drm/vmwgfx: Improve on IOMMU detection

instead of relying on intel_iommu_enabled, use the fact that the
dma_map_ops::map_page != dma_direct_map_page.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Deepak Rawat <drawat@vmware.com>
This commit is contained in:
Thomas Hellstrom 2019-01-17 14:34:52 +01:00
parent 4cbfa1e6c0
commit 9ddac734aa

View File

@ -26,6 +26,7 @@
**************************************************************************/
#include <linux/module.h>
#include <linux/console.h>
#include <linux/dma-mapping.h>
#include <drm/drmP.h>
#include "vmwgfx_drv.h"
@ -34,7 +35,6 @@
#include <drm/ttm/ttm_placement.h>
#include <drm/ttm/ttm_bo_driver.h>
#include <drm/ttm/ttm_module.h>
#include <linux/intel-iommu.h>
#define VMWGFX_DRIVER_DESC "Linux drm driver for VMware graphics devices"
#define VMWGFX_CHIP_SVGAII 0
@ -545,6 +545,21 @@ static void vmw_get_initial_size(struct vmw_private *dev_priv)
dev_priv->initial_height = height;
}
/**
* vmw_assume_iommu - Figure out whether coherent dma-remapping might be
* taking place.
* @dev: Pointer to the struct drm_device.
*
* Return: true if iommu present, false otherwise.
*/
static bool vmw_assume_iommu(struct drm_device *dev)
{
const struct dma_map_ops *ops = get_dma_ops(dev->dev);
return !dma_is_direct(ops) && ops &&
ops->map_page != dma_direct_map_page;
}
/**
* vmw_dma_select_mode - Determine how DMA mappings should be set up for this
* system.
@ -568,7 +583,7 @@ static int vmw_dma_select_mode(struct vmw_private *dev_priv)
if (vmw_force_coherent)
dev_priv->map_mode = vmw_dma_alloc_coherent;
else if (intel_iommu_enabled)
else if (vmw_assume_iommu(dev_priv->dev))
dev_priv->map_mode = vmw_dma_map_populate;
else if (!vmw_force_iommu)
dev_priv->map_mode = vmw_dma_phys;