Re: [RFC 3/4] accel/ivpu: Remove support for uncached buffers

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 9/19/2023 3:49 AM, Stanislaw Gruszka wrote:
On Mon, Sep 11, 2023 at 09:24:42AM -0600, Jeffrey Hugo wrote:
On 9/1/2023 10:48 AM, Stanislaw Gruszka wrote:
From: Jacek Lawrynowicz <jacek.lawrynowicz@xxxxxxxxxxxxxxx>

Usages of DRM_IVPU_BO_UNCACHED should be replaced by DRM_IVPU_BO_WC.
There is no functional benefit from DRM_IVPU_BO_UNCACHED if these
buffers are never mapped to host VM.

This allows to cut the buffer handling code in the kernel driver
by half.

Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz@xxxxxxxxxxxxxxx>
Signed-off-by: Stanislaw Gruszka <stanislaw.gruszka@xxxxxxxxxxxxxxx>
---
   drivers/accel/ivpu/ivpu_fw.c  | 2 +-
   drivers/accel/ivpu/ivpu_gem.c | 3 ---
   include/uapi/drm/ivpu_accel.h | 2 +-
   3 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/accel/ivpu/ivpu_fw.c b/drivers/accel/ivpu/ivpu_fw.c
index 2fef9fe154aa..8ab0f3225205 100644
--- a/drivers/accel/ivpu/ivpu_fw.c
+++ b/drivers/accel/ivpu/ivpu_fw.c
@@ -248,7 +248,7 @@ static int ivpu_fw_mem_init(struct ivpu_device *vdev)
   	if (fw->shave_nn_size) {
   		fw->mem_shave_nn = ivpu_bo_alloc_internal(vdev, vdev->hw->ranges.shave.start,
-							  fw->shave_nn_size, DRM_IVPU_BO_UNCACHED);
+							  fw->shave_nn_size, DRM_IVPU_BO_WC);
   		if (!fw->mem_shave_nn) {
   			ivpu_err(vdev, "Failed to allocate shavenn buffer\n");
   			ret = -ENOMEM;
diff --git a/drivers/accel/ivpu/ivpu_gem.c b/drivers/accel/ivpu/ivpu_gem.c
index 915c53d7bb97..2a91eb1e3627 100644
--- a/drivers/accel/ivpu/ivpu_gem.c
+++ b/drivers/accel/ivpu/ivpu_gem.c
@@ -89,8 +89,6 @@ static int __must_check shmem_alloc_pages_locked(struct ivpu_bo *bo)
   	if (bo->flags & DRM_IVPU_BO_WC)
   		set_pages_array_wc(pages, npages);
-	else if (bo->flags & DRM_IVPU_BO_UNCACHED)
-		set_pages_array_uc(pages, npages);
   	bo->pages = pages;
   	return 0;
@@ -366,7 +364,6 @@ ivpu_bo_alloc(struct ivpu_device *vdev, u64 size, u32 flags, const struct ivpu_b
   	switch (flags & DRM_IVPU_BO_CACHE_MASK) {
   	case DRM_IVPU_BO_CACHED:
-	case DRM_IVPU_BO_UNCACHED:
   	case DRM_IVPU_BO_WC:
   		break;
   	default:
diff --git a/include/uapi/drm/ivpu_accel.h b/include/uapi/drm/ivpu_accel.h
index 262db0c3beee..de1944e42c65 100644
--- a/include/uapi/drm/ivpu_accel.h
+++ b/include/uapi/drm/ivpu_accel.h
@@ -196,7 +196,7 @@ struct drm_ivpu_bo_create {
   	 *
   	 * %DRM_IVPU_BO_UNCACHED:
   	 *
-	 * Allocated BO will not be cached on host side nor snooped on the VPU side.
+	 * Not supported. Use DRM_IVPU_BO_WC instead.
   	 *
   	 * %DRM_IVPU_BO_WC:
   	 *

Feels like this will break existing userspace.  You could see if userspace
specified UNCACHED and change it to WC before processing the request.  Maybe
also use WARN_ONCE to indicate that userspace should be updated.

Or is it the case that userspace never actually used this?

Usage of those buffers was removed some time ago:
https://github.com/intel/linux-vpu-driver/commit/c473c9826cb28fa3dcf8883fc804b1e84c6b5fb1

And will not be part of first user-mode driver release. I think we can
safely do the change.

Fair enough.  Thanks for the clarification.

Reviewed-by: Jeffrey Hugo <quic_jhugo@xxxxxxxxxxx>



[Index of Archives]     [Linux DRI Users]     [Linux Intel Graphics]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux