Commit 0b9e2988 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Tejun Heo
Browse files

ahci: use pci_alloc_irq_vectors 



Use the new pci_alloc_irq_vectors API to allocate MSI-X and MSI vectors.
The big advantage over the old code is that we can use the same API for
MSI and MSI-X, and that we don't need to store the MSI-X vector mapping
in driver-private data structures.

This first conversion keeps the probe order as-is: MSI-X multi vector,
MSI multi vector, MSI single vector, MSI-X single vector and last a
single least legacy interrupt line.  There is one small change of
behavior: we now check the "MSI Revert to Single Message" flag for
MSI-X in addition to MSI.

Because the API to find the Linux IRQ number for a MSI/MSI-X vector
is PCI specific, but libahaci is bus-agnostic I had to a
get_irq_vector function pointer to struct ahci_host_priv.  The
alternative would be to move the multi-vector case of ahci_host_activate
to ahci.c and just call ata_host_activate directly from the others
users of ahci_host_activate.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 2536524a

drivers/ata/ahci.c

+32 −117
Original line number Diff line number Diff line
@@ -1400,142 +1400,56 @@ static irqreturn_t ahci_thunderx_irq_handler(int irq, void *dev_instance) 
}

#endif



/*

 * ahci_init_msix() - optionally enable per-port MSI-X otherwise defer

 * to single msi.

 */

static int ahci_init_msix(struct pci_dev *pdev, unsigned int n_ports,

			  struct ahci_host_priv *hpriv, unsigned long flags)

static int ahci_get_irq_vector(struct ata_host *host, int port)

{

	int nvec, i, rc;



	/* Do not init MSI-X if MSI is disabled for the device */

	if (hpriv->flags & AHCI_HFLAG_NO_MSI)

		return -ENODEV;



	nvec = pci_msix_vec_count(pdev);

	if (nvec < 0)

		return nvec;



	/*

	 * Proper MSI-X implementations will have a vector per-port.

	 * Barring that, we prefer single-MSI over single-MSIX.  If this

	 * check fails (not enough MSI-X vectors for all ports) we will

	 * be called again with the flag clear iff ahci_init_msi()

	 * fails.

	 */

	if (flags & AHCI_HFLAG_MULTI_MSIX) {

		if (nvec < n_ports)

			return -ENODEV;

		nvec = n_ports;

	} else if (nvec) {

		nvec = 1;

	} else {

		/*

		 * Emit dev_err() since this was the non-legacy irq

		 * method of last resort.

		 */

		rc = -ENODEV;

		goto fail;

	}



	for (i = 0; i < nvec; i++)

		hpriv->msix[i].entry = i;

	rc = pci_enable_msix_exact(pdev, hpriv->msix, nvec);

	if (rc < 0)

		goto fail;



	if (nvec > 1)

		hpriv->flags |= AHCI_HFLAG_MULTI_MSIX;

	hpriv->irq = hpriv->msix[0].vector; /* for single msi-x */



	return nvec;

fail:

	dev_err(&pdev->dev,

		"failed to enable MSI-X with error %d, # of vectors: %d\n",

		rc, nvec);



	return rc;

	return pci_irq_vector(to_pci_dev(host->dev), port);

}



static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports,

			struct ahci_host_priv *hpriv)

{

	int rc, nvec;

	int nvec;



	if (hpriv->flags & AHCI_HFLAG_NO_MSI)

		return -ENODEV;



	nvec = pci_msi_vec_count(pdev);

	if (nvec < 0)

		return nvec;



	/*

	 * If number of MSIs is less than number of ports then Sharing Last

	 * Message mode could be enforced. In this case assume that advantage

	 * of multipe MSIs is negated and use single MSI mode instead.

	 */

	if (nvec < n_ports)

		goto single_msi;



	rc = pci_enable_msi_exact(pdev, nvec);

	if (rc == -ENOSPC)

		goto single_msi;

	if (rc < 0)

		return rc;



	/* fallback to single MSI mode if the controller enforced MRSM mode */

	if (readl(hpriv->mmio + HOST_CTL) & HOST_MRSM) {

		pci_disable_msi(pdev);

		printk(KERN_INFO "ahci: MRSM is on, fallback to single MSI\n");

		goto single_msi;

	}



	if (nvec > 1)

	nvec = pci_alloc_irq_vectors(pdev, n_ports, INT_MAX,

			PCI_IRQ_MSIX | PCI_IRQ_MSI);

	if (nvec > 0) {

		if (!(readl(hpriv->mmio + HOST_CTL) & HOST_MRSM)) {

			hpriv->get_irq_vector = ahci_get_irq_vector;

			hpriv->flags |= AHCI_HFLAG_MULTI_MSI;



	goto out;



single_msi:

	nvec = 1;



	rc = pci_enable_msi(pdev);

	if (rc < 0)

		return rc;

out:

	hpriv->irq = pdev->irq;



			return nvec;

		}



static int ahci_init_interrupts(struct pci_dev *pdev, unsigned int n_ports,

				struct ahci_host_priv *hpriv)

{

	int nvec;



		/*

	 * Try to enable per-port MSI-X.  If the host is not capable

	 * fall back to single MSI before finally attempting single

	 * MSI-X.

		 * Fallback to single MSI mode if the controller enforced MRSM

		 * mode.

