Re: [PATCH v2 1/7] PCI: endpoint: Add MSI-X interfaces

[Kishon Vijay Abraham I <kishon@ti.com>]

On Thursday 17 May 2018 10:39 PM, Gustavo Pimentel wrote:
> Add PCI_EPC_IRQ_MSIX type.
> 
> Add MSI-X callbacks signatures to the ops structure.
> 
> Add sysfs interface for set/get MSI-X capability maximum number.
> 
> Change pci_epc_raise_irq() signature, namely the interrupt_num variable type
> from u8 to u16 to accommodate 2048 maximum MSI-X interrupts.
> 
> Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>

Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
> ---
> Change v1->v2:
>  - Nothing changed, just to follow the patch set version.
> 
>  drivers/pci/endpoint/pci-ep-cfs.c   | 24 +++++++++++++++
>  drivers/pci/endpoint/pci-epc-core.c | 59 ++++++++++++++++++++++++++++++++++++-
>  include/linux/pci-epc.h             | 13 ++++++--
>  include/linux/pci-epf.h             |  1 +
>  4 files changed, 94 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/endpoint/pci-ep-cfs.c b/drivers/pci/endpoint/pci-ep-cfs.c
> index 018ea34..d1288a0 100644
> --- a/drivers/pci/endpoint/pci-ep-cfs.c
> +++ b/drivers/pci/endpoint/pci-ep-cfs.c
> @@ -286,6 +286,28 @@ static ssize_t pci_epf_msi_interrupts_show(struct config_item *item,
>  		       to_pci_epf_group(item)->epf->msi_interrupts);
>  }
>  
> +static ssize_t pci_epf_msix_interrupts_store(struct config_item *item,
> +					     const char *page, size_t len)
> +{
> +	u16 val;
> +	int ret;
> +
> +	ret = kstrtou16(page, 0, &val);
> +	if (ret)
> +		return ret;
> +
> +	to_pci_epf_group(item)->epf->msix_interrupts = val;
> +
> +	return len;
> +}
> +
> +static ssize_t pci_epf_msix_interrupts_show(struct config_item *item,
> +					    char *page)
> +{
> +	return sprintf(page, "%d\n",
> +		       to_pci_epf_group(item)->epf->msix_interrupts);
> +}
> +
>  PCI_EPF_HEADER_R(vendorid)
>  PCI_EPF_HEADER_W_u16(vendorid)
>  
> @@ -327,6 +349,7 @@ CONFIGFS_ATTR(pci_epf_, subsys_vendor_id);
>  CONFIGFS_ATTR(pci_epf_, subsys_id);
>  CONFIGFS_ATTR(pci_epf_, interrupt_pin);
>  CONFIGFS_ATTR(pci_epf_, msi_interrupts);
> +CONFIGFS_ATTR(pci_epf_, msix_interrupts);
>  
>  static struct configfs_attribute *pci_epf_attrs[] = {
>  	&pci_epf_attr_vendorid,
> @@ -340,6 +363,7 @@ static struct configfs_attribute *pci_epf_attrs[] = {
>  	&pci_epf_attr_subsys_id,
>  	&pci_epf_attr_interrupt_pin,
>  	&pci_epf_attr_msi_interrupts,
> +	&pci_epf_attr_msix_interrupts,
>  	NULL,
>  };
>  
> diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
> index b0ee427..a23aa75 100644
> --- a/drivers/pci/endpoint/pci-epc-core.c
> +++ b/drivers/pci/endpoint/pci-epc-core.c
> @@ -137,7 +137,7 @@ EXPORT_SYMBOL_GPL(pci_epc_start);
>   * Invoke to raise an MSI or legacy interrupt
>   */
>  int pci_epc_raise_irq(struct pci_epc *epc, u8 func_no,
> -		      enum pci_epc_irq_type type, u8 interrupt_num)
> +		      enum pci_epc_irq_type type, u16 interrupt_num)
>  {
>  	int ret;
>  	unsigned long flags;
> @@ -218,6 +218,63 @@ int pci_epc_set_msi(struct pci_epc *epc, u8 func_no, u8 interrupts)
>  EXPORT_SYMBOL_GPL(pci_epc_set_msi);
>  
>  /**
> + * pci_epc_get_msix() - get the number of MSI-X interrupt numbers allocated
> + * @epc: the EPC device to which MSI-X interrupts was requested
> + * @func_no: the endpoint function number in the EPC device
> + *
> + * Invoke to get the number of MSI-X interrupts allocated by the RC
> + */
> +int pci_epc_get_msix(struct pci_epc *epc, u8 func_no)
> +{
> +	int interrupt;
> +	unsigned long flags;
> +
> +	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
> +		return 0;
> +
> +	if (!epc->ops->get_msix)
> +		return 0;
> +
> +	spin_lock_irqsave(&epc->lock, flags);
> +	interrupt = epc->ops->get_msix(epc, func_no);
