[RFC 01/10] PCI: dwc: Add MSI-X callbacks handler

[Gustavo Pimentel]

Changes the pcie_raise_irq function signature, namely the interrupt_num
variable type from u8 to u16 to accommodate the MSI-X maximum interrupts
of 2048.

Implements a PCIe config space capability iterator function to search and
save the MSI and MSI-X pointers. With this method the code becomes more
generic and flexible.

Implements MSI-X set/get functions for sysfs interface in order to change
the EP entries number.

Implements EP MSI-X interface for triggering interruptions.

Signed-off-by: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
---
 drivers/pci/dwc/pci-dra7xx.c           |   2 +-
 drivers/pci/dwc/pcie-artpec6.c         |   2 +-
 drivers/pci/dwc/pcie-designware-ep.c   | 145 ++++++++++++++++++++++++++++++++-
 drivers/pci/dwc/pcie-designware-plat.c |   6 +-
 drivers/pci/dwc/pcie-designware.h      |  23 +++++-
 5 files changed, 173 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/dwc/pci-dra7xx.c b/drivers/pci/dwc/pci-dra7xx.c
index ed8558d..5265725 100644
--- a/drivers/pci/dwc/pci-dra7xx.c
+++ b/drivers/pci/dwc/pci-dra7xx.c
@@ -369,7 +369,7 @@ static void dra7xx_pcie_raise_msi_irq(struct dra7xx_pcie *dra7xx,
 }
 
 static int dra7xx_pcie_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
-				 enum pci_epc_irq_type type, u8 interrupt_num)
+				 enum pci_epc_irq_type type, u16 interrupt_num)
 {
 	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
 	struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pci);
diff --git a/drivers/pci/dwc/pcie-artpec6.c b/drivers/pci/dwc/pcie-artpec6.c
index e66cede..96dc259 100644
--- a/drivers/pci/dwc/pcie-artpec6.c
+++ b/drivers/pci/dwc/pcie-artpec6.c
@@ -428,7 +428,7 @@ static void artpec6_pcie_ep_init(struct dw_pcie_ep *ep)
 }
 
 static int artpec6_pcie_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
-				  enum pci_epc_irq_type type, u8 interrupt_num)
+				  enum pci_epc_irq_type type, u16 interrupt_num)
 {
 	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
 
diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
index 15b22a6..874d4c2 100644
--- a/drivers/pci/dwc/pcie-designware-ep.c
+++ b/drivers/pci/dwc/pcie-designware-ep.c
@@ -40,6 +40,44 @@ void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar)
 	__dw_pcie_ep_reset_bar(pci, bar, 0);
 }
 
+void dw_pcie_ep_find_cap_addr(struct dw_pcie_ep *ep)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+	u8 next_ptr, curr_ptr, cap_id;
+	u16 reg;
+
+	memset(&ep->cap_addr, 0, sizeof(ep->cap_addr));
+
+	reg = dw_pcie_readw_dbi(pci, PCI_STATUS);
+	if (!(reg & PCI_STATUS_CAP_LIST))
+		return;
+
+	reg = dw_pcie_readw_dbi(pci, PCI_CAPABILITY_LIST);
+	next_ptr = (reg & 0x00ff);
+	if (!next_ptr)
+		return;
+
+	reg = dw_pcie_readw_dbi(pci, next_ptr);
+	curr_ptr = next_ptr;
+	next_ptr = (reg & 0xff00) >> 8;
+	cap_id = (reg & 0x00ff);
+
+	while (next_ptr && (cap_id <= PCI_CAP_ID_MAX)) {
+		switch (cap_id) {
+		case PCI_CAP_ID_MSI:
+			ep->cap_addr.msi_addr = curr_ptr;
+			break;
+		case PCI_CAP_ID_MSIX:
+			ep->cap_addr.msix_addr = curr_ptr;
+			break;
+		}
+		reg = dw_pcie_readw_dbi(pci, next_ptr);
+		curr_ptr = next_ptr;
+		next_ptr = (reg & 0xff00) >> 8;
+		cap_id = (reg & 0x00ff);
+	}
+}
+
 static int dw_pcie_ep_write_header(struct pci_epc *epc, u8 func_no,
 				   struct pci_epf_header *hdr)
 {
@@ -241,8 +279,47 @@ 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->cap_addr.msix_addr == 0)
+		return 0;
+
+	reg = ep->cap_addr.msix_addr + 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->cap_addr.msix_addr == 0)
+		return 0;
+
+	reg = ep->cap_addr.msix_addr + 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, u8 interrupt_num)
+				enum pci_epc_irq_type type, u16 interrupt_num)
 {
 	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
 
