Re: [PATCH v6 04/11] PCI: designware-ep: Modify MSI and MSIX CAP way of finding

Bjorn Helgaas <helgaas@xxxxxxxxxx> · Wed, 23 Sep 2020 15:16:13 -0500

s/MSIX/MSI-X/ (subject and below)

On Sat, Mar 14, 2020 at 11:30:31AM +0800, Xiaowei Bao wrote:
> Each PF of EP device should have it's own MSI or MSIX capabitily
> struct, so create a dw_pcie_ep_func struct and remove the msi_cap
> and msix_cap to this struct from dw_pcie_ep, and manage the PFs
> with a list.

s/capabitily/capability/

I know Lorenzo has already applied this, but for the future, or
in case there are other reasons to update this patch.

There are a bunch of unnecessary initializations below for future
cleanup.

> Signed-off-by: Xiaowei Bao <xiaowei.bao@xxxxxxx>
> ---
> v3:
>  - This is a new patch, to fix the issue of MSI and MSIX CAP way of
>    finding.
> v4:
>  - Correct some word of commit message.
> v5:
>  - No change.
> v6:
>  - Fix up the compile error.
> 
>  drivers/pci/controller/dwc/pcie-designware-ep.c | 135 +++++++++++++++++++++---
>  drivers/pci/controller/dwc/pcie-designware.h    |  18 +++-
>  2 files changed, 134 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> index 933bb89..fb915f2 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> @@ -19,6 +19,19 @@ void dw_pcie_ep_linkup(struct dw_pcie_ep *ep)
>  	pci_epc_linkup(epc);
>  }
>  
> +struct dw_pcie_ep_func *
> +dw_pcie_ep_get_func_from_ep(struct dw_pcie_ep *ep, u8 func_no)
> +{
> +	struct dw_pcie_ep_func *ep_func;
> +
> +	list_for_each_entry(ep_func, &ep->func_list, list) {
> +		if (ep_func->func_no == func_no)
> +			return ep_func;
> +	}
> +
> +	return NULL;
> +}
> +
>  static unsigned int dw_pcie_ep_func_select(struct dw_pcie_ep *ep, u8 func_no)
>  {
>  	unsigned int func_offset = 0;
> @@ -59,6 +72,47 @@ void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar)
>  		__dw_pcie_ep_reset_bar(pci, func_no, bar, 0);
>  }
>  
> +static u8 __dw_pcie_ep_find_next_cap(struct dw_pcie_ep *ep, u8 func_no,
> +		u8 cap_ptr, u8 cap)
> +{
> +	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> +	unsigned int func_offset = 0;

Unnecessary initialization.

> +	u8 cap_id, next_cap_ptr;
> +	u16 reg;
> +
> +	if (!cap_ptr)
> +		return 0;
> +
> +	func_offset = dw_pcie_ep_func_select(ep, func_no);
> +
> +	reg = dw_pcie_readw_dbi(pci, func_offset + cap_ptr);
> +	cap_id = (reg & 0x00ff);
> +
> +	if (cap_id > PCI_CAP_ID_MAX)
> +		return 0;
> +
> +	if (cap_id == cap)
> +		return cap_ptr;
> +
> +	next_cap_ptr = (reg & 0xff00) >> 8;
> +	return __dw_pcie_ep_find_next_cap(ep, func_no, next_cap_ptr, cap);
> +}
> +
> +static u8 dw_pcie_ep_find_capability(struct dw_pcie_ep *ep, u8 func_no, u8 cap)
> +{
> +	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> +	unsigned int func_offset = 0;

Unnecessary initialization.

> +	u8 next_cap_ptr;
> +	u16 reg;
> +
> +	func_offset = dw_pcie_ep_func_select(ep, func_no);
> +
> +	reg = dw_pcie_readw_dbi(pci, func_offset + PCI_CAPABILITY_LIST);
> +	next_cap_ptr = (reg & 0x00ff);
> +
> +	return __dw_pcie_ep_find_next_cap(ep, func_no, next_cap_ptr, cap);
> +}
> +
>  static int dw_pcie_ep_write_header(struct pci_epc *epc, u8 func_no,
>  				   struct pci_epf_header *hdr)
>  {
> @@ -246,13 +300,18 @@ static int dw_pcie_ep_get_msi(struct pci_epc *epc, u8 func_no)
>  	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
>  	u32 val, reg;
>  	unsigned int func_offset = 0;