drm/i915: Define multicast registers as a new type

Rather than treating multicast registers as 'i915_reg_t' let's define
them as a completely new type.  This will allow the compiler to help us
make sure we're using multicast-aware functions to operate on multicast
registers.

This plan does break down a bit in places where we're just maintaining
heterogeneous lists of registers (e.g., various MMIO whitelists used by
perf, GVT, etc.) rather than performing reads/writes.  We only really
care about the offset in those cases, so for now we can "cast" the
registers as non-MCR, leaving us with a list of i915_reg_t's, but we may
want to look for better ways to store mixed collections of i915_reg_t
and i915_mcr_reg_t in the future.

v2:
 - Add TLB invalidation registers
v3:
 - Make type checking of i915_mmio_reg_offset() stricter.  It will
   accept either i915_reg_t or i915_mcr_reg_t, but will now raise a
   compile error if any other type is passed, even if that type contains
   a 'reg' field.  (Jani)
 - Drop a ton of GVT changes; allowing i915_mmio_reg_offset() to take
   either an i915_reg_t or an i915_mcr_reg_t means that the huge lists
   of MMIO_D*() macros used in GVT will continue to work without
   modification.  We need only make changes to structures that have an
   explicit i915_reg_t in them now.

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Balasubramani Vivekanandan <balasubramani.vivekanandan@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221014230239.1023689-13-matthew.d.roper@intel.com

1 files changed, 12 insertions, 4 deletions

diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c
index 3df0d0336dbc..27dbb9e4bd6c 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt.c
@@ -991,7 +991,10 @@ void intel_gt_info_print(const struct intel_gt_info *info,
 }
 
 struct reg_and_bit {
-	i915_reg_t reg;
+	union {
+		i915_reg_t reg;
+		i915_mcr_reg_t mcr_reg;
+	};
 	u32 bit;
 };
 
@@ -1033,7 +1036,7 @@ get_reg_and_bit(const struct intel_engine_cs *engine, const bool gen8,
 static int wait_for_invalidate(struct intel_gt *gt, struct reg_and_bit rb)
 {
 	if (GRAPHICS_VER_FULL(gt->i915) >= IP_VER(12, 50))
-		return intel_gt_mcr_wait_for_reg_fw(gt, rb.reg, rb.bit, 0,
+		return intel_gt_mcr_wait_for_reg_fw(gt, rb.mcr_reg, rb.bit, 0,
 						    TLB_INVAL_TIMEOUT_US,
 						    TLB_INVAL_TIMEOUT_MS);
 	else
@@ -1058,7 +1061,7 @@ static void mmio_invalidate_full(struct intel_gt *gt)
 		[COPY_ENGINE_CLASS]		= GEN12_BLT_TLB_INV_CR,
 		[COMPUTE_CLASS]			= GEN12_COMPCTX_TLB_INV_CR,
 	};
-	static const i915_reg_t xehp_regs[] = {
+	static const i915_mcr_reg_t xehp_regs[] = {
 		[RENDER_CLASS]			= XEHP_GFX_TLB_INV_CR,
 		[VIDEO_DECODE_CLASS]		= XEHP_VD_TLB_INV_CR,
 		[VIDEO_ENHANCEMENT_CLASS]	= XEHP_VE_TLB_INV_CR,
@@ -1131,7 +1134,12 @@ static void mmio_invalidate_full(struct intel_gt *gt)
 	for_each_engine_masked(engine, gt, awake, tmp) {
 		struct reg_and_bit rb;
 
-		rb = get_reg_and_bit(engine, regs == gen8_regs, regs, num);
+		if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 50)) {
+			rb.mcr_reg = xehp_regs[engine->class];
+			rb.bit = BIT(engine->instance);
+		} else {
+			rb = get_reg_and_bit(engine, regs == gen8_regs, regs, num);
+		}
 
 		if (wait_for_invalidate(gt, rb))
 			drm_err_ratelimited(&gt->i915->drm,