[PATCH v5 2/5] drm/xe/irq: Separate MSI and MSI-X flows

Piotr Piórkowski piotr.piorkowski at intel.com
Mon Dec 2 18:59:18 UTC 2024


Ilia Levi <ilia.levi at intel.com> wrote on czw [2024-lis-28 14:53:42 +0200]:
> A new flow is added for devices that support MSI-X:
> - MSI-X vector 0 is used for GuC-to-host interrupt
> - MSI-X vector 1 (aka default MSI-X) is used for HW engines
> 
> The default MSI-X will be passed to the HW engines in a subsequent
> patch.
> 
> Signed-off-by: Ilia Levi <ilia.levi at intel.com>
> ---
>  drivers/gpu/drm/xe/xe_device.c       |   4 +-
>  drivers/gpu/drm/xe/xe_device.h       |   3 +-
>  drivers/gpu/drm/xe/xe_device_types.h |   6 +
>  drivers/gpu/drm/xe/xe_irq.c          | 257 +++++++++++++++++++++++----
>  drivers/gpu/drm/xe/xe_irq.h          |   3 +
>  5 files changed, 237 insertions(+), 36 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
> index 930bb2750e2e..f1246fa8b5cc 100644
> --- a/drivers/gpu/drm/xe/xe_device.c
> +++ b/drivers/gpu/drm/xe/xe_device.c
> @@ -325,7 +325,9 @@ struct xe_device *xe_device_create(struct pci_dev *pdev,
>  	xe->info.revid = pdev->revision;
>  	xe->info.force_execlist = xe_modparam.force_execlist;
>  
> -	spin_lock_init(&xe->irq.lock);
> +	err = xe_irq_init(xe);
> +	if (err)
> +		goto err;
>  
>  	init_waitqueue_head(&xe->ufence_wq);
>  
> diff --git a/drivers/gpu/drm/xe/xe_device.h b/drivers/gpu/drm/xe/xe_device.h
> index f1fbfe916867..fc3c2af3fb7f 100644
> --- a/drivers/gpu/drm/xe/xe_device.h
> +++ b/drivers/gpu/drm/xe/xe_device.h
> @@ -157,8 +157,7 @@ static inline bool xe_device_has_sriov(struct xe_device *xe)
>  
>  static inline bool xe_device_has_msix(struct xe_device *xe)
>  {
I still think you should use the name xe_device_use_msix.

We use xe_device_has_* in case, when the capability based on Platform
version (for example xe_device_has_memirq) based on intel_device_info
(for example xe_device_has_sriov or xe_device_has_flat_css).

IMO in case you are basing it on a variable that you set yourself in init you should use
a different name (for example with “uses” instead of “has”)

My motivation is that for me xe_device_has-* is used when it is the capability of a given device
and we base on the information that intel_device_info or infromation about the platform version
provides us with.

> -	/* TODO: change this when MSI-X support is fully integrated */
> -	return false;
> +	return xe->irq.msix.nvec > 0;
>  }
>  
>  static inline bool xe_device_has_memirq(struct xe_device *xe)
> diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
> index 7ee114c17552..ed638067aa26 100644
> --- a/drivers/gpu/drm/xe/xe_device_types.h
> +++ b/drivers/gpu/drm/xe/xe_device_types.h
> @@ -348,6 +348,12 @@ struct xe_device {
>  
>  		/** @irq.enabled: interrupts enabled on this device */
>  		atomic_t enabled;
> +
> +		/** @irq.msix: irq info for platforms that support MSI-X */
> +		struct {
> +			/** @irq.msix.nvec: number of MSI-X interrupts */
> +			u16 nvec;
> +		} msix;
>  	} irq;
>  
>  	/** @ttm: ttm device */
> diff --git a/drivers/gpu/drm/xe/xe_irq.c b/drivers/gpu/drm/xe/xe_irq.c
> index 1c509e66694d..b8a0b9bbf24c 100644
> --- a/drivers/gpu/drm/xe/xe_irq.c
> +++ b/drivers/gpu/drm/xe/xe_irq.c
> @@ -10,6 +10,7 @@
>  #include <drm/drm_managed.h>
>  
>  #include "display/xe_display.h"
> +#include "regs/xe_guc_regs.h"

