Re: [PATCH v3 09/14] PCI: cadence: Add MSI-X support to Endpoint driver

From: Kishon Vijay Abraham I
Date: Tue May 05 2020 - 23:58:56 EST


Hi Rob,

On 4/30/2020 7:25 AM, Rob Herring wrote:
> 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.

Will fix this!

Thanks
Kishon
>
>> ---
>> .../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
>>