Re: [PATCH v3 09/14] PCI: cadence: Add MSI-X support to Endpoint driver
From: Rob Herring
Date: Wed Apr 29 2020 - 21:55:31 EST
On Fri, Apr 17, 2020 at 06:27:48PM +0530, Kishon Vijay Abraham I wrote:
> From: Alan Douglas <adouglas@xxxxxxxxxxx>
>
> Implement ->set_msix() and ->get_msix() callback functions in order
> to configure MSIX capability in the PCIe endpoint controller.
>
> Add cdns_pcie_ep_send_msix_irq() to send MSIX interrupts to Host.
> cdns_pcie_ep_send_msix_irq() gets the MSIX table address (virtual
> address) from "struct cdns_pcie_epf" that gets initialized in
> ->set_bar() call back function.
>
> [kishon@xxxxxx: Re-implement MSIX support in accordance with the
> re-designed core MSI-X interfaces]
> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
> Signed-off-by: Alan Douglas <adouglas@xxxxxxxxxxx>
Your Sob should be last.
> ---
> .../pci/controller/cadence/pcie-cadence-ep.c | 112 +++++++++++++++++-
> drivers/pci/controller/cadence/pcie-cadence.h | 10 ++
> 2 files changed, 121 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/controller/cadence/pcie-cadence-ep.c b/drivers/pci/controller/cadence/pcie-cadence-ep.c
> index 14021d760482..c43340ca0630 100644
> --- a/drivers/pci/controller/cadence/pcie-cadence-ep.c
> +++ b/drivers/pci/controller/cadence/pcie-cadence-ep.c
> @@ -51,6 +51,7 @@ static int cdns_pcie_ep_set_bar(struct pci_epc *epc, u8 fn,
> struct pci_epf_bar *epf_bar)
> {
> struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
> + struct cdns_pcie_epf *epf = &ep->epf[fn];
> struct cdns_pcie *pcie = &ep->pcie;
> dma_addr_t bar_phys = epf_bar->phys_addr;
> enum pci_barno bar = epf_bar->barno;
> @@ -111,6 +112,8 @@ static int cdns_pcie_ep_set_bar(struct pci_epc *epc, u8 fn,
> CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL(b, ctrl));
> cdns_pcie_writel(pcie, reg, cfg);
>
> + epf->epf_bar[bar] = epf_bar;
> +
> return 0;
> }
>
> @@ -118,6 +121,7 @@ static void cdns_pcie_ep_clear_bar(struct pci_epc *epc, u8 fn,
> struct pci_epf_bar *epf_bar)
> {
> struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
> + struct cdns_pcie_epf *epf = &ep->epf[fn];
> struct cdns_pcie *pcie = &ep->pcie;
> enum pci_barno bar = epf_bar->barno;
> u32 reg, cfg, b, ctrl;
> @@ -139,6 +143,8 @@ static void cdns_pcie_ep_clear_bar(struct pci_epc *epc, u8 fn,
>
> cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR0(fn, bar), 0);
> cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR1(fn, bar), 0);
> +
> + epf->epf_bar[bar] = NULL;
> }
>
> static int cdns_pcie_ep_map_addr(struct pci_epc *epc, u8 fn, phys_addr_t addr,
> @@ -224,6 +230,50 @@ static int cdns_pcie_ep_get_msi(struct pci_epc *epc, u8 fn)
> return mme;
> }
>
> +static int cdns_pcie_ep_get_msix(struct pci_epc *epc, u8 func_no)
> +{
> + struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
