[PATCH v2 20/29] drm/xe: Add drm_pagemap ops to SVM

[Matthew Brost]

From: Thomas Hellström <thomas.hellstrom at linux.intel.com>

Add support for mapping device pages to Xe SVM.

Signed-off-by: Matthew Brost <matthew.brost at intel.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>
---
 drivers/gpu/drm/xe/xe_device_types.h |  7 +++++++
 drivers/gpu/drm/xe/xe_svm.c          | 30 ++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
index 2ac5de7751c9..72264f9f64d7 100644
--- a/drivers/gpu/drm/xe/xe_device_types.h
+++ b/drivers/gpu/drm/xe/xe_device_types.h
@@ -12,6 +12,8 @@
 #include <drm/drm_file.h>
 #include <drm/ttm/ttm_device.h>
 
+#include "drm_pagemap.h"
+
 #include "xe_devcoredump_types.h"
 #include "xe_heci_gsc.h"
 #include "xe_lmtt_types.h"
@@ -106,6 +108,11 @@ struct xe_mem_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
 	 *
diff --git a/drivers/gpu/drm/xe/xe_svm.c b/drivers/gpu/drm/xe/xe_svm.c
index b33fd42d035b..4f01941b2cc2 100644
--- a/drivers/gpu/drm/xe/xe_svm.c
+++ b/drivers/gpu/drm/xe/xe_svm.c
@@ -431,6 +431,32 @@ static const u64 fault_chunk_sizes[] = {
 	SZ_4K,
 };
 
+static struct drm_pagemap_dma_addr
+xe_drm_pagemap_map_dma(struct drm_pagemap *dpagemap,
+		       struct device *dev,
+		       struct page *page,
+		       unsigned int order,
+		       enum dma_data_direction dir)
+{
+	struct device *pgmap_dev = dpagemap->dev;
+	dma_addr_t addr;
+	enum drm_interconnect_protocol prot;
+
+	if (pgmap_dev == dev) {
+		addr = xe_mem_region_page_to_dpa(page_to_mr(page), page);
+		prot = XE_INTERCONNECT_VRAM;
+	} else {
+		addr = DMA_MAPPING_ERROR;
+		prot = 0;
+	}
+
+	return drm_pagemap_dma_addr_encode(addr, prot, order, dir);
+}
+
+static const struct drm_pagemap_ops xe_drm_pagemap_ops = {
+	.map_dma = xe_drm_pagemap_map_dma,
+};
+
 int xe_svm_init(struct xe_vm *vm)
 {
 	spin_lock_init(&vm->svm.garbage_collector.lock);
@@ -572,6 +598,10 @@ int xe_devm_add(struct xe_tile *tile, struct xe_mem_region *mr)
 	mr->pagemap.ops = drm_gpusvm_pagemap_ops_get();
 	mr->pagemap.owner = xe_svm_devm_owner(xe);
 	addr = devm_memremap_pages(dev, &mr->pagemap);
+
+	mr->dpagemap.dev = dev;
+	mr->dpagemap.ops = &xe_drm_pagemap_ops;
+
 	if (IS_ERR(addr)) {
 		devm_release_mem_region(dev, res->start, resource_size(res));
 		ret = PTR_ERR(addr);
-- 
2.34.1