[RFC PATCH] drm/amdgpu: add support for user trap handlers
Alex Deucher
alexdeucher at gmail.com
Mon Aug 24 18:33:06 UTC 2020
On Mon, Aug 24, 2020 at 7:57 AM Samuel Pitoiset
<samuel.pitoiset at gmail.com> wrote:
>
> A trap handler can be used by userspace to catch shader exceptions
> like divide by zero, memory violations etc.
>
> On GFX6-GFX8, the registers used to configure TBA/TMA aren't
> privileged while on GFX9+ they are per VMID and privileged,
> so that only the KMD can configure them.
>
> This introduces a new CS chunk that can be used to set the
> TBA/TMA virtual address at submit time.
>
> TODO:
> - add GFX 6,7 and 10 support
> - rebase on top of amd-staging-drm-next (this branch currently
> hangs my GPU at boot)
>
> Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 31 +++++++++++++++++
> drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 3 +-
> drivers/gpu/drm/amd/amdgpu/amdgpu_ids.h | 4 +++
> drivers/gpu/drm/amd/amdgpu/amdgpu_job.h | 4 +++
> drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h | 4 +++
> drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 15 ++++++++-
> drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c | 42 ++++++++++++++++++++++--
> drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c | 19 +++++++++++
> include/uapi/drm/amdgpu_drm.h | 8 +++++
> 9 files changed, 126 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> index a512ccbc4dea..6ca5c4912e3a 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> @@ -104,6 +104,19 @@ static int amdgpu_cs_bo_handles_chunk(struct amdgpu_cs_parser *p,
> return r;
> }
>
> +static int amdgpu_cs_user_trap_chunk(struct amdgpu_cs_parser *p,
> + struct drm_amdgpu_cs_chunk_trap *data,
> + uint64_t *tba_addr, uint64_t *tma_addr)
> +{
> + if (!data->tba_addr || !data->tma_addr)
> + return -EINVAL;
> +
> + *tba_addr = data->tba_addr;
> + *tma_addr = data->tma_addr;
> +
> + return 0;
> +}
> +
> static int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, union drm_amdgpu_cs *cs)
> {
> struct amdgpu_fpriv *fpriv = p->filp->driver_priv;
> @@ -112,6 +125,7 @@ static int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, union drm_amdgpu_cs
> uint64_t *chunk_array;
> unsigned size, num_ibs = 0;
> uint32_t uf_offset = 0;
> + uint64_t tba_addr = 0, tma_addr = 0;
> int i;
> int ret;
>
> @@ -214,6 +228,19 @@ static int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, union drm_amdgpu_cs
>
> break;
>
> + case AMDGPU_CHUNK_ID_TRAP:
> + size = sizeof(struct drm_amdgpu_cs_chunk_trap);
> + if (p->chunks[i].length_dw * sizeof(uint32_t) < size) {
> + ret = -EINVAL;
> + goto free_partial_kdata;
> + }
> +
> + ret = amdgpu_cs_user_trap_chunk(p, p->chunks[i].kdata,
> + &tba_addr, &tma_addr);
> + if (ret)
> + goto free_partial_kdata;
> + break;
> +
> case AMDGPU_CHUNK_ID_DEPENDENCIES:
> case AMDGPU_CHUNK_ID_SYNCOBJ_IN:
> case AMDGPU_CHUNK_ID_SYNCOBJ_OUT:
> @@ -239,6 +266,10 @@ static int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, union drm_amdgpu_cs
>
> if (p->uf_entry.tv.bo)
> p->job->uf_addr = uf_offset;
> +
> + p->job->tba_addr = tba_addr;
> + p->job->tma_addr = tma_addr;
