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author | 2019-10-14 11:36:01 -0700 | |
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committer | 2019-10-17 09:30:32 -0700 | |
commit | 218151e997449717cbb70f304b7b8f9918ba6af4 (patch) | |
tree | 2aa9c092db449dd9baa4a4e276feb609b5c95fab | |
parent | drm/i915: Add microcontrollers documentation section (diff) | |
download | linux-218151e997449717cbb70f304b7b8f9918ba6af4.tar.gz linux-218151e997449717cbb70f304b7b8f9918ba6af4.tar.bz2 linux-218151e997449717cbb70f304b7b8f9918ba6af4.zip |
drm/i915/guc: improve documentation
Add a short description of what we expect from GuC and some minor
improvements to existing documentation. Also remove a comment about a
difference between GuC and HuC that is not true anymore.
v2: add that the GuC is not mandatory (Martin)
v3: add extra newline for better text organization (Martin)
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Martin Peres <martin.peres@linux.intel.com>
Acked-by: Anna Karas <anna.karas@intel.com>
Reviewed-by: Martin Peres <martin.peres@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191014183602.3643-2-daniele.ceraolospurio@intel.com
-rw-r--r-- | Documentation/gpu/i915.rst | 22 | ||||
-rw-r--r-- | drivers/gpu/drm/i915/gt/uc/intel_guc.c | 31 | ||||
-rw-r--r-- | drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 6 | ||||
-rw-r--r-- | drivers/gpu/drm/i915/gt/uc/intel_uc_fw_abi.h | 3 |
4 files changed, 49 insertions, 13 deletions
diff --git a/Documentation/gpu/i915.rst b/Documentation/gpu/i915.rst index f1bae7867045..357e9dfa7de1 100644 --- a/Documentation/gpu/i915.rst +++ b/Documentation/gpu/i915.rst @@ -436,12 +436,24 @@ WOPCM Layout GuC --- -Firmware Layout -~~~~~~~~~~~~~~~ +.. kernel-doc:: drivers/gpu/drm/i915/gt/uc/intel_guc.c + :doc: GuC + +GuC Firmware Layout +~~~~~~~~~~~~~~~~~~~ .. kernel-doc:: drivers/gpu/drm/i915/gt/uc/intel_uc_fw_abi.h :doc: Firmware Layout +GuC Memory Management +~~~~~~~~~~~~~~~~~~~~~ + +.. kernel-doc:: drivers/gpu/drm/i915/gt/uc/intel_guc.c + :doc: GuC Memory Management +.. kernel-doc:: drivers/gpu/drm/i915/gt/uc/intel_guc.c + :functions: intel_guc_allocate_vma + + GuC-specific firmware loader ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -457,12 +469,6 @@ GuC-based command submission .. kernel-doc:: drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c :internal: -GuC Address Space -~~~~~~~~~~~~~~~~~ - -.. kernel-doc:: drivers/gpu/drm/i915/gt/uc/intel_guc.c - :doc: GuC Address Space - HuC --- .. kernel-doc:: drivers/gpu/drm/i915/gt/uc/intel_huc_fw.c diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc.c b/drivers/gpu/drm/i915/gt/uc/intel_guc.c index 249c747e9756..37f7bcbf7dac 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc.c @@ -9,6 +9,27 @@ #include "intel_guc_submission.h" #include "i915_drv.h" +/** + * DOC: GuC + * + * The GuC is a microcontroller inside the GT HW, introduced in gen9. The GuC is + * designed to offload some of the functionality usually performed by the host + * driver; currently the main operations it can take care of are: + * + * - Authentication of the HuC, which is required to fully enable HuC usage. + * - Low latency graphics context scheduling (a.k.a. GuC submission). + * - GT Power management. + * + * The enable_guc module parameter can be used to select which of those + * operations to enable within GuC. Note that not all the operations are + * supported on all gen9+ platforms. + * + * Enabling the GuC is not mandatory and therefore the firmware is only loaded + * if at least one of the operations is selected. However, not loading the GuC + * might result in the loss of some features that do require the GuC (currently + * just the HuC, but more are expected to land in the future). + */ + static void gen8_guc_raise_irq(struct intel_guc *guc) { struct intel_gt *gt = guc_to_gt(guc); @@ -548,9 +569,15 @@ int intel_guc_resume(struct intel_guc *guc) } /** - * DOC: GuC Address Space + * DOC: GuC Memory Management * - * The layout of GuC address space is shown below: + * GuC can't allocate any memory for its own usage, so all the allocations must + * be handled by the host driver. GuC accesses the memory via the GGTT, with the + * exception of the top and bottom parts of the 4GB address space, which are + * instead re-mapped by the GuC HW to memory location of the FW itself (WOPCM) + * or other parts of the HW. The driver must take care not to place objects that + * the GuC is going to access in these reserved ranges. The layout of the GuC + * address space is shown below: * * :: * diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c index f325d3dd564f..849a44add424 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c @@ -29,6 +29,12 @@ enum { /** * DOC: GuC-based command submission * + * IMPORTANT NOTE: GuC submission is currently not supported in i915. The GuC + * firmware is moving to an updated submission interface and we plan to + * turn submission back on when that lands. The below documentation (and related + * code) matches the old submission model and will be updated as part of the + * upgrade to the new flow. + * * GuC client: * A intel_guc_client refers to a submission path through GuC. Currently, there * is only one client, which is charged with all submissions to the GuC. This diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw_abi.h b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw_abi.h index f8f6c91a0df6..029214cdedd5 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw_abi.h +++ b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw_abi.h @@ -39,9 +39,6 @@ * 3. Length info of each component can be found in header, in dwords. * 4. Modulus and exponent key are not required by driver. They may not appear * in fw. So driver will load a truncated firmware in this case. - * - * The only difference between GuC and HuC firmwares is how the version - * information is saved. */ struct uc_css_header { |