		 */

	nvec = ahci_init_msix(pdev, n_ports, hpriv, AHCI_HFLAG_MULTI_MSIX);

	if (nvec >= 0)

		return nvec;

		printk(KERN_INFO "ahci: MRSM is on, fallback to single MSI\n");

		pci_free_irq_vectors(pdev);

	}



	nvec = ahci_init_msi(pdev, n_ports, hpriv);

	if (nvec >= 0)

	/*

	 * -ENOSPC indicated we don't have enough vectors.  Don't bother trying

	 * a single vectors for any other error:

	 */

	if (nvec < 0 && nvec != -ENOSPC)

		return nvec;



	/* try single-msix */

	nvec = ahci_init_msix(pdev, n_ports, hpriv, 0);

	if (nvec >= 0)

	/*

	 * If the host is not capable of supporting per-port vectors, fall

	 * back to single MSI before finally attempting single MSI-X.

	 */

	nvec = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);

	if (nvec == 1)

		return nvec;



	/* legacy intx interrupts */

	pci_intx(pdev, 1);

	hpriv->irq = pdev->irq;



	return 0;

	return pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSIX);

}



static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
@@ -1698,11 +1612,12 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) 
	if (!host)

		return -ENOMEM;

	host->private_data = hpriv;

	hpriv->msix = devm_kzalloc(&pdev->dev,

			sizeof(struct msix_entry) * n_ports, GFP_KERNEL);

	if (!hpriv->msix)

		return -ENOMEM;

	ahci_init_interrupts(pdev, n_ports, hpriv);



	if (ahci_init_msi(pdev, n_ports, hpriv) < 0) {

		/* legacy intx interrupts */

		pci_intx(pdev, 1);

	}

	hpriv->irq = pdev->irq;



	if (!(hpriv->cap & HOST_CAP_SSS) || ahci_ignore_sss)

		host->flags |= ATA_HOST_PARALLEL_SCAN;

drivers/ata/ahci.h

+5 −19
Original line number Diff line number Diff line
@@ -242,12 +242,10 @@ enum { 
	AHCI_HFLAG_NO_FBS		= (1 << 18), /* no FBS */



#ifdef CONFIG_PCI_MSI

	AHCI_HFLAG_MULTI_MSI		= (1 << 20), /* multiple PCI MSIs */

	AHCI_HFLAG_MULTI_MSIX		= (1 << 21), /* per-port MSI-X */

	AHCI_HFLAG_MULTI_MSI		= (1 << 20), /* per-port MSI(-X) */

#else

	/* compile out MSI infrastructure */

	AHCI_HFLAG_MULTI_MSI		= 0,

	AHCI_HFLAG_MULTI_MSIX		= 0,

#endif

	AHCI_HFLAG_WAKE_BEFORE_STOP	= (1 << 22), /* wake before DMA stop */
@@ -351,7 +349,6 @@ struct ahci_host_priv { 
	 * the PHY position in this array.

	 */

	struct phy		**phys;

	struct msix_entry	*msix;		/* Optional MSI-X support */

	unsigned		nports;		/* Number of ports */

	void			*plat_data;	/* Other platform data */

	unsigned int		irq;		/* interrupt line */
@@ -362,22 +359,11 @@ struct ahci_host_priv { 
	 */

	void			(*start_engine)(struct ata_port *ap);

	irqreturn_t 		(*irq_handler)(int irq, void *dev_instance);

};



#ifdef CONFIG_PCI_MSI

static inline int ahci_irq_vector(struct ahci_host_priv *hpriv, int port)

{

	if (hpriv->flags & AHCI_HFLAG_MULTI_MSIX)

		return hpriv->msix[port].vector;

	else

		return hpriv->irq + port;

}

#else

static inline int ahci_irq_vector(struct ahci_host_priv *hpriv, int port)

{

	return hpriv->irq;

}

#endif

	/* only required for per-port MSI(-X) support */

	int			(*get_irq_vector)(struct ata_host *host,

						  int port);

};



extern int ahci_ignore_sss;

drivers/ata/libahci.c

+8 −3
Original line number Diff line number Diff line
@@ -2378,7 +2378,7 @@ static int ahci_port_start(struct ata_port *ap) 
	/*

	 * Switch to per-port locking in case each port has its own MSI vector.

	 */

	if (hpriv->flags & (AHCI_HFLAG_MULTI_MSI | AHCI_HFLAG_MULTI_MSIX)) {

	if (hpriv->flags & AHCI_HFLAG_MULTI_MSI) {

		spin_lock_init(&pp->lock);

		ap->lock = &pp->lock;

	}
@@ -2520,7 +2520,7 @@ static int ahci_host_activate_multi_irqs(struct ata_host *host, 
	 */

	for (i = 0; i < host->n_ports; i++) {

		struct ahci_port_priv *pp = host->ports[i]->private_data;

		int irq = ahci_irq_vector(hpriv, i);

		int irq = hpriv->get_irq_vector(host, i);



		/* Do not receive interrupts sent by dummy ports */

		if (!pp) {
@@ -2556,10 +2556,15 @@ int ahci_host_activate(struct ata_host *host, struct scsi_host_template *sht) 
	int irq = hpriv->irq;

	int rc;



	if (hpriv->flags & (AHCI_HFLAG_MULTI_MSI | AHCI_HFLAG_MULTI_MSIX)) {

	if (hpriv->flags & AHCI_HFLAG_MULTI_MSI) {

		if (hpriv->irq_handler)

			dev_warn(host->dev,

			         "both AHCI_HFLAG_MULTI_MSI flag set and custom irq handler implemented\n");

		if (!hpriv->get_irq_vector) {

			dev_err(host->dev,

				"AHCI_HFLAG_MULTI_MSI requires ->get_irq_vector!\n");

			return -EIO;

		}



		rc = ahci_host_activate_multi_irqs(host, sht);

	} else {

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