I don't see why you are adding this header


Thanks,
Piotr
>  #include "regs/xe_irq_regs.h"
>  #include "xe_device.h"
>  #include "xe_drv.h"
> @@ -29,6 +30,11 @@
>  #define IIR(offset)				XE_REG(offset + 0x8)
>  #define IER(offset)				XE_REG(offset + 0xc)
>  
> +static int xe_irq_msix_init(struct xe_device *xe);
> +static void xe_irq_msix_free(struct xe_device *xe);
> +static int xe_irq_msix_request_irqs(struct xe_device *xe);
> +static void xe_irq_msix_synchronize_irq(struct xe_device *xe);
> +
>  static void assert_iir_is_zero(struct xe_mmio *mmio, struct xe_reg reg)
>  {
>  	u32 val = xe_mmio_read32(mmio, reg);
> @@ -572,6 +578,11 @@ static void xe_irq_reset(struct xe_device *xe)
>  	if (IS_SRIOV_VF(xe))
>  		return vf_irq_reset(xe);
>  
> +	if (xe_device_uses_memirq(xe)) {
> +		for_each_tile(tile, xe, id)
> +			xe_memirq_reset(&tile->memirq);
> +	}
> +
>  	for_each_tile(tile, xe, id) {
>  		if (GRAPHICS_VERx100(xe) >= 1210)
>  			dg1_irq_reset(tile);
> @@ -614,6 +625,14 @@ static void xe_irq_postinstall(struct xe_device *xe)
>  	if (IS_SRIOV_VF(xe))
>  		return vf_irq_postinstall(xe);
>  
> +	if (xe_device_uses_memirq(xe)) {
> +		struct xe_tile *tile;
> +		unsigned int id;
> +
> +		for_each_tile(tile, xe, id)
> +			xe_memirq_postinstall(&tile->memirq);
> +	}
> +
>  	xe_display_irq_postinstall(xe, xe_root_mmio_gt(xe));
>  
>  	/*
> @@ -656,60 +675,83 @@ static irq_handler_t xe_irq_handler(struct xe_device *xe)
>  		return xelp_irq_handler;
>  }
>  
> -static void irq_uninstall(void *arg)
> +static int xe_irq_msi_request_irqs(struct xe_device *xe)
> +{
> +	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
> +	irq_handler_t irq_handler;
> +	int irq, err;
> +
> +	irq_handler = xe_irq_handler(xe);
> +	if (!irq_handler) {
> +		drm_err(&xe->drm, "No supported interrupt handler");
> +		return -EINVAL;
> +	}
> +
> +	irq = pci_irq_vector(pdev, 0);
> +	err = request_irq(irq, irq_handler, IRQF_SHARED, DRIVER_NAME, xe);
> +	if (err < 0) {
> +		drm_err(&xe->drm, "Failed to request MSI IRQ %d\n", err);
> +		return err;
> +	}
> +
> +	return 0;
> +}
> +
> +static void xe_irq_msi_free(struct xe_device *xe)
>  {
> -	struct xe_device *xe = arg;
>  	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
>  	int irq;
>  
> +	irq = pci_irq_vector(pdev, 0);
> +	free_irq(irq, xe);
> +}
> +
> +static void irq_uninstall(void *arg)
> +{
> +	struct xe_device *xe = arg;
> +
>  	if (!atomic_xchg(&xe->irq.enabled, 0))
>  		return;
>  
>  	xe_irq_reset(xe);
>  
> -	irq = pci_irq_vector(pdev, 0);
> -	free_irq(irq, xe);
> +	if (xe_device_has_msix(xe))
> +		xe_irq_msix_free(xe);
> +	else
> +		xe_irq_msi_free(xe);
> +}
> +
> +int xe_irq_init(struct xe_device *xe)
> +{
> +	spin_lock_init(&xe->irq.lock);
> +
> +	return xe_irq_msix_init(xe);
>  }
>  
>  int xe_irq_install(struct xe_device *xe)
>  {
>  	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
> -	unsigned int irq_flags = PCI_IRQ_MSIX;
> -	irq_handler_t irq_handler;
> -	int err, irq, nvec;
> -
> -	irq_handler = xe_irq_handler(xe);
> -	if (!irq_handler) {
> -		drm_err(&xe->drm, "No supported interrupt handler");
