PCI: rockchip: Fix window mapping and address translation for endpoint

The RK3399 PCI endpoint core has 33 windows for PCIe space, now in the
driver up to 32 fixed size (1M) windows are used and pages are allocated
and mapped accordingly. The driver first used a single window and allocated
space inside which caused translation issues (between CPU space and PCI
space) because a window can only have a single translation at a given
time, which if multiple pages are allocated inside will cause conflicts.
Now each window is a single region of 1M which will always guarantee that
the translation is not in conflict.

Set the translation register addresses for physical function. As documented
in the technical reference manual (TRM) section 17.5.5 "PCIe Address
Translation" and section 17.6.8 "Address Translation Registers Description"

Link: https://lore.kernel.org/r/20230418074700.1083505-9-rick.wertenbroek@gmail.com
Fixes: cf590b078391 ("PCI: rockchip: Add EP driver for Rockchip PCIe controller")
Tested-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Rick Wertenbroek <rick.wertenbroek@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Cc: stable@vger.kernel.org

1 files changed, 55 insertions, 73 deletions

diff --git a/drivers/pci/controller/pcie-rockchip-ep.c b/drivers/pci/controller/pcie-rockchip-ep.c
index d6d4b0f2e733..771f1bb93251 100644
--- a/drivers/pci/controller/pcie-rockchip-ep.c
+++ b/drivers/pci/controller/pcie-rockchip-ep.c
@@ -64,52 +64,29 @@ static void rockchip_pcie_clear_ep_ob_atu(struct rockchip_pcie *rockchip,
 }
 
 static void rockchip_pcie_prog_ep_ob_atu(struct rockchip_pcie *rockchip, u8 fn,
-					 u32 r, u32 type, u64 cpu_addr,
-					 u64 pci_addr, size_t size)
+					 u32 r, u64 cpu_addr, u64 pci_addr,
+					 size_t size)
 {
-	u64 sz = 1ULL << fls64(size - 1);
-	int num_pass_bits = ilog2(sz);
-	u32 addr0, addr1, desc0, desc1;
-	bool is_nor_msg = (type == AXI_WRAPPER_NOR_MSG);
+	int num_pass_bits = fls64(size - 1);
+	u32 addr0, addr1, desc0;
 
-	/* The minimal region size is 1MB */
 	if (num_pass_bits < 8)
 		num_pass_bits = 8;
 
-	cpu_addr -= rockchip->mem_res->start;
-	addr0 = ((is_nor_msg ? 0x10 : (num_pass_bits - 1)) &
-		PCIE_CORE_OB_REGION_ADDR0_NUM_BITS) |
-		(lower_32_bits(cpu_addr) & PCIE_CORE_OB_REGION_ADDR0_LO_ADDR);
-	addr1 = upper_32_bits(is_nor_msg ? cpu_addr : pci_addr);
-	desc0 = ROCKCHIP_PCIE_AT_OB_REGION_DESC0_DEVFN(fn) | type;
-	desc1 = 0;
-
-	if (is_nor_msg) {
-		rockchip_pcie_write(rockchip, 0,
-				    ROCKCHIP_PCIE_AT_OB_REGION_PCI_ADDR0(r));
-		rockchip_pcie_write(rockchip, 0,
-				    ROCKCHIP_PCIE_AT_OB_REGION_PCI_ADDR1(r));
-		rockchip_pcie_write(rockchip, desc0,
-				    ROCKCHIP_PCIE_AT_OB_REGION_DESC0(r));
-		rockchip_pcie_write(rockchip, desc1,
-				    ROCKCHIP_PCIE_AT_OB_REGION_DESC1(r));
-	} else {
-		/* PCI bus address region */
-		rockchip_pcie_write(rockchip, addr0,
-				    ROCKCHIP_PCIE_AT_OB_REGION_PCI_ADDR0(r));
-		rockchip_pcie_write(rockchip, addr1,
-				    ROCKCHIP_PCIE_AT_OB_REGION_PCI_ADDR1(r));
-		rockchip_pcie_write(rockchip, desc0,
-				    ROCKCHIP_PCIE_AT_OB_REGION_DESC0(r));
-		rockchip_pcie_write(rockchip, desc1,
-				    ROCKCHIP_PCIE_AT_OB_REGION_DESC1(r));
-
-		addr0 =
-		    ((num_pass_bits - 1) & PCIE_CORE_OB_REGION_ADDR0_NUM_BITS) |
-		    (lower_32_bits(cpu_addr) &
-		     PCIE_CORE_OB_REGION_ADDR0_LO_ADDR);
-		addr1 = upper_32_bits(cpu_addr);
-	}
+	addr0 = ((num_pass_bits - 1) & PCIE_CORE_OB_REGION_ADDR0_NUM_BITS) |
+		(lower_32_bits(pci_addr) & PCIE_CORE_OB_REGION_ADDR0_LO_ADDR);
+	addr1 = upper_32_bits(pci_addr);
+	desc0 = ROCKCHIP_PCIE_AT_OB_REGION_DESC0_DEVFN(fn) | AXI_WRAPPER_MEM_WRITE;
+
+	/* PCI bus address region */
+	rockchip_pcie_write(rockchip, addr0,
+			    ROCKCHIP_PCIE_AT_OB_REGION_PCI_ADDR0(r));
+	rockchip_pcie_write(rockchip, addr1,
+			    ROCKCHIP_PCIE_AT_OB_REGION_PCI_ADDR1(r));
+	rockchip_pcie_write(rockchip, desc0,
+			    ROCKCHIP_PCIE_AT_OB_REGION_DESC0(r));
+	rockchip_pcie_write(rockchip, 0,
+			    ROCKCHIP_PCIE_AT_OB_REGION_DESC1(r));
 }
 
