Re: [PATCH v8 11/18] PCI: cadence: Implement ->msi_map_irq() ops

From: Rob Herring
Date: Tue Dec 15 2020 - 11:03:15 EST


On Wed, Nov 11, 2020 at 9:37 AM Kishon Vijay Abraham I <kishon@xxxxxx> wrote:
>
> Implement ->msi_map_irq() ops in order to map physical address to
> MSI address and return MSI data.
>
> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
> ---
> .../pci/controller/cadence/pcie-cadence-ep.c | 53 +++++++++++++++++++
> 1 file changed, 53 insertions(+)
>
> diff --git a/drivers/pci/controller/cadence/pcie-cadence-ep.c b/drivers/pci/controller/cadence/pcie-cadence-ep.c
> index 84cc58dc8512..1fe6b8baca97 100644
> --- a/drivers/pci/controller/cadence/pcie-cadence-ep.c
> +++ b/drivers/pci/controller/cadence/pcie-cadence-ep.c
> @@ -382,6 +382,57 @@ static int cdns_pcie_ep_send_msi_irq(struct cdns_pcie_ep *ep, u8 fn,
> return 0;
> }
>
> +static int cdns_pcie_ep_map_msi_irq(struct pci_epc *epc, u8 fn,
> + phys_addr_t addr, u8 interrupt_num,
> + u32 entry_size, u32 *msi_data,
> + u32 *msi_addr_offset)
> +{
> + struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
> + u32 cap = CDNS_PCIE_EP_FUNC_MSI_CAP_OFFSET;
> + struct cdns_pcie *pcie = &ep->pcie;
> + u64 pci_addr, pci_addr_mask = 0xff;
> + u16 flags, mme, data, data_mask;
> + u8 msi_count;
> + int ret;
> + int i;
> +


> + /* Check whether the MSI feature has been enabled by the PCI host. */
> + flags = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_MSI_FLAGS);
> + if (!(flags & PCI_MSI_FLAGS_ENABLE))
> + return -EINVAL;
> +
> + /* Get the number of enabled MSIs */
> + mme = (flags & PCI_MSI_FLAGS_QSIZE) >> 4;
> + msi_count = 1 << mme;
> + if (!interrupt_num || interrupt_num > msi_count)
> + return -EINVAL;
> +
> + /* Compute the data value to be written. */
> + data_mask = msi_count - 1;
> + data = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_MSI_DATA_64);
> + data = data & ~data_mask;
> +
> + /* Get the PCI address where to write the data into. */
> + pci_addr = cdns_pcie_ep_fn_readl(pcie, fn, cap + PCI_MSI_ADDRESS_HI);
> + pci_addr <<= 32;
> + pci_addr |= cdns_pcie_ep_fn_readl(pcie, fn, cap + PCI_MSI_ADDRESS_LO);
> + pci_addr &= GENMASK_ULL(63, 2);

Wouldn't all of the above be the same code for any endpoint driver? We
just need endpoint config space accessors for the same 32-bit only
access issues. Not asking for that in this series, but if that's the
direction we should go.

> +
> + for (i = 0; i < interrupt_num; i++) {
> + ret = cdns_pcie_ep_map_addr(epc, fn, addr,
> + pci_addr & ~pci_addr_mask,
> + entry_size);
> + if (ret)
> + return ret;
> + addr = addr + entry_size;
> + }
> +
> + *msi_data = data;
> + *msi_addr_offset = pci_addr & pci_addr_mask;
> +
> + return 0;
> +}
> +
> static int cdns_pcie_ep_send_msix_irq(struct cdns_pcie_ep *ep, u8 fn,
> u16 interrupt_num)
> {
> @@ -481,6 +532,7 @@ static const struct pci_epc_features cdns_pcie_epc_features = {
> .linkup_notifier = false,
> .msi_capable = true,
> .msix_capable = true,
> + .align = 256,
> };
>
> static const struct pci_epc_features*
> @@ -500,6 +552,7 @@ static const struct pci_epc_ops cdns_pcie_epc_ops = {
> .set_msix = cdns_pcie_ep_set_msix,
> .get_msix = cdns_pcie_ep_get_msix,
> .raise_irq = cdns_pcie_ep_raise_irq,
> + .map_msi_irq = cdns_pcie_ep_map_msi_irq,
> .start = cdns_pcie_ep_start,
> .get_features = cdns_pcie_ep_get_features,
> };
> --
> 2.17.1
>