drm/i915: Implement dynamic GuC WOPCM offset and size calculation

Hardware may have specific restrictions on GuC WOPCM offset and size. On
Gen9, the value of the GuC WOPCM size register needs to be larger than the
value of GuC WOPCM offset register + a Gen9 specific offset (144KB) for
reserved GuC WOPCM. Fail to enforce such a restriction on GuC WOPCM size
will lead to GuC firmware execution failures. On the other hand, with
current static GuC WOPCM offset and size values (512KB for both offset and
size), the GuC WOPCM size verification will fail on Gen9 even if it can be
fixed by lowering the GuC WOPCM offset by calculating its value based on
HuC firmware size (which is likely less than 200KB on Gen9), so that we can
have a GuC WOPCM size value which is large enough to pass the GuC WOPCM
size check.

This patch updates the reserved GuC WOPCM size for RC6 context on Gen9 to
24KB to strictly align with the Gen9 GuC WOPCM layout. It also adds support
to verify the GuC WOPCM size aganist the Gen9 hardware restrictions. To
meet all above requirements, let's provide dynamic partitioning of the
WOPCM that will be based on platform specific HuC/GuC firmware sizes.

v2:
 - Removed intel_wopcm_init (Ville/Sagar/Joonas)
 - Renamed and Moved the intel_wopcm_partition into intel_guc (Sagar)
 - Removed unnecessary function calls (Joonas)
 - Init GuC WOPCM partition as soon as firmware fetching is completed

v3:
 - Fixed indentation issues (Chris)
 - Removed layering violation code (Chris/Michal)
 - Created separat files for GuC wopcm code  (Michal)
 - Used inline function to avoid code duplication (Michal)

v4:
 - Preset the GuC WOPCM top during early GuC init (Chris)
 - Fail intel_uc_init_hw() as soon as GuC WOPCM partitioning failed

v5:
 - Moved GuC DMA WOPCM register updating code into intel_wopcm.c
 - Took care of the locking status before writing to GuC DMA
   Write-Once registers. (Joonas)

v6:
 - Made sure the GuC WOPCM size to be multiple of 4K (4K aligned)

v8:
 - Updated comments and fixed naming issues (Sagar/Joonas)
 - Updated commit message to include more description about the hardware
   restriction on GuC WOPCM size (Sagar)

v9:
 - Minor changes variable names and code comments (Sagar)
 - Added detailed GuC WOPCM layout drawing (Sagar/Michal)
 - Refined macro definitions to be reader friendly (Michal)
 - Removed redundent check to valid flag (Michal)
 - Unified first parameter for exported GuC WOPCM functions (Michal)
 - Refined the name and parameter list of hardware restriction checking
   functions (Michal)

v10:
 - Used shorter function name for internal functions (Joonas)
 - Moved init-ealry function into c file (Joonas)
 - Consolidated and removed redundant size checks (Joonas/Michal)
 - Removed unnecessary unlikely() from code which is only called once
   during boot (Joonas)
 - More fixes to kernel-doc format and content (Michal)
 - Avoided the use of PAGE_MASK for 4K pages (Michal)
 - Added error log messages to error paths (Michal)

v11:
 - Replaced intel_guc_wopcm with more generic intel_wopcm and attached
   intel_wopcm to drm_i915_private instead intel_guc (Michal)
 - dynamic calculation of GuC non-wopcm memory start (a.k.a WOPCM Top
   offset from GuC WOPCM base) (Michal)
 - Moved WOPCM marco definitions into .c source file (Michal)
 - Exported WOPCM layout diagram as kernel-doc (Michal)

v12:
 - Updated naming, function kernel-doc to align with new changes (Michal)

v13:
 - Updated the ordering of s-o-b/cc/r-b tags (Sagar)
 - Corrected one tense error in comment (Sagar)
 - Corrected typos and removed spurious comments (Joonas)

Bspec: 12690

Signed-off-by: Jackie Li <yaodong.li@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Cc: Sujaritha Sundaresan <sujaritha.sundaresan@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: John Spotswood <john.a.spotswood@intel.com>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Sagar Arun Kamble <sagar.a.kamble@intel.com> (v8)
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> (v9)
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com> (v11)
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> (v12)
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1520987574-19351-2-git-send-email-yaodong.li@intel.com

