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Diffstat (limited to 'src')
| -rw-r--r-- | src/intel/isl/isl.h | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/src/intel/isl/isl.h b/src/intel/isl/isl.h index 658f67e4ae3..95ecaf90d82 100644 --- a/src/intel/isl/isl.h +++ b/src/intel/isl/isl.h @@ -600,6 +600,175 @@ enum isl_aux_usage { ISL_AUX_USAGE_CCS_E, }; +/** + * Enum for keeping track of the state an auxiliary compressed surface. + * + * For any given auxiliary surface compression format (HiZ, CCS, or MCS), any + * given slice (lod + array layer) can be in one of the six states described + * by this enum. Draw and resolve operations may cause the slice to change + * from one state to another. The six valid states are: + * + * 1) Clear: In this state, each block in the auxiliary surface contains a + * magic value that indicates that the block is in the clear state. If + * a block is in the clear state, it's values in the primary surface are + * ignored and the color of the samples in the block is taken either the + * RENDER_SURFACE_STATE packet for color or 3DSTATE_CLEAR_PARAMS for + * depth. Since neither the primary surface nor the auxiliary surface + * contains the clear value, the surface can be cleared to a different + * color by simply changing the clear color without modifying either + * surface. + * + * 2) Compressed w/ Clear: In this state, neither the auxiliary surface + * nor the primary surface has a complete representation of the data. + * Instead, both surfaces must be used together or else rendering + * corruption may occur. Depending on the auxiliary compression format + * and the data, any given block in the primary surface may contain all, + * some, or none of the data required to reconstruct the actual sample + * values. Blocks may also be in the clear state (see Clear) and have + * their value taken from outside the surface. + * + * 3) Compressed w/o Clear: This state is identical to the state above + * except that no blocks are in the clear state. In this state, all of + * the data required to reconstruct the final sample values is contained + * in the auxiliary and primary surface and the clear value is not + * considered. + * + * 4) Resolved: In this state, the primary surface contains 100% of the + * data. The auxiliary surface is also valid so the surface can be + * validly used with or without aux enabled. The auxiliary surface may, + * however, contain non-trivial data and any update to the primary + * surface with aux disabled will cause the two to get out of sync. + * + * 5) Pass-through: In this state, the primary surface contains 100% of the + * data and every block in the auxiliary surface contains a magic value + * which indicates that the auxiliary surface should be ignored and the + * only the primary surface should be considered. Updating the primary + * surface without aux works fine and can be done repeatedly in this + * mode. Writing to a surface in pass-through mode with aux enabled may + * cause the auxiliary buffer to contain non-trivial data and no longer + * be in the pass-through state. + * + * 5) Aux Invalid: In this state, the primary surface contains 100% of the + * data and the auxiliary surface is completely bogus. Any attempt to + * use the auxiliary surface is liable to result in rendering + * corruption. The only thing that one can do to re-enable aux once + * this state is reached is to use an ambiguate pass to transition into + * the pass-through state. + * + * Drawing with or without aux enabled may implicitly cause the surface to + * transition between these states. There are also four types of auxiliary + * compression operations which cause an explicit transition: + * + * 1) Fast Clear: This operation writes the magic "clear" value to the + * auxiliary surface. This operation will safely transition any slice + * of a surface from any state to the clear state so long as the entire + * slice is fast cleared at once. + * + * 2) Full Resolve: This operation combines the auxiliary surface data + * with the primary surface data and writes the result to the primary. + * For HiZ, the docs call this a depth resolve. For CCS, the hardware + * full resolve operation does both a full resolve and an ambiguate so + * it actually takes you all the way to the pass-through state. + * + * 3) Partial Resolve: This operation considers blocks which are