[PATCH] drm/vmwgfx: fix a warning due to missing dma_parms

[Qian Cai]

Booting up with DMA_API_DEBUG_SG=y generates a warning below due to the
driver forgot to set dma_parms appropriately. Set it after
vmw_dma_masks(), so it can choose a size either DMA_BIT_MASK(64) or
DMA_BIT_MASK(44).

DMA-API: vmwgfx 0000:00:0f.0: mapping sg segment longer than device
claims to support [len=2097152] [max=65536]
WARNING: CPU: 2 PID: 261 at kernel/dma/debug.c:1232
debug_dma_map_sg+0x360/0x480
Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop
Reference Platform, BIOS 6.00 04/13/2018
RIP: 0010:debug_dma_map_sg+0x360/0x480
Call Trace:
 vmw_ttm_map_dma+0x3b1/0x5b0 [vmwgfx]
 vmw_bo_map_dma+0x25/0x30 [vmwgfx]
 vmw_otables_setup+0x2a8/0x750 [vmwgfx]
 vmw_request_device_late+0x78/0xc0 [vmwgfx]
 vmw_request_device+0xee/0x4e0 [vmwgfx]
 vmw_driver_load.cold+0x757/0xd84 [vmwgfx]
 drm_dev_register+0x1ff/0x340 [drm]
 drm_get_pci_dev+0x110/0x290 [drm]
 vmw_probe+0x15/0x20 [vmwgfx]
 local_pci_probe+0x7a/0xc0
 pci_device_probe+0x1b9/0x290
 really_probe+0x1b5/0x630
 driver_probe_device+0xa3/0x1a0
 device_driver_attach+0x94/0xa0
 __driver_attach+0xdd/0x1c0
 bus_for_each_dev+0xfe/0x150
 driver_attach+0x2d/0x40
 bus_add_driver+0x290/0x350
 driver_register+0xdc/0x1d0
 __pci_register_driver+0xda/0xf0
 vmwgfx_init+0x34/0x1000 [vmwgfx]
 do_one_initcall+0xe5/0x40a
 do_init_module+0x10f/0x3a0
 load_module+0x16a5/0x1a40
 __se_sys_finit_module+0x183/0x1c0
 __x64_sys_finit_module+0x43/0x50
 do_syscall_64+0xc8/0x606
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: fb1d9738ca05 ("drm/vmwgfx: Add DRM driver for VMware Virtual GPU")
Signed-off-by: Qian Cai <cai at lca.pw>
---
 drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index bf6c3500d363..5c567b81174f 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -747,6 +747,13 @@ static int vmw_driver_load(struct drm_device *dev, unsigned long chipset)
 	if (unlikely(ret != 0))
 		goto out_err0;
 
+	dev->dev->dma_parms =  kzalloc(sizeof(*dev->dev->dma_parms),
+				       GFP_KERNEL);
+	if (!dev->dev->dma_parms)
+		goto out_err0;
+
+	dma_set_max_seg_size(dev->dev, *dev->dev->dma_mask);
+
 	if (dev_priv->capabilities & SVGA_CAP_GMR2) {
 		DRM_INFO("Max GMR ids is %u\n",
 			 (unsigned)dev_priv->max_gmr_ids);
@@ -772,7 +779,7 @@ static int vmw_driver_load(struct drm_device *dev, unsigned long chipset)
 	if (unlikely(dev_priv->mmio_virt == NULL)) {
 		ret = -ENOMEM;
 		DRM_ERROR("Failed mapping MMIO.\n");
-		goto out_err0;
+		goto out_err1;
 	}
 
 	/* Need mmio memory to check for fifo pitchlock cap. */
@@ -781,7 +788,7 @@ static int vmw_driver_load(struct drm_device *dev, unsigned long chipset)
 	    !vmw_fifo_have_pitchlock(dev_priv)) {
 		ret = -ENOSYS;
 		DRM_ERROR("Hardware has no pitchlock\n");
-		goto out_err4;
+		goto out_err2;
 	}
 
 	dev_priv->tdev = ttm_object_device_init(&ttm_mem_glob, 12,
@@ -790,7 +797,7 @@ static int vmw_driver_load(struct drm_device *dev, unsigned long chipset)
 	if (unlikely(dev_priv->tdev == NULL)) {
 		DRM_ERROR("Unable to initialize TTM object management.\n");
 		ret = -ENOMEM;
-		goto out_err4;
+		goto out_err2;
 	}
 
 	dev->dev_private = dev_priv;
@@ -944,8 +951,11 @@ static int vmw_driver_load(struct drm_device *dev, unsigned long chipset)
 		pci_release_regions(dev->pdev);
 out_no_device:
 	ttm_object_device_release(&dev_priv->tdev);
-out_err4:
+out_err2:
 	memunmap(dev_priv->mmio_virt);
+out_err1:
+	kfree(dev->dev->dma_parms);
+	dev->dev->dma_parms = NULL;
 out_err0:
 	for (i = vmw_res_context; i < vmw_res_max; ++i)
 		idr_destroy(&dev_priv->res_idr[i]);
@@ -995,6 +1005,8 @@ static void vmw_driver_unload(struct drm_device *dev)
 
 	ttm_object_device_release(&dev_priv->tdev);
 	memunmap(dev_priv->mmio_virt);
+	kfree(dev->dev->dma_parms);
+	dev->dev->dma_parms = NULL;
 	if (dev_priv->ctx.staged_bindings)
 		vmw_binding_state_free(dev_priv->ctx.staged_bindings);
 
-- 
2.20.1 (Apple Git-117)