_smmu_info_init(gpu))
+ goto fail;
+
+ timer_setup(&a5xx_gpu->preempt_timer, a5xx_preempt_timer,
+ (unsigned long) a5xx_gpu);
+
+ return;
+fail:
+ /*
+ * On any failure our adventure is over. Clean up and
+ * set nr_rings to 1 to force preemption off
+ */
+ a5xx_preempt_fini(gpu);
+ gpu->nr_rings = 1;
}
--
2.7.4