On 1/8/2025 2:26 PM, Jiang Liu wrote:
> Introduce new interface amdgpu_xcp_drm_dev_free() to free a specific
> drm_device crreated by amdgpu_xcp_drm_dev_alloc(), which will be used
> to do error recovery.
>
> Signed-off-by: Jiang Liu <gerry@xxxxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.c | 76 +++++++++++++++++----
> drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.h | 1 +
> 2 files changed, 63 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.c b/drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.c
> index faed84172dd4..fc92b5fe1040 100644
> --- a/drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.c
> +++ b/drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.c
> @@ -45,21 +45,32 @@ static const struct drm_driver amdgpu_xcp_driver = {
>
> static int8_t pdev_num;
> static struct xcp_device *xcp_dev[MAX_XCP_PLATFORM_DEVICE];
> +static DEFINE_MUTEX(xcp_mutex);
>
> int amdgpu_xcp_drm_dev_alloc(struct drm_device **ddev)
> {
> struct platform_device *pdev;
> struct xcp_device *pxcp_dev;
> char dev_name[20];
> - int ret;
> + int ret, index;
>
> - if (pdev_num >= MAX_XCP_PLATFORM_DEVICE)
> - return -ENODEV;
> + mutex_lock(&xcp_mutex);
> + if (pdev_num >= MAX_XCP_PLATFORM_DEVICE) {
> + ret = -ENODEV;
> + goto out_unlock;
> + }
> +
> + for (index = 0; index < MAX_XCP_PLATFORM_DEVICE; index++) {
> + if (!xcp_dev[index])
> + break;
> + }
>
> - snprintf(dev_name, sizeof(dev_name), "amdgpu_xcp_%d", pdev_num);
> + snprintf(dev_name, sizeof(dev_name), "amdgpu_xcp_%d", index);
> pdev = platform_device_register_simple(dev_name, -1, NULL, 0);
> - if (IS_ERR(pdev))
> - return PTR_ERR(pdev);
> + if (IS_ERR(pdev)) {
> + ret = PTR_ERR(pdev);
> + goto out_unregister;
> + }
>
> if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) {
> ret = -ENOMEM;
> @@ -72,10 +83,11 @@ int amdgpu_xcp_drm_dev_alloc(struct drm_device **ddev)
> goto out_devres;
> }
>
> - xcp_dev[pdev_num] = pxcp_dev;
> - xcp_dev[pdev_num]->pdev = pdev;
> + xcp_dev[index] = pxcp_dev;
> + xcp_dev[index]->pdev = pdev;
> *ddev = &pxcp_dev->drm;
> pdev_num++;
> + mutex_unlock(&xcp_mutex);
>
> return 0;
>
> @@ -83,21 +95,57 @@ int amdgpu_xcp_drm_dev_alloc(struct drm_device **ddev)
> devres_release_group(&pdev->dev, NULL);
> out_unregister:
> platform_device_unregister(pdev);
> +out_unlock:
> + mutex_unlock(&xcp_mutex);
>
> return ret;
> }
> EXPORT_SYMBOL(amdgpu_xcp_drm_dev_alloc);
>
> +static void amdgpu_xcp_drm_dev_destroy(int index)
<Nit> Use something like __amdgpu_xcp_drm_dev_free(int index) to keep
the 'free' suffix.
> +{
> + struct platform_device *pdev;
> +
> + pdev = xcp_dev[index]->pdev;
> + devres_release_group(&pdev->dev, NULL);
> + platform_device_unregister(pdev);
> + xcp_dev[index] = NULL;
> + pdev_num--;
> +}
> +
> +void amdgpu_xcp_drm_dev_free(struct drm_device *ddev)
> +{
> + int index;
> + struct xcp_device *pxcp_dev;
> +
> + if (ddev == NULL)
Does it make sense to add !pdev_num check or a WARN_ON(!pdev_num) below?
> + return;
> +
> + pxcp_dev = container_of(ddev, struct xcp_device, drm);
> +
> + mutex_lock(&xcp_mutex);
> + for (index = 0; index < MAX_XCP_PLATFORM_DEVICE; index++) {
> + if (xcp_dev[index] == pxcp_dev) {
> + amdgpu_xcp_drm_dev_destroy(index);
> + break;
> + }
> + }
> + mutex_unlock(&xcp_mutex);
> +}
> +EXPORT_SYMBOL(amdgpu_xcp_drm_dev_free);
> +
> void amdgpu_xcp_drv_release(void)
> {
> - for (--pdev_num; pdev_num >= 0; --pdev_num) {
> - struct platform_device *pdev = xcp_dev[pdev_num]->pdev;
> + int index;
>
> - devres_release_group(&pdev->dev, NULL);
> - platform_device_unregister(pdev);
> - xcp_dev[pdev_num] = NULL;
To better optimize, add one check like below.
if (!pdev_num)
return;
Thanks,
Lijo
> + mutex_lock(&xcp_mutex);
> + for (index = 0; index < MAX_XCP_PLATFORM_DEVICE; index++) {
> + if (xcp_dev[index]) {
> + amdgpu_xcp_drm_dev_destroy(index);
> + }
> }
> - pdev_num = 0;
> + WARN_ON(pdev_num != 0);
> + mutex_unlock(&xcp_mutex);
> }
> EXPORT_SYMBOL(amdgpu_xcp_drv_release);
>
> diff --git a/drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.h b/drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.h
> index c1c4b679bf95..580a1602c8e3 100644
> --- a/drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.h
> +++ b/drivers/gpu/drm/amd/amdxcp/amdgpu_xcp_drv.h
> @@ -25,5 +25,6 @@
> #define _AMDGPU_XCP_DRV_H_
>
> int amdgpu_xcp_drm_dev_alloc(struct drm_device **ddev);
> +void amdgpu_xcp_drm_dev_free(struct drm_device *ddev);
> void amdgpu_xcp_drv_release(void);
> #endif /* _AMDGPU_XCP_DRV_H_ */
