drm/pagemap: Split drm_pagemap_migrate_map_pages into device / system

Split drm_pagemap_migrate_map_pages into device / system helpers clearly
seperating these operations. Will help with upcoming changes to split
IOVA allocation steps.

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Francois Dugast <francois.dugast@intel.com>
Link: https://patch.msgid.link/20260410205929.3914474-4-matthew.brost@intel.com

diff --git a/drivers/gpu/drm/drm_pagemap.c b/drivers/gpu/drm/drm_pagemap.c
index 63f32cf6e1a7d6a14274ea65750f300acfef265d..ee4d9f90bf672140b5bb3e7af05fe35a197c716f 100644 (file)
--- a/drivers/gpu/drm/drm_pagemap.c
+++ b/drivers/gpu/drm/drm_pagemap.c
@@ -216,7 +216,8 @@ static void drm_pagemap_get_devmem_page(struct page *page,
 }
 
 /**
- * drm_pagemap_migrate_map_pages() - Map migration pages for GPU SVM migration
+ * drm_pagemap_migrate_map_device_private_pages() - Map device private migration
+ * pages for GPU SVM migration
  * @dev: The device performing the migration.
  * @local_dpagemap: The drm_pagemap local to the migrating device.
  * @pagemap_addr: Array to store DMA information corresponding to mapped pages.
@@ -232,58 +233,50 @@ static void drm_pagemap_get_devmem_page(struct page *page,
  *
  * Returns: 0 on success, -EFAULT if an error occurs during mapping.
  */
-static int drm_pagemap_migrate_map_pages(struct device *dev,
-                                        struct drm_pagemap *local_dpagemap,
-                                        struct drm_pagemap_addr *pagemap_addr,
-                                        unsigned long *migrate_pfn,
-                                        unsigned long npages,
-                                        enum dma_data_direction dir,
-                                        const struct drm_pagemap_migrate_details *mdetails)
+static int
+drm_pagemap_migrate_map_device_private_pages(struct device *dev,
+                                            struct drm_pagemap *local_dpagemap,
+                                            struct drm_pagemap_addr *pagemap_addr,
+                                            unsigned long *migrate_pfn,
+                                            unsigned long npages,
+                                            enum dma_data_direction dir,
+                                            const struct drm_pagemap_migrate_details *mdetails)
 {
        unsigned long num_peer_pages = 0, num_local_pages = 0, i;
 
        for (i = 0; i < npages;) {
                struct page *page = migrate_pfn_to_page(migrate_pfn[i]);
-               dma_addr_t dma_addr;
+               struct drm_pagemap_zdd *zdd;
+               struct drm_pagemap *dpagemap;
+               struct drm_pagemap_addr addr;
                struct folio *folio;
                unsigned int order = 0;
 
                if (!page)
                        goto next;
 
+               WARN_ON_ONCE(!is_device_private_page(page));
                folio = page_folio(page);
                order = folio_order(folio);
 
-               if (is_device_private_page(page)) {
-                       struct drm_pagemap_zdd *zdd = drm_pagemap_page_zone_device_data(page);
-                       struct drm_pagemap *dpagemap = zdd->dpagemap;
-                       struct drm_pagemap_addr addr;
-
-                       if (dpagemap == local_dpagemap) {
-                               if (!mdetails->can_migrate_same_pagemap)
-                                       goto next;
-
-                               num_local_pages += NR_PAGES(order);
-                       } else {
-                               num_peer_pages += NR_PAGES(order);
-                       }
+               zdd = drm_pagemap_page_zone_device_data(page);
+               dpagemap = zdd->dpagemap;
 
-                       addr = dpagemap->ops->device_map(dpagemap, dev, page, order, dir);
-                       if (dma_mapping_error(dev, addr.addr))
-                               return -EFAULT;
+               if (dpagemap == local_dpagemap) {
+                       if (!mdetails->can_migrate_same_pagemap)
+                               goto next;
 
-                       pagemap_addr[i] = addr;
+                       num_local_pages += NR_PAGES(order);
                } else {
-                       dma_addr = dma_map_page(dev, page, 0, page_size(page), dir);
-                       if (dma_mapping_error(dev, dma_addr))
-                               return -EFAULT;
-
-                       pagemap_addr[i] =
-                               drm_pagemap_addr_encode(dma_addr,
-                                                       DRM_INTERCONNECT_SYSTEM,
-                                                       order, dir);
+                       num_peer_pages += NR_PAGES(order);
                }
 
+               addr = dpagemap->ops->device_map(dpagemap, dev, page, order, dir);
+               if (dma_mapping_error(dev, addr.addr))
+                       return -EFAULT;
+
+               pagemap_addr[i] = addr;
+
 next:
                i += NR_PAGES(order);
        }
@@ -298,6 +291,60 @@ next:
        return 0;
 }
 
