Re: [PATCH 19/49] drm/i915/bdw: Populate LR contexts (somewhat)

Jeff McGee
2014-04-15T15:52:23Z

On Thu, Mar 27, 2014 at 05:59:48PM +0000, oscar.mateo@intel.com wrote:
> From: Ben Widawsky <benjamin.widawsky@intel.com>
>
> For the most part, logical rinf context objects are similar to hardware
> contexts in that the backing object is meant to be opaque. There are
> some exceptions where we need to poke certain offsets of the object for
> initialization, updating the tail pointer or updating the PDPs.
>
> For our basic execlist implementation we'll only need our PPGTT PDs,
> and ringbuffer addresses in order to set up the context. With previous
> patches, we have both, so start prepping the context to be load.
>
> Before running a context for the first time you must populate some
> fields in the context object. These fields begin 1 PAGE + LRCA, ie. the
> first page (in 0 based counting) of the context image. These same
> fields will be read and written to as contexts are saved and restored
> once the system is up and running.
>
> Many of these fields are completely reused from previous global
> registers: ringbuffer head/tail/control, context control matches some
> previous MI_SET_CONTEXT flags, and page directories. There are other
> fields which we don't touch which we may want in the future.
>
> Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
>
> v2: CTX_LRI_HEADER_0 is MI_LOAD_REGISTER_IMM(14) for render and (11)
> for other engines.
>
> Signed-off-by: Rafael Barbalho <rafael.barbalho@intel.com>
>
> v3: Several rebases and general changes to the code.
>
> Signed-off-by: Oscar Mateo <oscar.mateo@intel.com>
> ---
> drivers/gpu/drm/i915/i915_lrc.c | 145 ++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 138 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_lrc.c b/drivers/gpu/drm/i915/i915_lrc.c
> index 40dfa95..f0176ff 100644
> --- a/drivers/gpu/drm/i915/i915_lrc.c
> +++ b/drivers/gpu/drm/i915/i915_lrc.c
> @@ -43,6 +43,38 @@
>
> #define GEN8_LR_CONTEXT_SIZE (21 * PAGE_SIZE)
>
> +#define RING_ELSP(ring) ((ring)->mmio_base+0x230)
> +#define RING_CONTEXT_CONTROL(ring) ((ring)->mmio_base+0x244)
> +
> +#define CTX_LRI_HEADER_0 0x01
> +#define CTX_CONTEXT_CONTROL 0x02
> +#define CTX_RING_HEAD 0x04
> +#define CTX_RING_TAIL 0x06
> +#define CTX_RING_BUFFER_START 0x08
> +#define CTX_RING_BUFFER_CONTROL 0x0a
> +#define CTX_BB_HEAD_U 0x0c
> +#define CTX_BB_HEAD_L 0x0e
> +#define CTX_BB_STATE 0x10
> +#define CTX_SECOND_BB_HEAD_U 0x12
> +#define CTX_SECOND_BB_HEAD_L 0x14
> +#define CTX_SECOND_BB_STATE 0x16
> +#define CTX_BB_PER_CTX_PTR 0x18
> +#define CTX_RCS_INDIRECT_CTX 0x1a
> +#define CTX_RCS_INDIRECT_CTX_OFFSET 0x1c
> +#define CTX_LRI_HEADER_1 0x21
> +#define CTX_CTX_TIMESTAMP 0x22
> +#define CTX_PDP3_UDW 0x24
> +#define CTX_PDP3_LDW 0x26
> +#define CTX_PDP2_UDW 0x28
> +#define CTX_PDP2_LDW 0x2a
> +#define CTX_PDP1_UDW 0x2c
> +#define CTX_PDP1_LDW 0x2e
> +#define CTX_PDP0_UDW 0x30
> +#define CTX_PDP0_LDW 0x32
> +#define CTX_LRI_HEADER_2 0x41
> +#define CTX_R_PWR_CLK_STATE 0x42
> +#define CTX_GPGPU_CSR_BASE_ADDRESS 0x44
> +
> struct i915_hw_context *
> gen8_gem_create_context(struct drm_device *dev,
> struct intel_engine *ring,
> @@ -51,6 +83,9 @@ gen8_gem_create_context(struct drm_device *dev,
> {
> struct i915_hw_context *ctx = NULL;
> struct drm_i915_gem_object *ring_obj = NULL;
> + struct i915_hw_ppgtt *ppgtt = NULL;
> + struct page *page;
> + uint32_t *reg_state;
> int ret;
>
> ctx = i915_gem_create_context(dev, file_priv, create_vm);
> @@ -79,18 +114,114 @@ gen8_gem_create_context(struct drm_device *dev,
>
> /* Failure at this point is almost impossible */
> ret = i915_gem_object_set_to_gtt_domain(ring_obj, true);
> - if (ret) {
> - i915_gem_object_ggtt_unpin(ring_obj);
> - drm_gem_object_unreference(&ring_obj->base);
> - i915_gem_object_ggtt_unpin(ctx->obj);
> - i915_gem_context_unreference(ctx);
> - return ERR_PTR(ret);
> - }
> + if (ret)
> + goto destroy_ring_obj;
>
> ctx->ringbuf = &ring->default_ringbuf;
> ctx->ringbuf->obj = ring_obj;
>
> + ppgtt = ctx_to_ppgtt(ctx);
> +
> + ret = i915_gem_object_set_to_cpu_domain(ctx->obj, true);
> + if (ret)
> + goto destroy_ring_obj;
> +
> + ret = i915_gem_object_get_pages(ctx->obj);
> + if (ret)
> + goto destroy_ring_obj;
> +
> + i915_gem_object_pin_pages(ctx->obj);
> +
> + /* The second page of the context object contains some fields which must
> + * be set up prior to the first execution.
> + */
> + page = i915_gem_object_get_page(ctx->obj, 1);
> + reg_state = kmap_atomic(page);
> +
> + if (ring->id == RCS)
> + reg_state[CTX_LRI_HEADER_0] = MI_LOAD_REGISTER_IMM(14);
> + else
> + reg_state[CTX_LRI_HEADER_0] = MI_LOAD_REGISTER_IMM(11);
> + reg_state[CTX_CONTEXT_CONTROL] = RING_CONTEXT_CONTROL(ring);
> + reg_state[CTX_CONTEXT_CONTROL+1] = (1<<3) | MI_RESTORE_INHIBIT;
> + reg_state[CTX_CONTEXT_CONTROL+1] |= reg_state[CTX_CONTEXT_CONTROL+1] << 16;
> + reg_state[CTX_RING_HEAD] = RING_HEAD(ring->mmio_base);
> + reg_state[CTX_RING_HEAD+1] = 0;
> + reg_state[CTX_RING_TAIL] = RING_TAIL(ring->mmio_base);
> + reg_state[CTX_RING_TAIL+1] = 0;
> + reg_state[CTX_RING_BUFFER_START] = RING_START(ring->mmio_base);
> + reg_state[CTX_RING_BUFFER_START+1] = i915_gem_obj_ggtt_offset(ring_obj);
> + reg_state[CTX_RING_BUFFER_CONTROL] = RING_CTL(ring->mmio_base);
> + reg_state[CTX_RING_BUFFER_CONTROL+1] = (31 * PAGE_SIZE) | RING_VALID;
> + reg_state[CTX_BB_HEAD_U] = ring->mmio_base + 0x168;
> + reg_state[CTX_BB_HEAD_U+1] = 0;
> + reg_state[CTX_BB_HEAD_L] = ring->mmio_base + 0x140;
> + reg_state[CTX_BB_HEAD_L+1] = 0;
> + reg_state[CTX_BB_STATE] = ring->mmio_base + 0x110;
> + reg_state[CTX_BB_STATE+1] = (1<<5);