in the + * "clear" state and writes the clear value directly into the primary or + * auxiliary surface. Once this operation completes, the surface is + * still compressed but no longer references the clear color. This + * operation is only available for CCS. + * + * 4) Ambiguate: This operation throws away the current auxiliary data and + * replaces it with the magic pass-through value. If an ambiguate + * operation is performed when the primary surface does not contain 100% + * of the data, data will be lost. This operation is only implemented + * in hardware for depth where it is called a HiZ resolve. + * + * Not all operations are valid or useful in all states. The diagram below + * contains a complete description of the states and all valid and useful + * transitions except clear. + * + * Draw w/ Aux + * +----------+ + * | | + * | +-------------+ Draw w/ Aux +-------------+ + * +------>| Compressed |<---------------------| Clear | + * | w/ Clear | | | + * +-------------+ +-------------+ + * | | | + * Partial | | | + * Resolve | | Full Resolve | + * | +----------------------------+ | Full + * | | | Resolve + * Draw w/ aux | | | + * +----------+ | | | + * | | \|/ \|/ \|/ + * | +-------------+ Full Resolve +-------------+ + * +------>| Compressed |--------------------->| Resolved | + * | w/o Clear |<---------------------| | + * +-------------+ Draw w/ Aux +-------------+ + * /|\ | | + * | Draw | | Draw + * | w/ Aux | | w/o Aux + * | Ambiguate | | + * | +----------------------------+ | + * Draw w/o Aux | | | Draw w/o Aux + * +----------+ | | | +----------+ + * | | | \|/ \|/ | | + * | +-------------+ Ambiguate +-------------+ | + * +------>| Pass- |<---------------------| Aux |<------+ + * | through | | Invalid | + * +-------------+ +-------------+ + * + * + * While the above general theory applies to all forms of auxiliary + * compression on Intel hardware, not all states and operations are available + * on all compression types. However, each of the auxiliary states and + * operations can be fairly easily mapped onto the above diagram: + * + * HiZ: Hierarchical depth compression is capable of being in any of the + * states above. Hardware provides three HiZ operations: "Depth + * Clear", "Depth Resolve", and "HiZ Resolve" which map to "Fast + * Clear", "Full Resolve", and "Ambiguate" respectively. The + * hardware provides no HiZ partial resolve operation so the only way + * to get into the "Compressed w/o Clear" state is to render with HiZ + * when the surface is in the resolved or pass-through states. + * + * MCS: Multisample compression is technically capable of being in any of + * the states above except that most of them aren't useful. Both the + * render engine and the sampler support MCS compression and, apart + * from clear color, MCS is format-unaware so we leave the surface + * compressed 100% of the time. The hardware provides no MCS + * operations. + * + * CCS_D: Single-sample fast-clears (also called CCS_D in ISL) are one of + * the simplest forms of compression since they don't do anything + * beyond clear color tracking. They really only support three of + * the six states: Clear, Compressed w/ Clear, and Pass-through. The + * only CCS_D operation is "Resolve" which maps to a full resolve + * followed by an ambiguate. + * + * CCS_E: Single-sample render target compression (also called CCS_E in ISL) + * is capable of being in almost all of the above states. THe only + * exception is that it does not have separate resolved and pass- + * through states. Instead, the CCS_E full resolve operation does + * both a resolve and an ambiguate so it goes directly into the + * pass-through state. CCS_E also provides fast clear and partial + * resolve operations which work as described above. + * + * While it is technically possible to perform a CCS_E ambiguate, it + * is not provided by Sky Lake hardware so we choose to avoid the aux + * invalid state. If the aux invalid state were determined to be + * useful, a CCS ambiguate could be done by carefully rendering to + * the CCS and filling it with zeros. + */ +enum isl_aux_state { + ISL_AUX_STATE_CLEAR = 0, + ISL_AUX_STATE_COMPRESSED_CLEAR, + ISL_AUX_STATE_COMPRESSED_NO_CLEAR, + ISL_AUX_STATE_RESOLVED, + ISL_AUX_STATE_PASS_THROUGH, + ISL_AUX_STATE_AUX_INVALID, +}; + /* TODO(chadv): Explain */ enum isl_array_pitch_span { ISL_ARRAY_PITCH_SPAN_FULL, |