Re: [PATCH v2 2/7] PCI: dwc: Add MSI-X callbacks handler

[Kishon Vijay Abraham I]

Hi,

On Thursday 17 May 2018 10:39 PM, Gustavo Pimentel wrote:
> Change pcie_raise_irq() signature, namely the interrupt_num variable type
> from u8 to u16 to accommodate 2048 maximum MSI-X interrupts.
> 
> Add PCIe config space capability search function.
> 
> Add sysfs set/get interface to allow the change of EP MSI-X maximum number.
> 
> Add EP MSI-X callback for triggering interruptions.
> 
> Signed-off-by: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
> ---
> Change v1->v2:
>  - Nothing changed, just to follow the patch set version.
> 
>  drivers/pci/dwc/pci-dra7xx.c           |   2 +-
>  drivers/pci/dwc/pcie-artpec6.c         |   2 +-
>  drivers/pci/dwc/pcie-designware-ep.c   | 146 ++++++++++++++++++++++++++++++++-
>  drivers/pci/dwc/pcie-designware-plat.c |   4 +-
>  drivers/pci/dwc/pcie-designware.h      |  14 +++-
>  5 files changed, 163 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/pci/dwc/pci-dra7xx.c b/drivers/pci/dwc/pci-dra7xx.c
> index f688204..bdf948b 100644
> --- a/drivers/pci/dwc/pci-dra7xx.c
> +++ b/drivers/pci/dwc/pci-dra7xx.c
> @@ -370,7 +370,7 @@ static void dra7xx_pcie_raise_msi_irq(struct dra7xx_pcie *dra7xx,
>  }
>  
>  static int dra7xx_pcie_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
> -				 enum pci_epc_irq_type type, u8 interrupt_num)
> +				 enum pci_epc_irq_type type, u16 interrupt_num)
>  {
>  	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
>  	struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pci);
> diff --git a/drivers/pci/dwc/pcie-artpec6.c b/drivers/pci/dwc/pcie-artpec6.c
> index 321b56c..9a2474b 100644
> --- a/drivers/pci/dwc/pcie-artpec6.c
> +++ b/drivers/pci/dwc/pcie-artpec6.c
> @@ -428,7 +428,7 @@ static void artpec6_pcie_ep_init(struct dw_pcie_ep *ep)
>  }
>  
>  static int artpec6_pcie_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
> -				  enum pci_epc_irq_type type, u8 interrupt_num)
> +				  enum pci_epc_irq_type type, u16 interrupt_num)
>  {
>  	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);

I think you should change pci_epc_raise_irq (in previous patch) and the above
two changes in a separate patch. You can also include pcie-cadence-ep.c along
with that.
>  
> diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
> index 1eec441..e5f2377 100644
> --- a/drivers/pci/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/dwc/pcie-designware-ep.c
> @@ -40,6 +40,39 @@ void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar)
>  	__dw_pcie_ep_reset_bar(pci, bar, 0);
>  }
>  
> +u8 __dw_pcie_ep_find_next_cap(struct dw_pcie *pci, u8 cap_ptr,
> +			      u8 cap)
> +{
> +	u8 cap_id, next_cap_ptr;
> +	u16 reg;
> +
> +	reg = dw_pcie_readw_dbi(pci, cap_ptr);
> +	next_cap_ptr = (reg & 0xff00) >> 8;
> +	cap_id = (reg & 0x00ff);
> +
> +	if (!next_cap_ptr || cap_id > PCI_CAP_ID_MAX)
> +		return 0;
> +
> +	if (cap_id == cap)
> +		return cap_ptr;
> +
> +	return __dw_pcie_ep_find_next_cap(pci, next_cap_ptr, cap);
> +}
> +
> +u8 dw_pcie_ep_find_capability(struct dw_pcie *pci, u8 cap)
> +{
> +	u8 next_cap_ptr;
> +	u16 reg;
> +
> +	reg = dw_pcie_readw_dbi(pci, PCI_CAPABILITY_LIST);
> +	next_cap_ptr = (reg & 0x00ff);
> +
> +	if (!next_cap_ptr)
> +		return 0;
> +
> +	return __dw_pcie_ep_find_next_cap(pci, next_cap_ptr, cap);
> +}
> +
>  static int dw_pcie_ep_write_header(struct pci_epc *epc, u8 func_no,
>  				   struct pci_epf_header *hdr)
>  {
> @@ -241,8 +274,47 @@ static int dw_pcie_ep_set_msi(struct pci_epc *epc, u8 func_no, u8 encode_int)
>  	return 0;
>  }
>  
> +static int dw_pcie_ep_get_msix(struct pci_epc *epc, u8 func_no)
> +{
> +	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
> +	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> +	u32 val, reg;
> +
> +	if (!ep->msix_cap)
> +		return 0;

return -EINVAL?