@@ -282,6 +359,8 @@ 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 +401,60 @@ 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;
+	u64 tbl_addr, msg_addr, reg_u64;
+	void __iomem *msix_tbl;
+	int ret;
+
+	reg = ep->cap_addr.msix_addr + 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_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);
+	else
+		bar_addr_upper = 0;
+
+	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, ep->addr_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);
+
+	iounmap(msix_tbl);
+
+	ret = dw_pcie_ep_map_addr(epc, func_no, ep->msix_mem_phys, msg_addr,
+				  epc->mem->page_size);
+	if (ret)
+		return ret;
+
+	writel(msg_data, ep->msix_mem);
+
+	dw_pcie_ep_unmap_addr(epc, func_no, ep->msix_mem_phys);
+
+	return 0;
+}
+
 void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
 {
 	struct pci_epc *epc = ep->epc;
@@ -329,6 +462,9 @@ void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
 	pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem,
 			      epc->mem->page_size);
 
+	pci_epc_mem_free_addr(epc, ep->msix_mem_phys, ep->msix_mem,
+			      epc->mem->page_size);
+
 	pci_epc_mem_exit(epc);
 }
 
@@ -411,6 +547,13 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 		return -ENOMEM;
 	}
 
+	ep->msix_mem = pci_epc_mem_alloc_addr(epc, &ep->msix_mem_phys,
+					     epc->mem->page_size);
+	if (!ep->msix_mem) {
+		dev_err(dev, "Failed to reserve memory for MSI-\n");
+		return -ENOMEM;
+	}
+
 	ep->epc = epc;
 	epc_set_drvdata(epc, ep);
 	dw_pcie_setup(pci);
diff --git a/drivers/pci/dwc/pcie-designware-plat.c b/drivers/pci/dwc/pcie-designware-plat.c
index 2bad68d..c3a4707 100644
--- a/drivers/pci/dwc/pcie-designware-plat.c
+++ b/drivers/pci/dwc/pcie-designware-plat.c
@@ -74,11 +74,13 @@ static void dw_plat_pcie_ep_init(struct dw_pcie_ep *ep)
 
 	for (bar = BAR_0; bar <= BAR_5; bar++)
 		dw_pcie_ep_reset_bar(pci, bar);
+
+	dw_pcie_ep_find_cap_addr(ep);
 }
 
 static int dw_plat_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
 				     enum pci_epc_irq_type type,
-				     u8 interrupt_num)
+				     u16 interrupt_num)
 {
 	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
 
@@ -88,6 +90,8 @@ 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/dwc/pcie-designware.h b/drivers/pci/dwc/pcie-designware.h
index bee4e25..456fd94 100644
--- a/drivers/pci/dwc/pcie-designware.h
+++ b/drivers/pci/dwc/pcie-designware.h
@@ -191,7 +191,12 @@ enum dw_pcie_as_type {
 struct dw_pcie_ep_ops {
 	void	(*ep_init)(struct dw_pcie_ep *ep);
 	int	(*raise_irq)(struct dw_pcie_ep *ep, u8 func_no,
-			     enum pci_epc_irq_type type, u8 interrupt_num);
+			     enum pci_epc_irq_type type, u16 interrupt_num);
+};
+
+struct dw_pcie_cap_addr {
+	u8	msi_addr;
+	u8	msix_addr;
 };
 
 struct dw_pcie_ep {
@@ -208,6 +213,9 @@ struct dw_pcie_ep {
 	u32			num_ob_windows;
 	void __iomem		*msi_mem;
 	phys_addr_t		msi_mem_phys;
+	void __iomem		*msix_mem;
+	phys_addr_t		msix_mem_phys;
+	struct dw_pcie_cap_addr	cap_addr;
 };
 
 struct dw_pcie_ops {
@@ -359,7 +367,10 @@ 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);
+void dw_pcie_ep_find_cap_addr(struct dw_pcie_ep *ep);
 #else
 static inline void dw_pcie_ep_linkup(struct dw_pcie_ep *ep)
 {
@@ -380,8 +391,18 @@ 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)
 {
 }
+
+static inline void dw_pcie_ep_find_cap_addr(struct dw_pcie_ep *ep)
+{
+}
 #endif
 #endif /* _PCIE_DESIGNWARE_H */
-- 
2.7.4