Re: [PATCH v6 06/18] PCI: designware-ep: Add generic function for raising MSI irq

[Joao Pinto]

Hi,

Ãs 11:29 PM de 12/19/2017, Niklas Cassel escreveu:
> Add a generic function for raising MSI irqs that can be used by all
> DWC based controllers.
> 
> Note that certain controllers, like DRA7xx, have a special convenience
> register for raising MSI irqs that doesn't require you to explicitly map
> the MSI address. Therefore, it is likely that certain drivers will
> not use this generic function, even if they can.
> 
> Signed-off-by: Niklas Cassel <niklas.cassel@xxxxxxxx>
> ---
>  drivers/pci/dwc/pcie-designware-ep.c | 35 +++++++++++++++++++++++++++++++++++
>  drivers/pci/dwc/pcie-designware.h    |  9 +++++++++
>  2 files changed, 44 insertions(+)
> 
> diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
> index 700ed2f4becf..c5aa1cac5041 100644
> --- a/drivers/pci/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/dwc/pcie-designware-ep.c
> @@ -282,6 +282,41 @@ static const struct pci_epc_ops epc_ops = {
>  	.stop			= dw_pcie_ep_stop,
>  };
>  
> +int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep,
> +			     u8 interrupt_num)
> +{
> +	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> +	struct pci_epc *epc = ep->epc;
> +	u16 msg_ctrl, msg_data;
> +	u32 msg_addr_lower, msg_addr_upper;
> +	u64 msg_addr;
> +	bool has_upper;
> +	int ret;
> +
> +	/* Raise MSI per the PCI Local Bus Specification Revision 3.0, 6.8.1. */
> +	msg_ctrl = dw_pcie_readw_dbi(pci, MSI_MESSAGE_CONTROL);
> +	has_upper = !!(msg_ctrl & PCI_MSI_FLAGS_64BIT);
> +	msg_addr_lower = dw_pcie_readl_dbi(pci, MSI_MESSAGE_ADDR_L32);
> +	if (has_upper) {
> +		msg_addr_upper = dw_pcie_readl_dbi(pci, MSI_MESSAGE_ADDR_U32);
> +		msg_data = dw_pcie_readw_dbi(pci, MSI_MESSAGE_DATA_64);
> +	} else {
> +		msg_addr_upper = 0;
> +		msg_data = dw_pcie_readw_dbi(pci, MSI_MESSAGE_DATA_32);
> +	}
> +	msg_addr = ((u64) msg_addr_upper) << 32 | msg_addr_lower;
> +	ret = dw_pcie_ep_map_addr(epc, ep->msi_mem_phys, msg_addr,
> +				  epc->mem->page_size);
> +	if (ret)
> +		return ret;
> +
> +	writel(msg_data | (interrupt_num - 1), ep->msi_mem);
> +
> +	dw_pcie_ep_unmap_addr(epc, ep->msi_mem_phys);
> +
> +	return 0;
> +}
> +
>  void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
>  {
>  	struct pci_epc *epc = ep->epc;
> diff --git a/drivers/pci/dwc/pcie-designware.h b/drivers/pci/dwc/pcie-designware.h
> index 37dfad8d003f..24edac035160 100644
> --- a/drivers/pci/dwc/pcie-designware.h
> +++ b/drivers/pci/dwc/pcie-designware.h
> @@ -106,6 +106,8 @@
>  #define MSI_CAP_MME_MASK		(7 << MSI_CAP_MME_SHIFT)
>  #define MSI_MESSAGE_ADDR_L32		0x54
>  #define MSI_MESSAGE_ADDR_U32		0x58
> +#define MSI_MESSAGE_DATA_32		0x58
> +#define MSI_MESSAGE_DATA_64		0x5C
>  
>  /*
>   * Maximum number of MSI IRQs can be 256 per controller. But keep
> @@ -338,6 +340,7 @@ static inline int dw_pcie_host_init(struct pcie_port *pp)
>  void dw_pcie_ep_linkup(struct dw_pcie_ep *ep);
>  int dw_pcie_ep_init(struct dw_pcie_ep *ep);
>  void dw_pcie_ep_exit(struct dw_pcie_ep *ep);
> +int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 interrupt_num);
>  void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar);
>  #else
>  static inline void dw_pcie_ep_linkup(struct dw_pcie_ep *ep)
> @@ -353,6 +356,12 @@ static inline void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
>  {
>  }
>  
> +static inline int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep,
> +					   u8 interrupt_num)
> +{
> +	return 0;
> +}
> +
>  static inline void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar)
>  {
>  }
> 

Acked-by: Joao Pinto <jpinto@xxxxxxxxxxxx>