[PATCH v5 09/14] PCI: cadence: Add MSI-X support to Endpoint driver

Kishon Vijay Abraham I
2020-05-22T03:37:59Z

From: Alan Douglas <adouglas@cadence.com>

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.

Signed-off-by: Alan Douglas <adouglas@cadence.com>
[kishon@ti.com: Re-implement MSIX support in accordance with the
re-designed core MSI-X interfaces]
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
.../pci/controller/cadence/pcie-cadence-ep.c | 108 +++++++++++++++++-
drivers/pci/controller/cadence/pcie-cadence.h | 10 ++
2 files changed, 117 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..c5696274d81f 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 +380,52 @@ 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 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];
+ msix_tbl = epf->epf_bar[bir]->addr + 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 +439,9 @@ 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 +479,7 @@ 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 +496,8 @@ 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 +556,11 @@ 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 3490723169c6..1bf7d4e09b8a 100644
--- a/drivers/pci/controller/cadence/pcie-cadence.h
+++ b/drivers/pci/controller/cadence/pcie-cadence.h
@@ -113,6 +113,7 @@
#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)
@@ -302,6 +303,14 @@ struct cdns_pcie_rc {
bool avail_ib_bar[CDNS_PCIE_RP_MAX_IB];
};

+/**
+ * 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
@@ -329,6 +338,7 @@ struct cdns_pcie_ep {
u64 irq_pci_addr;
u8 irq_pci_fn;
u8 irq_pending;
+ struct cdns_pcie_epf *epf;
};

--
2.17.1