Re: [PATCH v2 2/2] PCI/MSI: Remove arch_msi_check_device()

[Alexander Gordeev]

On Mon, Aug 11, 2014 at 02:33:25PM +0000, Bharat.Bhushan@xxxxxxxxxxxxx wrote:
> 
> 
> > -----Original Message-----
> > From: linux-pci-owner@xxxxxxxxxxxxxxx [mailto:linux-pci-owner@xxxxxxxxxxxxxxx]
> > On Behalf Of Alexander Gordeev
> > Sent: Monday, August 11, 2014 5:16 PM
> > To: Bjorn Helgaas
> > Cc: linux-kernel@xxxxxxxxxxxxxxx; linuxppc-dev@xxxxxxxxxxxxxxxx; linux-
> > pci@xxxxxxxxxxxxxxx
> > Subject: [PATCH v2 2/2] PCI/MSI: Remove arch_msi_check_device()
> > 
> > There are no archs that override arch_msi_check_device() hook. Remove it as it
> > is completely redundant.
> 
> Is not we are still overriding this in powerpc (not sure I missed some patch , if so please point to that).

Patch 1/2 ;)

> $ grep -r  arch_msi_check_device arch/powerpc/
> Binary file arch/powerpc/kernel/msi.o matches
> arch/powerpc/kernel/msi.c:int arch_msi_check_device(struct pci_dev* dev, int nvec, int type)
> Binary file arch/powerpc/kernel/built-in.o matches
> 
> Thanks
> -Bharat
> 
> > 
> > If an arch would need to check MSI/MSI-X possibility for a device it should make
> > it within arch_setup_msi_irqs() hook.
> > 
> > Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
> > Cc: linux-pci@xxxxxxxxxxxxxxx
> > Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxx>
> > ---
> >  drivers/pci/msi.c   | 49 +++++++++++++------------------------------------
> >  include/linux/msi.h |  3 ---
> >  2 files changed, 13 insertions(+), 39 deletions(-)
> > 
> > diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 5a40516..6c2cc41 100644
> > --- a/drivers/pci/msi.c
> > +++ b/drivers/pci/msi.c
> > @@ -56,16 +56,6 @@ void __weak arch_teardown_msi_irq(unsigned int irq)
> >  	chip->teardown_irq(chip, irq);
> >  }
> > 
> > -int __weak arch_msi_check_device(struct pci_dev *dev, int nvec, int type) -{
> > -	struct msi_chip *chip = dev->bus->msi;
> > -
> > -	if (!chip || !chip->check_device)
> > -		return 0;
> > -
> > -	return chip->check_device(chip, dev, nvec, type);
> > -}
> > -
> >  int __weak arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)  {
> >  	struct msi_desc *entry;
> > @@ -806,22 +796,23 @@ out_free:
> >  }
> > 
> >  /**
> > - * pci_msi_check_device - check whether MSI may be enabled on a device
> > + * pci_msi_supported - check whether MSI may be enabled on a device
> >   * @dev: pointer to the pci_dev data structure of MSI device function
> >   * @nvec: how many MSIs have been requested ?
> > - * @type: are we checking for MSI or MSI-X ?
> >   *
> >   * Look at global flags, the device itself, and its parent buses
> >   * to determine if MSI/-X are supported for the device. If MSI/-X is
> >   * supported return 0, else return an error code.
> >   **/
> > -static int pci_msi_check_device(struct pci_dev *dev, int nvec, int type)
> > +static int pci_msi_supported(struct pci_dev *dev, int nvec)
> >  {
> >  	struct pci_bus *bus;
> > -	int ret;
> > 
> >  	/* MSI must be globally enabled and supported by the device */
> > -	if (!pci_msi_enable || !dev || dev->no_msi)
> > +	if (!pci_msi_enable)
> > +		return -EINVAL;
> > +
> > +	if (!dev || dev->no_msi || dev->current_state != PCI_D0)
> >  		return -EINVAL;
> > 
> >  	/*
> > @@ -843,10 +834,6 @@ static int pci_msi_check_device(struct pci_dev *dev, int
> > nvec, int type)
> >  		if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI)
> >  			return -EINVAL;
> > 
> > -	ret = arch_msi_check_device(dev, nvec, type);
> > -	if (ret)
> > -		return ret;
> > -
> >  	return 0;
> >  }
> > 
> > @@ -949,13 +936,13 @@ int pci_enable_msix(struct pci_dev *dev, struct msix_entry
> > *entries, int nvec)
> >  	int status, nr_entries;
> >  	int i, j;
> > 
> > -	if (!entries || !dev->msix_cap || dev->current_state != PCI_D0)
> > -		return -EINVAL;
> > -
> > -	status = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSIX);
> > +	status = pci_msi_supported(dev, nvec);
> >  	if (status)
> >  		return status;
> > 
> > +	if (!entries)
> > +		return -EINVAL;
> > +
> >  	nr_entries = pci_msix_vec_count(dev);
> >  	if (nr_entries < 0)
> >  		return nr_entries;
> > @@ -1062,8 +1049,9 @@ int pci_enable_msi_range(struct pci_dev *dev, int minvec,
> > int maxvec)
> >  	int nvec;
> >  	int rc;
> > 
> > -	if (dev->current_state != PCI_D0)
> > -		return -EINVAL;
> > +	rc = pci_msi_supported(dev, minvec);
> > +	if (rc)
> > +		return rc;
> > 
> >  	WARN_ON(!!dev->msi_enabled);
> > 
> > @@ -1086,17 +1074,6 @@ int pci_enable_msi_range(struct pci_dev *dev, int minvec,
> > int maxvec)
> >  		nvec = maxvec;
> > 
> >  	do {
> > -		rc = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSI);
> > -		if (rc < 0) {
> > -			return rc;
> > -		} else if (rc > 0) {
> > -			if (rc < minvec)
> > -				return -ENOSPC;
> > -			nvec = rc;
> > -		}
> > -	} while (rc);
> > -
> > -	do {
> >  		rc = msi_capability_init(dev, nvec);
> >  		if (rc < 0) {
> >  			return rc;
> > diff --git a/include/linux/msi.h b/include/linux/msi.h index 8103f32..dbf7cc9
> > 100644
> > --- a/include/linux/msi.h
> > +++ b/include/linux/msi.h
> > @@ -60,7 +60,6 @@ int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc
> > *desc);  void arch_teardown_msi_irq(unsigned int irq);  int
> > arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type);  void
> > arch_teardown_msi_irqs(struct pci_dev *dev); -int arch_msi_check_device(struct
> > pci_dev* dev, int nvec, int type);  void arch_restore_msi_irqs(struct pci_dev
> > *dev);
> > 
> >  void default_teardown_msi_irqs(struct pci_dev *dev); @@ -77,8 +76,6 @@ struct
> > msi_chip {
> >  	int (*setup_irq)(struct msi_chip *chip, struct pci_dev *dev,
> >  			 struct msi_desc *desc);
> >  	void (*teardown_irq)(struct msi_chip *chip, unsigned int irq);
> > -	int (*check_device)(struct msi_chip *chip, struct pci_dev *dev,
> > -			    int nvec, int type);
> >  };
> > 
> >  #endif /* LINUX_MSI_H */
> > --
> > 1.9.3
> > 
> > --
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-- 
Regards,
Alexander Gordeev
agordeev@xxxxxxxxxx
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