Re: [PATCH 4/7] pci/msi: Propagate irq affinity description through the MSI code

[Bjorn Helgaas <helgaas@kernel.org>]

s|pci/msi|PCI/MSI| (subject)
s/irq/IRQ/ (subject)

On Mon, Nov 07, 2016 at 10:47:39AM -0800, Christoph Hellwig wrote:
> From: Christogh Hellwig <hch@lst.de>
> 
> No API change yet, just pass it down all the way from
> pci_alloc_irq_vectors to the core MSI code.

pci_alloc_irq_vectors()

> Signed-off-by: Christogh Hellwig <hch@lst.de>

Acked-by: Bjorn Helgaas <bhelgaas@google.com>

> ---
>  drivers/pci/msi.c | 62 +++++++++++++++++++++++++++++--------------------------
>  1 file changed, 33 insertions(+), 29 deletions(-)
> 
> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
> index 1761b8a..512f388 100644
> --- a/drivers/pci/msi.c
> +++ b/drivers/pci/msi.c
> @@ -551,14 +551,14 @@ static int populate_msi_sysfs(struct pci_dev *pdev)
>  }
>  
>  static struct msi_desc *
> -msi_setup_entry(struct pci_dev *dev, int nvec, bool affinity)
> +msi_setup_entry(struct pci_dev *dev, int nvec, const struct irq_affinity *affd)
>  {
>  	struct cpumask *masks = NULL;
>  	struct msi_desc *entry;
>  	u16 control;
>  
> -	if (affinity) {
> -		masks = irq_create_affinity_masks(nvec, NULL);
> +	if (affd) {
> +		masks = irq_create_affinity_masks(nvec, affd);
>  		if (!masks)
>  			pr_err("Unable to allocate affinity masks, ignoring\n");
>  	}
> @@ -618,7 +618,8 @@ static int msi_verify_entries(struct pci_dev *dev)
>   * an error, and a positive return value indicates the number of interrupts
>   * which could have been allocated.
>   */
> -static int msi_capability_init(struct pci_dev *dev, int nvec, bool affinity)
> +static int msi_capability_init(struct pci_dev *dev, int nvec,
> +			       const struct irq_affinity *affd)
>  {
>  	struct msi_desc *entry;
>  	int ret;
> @@ -626,7 +627,7 @@ static int msi_capability_init(struct pci_dev *dev, int nvec, bool affinity)
>  
>  	pci_msi_set_enable(dev, 0);	/* Disable MSI during set up */
>  
> -	entry = msi_setup_entry(dev, nvec, affinity);
> +	entry = msi_setup_entry(dev, nvec, affd);
>  	if (!entry)
>  		return -ENOMEM;
>  
> @@ -690,14 +691,14 @@ static void __iomem *msix_map_region(struct pci_dev *dev, unsigned nr_entries)
>  
>  static int msix_setup_entries(struct pci_dev *dev, void __iomem *base,
>  			      struct msix_entry *entries, int nvec,
> -			      bool affinity)
> +			      const struct irq_affinity *affd)
>  {
>  	struct cpumask *curmsk, *masks = NULL;
>  	struct msi_desc *entry;
>  	int ret, i;
>  
> -	if (affinity) {
> -		masks = irq_create_affinity_masks(nvec, NULL);
> +	if (affd) {
> +		masks = irq_create_affinity_masks(nvec, affd);
>  		if (!masks)
>  			pr_err("Unable to allocate affinity masks, ignoring\n");
>  	}
> @@ -753,14 +754,14 @@ static void msix_program_entries(struct pci_dev *dev,
>   * @dev: pointer to the pci_dev data structure of MSI-X device function
>   * @entries: pointer to an array of struct msix_entry entries
>   * @nvec: number of @entries
> - * @affinity: flag to indicate cpu irq affinity mask should be set
> + * @affd: Optional pointer to enable automatic affinity assignement
>   *
>   * Setup the MSI-X capability structure of device function with a
>   * single MSI-X irq. A return of zero indicates the successful setup of
>   * requested MSI-X entries with allocated irqs or non-zero for otherwise.
>   **/
>  static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries,
> -				int nvec, bool affinity)
> +				int nvec, const struct irq_affinity *affd)
>  {
>  	int ret;
>  	u16 control;
> @@ -775,7 +776,7 @@ static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries,
>  	if (!base)
>  		return -ENOMEM;
>  
> -	ret = msix_setup_entries(dev, base, entries, nvec, affinity);
> +	ret = msix_setup_entries(dev, base, entries, nvec, affd);
>  	if (ret)
>  		return ret;
>  
> @@ -956,7 +957,7 @@ int pci_msix_vec_count(struct pci_dev *dev)
>  EXPORT_SYMBOL(pci_msix_vec_count);