or pci_epc_get_msix() will return 1.
> +
> +	reg = ep->msix_cap + PCI_MSIX_FLAGS;
> +	val = dw_pcie_readw_dbi(pci, reg);
> +	if (!(val & PCI_MSIX_FLAGS_ENABLE))
> +		return -EINVAL;
> +
> +	val &= PCI_MSIX_FLAGS_QSIZE;
> +
> +	return val;
> +}
> +
> +static int dw_pcie_ep_set_msix(struct pci_epc *epc, u8 func_no, u16 interrupts)
> +{
> +	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
> +	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> +	u32 val, reg;
> +
> +	if (!ep->msix_cap)
> +		return 0;

here too return -EINVAL.
> +
> +	reg = ep->msix_cap + PCI_MSIX_FLAGS;
> +	val = dw_pcie_readw_dbi(pci, reg);
> +	val &= ~PCI_MSIX_FLAGS_QSIZE;
> +	val |= interrupts;
> +	dw_pcie_dbi_ro_wr_en(pci);
> +	dw_pcie_writew_dbi(pci, reg, val);
> +	dw_pcie_dbi_ro_wr_dis(pci);
> +
> +	return 0;
> +}
> +
>  static int dw_pcie_ep_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)
>  {
>  	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
>  
> @@ -282,6 +354,8 @@ static const struct pci_epc_ops epc_ops = {
>  	.unmap_addr		= dw_pcie_ep_unmap_addr,
>  	.set_msi		= dw_pcie_ep_set_msi,
>  	.get_msi		= dw_pcie_ep_get_msi,
> +	.set_msix		= dw_pcie_ep_set_msix,
> +	.get_msix		= dw_pcie_ep_get_msix,
>  	.raise_irq		= dw_pcie_ep_raise_irq,
>  	.start			= dw_pcie_ep_start,
>  	.stop			= dw_pcie_ep_stop,
> @@ -322,6 +396,64 @@ int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
>  	return 0;
>  }
>  
> +int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
> +			     u16 interrupt_num)
> +{
> +	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> +	struct pci_epc *epc = ep->epc;
> +	u16 tbl_offset, bir;
> +	u32 bar_addr_upper, bar_addr_lower;
> +	u32 msg_addr_upper, msg_addr_lower;
> +	u32 reg, msg_data, vec_ctrl;
> +	u64 tbl_addr, msg_addr, reg_u64;
> +	void __iomem *msix_tbl;
> +	int ret;
> +
> +	reg = ep->msix_cap + PCI_MSIX_TABLE;
> +	tbl_offset = dw_pcie_readl_dbi(pci, reg);
> +	bir = (tbl_offset & PCI_MSIX_TABLE_BIR);
> +	tbl_offset &= PCI_MSIX_TABLE_OFFSET;
> +	tbl_offset >>= 3;
> +
> +	reg = PCI_BASE_ADDRESS_0 + (4 * bir);
> +	bar_addr_lower = dw_pcie_readl_dbi(pci, reg);
> +	reg_u64 = (bar_addr_lower & PCI_BASE_ADDRESS_MEM_TYPE_MASK);
> +	if (reg_u64 == PCI_BASE_ADDRESS_MEM_TYPE_64)
> +		bar_addr_upper = dw_pcie_readl_dbi(pci, reg + 4);
> +	else
> +		bar_addr_upper = 0;

You can skip else if you can use something like below

bar_addr_upper = 0
bar_addr_lower = dw_pcie_readl_dbi(pci, reg);
reg_u64 = (bar_addr_lower & PCI_BASE_ADDRESS_MEM_TYPE_MASK);
if (reg_u64 == PCI_BASE_ADDRESS_MEM_TYPE_64)
	bar_addr_upper = dw_pcie_readl_dbi(pci, reg + 4);
> +
> +	tbl_addr = ((u64) bar_addr_upper) << 32 | bar_addr_lower;
> +	tbl_addr += (tbl_offset + ((interrupt_num - 1) * PCI_MSIX_ENTRY_SIZE));
> +	tbl_addr &= PCI_BASE_ADDRESS_MEM_MASK;
> +
> +	msix_tbl = ioremap_nocache(ep->phys_base + tbl_addr, ep->addr_size);

Why do you want to ioremap the entire address region?
> +	if (!msix_tbl)
> +		return -EINVAL;
> +
> +	msg_addr_lower = readl(msix_tbl + PCI_MSIX_ENTRY_LOWER_ADDR);
> +	msg_addr_upper = readl(msix_tbl + PCI_MSIX_ENTRY_UPPER_ADDR);
> +	msg_addr = ((u64) msg_addr_upper) << 32 | msg_addr_lower;
> +	msg_data = readl(msix_tbl + PCI_MSIX_ENTRY_DATA);
> +	vec_ctrl = readl(msix_tbl + PCI_MSIX_ENTRY_VECTOR_CTRL);
> +
> +	if (vec_ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT)
> +		return -EPERM;
> +
> +	iounmap(msix_tbl);
> +
> +	ret = dw_pcie_ep_map_addr(epc, func_no, ep->msix_mem_phys, msg_addr,
> +				  epc->mem->page_size);
> +	if (ret)
> +		return ret;
> +
> +	writel(msg_data, ep->msix_mem);
> +
> +	dw_pcie_ep_unmap_addr(epc, func_no, ep->msix_mem_phys);
> +
> +	return 0;
> +}
> +
>  void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
>  {
>  	struct pci_epc *epc = ep->epc;
> @@ -329,6 +461,9 @@ void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
>  	pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem,
>  			      epc->mem->page_size);
>  
> +	pci_epc_mem_free_addr(epc, ep->msix_mem_phys, ep->msix_mem,
> +			      epc->mem->page_size);
> +
>  	pci_epc_mem_exit(epc);
>  }
>  
> @@ -410,6 +545,15 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
>  		dev_err(dev, "Failed to reserve memory for MSI\n");
>  		return -ENOMEM;
>  	}
> +	ep->msi_cap = dw_pcie_ep_find_capability(pci, PCI_CAP_ID_MSI);

msi_cap is not used anywhere else.

Thanks
Kishon