> -		return -EINVAL;
> -	}
> +	unsigned int irq_flags = PCI_IRQ_MSI;
> +	int nvec = 1;
> +	int err;
>  
>  	xe_irq_reset(xe);
>  
> -	nvec = pci_msix_vec_count(pdev);
> -	if (nvec <= 0) {
> -		if (nvec == -EINVAL) {
> -			/* MSIX capability is not supported in the device, using MSI */
> -			irq_flags = PCI_IRQ_MSI;
> -			nvec = 1;
> -		} else {
> -			drm_err(&xe->drm, "MSIX: Failed getting count\n");
> -			return nvec;
> -		}
> +	if (xe_device_has_msix(xe)) {
> +		nvec = xe->irq.msix.nvec;
> +		irq_flags = PCI_IRQ_MSIX;
>  	}
>  
>  	err = pci_alloc_irq_vectors(pdev, nvec, nvec, irq_flags);
>  	if (err < 0) {
> -		drm_err(&xe->drm, "MSI/MSIX: Failed to enable support %d\n", err);
> +		drm_err(&xe->drm, "Failed to allocate IRQ vectors: %d\n", err);
>  		return err;
>  	}
>  
> -	irq = pci_irq_vector(pdev, 0);
> -	err = request_irq(irq, irq_handler, IRQF_SHARED, DRIVER_NAME, xe);
> -	if (err < 0) {
> -		drm_err(&xe->drm, "Failed to request MSI/MSIX IRQ %d\n", err);
> +	err = xe_device_has_msix(xe) ? xe_irq_msix_request_irqs(xe) :
> +					xe_irq_msi_request_irqs(xe);
> +	if (err)
>  		return err;
> -	}
>  
>  	atomic_set(&xe->irq.enabled, 1);
>  
> @@ -722,18 +764,28 @@ int xe_irq_install(struct xe_device *xe)
>  	return 0;
>  
>  free_irq_handler:
> -	free_irq(irq, xe);
> +	if (xe_device_has_msix(xe))
> +		xe_irq_msix_free(xe);
> +	else
> +		xe_irq_msi_free(xe);
>  
>  	return err;
>  }
>  
> -void xe_irq_suspend(struct xe_device *xe)
> +static void xe_irq_msi_synchronize_irq(struct xe_device *xe)
>  {
> -	int irq = to_pci_dev(xe->drm.dev)->irq;
> +	synchronize_irq(to_pci_dev(xe->drm.dev)->irq);
> +}
>  
> +void xe_irq_suspend(struct xe_device *xe)
> +{
>  	atomic_set(&xe->irq.enabled, 0); /* no new irqs */
>  
> -	synchronize_irq(irq); /* flush irqs */
> +	/* flush irqs */
> +	if (xe_device_has_msix(xe))
> +		xe_irq_msix_synchronize_irq(xe);
> +	else
> +		xe_irq_msi_synchronize_irq(xe);
>  	xe_irq_reset(xe); /* turn irqs off */
>  }
>  
> @@ -754,3 +806,142 @@ void xe_irq_resume(struct xe_device *xe)
>  	for_each_gt(gt, xe, id)
>  		xe_irq_enable_hwe(gt);
>  }
> +
> +/* MSI-X related definitions and functions below. */
> +
> +enum xe_irq_msix_static {
> +	GUC2HOST_MSIX = 0,
> +	DEFAULT_MSIX = XE_IRQ_DEFAULT_MSIX,
> +	/* Must be last */
> +	NUM_OF_STATIC_MSIX,
> +};
> +
> +static int xe_irq_msix_init(struct xe_device *xe)
> +{
> +	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
> +	int nvec = pci_msix_vec_count(pdev);
> +
> +	if (nvec == -EINVAL)
> +		return 0;  /* MSI */
> +
> +	if (nvec < 0) {
> +		drm_err(&xe->drm, "Failed getting MSI-X vectors count: %d\n", nvec);
> +		return nvec;
> +	}
> +
> +	xe->irq.msix.nvec = nvec;
> +	return 0;
> +}
> +
> +static irqreturn_t guc2host_irq_handler(int irq, void *arg)
> +{
> +	struct xe_device *xe = arg;
> +	struct xe_tile *tile;
> +	u8 id;
> +
> +	if (!atomic_read(&xe->irq.enabled))
> +		return IRQ_NONE;
> +
> +	for_each_tile(tile, xe, id)
> +		xe_guc_irq_handler(&tile->primary_gt->uc.guc,