>  
>  static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries,
> -			     int nvec, bool affinity)
> +			     int nvec, const struct irq_affinity *affd)
>  {
>  	int nr_entries;
>  	int i, j;
> @@ -988,7 +989,7 @@ static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries,
>  		dev_info(&dev->dev, "can't enable MSI-X (MSI IRQ already assigned)\n");
>  		return -EINVAL;
>  	}
> -	return msix_capability_init(dev, entries, nvec, affinity);
> +	return msix_capability_init(dev, entries, nvec, affd);
>  }
>  
>  /**
> @@ -1008,7 +1009,7 @@ static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries,
>   **/
>  int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
>  {
> -	return __pci_enable_msix(dev, entries, nvec, false);
> +	return __pci_enable_msix(dev, entries, nvec, NULL);
>  }
>  EXPORT_SYMBOL(pci_enable_msix);
>  
> @@ -1059,9 +1060,8 @@ int pci_msi_enabled(void)
>  EXPORT_SYMBOL(pci_msi_enabled);
>  
>  static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
> -		unsigned int flags)
> +				  const struct irq_affinity *affd)
>  {
> -	bool affinity = flags & PCI_IRQ_AFFINITY;
>  	int nvec;
>  	int rc;
>  
> @@ -1090,13 +1090,13 @@ static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
>  		nvec = maxvec;
>  
>  	for (;;) {
> -		if (affinity) {
> -			nvec = irq_calc_affinity_vectors(nvec, NULL);
> +		if (affd) {
> +			nvec = irq_calc_affinity_vectors(nvec, affd);
>  			if (nvec < minvec)
>  				return -ENOSPC;
>  		}
>  
> -		rc = msi_capability_init(dev, nvec, affinity);
> +		rc = msi_capability_init(dev, nvec, affd);
>  		if (rc == 0)
>  			return nvec;
>  
> @@ -1123,28 +1123,27 @@ static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
>   **/
>  int pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec)
>  {
> -	return __pci_enable_msi_range(dev, minvec, maxvec, 0);
> +	return __pci_enable_msi_range(dev, minvec, maxvec, NULL);
>  }
>  EXPORT_SYMBOL(pci_enable_msi_range);
>  
>  static int __pci_enable_msix_range(struct pci_dev *dev,
> -		struct msix_entry *entries, int minvec, int maxvec,
> -		unsigned int flags)
> +				   struct msix_entry *entries, int minvec,
> +				   int maxvec, const struct irq_affinity *affd)
>  {
> -	bool affinity = flags & PCI_IRQ_AFFINITY;
>  	int rc, nvec = maxvec;
>  
>  	if (maxvec < minvec)
>  		return -ERANGE;
>  
>  	for (;;) {
> -		if (affinity) {
> -			nvec = irq_calc_affinity_vectors(nvec, NULL);
> +		if (affd) {
> +			nvec = irq_calc_affinity_vectors(nvec, affd);
>  			if (nvec < minvec)
>  				return -ENOSPC;
>  		}
>  
> -		rc = __pci_enable_msix(dev, entries, nvec, affinity);
> +		rc = __pci_enable_msix(dev, entries, nvec, affd);
>  		if (rc == 0)
>  			return nvec;
>  
> @@ -1175,7 +1174,7 @@ static int __pci_enable_msix_range(struct pci_dev *dev,
>  int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries,
>  		int minvec, int maxvec)
>  {
> -	return __pci_enable_msix_range(dev, entries, minvec, maxvec, 0);
> +	return __pci_enable_msix_range(dev, entries, minvec, maxvec, NULL);
>  }
>  EXPORT_SYMBOL(pci_enable_msix_range);
>  
> @@ -1199,17 +1198,22 @@ EXPORT_SYMBOL(pci_enable_msix_range);
>  int pci_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,
>  		unsigned int max_vecs, unsigned int flags)
>  {
> +	static const struct irq_affinity msi_default_affd;
> +	const struct irq_affinity *affd = NULL;
>  	int vecs = -ENOSPC;
>  
> +	if (flags & PCI_IRQ_AFFINITY)
> +		affd = &msi_default_affd;
> +
>  	if (flags & PCI_IRQ_MSIX) {
>  		vecs = __pci_enable_msix_range(dev, NULL, min_vecs, max_vecs,
> -				flags);
> +				affd);
>  		if (vecs > 0)
>  			return vecs;
>  	}
>  
>  	if (flags & PCI_IRQ_MSI) {
> -		vecs = __pci_enable_msi_range(dev, min_vecs, max_vecs, flags);
> +		vecs = __pci_enable_msi_range(dev, min_vecs, max_vecs, affd);
>  		if (vecs > 0)
>  			return vecs;
>  	}
> -- 
> 2.1.4
> 
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