PCI: dwc: Add MSI-X callbacks handler

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@synopsys.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>

3 files changed, 148 insertions, 1 deletions

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index 69d039de2af6..23be2c0249ee 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/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);
 }
 
+static 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);
+}
+
+static 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)
 {
@@ -241,6 +274,45 @@ 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 -EINVAL;
+
+        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 -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, u16 interrupt_num)
 {
@@ -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_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,
+                                   PCI_MSIX_ENTRY_SIZE);
+        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);
+
+        iounmap(msix_tbl);
+
+        if (vec_ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT)
+                return -EPERM;
+
+        ret = dw_pcie_ep_map_addr(epc, func_no, ep->msi_mem_phys, msg_addr,
+                                  epc->mem->page_size);
+        if (ret)
+                return ret;
+
+        writel(msg_data, ep->msi_mem);
+
+        dw_pcie_ep_unmap_addr(epc, func_no, ep->msi_mem_phys);
+
+        return 0;
+}
+
 void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
 {
         struct pci_epc *epc = ep->epc;
@@ -412,9 +544,12 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
         ep->msi_mem = pci_epc_mem_alloc_addr(epc, &ep->msi_mem_phys,
                                              epc->mem->page_size);
         if (!ep->msi_mem) {
-                dev_err(dev, "Failed to reserve memory for MSI\n");
+                dev_err(dev, "Failed to reserve memory for MSI/MSI-X\n");
                 return -ENOMEM;
         }
+        ep->msi_cap = dw_pcie_ep_find_capability(pci, PCI_CAP_ID_MSI);
+
+        ep->msix_cap = dw_pcie_ep_find_capability(pci, PCI_CAP_ID_MSIX);
 
         dw_pcie_setup(pci);
 
diff --git a/drivers/pci/controller/dwc/pcie-designware-plat.c b/drivers/pci/controller/dwc/pcie-designware-plat.c
index cca69ac63319..35d2291c6ba5 100644
--- a/drivers/pci/controller/dwc/pcie-designware-plat.c
+++ b/drivers/pci/controller/dwc/pcie-designware-plat.c
@@ -91,6 +91,8 @@ static int dw_plat_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
                 return -EINVAL;
         case PCI_EPC_IRQ_MSI:
                 return dw_pcie_ep_raise_msi_irq(ep, func_no, interrupt_num);
+        case PCI_EPC_IRQ_MSIX:
+                return dw_pcie_ep_raise_msix_irq(ep, func_no, interrupt_num);
         default:
                 dev_err(pci->dev, "UNKNOWN IRQ type\n");
         }
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 9d581c077329..00ac4197c457 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -208,6 +208,8 @@ struct dw_pcie_ep {
         u32                     num_ob_windows;
         void __iomem            *msi_mem;
         phys_addr_t             msi_mem_phys;
+        u8                      msi_cap;        /* MSI capability offset */
+        u8                      msix_cap;       /* MSI-X capability offset */
 };
 
 struct dw_pcie_ops {
@@ -359,6 +361,8 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep);
 void dw_pcie_ep_exit(struct dw_pcie_ep *ep);
 int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
                              u8 interrupt_num);
+int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
+                             u16 interrupt_num);
 void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar);
 #else
 static inline void dw_pcie_ep_linkup(struct dw_pcie_ep *ep)
@@ -380,6 +384,12 @@ static inline int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
         return 0;
 }
 
+static inline int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
+                                           u16 interrupt_num)
+{
+        return 0;
+}
+
 static inline void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar)
 {
 }