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

Piotr Piórkowski piotr.piorkowski at intel.com
Thu Dec 5 08:35:51 UTC 2024


Levi, Ilia <ilia.levi at intel.com> wrote on wto [2024-gru-03 11:04:14 +0200]:
> On 02/12/2024 20:59, Piotr Piórkowski wrote:
> > 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.
> 
> As we discussed, it is akin to xe_device_has_flat_ccs - where xe->info.has_flat_ccs is set by probe_has_flat_ccs.
> xe->irq.msix.nvec is set according to pci_msix_vec_count which reads MSI-X capability from the PCI.
> 
> >> -	/* 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
> 
> GUC_INTR_GUC2HOST is defined there. It was not needed before as it was called by gt_other_irq_handler (the type of the interrupt was read from the registers).
> For MSI-X those registers are no longer set - and the only type of interrupt we expect on MSI-X vector 0 is guc-to-host.
> 
> >
> > Thanks,
> > Piotr

I'm ok with that:
Reviewed-by: Piotr Piórkowski <piotr.piorkowski at intel.com>

> >>  #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
> >>

-- 


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