> +
> kfree(chunk_array);
>
> /* Use this opportunity to fill in task info for the vm */
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> index 26127c7d2f32..1e703119e4c2 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> @@ -88,9 +88,10 @@
> * - 3.37.0 - L2 is invalidated before SDMA IBs, needed for correctness
> * - 3.38.0 - Add AMDGPU_IB_FLAG_EMIT_MEM_SYNC
> * - 3.39.0 - DMABUF implicit sync does a full pipeline sync
> + * - 3.40.0 - Add AMDGPU_CHUNK_ID_TRAP
> */
> #define KMS_DRIVER_MAJOR 3
> -#define KMS_DRIVER_MINOR 39
> +#define KMS_DRIVER_MINOR 40
> #define KMS_DRIVER_PATCHLEVEL 0
>
> int amdgpu_vram_limit = 0;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.h
> index 8e58325bbca2..fd0d56724b4d 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.h
> @@ -58,6 +58,10 @@ struct amdgpu_vmid {
> uint32_t oa_base;
> uint32_t oa_size;
>
> + /* user trap */
> + uint64_t tba_addr;
> + uint64_t tma_addr;
> +
> unsigned pasid;
> struct dma_fence *pasid_mapping;
> };
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.h
> index 81caac9b958a..b8ed5b13ea44 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.h
> @@ -62,6 +62,10 @@ struct amdgpu_job {
> /* user fence handling */
> uint64_t uf_addr;
> uint64_t uf_sequence;
> +
> + /* user trap handling */
> + uint64_t tba_addr;
> + uint64_t tma_addr;
> };
>
> int amdgpu_job_alloc(struct amdgpu_device *adev, unsigned num_ibs,
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> index da871d84b742..1f165a6295d9 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> @@ -197,6 +197,9 @@ struct amdgpu_ring_funcs {
> void (*soft_recovery)(struct amdgpu_ring *ring, unsigned vmid);
> int (*preempt_ib)(struct amdgpu_ring *ring);
> void (*emit_mem_sync)(struct amdgpu_ring *ring);
> + void (*emit_trap_handler)(struct amdgpu_ring *ring,
> + uint32_t vmid,
> + uint64_t tba_addr, uint64_t tma_addr);
> };
>
> struct amdgpu_ring {
> @@ -265,6 +268,7 @@ struct amdgpu_ring {
> #define amdgpu_ring_emit_vm_flush(r, vmid, addr) (r)->funcs->emit_vm_flush((r), (vmid), (addr))
> #define amdgpu_ring_emit_fence(r, addr, seq, flags) (r)->funcs->emit_fence((r), (addr), (seq), (flags))
> #define amdgpu_ring_emit_gds_switch(r, v, db, ds, wb, ws, ab, as) (r)->funcs->emit_gds_switch((r), (v), (db), (ds), (wb), (ws), (ab), (as))
> +#define amdgpu_ring_emit_trap_handler(r, v, tba, tma) (r)->funcs->emit_trap_handler((r), (v), (tba), (tma))
> #define amdgpu_ring_emit_hdp_flush(r) (r)->funcs->emit_hdp_flush((r))
> #define amdgpu_ring_emit_switch_buffer(r) (r)->funcs->emit_switch_buffer((r))
> #define amdgpu_ring_emit_cntxcntl(r, d) (r)->funcs->emit_cntxcntl((r), (d))
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index 71e005cf2952..24916082de0b 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -1076,6 +1076,9 @@ int amdgpu_vm_flush(struct amdgpu_ring *ring, struct amdgpu_job *job,
> id->gws_size != job->gws_size ||
> id->oa_base != job->oa_base ||
> id->oa_size != job->oa_size);
> + bool trap_handler_needed = ring->funcs->emit_trap_handler && (
> + id->tba_addr != job->tba_addr ||
> + id->tma_addr != job->tma_addr);
> bool vm_flush_needed = job->vm_needs_flush;
> struct dma_fence *fence = NULL;
> bool pasid_mapping_needed = false;
> @@ -1088,6 +1091,7 @@ int amdgpu_vm_flush(struct amdgpu_ring *ring, struct amdgpu_job *job,
>
> if (amdgpu_vmid_had_gpu_reset(adev, id)) {
> gds_switch_needed = true;
> + trap_handler_needed = true;
> vm_flush_needed = true;
> pasid_mapping_needed = true;
> }
> @@ -1099,12 +1103,14 @@ int amdgpu_vm_flush(struct amdgpu_ring *ring, struct amdgpu_job *job,
> mutex_unlock(&id_mgr->lock);
>
> gds_switch_needed &= !!ring->funcs->emit_gds_switch;
> + trap_handler_needed &= !!ring->funcs->emit_trap_handler;
> vm_flush_needed &= !!ring->funcs->emit_vm_flush &&
> job->vm_pd_addr != AMDGPU_BO_INVALID_OFFSET;
> pasid_mapping_needed &= adev->gmc.gmc_funcs->emit_pasid_mapping &&
> ring->funcs->emit_wreg;
>
> - if (!vm_flush_needed && !gds_switch_needed && !need_pipe_sync)
> + if (!vm_flush_needed && !gds_switch_needed &&
> + !trap_handler_needed && !need_pipe_sync)
> return 0;
>
> if (ring->funcs->init_cond_exec)
> @@ -1158,6 +1164,13 @@ int amdgpu_vm_flush(struct amdgpu_ring *ring, struct amdgpu_job *job,
> job->oa_size);
> }
>
> + if (ring->funcs->emit_trap_handler && trap_handler_needed) {
> + id->tba_addr = job->tba_addr;
> + id->tma_addr = job->tma_addr;
> + amdgpu_ring_emit_trap_handler(ring, job->vmid, job->tba_addr,
> + job->tma_addr);
> + }
> +
> if (ring->funcs->patch_cond_exec)
> amdgpu_ring_patch_cond_exec(ring, patch_offset);
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
> index 33f1c4a46ebe..59db577e8c8f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
> @@ -5222,6 +5222,40 @@ static void gfx_v8_0_ring_emit_gds_switch(struct amdgpu_ring *ring,
> amdgpu_ring_write(ring, (1 << (oa_size + oa_base)) - (1 << oa_base));
> }
>
> +static void gfx_v8_0_ring_emit_trap_handler(struct amdgpu_ring *ring,
> + uint32_t vmid,
> + uint64_t tba_addr,
> + uint64_t tma_addr)
> +{
> + if (ring->funcs->type == AMDGPU_RING_TYPE_GFX) {
> + static const u32 regs[] = {
> + mmSPI_SHADER_TBA_LO_PS,
> + mmSPI_SHADER_TBA_LO_VS,
> + mmSPI_SHADER_TBA_LO_GS,
> + mmSPI_SHADER_TBA_LO_ES,
> + mmSPI_SHADER_TBA_LO_HS,
> + mmSPI_SHADER_TBA_LO_LS,
> + };
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(regs); i++) {
> + amdgpu_ring_write(ring, PACKET3(PACKET3_SET_SH_REG, 4));
> + amdgpu_ring_write(ring, regs[i] - PACKET3_SET_SH_REG_START);
> + amdgpu_ring_write(ring, lower_32_bits(tba_addr >> 8));
> + amdgpu_ring_write(ring, upper_32_bits(tba_addr >> 8));
> + amdgpu_ring_write(ring, lower_32_bits(tma_addr >> 8));
> + amdgpu_ring_write(ring, upper_32_bits(tma_addr >> 8));
> + }
> + } else {
> + amdgpu_ring_write(ring, PACKET3(PACKET3_SET_SH_REG, 4));
> + amdgpu_ring_write(ring, mmCOMPUTE_TBA_LO - PACKET3_SET_SH_REG_START);
> + amdgpu_ring_write(ring, lower_32_bits(tba_addr >> 8));
> + amdgpu_ring_write(ring, upper_32_bits(tba_addr >> 8));
> + amdgpu_ring_write(ring, lower_32_bits(tma_addr >> 8));
> + amdgpu_ring_write(ring, upper_32_bits(tma_addr >> 8));
> + }
> +}
> +
> static uint32_t wave_read_ind(struct amdgpu_device *adev, uint32_t simd, uint32_t wave, uint32_t address)