> + struct cdns_pcie *pcie = &ep->pcie;
> + u32 cap = CDNS_PCIE_EP_FUNC_MSIX_CAP_OFFSET;
> + u32 val, reg;
> +
> + reg = cap + PCI_MSIX_FLAGS;
> + val = cdns_pcie_ep_fn_readw(pcie, func_no, reg);
> + if (!(val & PCI_MSIX_FLAGS_ENABLE))
> + return -EINVAL;
> +
> + val &= PCI_MSIX_FLAGS_QSIZE;
> +
> + return val;
> +}
> +
> +static int cdns_pcie_ep_set_msix(struct pci_epc *epc, u8 fn, u16 interrupts,
> + enum pci_barno bir, u32 offset)
> +{
> + struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
> + struct cdns_pcie *pcie = &ep->pcie;
> + u32 cap = CDNS_PCIE_EP_FUNC_MSIX_CAP_OFFSET;
> + u32 val, reg;
> +
> + reg = cap + PCI_MSIX_FLAGS;
> + val = cdns_pcie_ep_fn_readw(pcie, fn, reg);
> + val &= ~PCI_MSIX_FLAGS_QSIZE;
> + val |= interrupts;
> + cdns_pcie_ep_fn_writew(pcie, fn, reg, val);
> +
> + /* Set MSIX BAR and offset */
> + reg = cap + PCI_MSIX_TABLE;
> + val = offset | bir;
> + cdns_pcie_ep_fn_writel(pcie, fn, reg, val);
> +
> + /* Set PBA BAR and offset. BAR must match MSIX BAR */
> + reg = cap + PCI_MSIX_PBA;
> + val = (offset + (interrupts * PCI_MSIX_ENTRY_SIZE)) | bir;
> + cdns_pcie_ep_fn_writel(pcie, fn, reg, val);
> +
> + return 0;
> +}
> +
> static void cdns_pcie_ep_assert_intx(struct cdns_pcie_ep *ep, u8 fn,
> u8 intx, bool is_asserted)
> {
> @@ -330,6 +380,56 @@ static int cdns_pcie_ep_send_msi_irq(struct cdns_pcie_ep *ep, u8 fn,
> return 0;
> }
>
> +static int cdns_pcie_ep_send_msix_irq(struct cdns_pcie_ep *ep, u8 fn,
> + u16 interrupt_num)
> +{
> + u32 cap = CDNS_PCIE_EP_FUNC_MSIX_CAP_OFFSET;
> + u32 tbl_offset, msg_data, reg, vec_ctrl;
> + struct cdns_pcie *pcie = &ep->pcie;
> + struct pci_epf_msix_tbl *msix_tbl;
> + struct pci_epf_bar *epf_bar;
> + struct cdns_pcie_epf *epf;
> + u64 pci_addr_mask = 0xff;
> + u64 msg_addr;
> + u16 flags;
> + u8 bir;
> +
> + /* Check whether the MSI-X feature has been enabled by the PCI host. */
> + flags = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_MSIX_FLAGS);
> + if (!(flags & PCI_MSIX_FLAGS_ENABLE))
> + return -EINVAL;
> +
> + reg = cap + PCI_MSIX_TABLE;
> + tbl_offset = cdns_pcie_ep_fn_readl(pcie, fn, reg);
> + bir = tbl_offset & PCI_MSIX_TABLE_BIR;
> + tbl_offset &= PCI_MSIX_TABLE_OFFSET;
> +
> + epf = &ep->epf[fn];
> + epf_bar = epf->epf_bar[bir];
> + msix_tbl = epf_bar->addr;
> + msix_tbl = (struct pci_epf_msix_tbl *)((char *)msix_tbl + tbl_offset);
> +
> + msg_addr = msix_tbl[(interrupt_num - 1)].msg_addr;
> + msg_data = msix_tbl[(interrupt_num - 1)].msg_data;
> + vec_ctrl = msix_tbl[(interrupt_num - 1)].vector_ctrl;
> +
> + /* Set the outbound region if needed. */
> + if (ep->irq_pci_addr != (msg_addr & ~pci_addr_mask) ||
> + ep->irq_pci_fn != fn) {
> + /* First region was reserved for IRQ writes. */
> + cdns_pcie_set_outbound_region(pcie, fn, 0,
> + false,
> + ep->irq_phys_addr,
> + msg_addr & ~pci_addr_mask,
