[01/14] drm/amdgpu: Convert to Linux IRQ interfaces

Drop the DRM IRQ midlayer in favor of Linux IRQ interfaces. DRM's
IRQ helpers are mostly useful for UMS drivers. Modern KMS drivers
don't benefit from using it.

DRM IRQ callbacks are now being called directly or inlined.

The interrupt number returned by pci_msi_vector() is now stored
in struct amdgpu_irq. Calls to pci_msi_vector() can fail and return
a negative errno code. Abort initlaizaton in thi case. The DRM IRQ
midlayer does not handle this correctly.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c |  1 -
 drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c | 21 ++++++++++++++-------
 drivers/gpu/drm/amd/amdgpu/amdgpu_irq.h |  2 +-
 3 files changed, 15 insertions(+), 9 deletions(-)

Am 27.07.21 um 20:27 schrieb Thomas Zimmermann:
> Drop the DRM IRQ midlayer in favor of Linux IRQ interfaces. DRM's
> IRQ helpers are mostly useful for UMS drivers. Modern KMS drivers
> don't benefit from using it.
>
> DRM IRQ callbacks are now being called directly or inlined.
>
> The interrupt number returned by pci_msi_vector() is now stored
> in struct amdgpu_irq. Calls to pci_msi_vector() can fail and return
> a negative errno code. Abort initlaizaton in thi case. The DRM IRQ
> midlayer does not handle this correctly.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Alex needs to take a look at this as well, but of hand the patch is 
Acked-by: Christian König <christian.koenig@amd.com>.

Thanks,
Christian.

> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c |  1 -
>   drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c | 21 ++++++++++++++-------
>   drivers/gpu/drm/amd/amdgpu/amdgpu_irq.h |  2 +-
>   3 files changed, 15 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> index 2bd13fc2541a..1e05b5aa94e7 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> @@ -1775,7 +1775,6 @@ static const struct drm_driver amdgpu_kms_driver = {
>   	.open = amdgpu_driver_open_kms,
>   	.postclose = amdgpu_driver_postclose_kms,
>   	.lastclose = amdgpu_driver_lastclose_kms,
> -	.irq_handler = amdgpu_irq_handler,
>   	.ioctls = amdgpu_ioctls_kms,
>   	.num_ioctls = ARRAY_SIZE(amdgpu_ioctls_kms),
>   	.dumb_create = amdgpu_mode_dumb_create,
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
> index 0d01cfaca77e..a36cdc7323f4 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
> @@ -46,7 +46,6 @@
>   #include <linux/pci.h>
>   
>   #include <drm/drm_crtc_helper.h>
> -#include <drm/drm_irq.h>
>   #include <drm/drm_vblank.h>
>   #include <drm/amdgpu_drm.h>
>   #include <drm/drm_drv.h>
> @@ -184,7 +183,7 @@ void amdgpu_irq_disable_all(struct amdgpu_device *adev)
>    * Returns:
>    * result of handling the IRQ, as defined by &irqreturn_t
>    */
> -irqreturn_t amdgpu_irq_handler(int irq, void *arg)
> +static irqreturn_t amdgpu_irq_handler(int irq, void *arg)
>   {
>   	struct drm_device *dev = (struct drm_device *) arg;
>   	struct amdgpu_device *adev = drm_to_adev(dev);
> @@ -307,6 +306,7 @@ static void amdgpu_restore_msix(struct amdgpu_device *adev)
>   int amdgpu_irq_init(struct amdgpu_device *adev)
>   {
>   	int r = 0;
> +	unsigned int irq;
>   
>   	spin_lock_init(&adev->irq.lock);
>   
> @@ -349,15 +349,22 @@ int amdgpu_irq_init(struct amdgpu_device *adev)
>   	INIT_WORK(&adev->irq.ih2_work, amdgpu_irq_handle_ih2);
>   	INIT_WORK(&adev->irq.ih_soft_work, amdgpu_irq_handle_ih_soft);
>   
> -	adev->irq.installed = true;
> -	/* Use vector 0 for MSI-X */
> -	r = drm_irq_install(adev_to_drm(adev), pci_irq_vector(adev->pdev, 0));
> +	/* Use vector 0 for MSI-X. */
> +	r = pci_irq_vector(adev->pdev, 0);
> +	if (r < 0)
> +		return r;
> +	irq = r;
> +
> +	/* PCI devices require shared interrupts. */
> +	r = request_irq(irq, amdgpu_irq_handler, IRQF_SHARED, adev_to_drm(adev)->driver->name,
> +			adev_to_drm(adev));
>   	if (r) {
> -		adev->irq.installed = false;
>   		if (!amdgpu_device_has_dc_support(adev))
>   			flush_work(&adev->hotplug_work);
>   		return r;
>   	}
> +	adev->irq.installed = true;
> +	adev->irq.irq = irq;
>   	adev_to_drm(adev)->max_vblank_count = 0x00ffffff;
>   
>   	DRM_DEBUG("amdgpu: irq initialized.\n");
> @@ -368,7 +375,7 @@ int amdgpu_irq_init(struct amdgpu_device *adev)
>   void amdgpu_irq_fini_hw(struct amdgpu_device *adev)
>   {
>   	if (adev->irq.installed) {
> -		drm_irq_uninstall(&adev->ddev);
> +		free_irq(adev->irq.irq, adev_to_drm(adev));
>   		adev->irq.installed = false;
>   		if (adev->irq.msi_enabled)
>   			pci_free_irq_vectors(adev->pdev);
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.h
> index 78ad4784cc74..e9f2c11ea416 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.h
> @@ -80,6 +80,7 @@ struct amdgpu_irq_src_funcs {
>   
>   struct amdgpu_irq {
>   	bool				installed;
> +	unsigned int			irq;
>   	spinlock_t			lock;
>   	/* interrupt sources */
>   	struct amdgpu_irq_client	client[AMDGPU_IRQ_CLIENTID_MAX];
> @@ -100,7 +101,6 @@ struct amdgpu_irq {
>   };
>   
>   void amdgpu_irq_disable_all(struct amdgpu_device *adev);
> -irqreturn_t amdgpu_irq_handler(int irq, void *arg);
>   
>   int amdgpu_irq_init(struct amdgpu_device *adev);
>   void amdgpu_irq_fini_sw(struct amdgpu_device *adev);