1 files changed, 53 insertions, 13 deletions

diff --git a/drivers/gpu/drm/i915/intel_guc.c b/drivers/gpu/drm/i915/intel_guc.c
index 78463842ea7b..3eb516e7c225 100644
--- a/drivers/gpu/drm/i915/intel_guc.c
+++ b/drivers/gpu/drm/i915/intel_guc.c
@@ -493,6 +493,57 @@ int intel_guc_resume(struct intel_guc *guc)
 }
 
 /**
+ * DOC: GuC Address Space
+ *
+ * The layout of GuC address space is shown as below:
+ *
+ *    +==============> +====================+ <== GUC_GGTT_TOP
+ *    ^                |                    |
+ *    |                |                    |
+ *    |                |        DRAM        |
+ *    |                |       Memory       |
+ *    |                |                    |
+ *   GuC               |                    |
+ * Address  +========> +====================+ <== WOPCM Top
+ *  Space   ^          |   HW contexts RSVD |
+ *    |     |          |        WOPCM       |
+ *    |     |     +==> +--------------------+ <== GuC WOPCM Top
+ *    |    GuC    ^    |                    |
+ *    |    GGTT   |    |                    |
+ *    |    Pin   GuC   |        GuC         |
+ *    |    Bias WOPCM  |       WOPCM        |
+ *    |     |    Size  |                    |
+ *    |     |     |    |                    |
+ *    v     v     v    |                    |
+ *    +=====+=====+==> +====================+ <== GuC WOPCM Base
+ *                     |   Non-GuC WOPCM    |
+ *                     |   (HuC/Reserved)   |
+ *                     +====================+ <== WOPCM Base
+ *
+ * The lower part [0, GuC ggtt_pin_bias) is mapped to WOPCM which consists of
+ * GuC WOPCM and WOPCM reserved for other usage (e.g.RC6 context). The value of
+ * the GuC ggtt_pin_bias is determined by the actually GuC WOPCM size which is
+ * set in GUC_WOPCM_SIZE register.
+ */
+
+/**
+ * intel_guc_init_ggtt_pin_bias() - Initialize the GuC ggtt_pin_bias value.
+ * @guc: intel_guc structure.
+ *
+ * This function will calculate and initialize the ggtt_pin_bias value based on
+ * overall WOPCM size and GuC WOPCM size.
+ */
+void intel_guc_init_ggtt_pin_bias(struct intel_guc *guc)
+{
+	struct drm_i915_private *i915 = guc_to_i915(guc);
+
+	GEM_BUG_ON(!i915->wopcm.size);
+	GEM_BUG_ON(i915->wopcm.size < i915->wopcm.guc.base);
+
+	guc->ggtt_pin_bias = i915->wopcm.size - i915->wopcm.guc.base;
+}
+
+/**
  * intel_guc_allocate_vma() - Allocate a GGTT VMA for GuC usage
  * @guc:	the guc
  * @size:	size of area to allocate (both virtual space and memory)
@@ -500,7 +551,7 @@ int intel_guc_resume(struct intel_guc *guc)
  * This is a wrapper to create an object for use with the GuC. In order to
  * use it inside the GuC, an object needs to be pinned lifetime, so we allocate
  * both some backing storage and a range inside the Global GTT. We must pin
- * it in the GGTT somewhere other than than [0, GUC_WOPCM_TOP) because that
+ * it in the GGTT somewhere other than than [0, GUC ggtt_pin_bias) because that
  * range is reserved inside GuC.
  *
  * Return:	A i915_vma if successful, otherwise an ERR_PTR.
@@ -521,7 +572,7 @@ struct i915_vma *intel_guc_allocate_vma(struct intel_guc *guc, u32 size)
 		goto err;
 
 	ret = i915_vma_pin(vma, 0, PAGE_SIZE,
-			   PIN_GLOBAL | PIN_OFFSET_BIAS | GUC_WOPCM_TOP);
+			   PIN_GLOBAL | PIN_OFFSET_BIAS | guc->ggtt_pin_bias);
 	if (ret) {
 		vma = ERR_PTR(ret);
 		goto err;
@@ -533,14 +584,3 @@ err:
 	i915_gem_object_put(obj);
 	return vma;
 }
-
-u32 intel_guc_wopcm_size(struct drm_i915_private *dev_priv)
-{
-	u32 wopcm_size = GUC_WOPCM_TOP;
-
-	/* On BXT, the top of WOPCM is reserved for RC6 context */
-	if (IS_GEN9_LP(dev_priv))
-		wopcm_size -= BXT_GUC_WOPCM_RC6_RESERVED;
-
-	return wopcm_size;
-}