> +	spin_unlock_irqrestore(&epc->lock, flags);
> +
> +	if (interrupt < 0)
> +		return 0;
> +
> +	return interrupt + 1;
> +}
> +EXPORT_SYMBOL_GPL(pci_epc_get_msix);
> +
> +/**
> + * pci_epc_set_msix() - set the number of MSI-X interrupt numbers required
> + * @epc: the EPC device on which MSI-X has to be configured
> + * @func_no: the endpoint function number in the EPC device
> + * @interrupts: number of MSI-X interrupts required by the EPF
> + *
> + * Invoke to set the required number of MSI-X interrupts.
> + */
> +int pci_epc_set_msix(struct pci_epc *epc, u8 func_no, u16 interrupts)
> +{
> +	int ret;
> +	unsigned long flags;
> +
> +	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||
> +	    interrupts < 1 || interrupts > 2048)
> +		return -EINVAL;
> +
> +	if (!epc->ops->set_msix)
> +		return 0;
> +
> +	spin_lock_irqsave(&epc->lock, flags);
> +	ret = epc->ops->set_msix(epc, func_no, interrupts - 1);
> +	spin_unlock_irqrestore(&epc->lock, flags);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(pci_epc_set_msix);
> +
> +/**
>   * pci_epc_unmap_addr() - unmap CPU address from PCI address
>   * @epc: the EPC device on which address is allocated
>   * @func_no: the endpoint function number in the EPC device
> diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
> index 243eaa5..c73abc2 100644
> --- a/include/linux/pci-epc.h
> +++ b/include/linux/pci-epc.h
> @@ -17,6 +17,7 @@ enum pci_epc_irq_type {
>  	PCI_EPC_IRQ_UNKNOWN,
>  	PCI_EPC_IRQ_LEGACY,
>  	PCI_EPC_IRQ_MSI,
> +	PCI_EPC_IRQ_MSIX,
>  };
>  
>  /**
> @@ -30,6 +31,10 @@ enum pci_epc_irq_type {
>   *	     capability register
>   * @get_msi: ops to get the number of MSI interrupts allocated by the RC from
>   *	     the MSI capability register
> + * @set_msix: ops to set the requested number of MSI-X interrupts in the
> + *	     MSI-X capability register
> + * @get_msix: ops to get the number of MSI-X interrupts allocated by the RC
> + *	     from the MSI-X capability register
>   * @raise_irq: ops to raise a legacy or MSI interrupt
>   * @start: ops to start the PCI link
>   * @stop: ops to stop the PCI link
> @@ -48,8 +53,10 @@ struct pci_epc_ops {
>  			      phys_addr_t addr);
>  	int	(*set_msi)(struct pci_epc *epc, u8 func_no, u8 interrupts);
>  	int	(*get_msi)(struct pci_epc *epc, u8 func_no);
> +	int	(*set_msix)(struct pci_epc *epc, u8 func_no, u16 interrupts);
> +	int	(*get_msix)(struct pci_epc *epc, u8 func_no);
>  	int	(*raise_irq)(struct pci_epc *epc, u8 func_no,
> -			     enum pci_epc_irq_type type, u8 interrupt_num);
> +			     enum pci_epc_irq_type type, u16 interrupt_num);
>  	int	(*start)(struct pci_epc *epc);
>  	void	(*stop)(struct pci_epc *epc);
>  	struct module *owner;
> @@ -144,8 +151,10 @@ void pci_epc_unmap_addr(struct pci_epc *epc, u8 func_no,
>  			phys_addr_t phys_addr);
>  int pci_epc_set_msi(struct pci_epc *epc, u8 func_no, u8 interrupts);
>  int pci_epc_get_msi(struct pci_epc *epc, u8 func_no);
> +int pci_epc_set_msix(struct pci_epc *epc, u8 func_no, u16 interrupts);
> +int pci_epc_get_msix(struct pci_epc *epc, u8 func_no);
>  int pci_epc_raise_irq(struct pci_epc *epc, u8 func_no,
> -		      enum pci_epc_irq_type type, u8 interrupt_num);
> +		      enum pci_epc_irq_type type, u16 interrupt_num);
>  int pci_epc_start(struct pci_epc *epc);
>  void pci_epc_stop(struct pci_epc *epc);
>  struct pci_epc *pci_epc_get(const char *epc_name);
> diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
> index f7d6f48..9bb1f31 100644
> --- a/include/linux/pci-epf.h
> +++ b/include/linux/pci-epf.h
> @@ -119,6 +119,7 @@ struct pci_epf {
>  	struct pci_epf_header	*header;
>  	struct pci_epf_bar	bar[6];
>  	u8			msi_interrupts;
> +	u16			msix_interrupts;
>  	u8			func_no;
>  
>  	struct pci_epc		*epc;
>