PCI: dwc: Fix dw_pcie_ep_raise_msix_irq() to get correct MSI-X table address

commit beb4641 ("PCI: dwc: Add MSI-X callbacks handler"),
in order to raise MSI-X interrupt, obtained MSIX table address from
Base Address Register (BAR). However BAR only holds PCI address
programmed by the host whereas the MSI-X table should be in the local
memory.

Store the MSI-X table address (virtual address) as part of ->set_bar()
callback and use that to get the message address and message data
here.

Fixes: beb4641 ("PCI: dwc: Add MSI-X callbacks handler")
Signed-off-by: Kishon Vijay Abraham I <[email protected]>
Signed-off-by: Lorenzo Pieralisi <[email protected]>

Author: kishon

drivers/pci/controller/dwc/pcie-designware-ep.c

@@ -134,6 +134,7 @@ static void dw_pcie_ep_clear_bar(struct pci_epc *epc, u8 func_no,
 
 	dw_pcie_disable_atu(pci, atu_index, DW_PCIE_REGION_INBOUND);
 	clear_bit(atu_index, ep->ib_window_map);
+	ep->epf_bar[bar] = NULL;
 }
 
 static int dw_pcie_ep_set_bar(struct pci_epc *epc, u8 func_no,
@@ -167,6 +168,7 @@ static int dw_pcie_ep_set_bar(struct pci_epc *epc, u8 func_no,
 		dw_pcie_writel_dbi(pci, reg + 4, 0);
 	}
 
+	ep->epf_bar[bar] = epf_bar;
 	dw_pcie_dbi_ro_wr_dis(pci);
 
 	return 0;
@@ -429,55 +431,41 @@ 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_epf_msix_tbl *msix_tbl;
 	struct pci_epc *epc = ep->epc;
-	u16 tbl_offset, bir;
-	u32 bar_addr_upper, bar_addr_lower;
-	u32 msg_addr_upper, msg_addr_lower;
+	struct pci_epf_bar *epf_bar;
 	u32 reg, msg_data, vec_ctrl;
-	u64 tbl_addr, msg_addr, reg_u64;
-	void __iomem *msix_tbl;
+	unsigned int aligned_offset;
+	u32 tbl_offset;
+	u64 msg_addr;
 	int ret;
+	u8 bir;
 
 	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;
 
-	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);
+	epf_bar = ep->epf_bar[bir];
+	msix_tbl = epf_bar->addr;
+	msix_tbl = (struct pci_epf_msix_tbl *)((char *)msix_tbl + tbl_offset);
 
-	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(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);
+	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;
 
 	if (vec_ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT) {
 		dev_dbg(pci->dev, "MSI-X entry ctrl set\n");
 		return -EPERM;
 	}
 
-	ret = dw_pcie_ep_map_addr(epc, func_no, ep->msi_mem_phys, msg_addr,
+	aligned_offset = msg_addr & (epc->mem->page_size - 1);
+	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);
+	writel(msg_data, ep->msi_mem + aligned_offset);
 
 	dw_pcie_ep_unmap_addr(epc, func_no, ep->msi_mem_phys);
 

drivers/pci/controller/dwc/pcie-designware.h

@@ -233,6 +233,7 @@ struct dw_pcie_ep {
 	phys_addr_t		msi_mem_phys;
 	u8			msi_cap;	/* MSI capability offset */
 	u8			msix_cap;	/* MSI-X capability offset */
+	struct pci_epf_bar	*epf_bar[PCI_STD_NUM_BARS];
 };
 
 struct dw_pcie_ops {

drivers/pci/endpoint/pci-epf-core.c

@@ -87,6 +87,7 @@ void pci_epf_free_space(struct pci_epf *epf, void *addr, enum pci_barno bar)
 			  epf->bar[bar].phys_addr);
 
 	epf->bar[bar].phys_addr = 0;
+	epf->bar[bar].addr = NULL;
 	epf->bar[bar].size = 0;
 	epf->bar[bar].barno = 0;
 	epf->bar[bar].flags = 0;
@@ -123,6 +124,7 @@ void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar,
 	}
 
 	epf->bar[bar].phys_addr = phys_addr;
+	epf->bar[bar].addr = space;
 	epf->bar[bar].size = size;
 	epf->bar[bar].barno = bar;
 	epf->bar[bar].flags |= upper_32_bits(size) ?

include/linux/pci-epf.h

@@ -94,10 +94,12 @@ struct pci_epf_driver {
 /**
  * struct pci_epf_bar - represents the BAR of EPF device
  * @phys_addr: physical address that should be mapped to the BAR
+ * @addr: virtual address corresponding to the @phys_addr
  * @size: the size of the address space present in BAR
  */
 struct pci_epf_bar {
 	dma_addr_t	phys_addr;
+	void		*addr;
 	size_t		size;
 	enum pci_barno	barno;
 	int		flags;
@@ -134,6 +136,19 @@ struct pci_epf {
 	struct mutex		lock;
 };
 
+/**
+ * struct pci_epf_msix_tbl - represents the MSIX table entry structure
+ * @msg_addr: Writes to this address will trigger MSIX interrupt in host
+ * @msg_data: Data that should be written to @msg_addr to trigger MSIX interrupt
+ * @vector_ctrl: Identifies if the function is prohibited from sending a message
+ * using this MSIX table entry
+ */
+struct pci_epf_msix_tbl {
+	u64 msg_addr;
+	u32 msg_data;
+	u32 vector_ctrl;
+};
+
 #define to_pci_epf(epf_dev) container_of((epf_dev), struct pci_epf, dev)
 
 #define pci_epf_register_driver(driver)    \