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.lawrynow...@linux.intel.com>

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.lawrynow...@linux.intel.com>
Signed-off-by: Stanislaw Gruszka <stanislaw.grus...@linux.intel.com>
---
   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_jh...@quicinc.com>

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