> {
> WREG32(mmSQ_IND_INDEX,
> @@ -6890,7 +6924,8 @@ static const struct amdgpu_ring_funcs gfx_v8_0_ring_funcs_gfx = {
> 5 + /* HDP_INVL */
> 12 + 12 + /* FENCE x2 */
> 2 + /* SWITCH_BUFFER */
> - 5, /* SURFACE_SYNC */
> + 5 + /* SURFACE_SYNC */
> + 36, /* gfx_v8_0_ring_emit_trap_handler */
> .emit_ib_size = 4, /* gfx_v8_0_ring_emit_ib_gfx */
> .emit_ib = gfx_v8_0_ring_emit_ib_gfx,
> .emit_fence = gfx_v8_0_ring_emit_fence_gfx,
> @@ -6909,6 +6944,7 @@ static const struct amdgpu_ring_funcs gfx_v8_0_ring_funcs_gfx = {
> .emit_wreg = gfx_v8_0_ring_emit_wreg,
> .soft_recovery = gfx_v8_0_ring_soft_recovery,
> .emit_mem_sync = gfx_v8_0_emit_mem_sync,
> + .emit_trap_handler = gfx_v8_0_ring_emit_trap_handler,
> };
>
> static const struct amdgpu_ring_funcs gfx_v8_0_ring_funcs_compute = {
> @@ -6926,7 +6962,8 @@ static const struct amdgpu_ring_funcs gfx_v8_0_ring_funcs_compute = {
> 7 + /* gfx_v8_0_ring_emit_pipeline_sync */
> VI_FLUSH_GPU_TLB_NUM_WREG * 5 + 7 + /* gfx_v8_0_ring_emit_vm_flush */
> 7 + 7 + 7 + /* gfx_v8_0_ring_emit_fence_compute x3 for user fence, vm fence */
> - 7, /* gfx_v8_0_emit_mem_sync_compute */
> + 7 + /* gfx_v8_0_emit_mem_sync_compute */
> + 6, /* gfx_v8_0_emit_trap_handler */
> .emit_ib_size = 7, /* gfx_v8_0_ring_emit_ib_compute */
> .emit_ib = gfx_v8_0_ring_emit_ib_compute,
> .emit_fence = gfx_v8_0_ring_emit_fence_compute,
> @@ -6940,6 +6977,7 @@ static const struct amdgpu_ring_funcs gfx_v8_0_ring_funcs_compute = {
> .pad_ib = amdgpu_ring_generic_pad_ib,
> .emit_wreg = gfx_v8_0_ring_emit_wreg,
> .emit_mem_sync = gfx_v8_0_emit_mem_sync_compute,
> + .emit_trap_handler = gfx_v8_0_ring_emit_trap_handler,
> };
>
> static const struct amdgpu_ring_funcs gfx_v8_0_ring_funcs_kiq = {
> diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> index cb9d60a4e05e..4fc00f196085 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> @@ -4162,6 +4162,23 @@ static void gfx_v9_0_ring_emit_gds_switch(struct amdgpu_ring *ring,
> (1 << (oa_size + oa_base)) - (1 << oa_base));
> }
>
> +static void gfx_v9_0_ring_emit_trap_handler(struct amdgpu_ring *ring,
> + uint32_t vmid,
> + uint64_t tba_addr,
> + uint64_t tma_addr)
> +{
> + struct amdgpu_device *adev = ring->adev;
> +
> + mutex_lock(&adev->srbm_mutex);
> + soc15_grbm_select(adev, 0, 0, 0, vmid);
> + WREG32_SOC15_RLC(GC, 0, mmSQ_SHADER_TBA_LO, lower_32_bits(tba_addr >> 8));
> + WREG32_SOC15_RLC(GC, 0, mmSQ_SHADER_TBA_HI, upper_32_bits(tba_addr >> 8));
> + WREG32_SOC15_RLC(GC, 0, mmSQ_SHADER_TMA_LO, lower_32_bits(tma_addr >> 8));
> + WREG32_SOC15_RLC(GC, 0, mmSQ_SHADER_TMA_HI, upper_32_bits(tma_addr >> 8));
> + soc15_grbm_select(adev, 0, 0, 0, 0);
> + mutex_unlock(&adev->srbm_mutex);
This won't work. This updates registers via MMIO using the CPU. We
need to have the registers updated asynchronously via the CP so they
get updated when the specific jobs are executed by the engine. vmid's
are shared resources and are assigned dynamically via the kernel
driver. If you update via MMIO the changes take effect immediately
rather than when the actual work is scheduled on the engine.