> + reg_state[CTX_SECOND_BB_HEAD_U] = ring->mmio_base + 0x11c;
> + reg_state[CTX_SECOND_BB_HEAD_U+1] = 0;
> + reg_state[CTX_SECOND_BB_HEAD_L] = ring->mmio_base + 0x114;
> + reg_state[CTX_SECOND_BB_HEAD_L+1] = 0;
> + reg_state[CTX_SECOND_BB_STATE] = ring->mmio_base + 0x118;
> + reg_state[CTX_SECOND_BB_STATE+1] = 0;
> + if (ring->id == RCS) {
> + reg_state[CTX_BB_PER_CTX_PTR] = ring->mmio_base + 0x1c0;
> + reg_state[CTX_BB_PER_CTX_PTR+1] = 0;
> + reg_state[CTX_RCS_INDIRECT_CTX] = ring->mmio_base + 0x1c4;
> + reg_state[CTX_RCS_INDIRECT_CTX+1] = 0;
> + reg_state[CTX_RCS_INDIRECT_CTX_OFFSET] = ring->mmio_base + 0x1c8;
> + reg_state[CTX_RCS_INDIRECT_CTX_OFFSET+1] = 0;
> + }
> +
> + reg_state[CTX_LRI_HEADER_1] = MI_LOAD_REGISTER_IMM(9);
> + reg_state[CTX_CTX_TIMESTAMP] = ring->mmio_base + 0x3a8;
> + reg_state[CTX_CTX_TIMESTAMP+1] = 0;
> + reg_state[CTX_PDP3_UDW] = GEN8_RING_PDP_UDW(ring, 3);
> + reg_state[CTX_PDP3_LDW] = GEN8_RING_PDP_LDW(ring, 3);
> + reg_state[CTX_PDP2_UDW] = GEN8_RING_PDP_UDW(ring, 2);
> + reg_state[CTX_PDP2_LDW] = GEN8_RING_PDP_LDW(ring, 2);
> + reg_state[CTX_PDP1_UDW] = GEN8_RING_PDP_UDW(ring, 1);
> + reg_state[CTX_PDP1_LDW] = GEN8_RING_PDP_LDW(ring, 1);
> + reg_state[CTX_PDP0_UDW] = GEN8_RING_PDP_UDW(ring, 0);
> + reg_state[CTX_PDP0_LDW] = GEN8_RING_PDP_LDW(ring, 0);
> + reg_state[CTX_PDP3_UDW+1] = ppgtt->pd_dma_addr[3] >> 32;
> + reg_state[CTX_PDP3_LDW+1] = ppgtt->pd_dma_addr[3];
> + reg_state[CTX_PDP2_UDW+1] = ppgtt->pd_dma_addr[2] >> 32;
> + reg_state[CTX_PDP2_LDW+1] = ppgtt->pd_dma_addr[2];
> + reg_state[CTX_PDP1_UDW+1] = ppgtt->pd_dma_addr[1] >> 32;
> + reg_state[CTX_PDP1_LDW+1] = ppgtt->pd_dma_addr[1];
> + reg_state[CTX_PDP0_UDW+1] = ppgtt->pd_dma_addr[0] >> 32;
> + reg_state[CTX_PDP0_LDW+1] = ppgtt->pd_dma_addr[0];
> + if (ring->id == RCS) {
> + reg_state[CTX_LRI_HEADER_2] = MI_LOAD_REGISTER_IMM(1);
> + reg_state[CTX_R_PWR_CLK_STATE] = 0x20c8;

You're writing the MMIO address for the R_PWR_CLK_STATE register to this
field. Shouldn't this receive the value we want programmed to the register?

> + reg_state[CTX_R_PWR_CLK_STATE+1] = 0;
> + }
> +
> +#if 0
> + /* Offsets not yet defined for these */
> + reg_state[CTX_GPGPU_CSR_BASE_ADDRESS[] = ;
> + reg_state[CTX_GPGPU_CSR_BASE_ADDRESS+1] = 0;
> +#endif
> +
> + kunmap_atomic(reg_state);
> +
> + ctx->obj->dirty = 1;
> + set_page_dirty(page);
> + i915_gem_object_unpin_pages(ctx->obj);
> +
> return ctx;
> +
> +destroy_ring_obj:
> + i915_gem_object_ggtt_unpin(ring_obj);
> + drm_gem_object_unreference(&ring_obj->base);
> + ctx->ringbuf->obj = NULL;
> + ctx->ringbuf = NULL;
> + i915_gem_object_ggtt_unpin(ctx->obj);
> + i915_gem_context_unreference(ctx);
> +
> + return ERR_PTR(ret);
> }
>
> void gen8_gem_context_fini(struct drm_device *dev)
> --
> 1.9.0
>
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