[PATCH 2/2] drm/xe: Add xe_mmio_init() initialization function

[Lucas De Marchi]

On Thu, Jan 30, 2025 at 12:50:57PM +0200, Ilia Levi wrote:
>Add a convenience function for minimal initialization of struct xe_mmio.
>This function also validates that the space referred by this xe_mmio is
>small enough to be accessed with struct xe_reg.
>
>Signed-off-by: Ilia Levi <ilia.levi at intel.com>
>---
> drivers/gpu/drm/xe/regs/xe_reg_defs.h |  4 +++-
> drivers/gpu/drm/xe/xe_gt.c            |  7 +++----
> drivers/gpu/drm/xe/xe_mmio.c          | 24 +++++++++++++-----------
> drivers/gpu/drm/xe/xe_mmio.h          |  2 ++
> 4 files changed, 21 insertions(+), 16 deletions(-)
>
>diff --git a/drivers/gpu/drm/xe/regs/xe_reg_defs.h b/drivers/gpu/drm/xe/regs/xe_reg_defs.h
>index 89716172fbb8..26d00d825454 100644
>--- a/drivers/gpu/drm/xe/regs/xe_reg_defs.h
>+++ b/drivers/gpu/drm/xe/regs/xe_reg_defs.h
>@@ -10,6 +10,8 @@
>
> #include "compat-i915-headers/i915_reg_defs.h"
>
>+#define XE_REG_ADDR_WIDTH	22
>+
> /**
>  * struct xe_reg - Register definition
>  *
>@@ -21,7 +23,7 @@ struct xe_reg {
> 	union {
> 		struct {
> 			/** @addr: address */
>-			u32 addr:22;
>+			u32 addr:XE_REG_ADDR_WIDTH;
> 			/**
> 			 * @masked: register is "masked", with upper 16bits used
> 			 * to identify the bits that are updated on the lower
>diff --git a/drivers/gpu/drm/xe/xe_gt.c b/drivers/gpu/drm/xe/xe_gt.c
>index 01a4a852b8f4..f10c1f5fbbe1 100644
>--- a/drivers/gpu/drm/xe/xe_gt.c
>+++ b/drivers/gpu/drm/xe/xe_gt.c
>@@ -637,10 +637,9 @@ int xe_gt_init(struct xe_gt *gt)
> void xe_gt_mmio_init(struct xe_gt *gt)
> {
> 	struct xe_tile *tile = gt_to_tile(gt);
>+	struct xe_device *xe = tile_to_xe(tile);
>
>-	gt->mmio.regs = tile->mmio.regs;
>-	gt->mmio.regs_size = tile->mmio.regs_size;
>-	gt->mmio.tile = tile;
>+	xe_mmio_init(&gt->mmio, tile, tile->mmio.regs, tile->mmio.regs_size);
>
> 	if (gt->info.type == XE_GT_TYPE_MEDIA) {
> 		gt->mmio.adj_offset = MEDIA_GT_GSI_OFFSET;
>@@ -650,7 +649,7 @@ void xe_gt_mmio_init(struct xe_gt *gt)
> 		gt->mmio.adj_limit = 0;
> 	}
>
>-	if (IS_SRIOV_VF(gt_to_xe(gt)))
>+	if (IS_SRIOV_VF(xe))
> 		gt->mmio.sriov_vf_gt = gt;
> }
>
>diff --git a/drivers/gpu/drm/xe/xe_mmio.c b/drivers/gpu/drm/xe/xe_mmio.c
>index 3aed849a128b..8cee986947bc 100644
>--- a/drivers/gpu/drm/xe/xe_mmio.c
>+++ b/drivers/gpu/drm/xe/xe_mmio.c
>@@ -55,7 +55,6 @@ static void tiles_fini(void *arg)
> static void mmio_multi_tile_setup(struct xe_device *xe, size_t tile_mmio_size)
> {
> 	struct xe_tile *tile;
>-	void __iomem *regs;
> 	u8 id;
>
> 	/*
>@@ -94,13 +93,8 @@ static void mmio_multi_tile_setup(struct xe_device *xe, size_t tile_mmio_size)
> 		}
> 	}
>
>-	regs = xe->mmio.regs;
>-	for_each_tile(tile, xe, id) {
>-		tile->mmio.regs_size = SZ_4M;
>-		tile->mmio.regs = regs;
>-		tile->mmio.tile = tile;
>-		regs += tile_mmio_size;
>-	}
>+	for_each_remote_tile(tile, xe, id)
>+		xe_mmio_init(&tile->mmio, tile, xe->mmio.regs + id * tile_mmio_size, SZ_4M);

nice


Reviewed-by: Lucas De Marchi <lucas.demarchi at intel.com>

thanks
Lucas De Marchi

> }
>
> int xe_mmio_probe_tiles(struct xe_device *xe)
>@@ -140,13 +134,21 @@ int xe_mmio_probe_early(struct xe_device *xe)
> 	}
>
> 	/* Setup first tile; other tiles (if present) will be setup later. */
>-	root_tile->mmio.regs_size = SZ_4M;
>-	root_tile->mmio.regs = xe->mmio.regs;
>-	root_tile->mmio.tile = root_tile;
>+	xe_mmio_init(&root_tile->mmio, root_tile, xe->mmio.regs, SZ_4M);
>
> 	return devm_add_action_or_reset(xe->drm.dev, mmio_fini, xe);
> }
>
>+void xe_mmio_init(struct xe_mmio *mmio, struct xe_tile *tile, void __iomem *ptr, u32 size)
>+{
>+	/* Validate that we can use XE_REG macro with this xe_mmio later */
>+	xe_assert(tile_to_xe(tile), size <= (1 << (XE_REG_ADDR_WIDTH + 1)));
>+
>+	mmio->regs = ptr;
>+	mmio->regs_size = size;
>+	mmio->tile = tile;
>+}
>+
> static void mmio_flush_pending_writes(struct xe_mmio *mmio)
> {
> #define DUMMY_REG_OFFSET	0x130030
>diff --git a/drivers/gpu/drm/xe/xe_mmio.h b/drivers/gpu/drm/xe/xe_mmio.h
>index b32e7ee4b23e..c151ba569003 100644
>--- a/drivers/gpu/drm/xe/xe_mmio.h
>+++ b/drivers/gpu/drm/xe/xe_mmio.h
>@@ -14,6 +14,8 @@ struct xe_reg;
> int xe_mmio_probe_early(struct xe_device *xe);
> int xe_mmio_probe_tiles(struct xe_device *xe);
>
>+void xe_mmio_init(struct xe_mmio *mmio, struct xe_tile *tile, void __iomem *ptr, u32 size);
>+
> u8 xe_mmio_read8(struct xe_mmio *mmio, struct xe_reg reg);
> u16 xe_mmio_read16(struct xe_mmio *mmio, struct xe_reg reg);
> void xe_mmio_write32(struct xe_mmio *mmio, struct xe_reg reg, u32 val);
>-- 
>2.43.2
>