> +				   GUC_INTR_GUC2HOST);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t xe_irq_msix_default_hwe_handler(int irq, void *arg)
> +{
> +	unsigned int tile_id, gt_id;
> +	struct xe_device *xe = arg;
> +	struct xe_memirq *memirq;
> +	struct xe_hw_engine *hwe;
> +	enum xe_hw_engine_id id;
> +	struct xe_tile *tile;
> +	struct xe_gt *gt;
> +
> +	if (!atomic_read(&xe->irq.enabled))
> +		return IRQ_NONE;
> +
> +	for_each_tile(tile, xe, tile_id) {
> +		memirq = &tile->memirq;
> +		if (!memirq->bo)
> +			continue;
> +
> +		for_each_gt(gt, xe, gt_id) {
> +			if (gt->tile != tile)
> +				continue;
> +
> +			for_each_hw_engine(hwe, gt, id)
> +				xe_memirq_hwe_handler(memirq, hwe);
> +		}
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int xe_irq_msix_request_irq(struct xe_device *xe, irq_handler_t handler,
> +				   const char *name, u16 msix)
> +{
> +	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
> +	int ret, irq;
> +
> +	irq = pci_irq_vector(pdev, msix);
> +	if (irq < 0)
> +		return irq;
> +
> +	ret = request_irq(irq, handler, IRQF_SHARED, name, xe);
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static void xe_irq_msix_free_irq(struct xe_device *xe, u16 msix)
> +{
> +	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
> +	int irq;
> +
> +	irq = pci_irq_vector(pdev, msix);
> +	if (irq < 0) {
> +		drm_err(&xe->drm, "MSI-X %u can't be released, there is no matching IRQ\n", msix);
> +		return;
> +	}
> +
> +	free_irq(irq, xe);
> +}
> +
> +static int xe_irq_msix_request_irqs(struct xe_device *xe)
> +{
> +	int err;
> +
> +	err = xe_irq_msix_request_irq(xe, guc2host_irq_handler,
> +				      DRIVER_NAME "-guc2host", GUC2HOST_MSIX);
> +	if (err) {
> +		drm_err(&xe->drm, "Failed to request MSI-X IRQ %d: %d\n", GUC2HOST_MSIX, err);
> +		return err;
> +	}
> +
> +	err = xe_irq_msix_request_irq(xe, xe_irq_msix_default_hwe_handler,
> +				      DRIVER_NAME "-default-msix", DEFAULT_MSIX);
> +	if (err) {
> +		drm_err(&xe->drm, "Failed to request MSI-X IRQ %d: %d\n", DEFAULT_MSIX, err);
> +		xe_irq_msix_free_irq(xe, GUC2HOST_MSIX);
> +		return err;
> +	}
> +
> +	return 0;
> +}
> +
> +static void xe_irq_msix_free(struct xe_device *xe)
> +{
> +	xe_irq_msix_free_irq(xe, GUC2HOST_MSIX);
> +	xe_irq_msix_free_irq(xe, DEFAULT_MSIX);
> +}
> +
> +static void xe_irq_msix_synchronize_irq(struct xe_device *xe)
> +{
> +	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
> +
> +	synchronize_irq(pci_irq_vector(pdev, GUC2HOST_MSIX));
> +	synchronize_irq(pci_irq_vector(pdev, DEFAULT_MSIX));
> +}
> diff --git a/drivers/gpu/drm/xe/xe_irq.h b/drivers/gpu/drm/xe/xe_irq.h
> index 067514e13675..24ff16111b96 100644
> --- a/drivers/gpu/drm/xe/xe_irq.h
> +++ b/drivers/gpu/drm/xe/xe_irq.h
> @@ -6,10 +6,13 @@
>  #ifndef _XE_IRQ_H_
>  #define _XE_IRQ_H_
>  
> +#define XE_IRQ_DEFAULT_MSIX 1
> +
>  struct xe_device;
>  struct xe_tile;
>  struct xe_gt;
>  
> +int xe_irq_init(struct xe_device *xe);
>  int xe_irq_install(struct xe_device *xe);
>  void xe_irq_suspend(struct xe_device *xe);
>  void xe_irq_resume(struct xe_device *xe);
> -- 
> 2.43.2
> 

-- 


More information about the Intel-xe mailing list