Commit 11bbe0d9 authored by Thomas Hellström's avatar Thomas Hellström Committed by Matthew Brost
Browse files

drm/xe: Add drm_pagemap ops to SVM 



Add support for mapping device pages to Xe SVM by attaching drm_pagemap
to a memory region, which is then linked to a GPU SVM devmem allocation.
This enables GPU SVM to derive the device page address.

v3:
 - Better commit message (Thomas)
 - New drm_pagemap.h location
v5:
 - s/xe_mem_region/xe_vram_region (Rebase)

Signed-off-by: default avatarMatthew Brost <matthew.brost@intel.com>
Signed-off-by: default avatarThomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: default avatarMatthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250306012657.3505757-24-matthew.brost@intel.com
parent 808c37ee

drivers/gpu/drm/xe/xe_device_types.h

+6 −0
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 


#include <drm/drm_device.h>

#include <drm/drm_file.h>

#include <drm/drm_pagemap.h>

#include <drm/ttm/ttm_device.h>



#include "xe_devcoredump_types.h"
@@ -108,6 +109,11 @@ struct xe_vram_region { 
	void __iomem *mapping;

	/** @pagemap: Used to remap device memory as ZONE_DEVICE */

	struct dev_pagemap pagemap;

	/**

	 * @dpagemap: The struct drm_pagemap of the ZONE_DEVICE memory

	 * pages of this tile.

	 */

	struct drm_pagemap dpagemap;

	/**

	 * @hpa_base: base host physical address

	 *

drivers/gpu/drm/xe/xe_svm.c

+57 −0
Original line number Diff line number Diff line
@@ -288,6 +288,33 @@ static void xe_svm_garbage_collector_work_func(struct work_struct *w) 
	up_write(&vm->lock);

}



static struct xe_vram_region *page_to_vr(struct page *page)

{

	return container_of(page->pgmap, struct xe_vram_region, pagemap);

}



static struct xe_tile *vr_to_tile(struct xe_vram_region *vr)

{

	return container_of(vr, struct xe_tile, mem.vram);

}



static u64 xe_vram_region_page_to_dpa(struct xe_vram_region *vr,

				      struct page *page)

{

	u64 dpa;

	struct xe_tile *tile = vr_to_tile(vr);

	u64 pfn = page_to_pfn(page);

	u64 offset;



	xe_tile_assert(tile, is_device_private_page(page));

	xe_tile_assert(tile, (pfn << PAGE_SHIFT) >= vr->hpa_base);



	offset = (pfn << PAGE_SHIFT) - vr->hpa_base;

	dpa = vr->dpa_base + offset;



	return dpa;

}



static const struct drm_gpusvm_ops gpusvm_ops = {

	.range_alloc = xe_svm_range_alloc,

	.range_free = xe_svm_range_free,
@@ -456,6 +483,32 @@ bool xe_svm_has_mapping(struct xe_vm *vm, u64 start, u64 end) 
}



#if IS_ENABLED(CONFIG_DRM_XE_DEVMEM_MIRROR)

static struct drm_pagemap_device_addr

xe_drm_pagemap_device_map(struct drm_pagemap *dpagemap,

			  struct device *dev,

			  struct page *page,

			  unsigned int order,

			  enum dma_data_direction dir)

{

	struct device *pgmap_dev = dpagemap->dev;

	enum drm_interconnect_protocol prot;

	dma_addr_t addr;



	if (pgmap_dev == dev) {

		addr = xe_vram_region_page_to_dpa(page_to_vr(page), page);

		prot = XE_INTERCONNECT_VRAM;

	} else {

		addr = DMA_MAPPING_ERROR;

		prot = 0;

	}



	return drm_pagemap_device_addr_encode(addr, prot, order, dir);

}



static const struct drm_pagemap_ops xe_drm_pagemap_ops = {

	.device_map = xe_drm_pagemap_device_map,

};



/**

 * xe_devm_add: Remap and provide memmap backing for device memory

 * @tile: tile that the memory region belongs to
@@ -488,6 +541,10 @@ int xe_devm_add(struct xe_tile *tile, struct xe_vram_region *vr) 
	vr->pagemap.ops = drm_gpusvm_pagemap_ops_get();

	vr->pagemap.owner = xe_svm_devm_owner(xe);

	addr = devm_memremap_pages(dev, &vr->pagemap);



	vr->dpagemap.dev = dev;

	vr->dpagemap.ops = &xe_drm_pagemap_ops;



	if (IS_ERR(addr)) {

		devm_release_mem_region(dev, res->start, resource_size(res));

		ret = PTR_ERR(addr);