> + pci_addr_mask + 1);
> + ep->irq_pci_addr = (msg_addr & ~pci_addr_mask);
> + ep->irq_pci_fn = fn;
> + }
> + writel(msg_data, ep->irq_cpu_addr + (msg_addr & pci_addr_mask));
> +
> + return 0;
> +}
> +
> static int cdns_pcie_ep_raise_irq(struct pci_epc *epc, u8 fn,
> enum pci_epc_irq_type type,
> u16 interrupt_num)
> @@ -343,6 +443,9 @@ static int cdns_pcie_ep_raise_irq(struct pci_epc *epc, u8 fn,
> case PCI_EPC_IRQ_MSI:
> return cdns_pcie_ep_send_msi_irq(ep, fn, interrupt_num);
>
> + case PCI_EPC_IRQ_MSIX:
> + return cdns_pcie_ep_send_msix_irq(ep, fn, interrupt_num);
> +
> default:
> break;
> }
> @@ -380,7 +483,7 @@ static int cdns_pcie_ep_start(struct pci_epc *epc)
> static const struct pci_epc_features cdns_pcie_epc_features = {
> .linkup_notifier = false,
> .msi_capable = true,
> - .msix_capable = false,
> + .msix_capable = true,
> };
>
> static const struct pci_epc_features*
> @@ -397,6 +500,8 @@ static const struct pci_epc_ops cdns_pcie_epc_ops = {
> .unmap_addr = cdns_pcie_ep_unmap_addr,
> .set_msi = cdns_pcie_ep_set_msi,
> .get_msi = cdns_pcie_ep_get_msi,
> + .set_msix = cdns_pcie_ep_set_msix,
> + .get_msix = cdns_pcie_ep_get_msix,
> .raise_irq = cdns_pcie_ep_raise_irq,
> .start = cdns_pcie_ep_start,
> .get_features = cdns_pcie_ep_get_features,
> @@ -455,6 +560,11 @@ int cdns_pcie_ep_setup(struct cdns_pcie_ep *ep)
> if (of_property_read_u8(np, "max-functions", &epc->max_functions) < 0)
> epc->max_functions = 1;
>
> + ep->epf = devm_kcalloc(dev, epc->max_functions, sizeof(*ep->epf),
> + GFP_KERNEL);
> + if (!ep->epf)
> + return -ENOMEM;
> +
> ret = pci_epc_mem_init(epc, pcie->mem_res->start,
> resource_size(pcie->mem_res));
> if (ret < 0) {
> diff --git a/drivers/pci/controller/cadence/pcie-cadence.h b/drivers/pci/controller/cadence/pcie-cadence.h
> index 16a6b0ee547c..ea850290a602 100644
> --- a/drivers/pci/controller/cadence/pcie-cadence.h
> +++ b/drivers/pci/controller/cadence/pcie-cadence.h
> @@ -99,6 +99,7 @@
> #define CDNS_PCIE_EP_FUNC_BASE(fn) (((fn) << 12) & GENMASK(19, 12))
>
> #define CDNS_PCIE_EP_FUNC_MSI_CAP_OFFSET 0x90
> +#define CDNS_PCIE_EP_FUNC_MSIX_CAP_OFFSET 0xb0
>
> /*
> * Root Port Registers (PCI configuration space for the root port function)
> @@ -280,6 +281,14 @@ struct cdns_pcie_rc {
> u32 device_id;
> };
>
> +/**
> + * struct cdns_pcie_epf - Structure to hold info about endpoint function
> + * @epf_bar: reference to the pci_epf_bar for the six Base Address Registers
> + */
> +struct cdns_pcie_epf {
> + struct pci_epf_bar *epf_bar[PCI_STD_NUM_BARS];
> +};
> +
> /**
> * struct cdns_pcie_ep - private data for this PCIe endpoint controller driver
> * @pcie: Cadence PCIe controller
> @@ -307,6 +316,7 @@ struct cdns_pcie_ep {
> u64 irq_pci_addr;
> u8 irq_pci_fn;
> u8 irq_pending;
> + struct cdns_pcie_epf *epf;
> };
>
>
> --
> 2.17.1
>