+/**
+ * drm_pagemap_migrate_map_system_pages() - Map system or device coherent
+ * migration pages for GPU SVM migration
+ * @dev: The device performing the migration.
+ * @pagemap_addr: Array to store DMA information corresponding to mapped pages.
+ * @migrate_pfn: Array of page frame numbers of system pages or peer pages to map.
+ * @npages: Number of system or device coherent pages to map.
+ * @dir: Direction of data transfer (e.g., DMA_BIDIRECTIONAL)
+ *
+ * This function maps pages of memory for migration usage in GPU SVM. It
+ * iterates over each page frame number provided in @migrate_pfn, maps the
+ * corresponding page, and stores the DMA address in the provided @dma_addr
+ * array.
+ *
+ * Returns: 0 on success, -EFAULT if an error occurs during mapping.
+ */
+static int
+drm_pagemap_migrate_map_system_pages(struct device *dev,
+                                    struct drm_pagemap_addr *pagemap_addr,
+                                    unsigned long *migrate_pfn,
+                                    unsigned long npages,
+                                    enum dma_data_direction dir)
+{
+       unsigned long i;
+
+       for (i = 0; i < npages;) {
+               struct page *page = migrate_pfn_to_page(migrate_pfn[i]);
+               dma_addr_t dma_addr;
+               struct folio *folio;
+               unsigned int order = 0;
+
+               if (!page)
+                       goto next;
+
+               WARN_ON_ONCE(is_device_private_page(page));
+               folio = page_folio(page);
+               order = folio_order(folio);
+
+               dma_addr = dma_map_page(dev, page, 0, page_size(page), dir);
+               if (dma_mapping_error(dev, dma_addr))
+                       return -EFAULT;
+
+               pagemap_addr[i] =
+                       drm_pagemap_addr_encode(dma_addr,
+                                               DRM_INTERCONNECT_SYSTEM,
+                                               order, dir);
+
+next:
+               i += NR_PAGES(order);
+       }
+
+       return 0;
+}
+
 /**
  * drm_pagemap_migrate_unmap_pages() - Unmap pages previously mapped for GPU SVM migration
  * @dev: The device for which the pages were mapped
@@ -358,9 +405,13 @@ drm_pagemap_migrate_remote_to_local(struct drm_pagemap_devmem *devmem,
                                    const struct drm_pagemap_migrate_details *mdetails)
 
 {
-       int err = drm_pagemap_migrate_map_pages(remote_device, remote_dpagemap,
-                                               pagemap_addr, local_pfns,
-                                               npages, DMA_FROM_DEVICE, mdetails);
+       int err = drm_pagemap_migrate_map_device_private_pages(remote_device,
+                                                              remote_dpagemap,
+                                                              pagemap_addr,
+                                                              local_pfns,
+                                                              npages,
+                                                              DMA_FROM_DEVICE,
+                                                              mdetails);
 
        if (err)
                goto out;
@@ -379,12 +430,11 @@ drm_pagemap_migrate_sys_to_dev(struct drm_pagemap_devmem *devmem,
                               struct page *local_pages[],
                               struct drm_pagemap_addr pagemap_addr[],
                               unsigned long npages,
-                              const struct drm_pagemap_devmem_ops *ops,
-                              const struct drm_pagemap_migrate_details *mdetails)
+                              const struct drm_pagemap_devmem_ops *ops)
 {
-       int err = drm_pagemap_migrate_map_pages(devmem->dev, devmem->dpagemap,
-                                               pagemap_addr, sys_pfns, npages,
-                                               DMA_TO_DEVICE, mdetails);
+       int err = drm_pagemap_migrate_map_system_pages(devmem->dev,
+                                                      pagemap_addr, sys_pfns,
+                                                      npages, DMA_TO_DEVICE);
 
        if (err)
                goto out;
@@ -448,7 +498,7 @@ static int drm_pagemap_migrate_range(struct drm_pagemap_devmem *devmem,
                                                     &pages[last->start],
                                                     &pagemap_addr[last->start],
                                                     cur->start - last->start,
-                                                    last->ops, mdetails);
+                                                    last->ops);
 
 out:
        *last = *cur;
@@ -1010,7 +1060,6 @@ EXPORT_SYMBOL(drm_pagemap_put);
 int drm_pagemap_evict_to_ram(struct drm_pagemap_devmem *devmem_allocation)
 {
        const struct drm_pagemap_devmem_ops *ops = devmem_allocation->ops;
-       struct drm_pagemap_migrate_details mdetails = {};
        unsigned long npages, mpages = 0;
        struct page **pages;
        unsigned long *src, *dst;
@@ -1049,10 +1098,10 @@ retry:
        if (err || !mpages)
                goto err_finalize;
 
-       err = drm_pagemap_migrate_map_pages(devmem_allocation->dev,
-                                           devmem_allocation->dpagemap, pagemap_addr,
-                                           dst, npages, DMA_FROM_DEVICE,
-                                           &mdetails);
+       err = drm_pagemap_migrate_map_system_pages(devmem_allocation->dev,
+                                                  pagemap_addr,
+                                                  dst, npages,
+                                                  DMA_FROM_DEVICE);
        if (err)
                goto err_finalize;
 
@@ -1121,7 +1170,6 @@ static int __drm_pagemap_migrate_to_ram(struct vm_area_struct *vas,
                                  MIGRATE_VMA_SELECT_COMPOUND,
                .fault_page     = page,
        };
-       struct drm_pagemap_migrate_details mdetails = {};
        struct drm_pagemap_zdd *zdd;
        const struct drm_pagemap_devmem_ops *ops;
        struct device *dev = NULL;
@@ -1179,8 +1227,9 @@ static int __drm_pagemap_migrate_to_ram(struct vm_area_struct *vas,
        if (err)
                goto err_finalize;
 
-       err = drm_pagemap_migrate_map_pages(dev, zdd->dpagemap, pagemap_addr, migrate.dst, npages,
-                                           DMA_FROM_DEVICE, &mdetails);
+       err = drm_pagemap_migrate_map_system_pages(dev, pagemap_addr,
+                                                  migrate.dst, npages,
+                                                  DMA_FROM_DEVICE);
        if (err)
                goto err_finalize;