linux-kernel - [PATCH 1/2] drm: remove usage of drm_pci

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Date:   Thu, 22 Apr 2021 19:02:43 -0700
From:   Joseph Kogut <joseph.kogut@...il.com>
To:     dri-devel@...ts.freedesktop.org
Cc:     Joseph Kogut <joseph.kogut@...il.com>,
        Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
        Maxime Ripard <mripard@...nel.org>,
        Thomas Zimmermann <tzimmermann@...e.de>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        Sam Ravnborg <sam@...nborg.org>,
        Lee Jones <lee.jones@...aro.org>, linux-kernel@...r.kernel.org
Subject: [PATCH 1/2] drm: remove usage of drm_pci_alloc/free

Remove usage of legacy dma-api abstraction in preparation for removal

Signed-off-by: Joseph Kogut <joseph.kogut@...il.com>
---
Checkpatch warns here that r128 is marked obsolete, and asks for no
unnecessary modifications.

This series aims to address the FIXME in drivers/gpu/drm/drm_pci.c
explaining that drm_pci_alloc/free is a needless abstraction of the
dma-api, and it should be removed. Unfortunately, doing this requires
removing the usage from an obsolete driver as well.

If this patch is rejected for modifying an obsolete driver, would it be
appropriate to follow up removing the FIXME from drm_pci?

 drivers/gpu/drm/drm_bufs.c         | 19 ++++++++++++++++---
 drivers/gpu/drm/drm_dma.c          |  8 +++++++-
 drivers/gpu/drm/r128/ati_pcigart.c | 22 ++++++++++++++++++----
 3 files changed, 41 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c
index e3d77dfefb0a..94bc1f6049c9 100644
--- a/drivers/gpu/drm/drm_bufs.c
+++ b/drivers/gpu/drm/drm_bufs.c
@@ -674,12 +674,17 @@ int drm_legacy_rmmap_ioctl(struct drm_device *dev, void *data,
 static void drm_cleanup_buf_error(struct drm_device *dev,
 				  struct drm_buf_entry *entry)
 {
+	drm_dma_handle_t *dmah;
 	int i;
 
 	if (entry->seg_count) {
 		for (i = 0; i < entry->seg_count; i++) {
 			if (entry->seglist[i]) {
-				drm_pci_free(dev, entry->seglist[i]);
+				dmah = entry->seglist[i];
+				dma_free_coherent(dev->dev,
+						  dmah->size,
+						  dmah->vaddr,
+						  dmah->busaddr);
 			}
 		}
 		kfree(entry->seglist);
@@ -978,10 +983,18 @@ int drm_legacy_addbufs_pci(struct drm_device *dev,
 	page_count = 0;
 
 	while (entry->buf_count < count) {
+		dmah = kmalloc(sizeof(drm_dma_handle_t), GFP_KERNEL);
+		if (!dmah)
+			return -ENOMEM;
 
-		dmah = drm_pci_alloc(dev, PAGE_SIZE << page_order, 0x1000);
+		dmah->size = total;
+		dmah->vaddr = dma_alloc_coherent(dev->dev,
+						 dmah->size,
+						 &dmah->busaddr,
+						 GFP_KERNEL);
+		if (!dmah->vaddr) {
+			kfree(dmah);
 
-		if (!dmah) {
 			/* Set count correctly so we free the proper amount. */
 			entry->buf_count = count;
 			entry->seg_count = count;
diff --git a/drivers/gpu/drm/drm_dma.c b/drivers/gpu/drm/drm_dma.c
index d07ba54ec945..eb6b741a6f99 100644
--- a/drivers/gpu/drm/drm_dma.c
+++ b/drivers/gpu/drm/drm_dma.c
@@ -81,6 +81,7 @@ int drm_legacy_dma_setup(struct drm_device *dev)
 void drm_legacy_dma_takedown(struct drm_device *dev)
 {
 	struct drm_device_dma *dma = dev->dma;
+	drm_dma_handle_t *dmah;
 	int i, j;
 
 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA) ||
@@ -100,7 +101,12 @@ void drm_legacy_dma_takedown(struct drm_device *dev)
 				  dma->bufs[i].seg_count);
 			for (j = 0; j < dma->bufs[i].seg_count; j++) {
 				if (dma->bufs[i].seglist[j]) {
-					drm_pci_free(dev, dma->bufs[i].seglist[j]);
+					dmah = dma->bufs[i].seglist[j];
+					dma_free_coherent(dev->dev,
+							  dmah->size,
+							  dmah->vaddr,
+							  dmah->busaddr);
+					kfree(dmah);
 				}
 			}
 			kfree(dma->bufs[i].seglist);
diff --git a/drivers/gpu/drm/r128/ati_pcigart.c b/drivers/gpu/drm/r128/ati_pcigart.c
index 1234ec60c0af..fbb0cfd79758 100644
--- a/drivers/gpu/drm/r128/ati_pcigart.c
+++ b/drivers/gpu/drm/r128/ati_pcigart.c
@@ -45,18 +45,32 @@
 static int drm_ati_alloc_pcigart_table(struct drm_device *dev,
 				       struct drm_ati_pcigart_info *gart_info)
 {
-	gart_info->table_handle = drm_pci_alloc(dev, gart_info->table_size,
-						PAGE_SIZE);
-	if (gart_info->table_handle == NULL)
+	drm_dma_handle_t *dmah = kmalloc(sizeof(drm_dma_handle_t), GFP_KERNEL);
+
+	if (!dmah)
+		return -ENOMEM;
+
+	dmah->size = gart_info->table_size;
+	dmah->vaddr = dma_alloc_coherent(dev->dev,
+					 dmah->size,
+					 &dmah->busaddr,
+					 GFP_KERNEL);
+
+	if (!dmah->vaddr) {
+		kfree(dmah);
 		return -ENOMEM;
+	}
 
+	gart_info->table_handle = dmah;
 	return 0;
 }
 
 static void drm_ati_free_pcigart_table(struct drm_device *dev,
 				       struct drm_ati_pcigart_info *gart_info)
 {
-	drm_pci_free(dev, gart_info->table_handle);
+	drm_dma_handle_t *dmah = gart_info->table_handle;
+
+	dma_free_coherent(dev->dev, dmah->size, dmah->vaddr, dmah->busaddr);
 	gart_info->table_handle = NULL;
 }
 
-- 
2.31.1