Unfortunately, at the moment, I don't see a way to do this with the CP
with the packets that are currently available.
Alex
> +}
> +
> static const u32 vgpr_init_compute_shader[] =
> {
> 0xb07c0000, 0xbe8000ff,
> @@ -6720,6 +6737,7 @@ static const struct amdgpu_ring_funcs gfx_v9_0_ring_funcs_gfx = {
> .emit_reg_write_reg_wait = gfx_v9_0_ring_emit_reg_write_reg_wait,
> .soft_recovery = gfx_v9_0_ring_soft_recovery,
> .emit_mem_sync = gfx_v9_0_emit_mem_sync,
> + .emit_trap_handler = gfx_v9_0_ring_emit_trap_handler,
> };
>
> static const struct amdgpu_ring_funcs gfx_v9_0_ring_funcs_compute = {
> @@ -6756,6 +6774,7 @@ static const struct amdgpu_ring_funcs gfx_v9_0_ring_funcs_compute = {
> .emit_reg_wait = gfx_v9_0_ring_emit_reg_wait,
> .emit_reg_write_reg_wait = gfx_v9_0_ring_emit_reg_write_reg_wait,
> .emit_mem_sync = gfx_v9_0_emit_mem_sync,
> + .emit_trap_handler = gfx_v9_0_ring_emit_trap_handler,
> };
>
> static const struct amdgpu_ring_funcs gfx_v9_0_ring_funcs_kiq = {
> diff --git a/include/uapi/drm/amdgpu_drm.h b/include/uapi/drm/amdgpu_drm.h
> index 3218576e109d..7eae264adb5d 100644
> --- a/include/uapi/drm/amdgpu_drm.h
> +++ b/include/uapi/drm/amdgpu_drm.h
> @@ -551,6 +551,7 @@ struct drm_amdgpu_gem_va {
> #define AMDGPU_CHUNK_ID_SCHEDULED_DEPENDENCIES 0x07
> #define AMDGPU_CHUNK_ID_SYNCOBJ_TIMELINE_WAIT 0x08
> #define AMDGPU_CHUNK_ID_SYNCOBJ_TIMELINE_SIGNAL 0x09
> +#define AMDGPU_CHUNK_ID_TRAP 0x0a
>
> struct drm_amdgpu_cs_chunk {
> __u32 chunk_id;
> @@ -645,6 +646,13 @@ struct drm_amdgpu_cs_chunk_syncobj {
> __u64 point;
> };
>
> +struct drm_amdgpu_cs_chunk_trap {
> + /** Trap Base Address */
> + __u64 tba_addr;
> + /** Trap Memory Address */
> + __u64 tma_addr;
> +};
> +
> #define AMDGPU_FENCE_TO_HANDLE_GET_SYNCOBJ 0
> #define AMDGPU_FENCE_TO_HANDLE_GET_SYNCOBJ_FD 1
> #define AMDGPU_FENCE_TO_HANDLE_GET_SYNC_FILE_FD 2
> --
> 2.28.0
>
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