Commit 565d065a authored by Tomas Henzl's avatar Tomas Henzl Committed by Niklas Cassel
Browse files

ata: ahci: simplify init function 



This patch moves all the IRQ vector allocations into a single
function. Instead of having the allocations spread out over
two separate call sites everything will be handled in ahci_init_irq.
Also a direct call into pci(m)_intx will be removed.

The main part of this change is done by adding a PCI_IRQ_INTX flag into
an already existing pci_alloc_irq_vectors invocation.
In the current implementation of the pci_alloc_irq_vectors is the sequence
of calls msi-x -> msi -> legacy irq and whatever there succeeds stops the
call chain. That makes it impossible to merge all instances into as
a single call to pci_alloc_irq_vectors since the order of calls there is:
multiple msi-x
a single msi
a single msi-x
a legacy irq.
The two last steps can be merged into a single one which are
the msi-x and legacy irq option.

When PCI_IRQ_INTX flag is set the pci_alloc_irq_vectors succeeds in almost
all cases - that makes it possible to convert ahci_init_irq(msi) into
a void function. The exception is when dev->irq is zero then the
pci_alloc_irq_vectors may return with an error code also pci_intx isn't
called from  pci_alloc_irq_vectors and thus certain pci calls aren't
performed.
That's just a negligible issue as later in ahci_init_one the (zero)
value of dev->irq is via pci_irq_vector assigned to hpriv->irq.
That value is then later tested in ahci_host_activate->ata_host_activate
where it is welcomed with a WARN_ON message and fails with setting up
irq and then the probe function (ahci_init_one) fails.
The special zero value's meaning is that polling mode is being be set
up which isn't the case.

No functional change.

Signed-off-by: default avatarTomas Henzl <thenzl@redhat.com>
Link: https://lore.kernel.org/r/20250319155030.16410-1-thenzl@redhat.com


Signed-off-by: default avatarNiklas Cassel <cassel@kernel.org>
parent 0507c777

drivers/ata/ahci.c

+12 −11
Original line number Diff line number Diff line
@@ -1676,13 +1676,15 @@ static int ahci_get_irq_vector(struct ata_host *host, int port) 
	return pci_irq_vector(to_pci_dev(host->dev), port);

}



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

static void ahci_init_irq(struct pci_dev *pdev, unsigned int n_ports,

			struct ahci_host_priv *hpriv)

{

	int nvec;



	if (hpriv->flags & AHCI_HFLAG_NO_MSI)

		return -ENODEV;

	if (hpriv->flags & AHCI_HFLAG_NO_MSI) {

		pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_INTX);

		return;

	}



	/*

	 * If number of MSIs is less than number of ports then Sharing Last
@@ -1696,7 +1698,7 @@ static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports, 
			if (!(readl(hpriv->mmio + HOST_CTL) & HOST_MRSM)) {

				hpriv->get_irq_vector = ahci_get_irq_vector;

				hpriv->flags |= AHCI_HFLAG_MULTI_MSI;

				return nvec;

				return;

			}



			/*
@@ -1711,12 +1713,13 @@ static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports, 


	/*

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

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

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

	 * a legacy INTx.

	 */

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

	if (nvec == 1)

		return nvec;

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

		return;

	pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSIX | PCI_IRQ_INTX);

}



static void ahci_mark_external_port(struct ata_port *ap)
@@ -1996,10 +1999,8 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) 
	}

	host->private_data = hpriv;



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

		/* legacy intx interrupts */

		pcim_intx(pdev, 1);

	}

	ahci_init_irq(pdev, n_ports, hpriv);



	hpriv->irq = pci_irq_vector(pdev, 0);



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