 static int rockchip_pcie_ep_write_header(struct pci_epc *epc, u8 fn, u8 vfn,
@@ -248,26 +225,20 @@ static void rockchip_pcie_ep_clear_bar(struct pci_epc *epc, u8 fn, u8 vfn,
 			    ROCKCHIP_PCIE_AT_IB_EP_FUNC_BAR_ADDR1(fn, bar));
 }
 
+static inline u32 rockchip_ob_region(phys_addr_t addr)
+{
+	return (addr >> ilog2(SZ_1M)) & 0x1f;
+}
+
 static int rockchip_pcie_ep_map_addr(struct pci_epc *epc, u8 fn, u8 vfn,
 				     phys_addr_t addr, u64 pci_addr,
 				     size_t size)
 {
 	struct rockchip_pcie_ep *ep = epc_get_drvdata(epc);
 	struct rockchip_pcie *pcie = &ep->rockchip;
-	u32 r;
+	u32 r = rockchip_ob_region(addr);
 
-	r = find_first_zero_bit(&ep->ob_region_map, BITS_PER_LONG);
-	/*
-	 * Region 0 is reserved for configuration space and shouldn't
-	 * be used elsewhere per TRM, so leave it out.
-	 */
-	if (r >= ep->max_regions - 1) {
-		dev_err(&epc->dev, "no free outbound region\n");
-		return -EINVAL;
-	}
-
-	rockchip_pcie_prog_ep_ob_atu(pcie, fn, r, AXI_WRAPPER_MEM_WRITE, addr,
-				     pci_addr, size);
+	rockchip_pcie_prog_ep_ob_atu(pcie, fn, r, addr, pci_addr, size);
 
 	set_bit(r, &ep->ob_region_map);
 	ep->ob_addr[r] = addr;
@@ -282,15 +253,11 @@ static void rockchip_pcie_ep_unmap_addr(struct pci_epc *epc, u8 fn, u8 vfn,
 	struct rockchip_pcie *rockchip = &ep->rockchip;
 	u32 r;
 
-	for (r = 0; r < ep->max_regions - 1; r++)
+	for (r = 0; r < ep->max_regions; r++)
 		if (ep->ob_addr[r] == addr)
 			break;
 
-	/*
-	 * Region 0 is reserved for configuration space and shouldn't
-	 * be used elsewhere per TRM, so leave it out.
-	 */
-	if (r == ep->max_regions - 1)
+	if (r == ep->max_regions)
 		return;
 
 	rockchip_pcie_clear_ep_ob_atu(rockchip, r);
@@ -387,7 +354,8 @@ static int rockchip_pcie_ep_send_msi_irq(struct rockchip_pcie_ep *ep, u8 fn,
 	struct rockchip_pcie *rockchip = &ep->rockchip;
 	u16 flags, mme, data, data_mask;
 	u8 msi_count;
-	u64 pci_addr, pci_addr_mask = 0xff;
+	u64 pci_addr;
+	u32 r;
 
 	/* Check MSI enable bit */
 	flags = rockchip_pcie_read(&ep->rockchip,
@@ -421,21 +389,20 @@ static int rockchip_pcie_ep_send_msi_irq(struct rockchip_pcie_ep *ep, u8 fn,
 				       ROCKCHIP_PCIE_EP_FUNC_BASE(fn) +
 				       ROCKCHIP_PCIE_EP_MSI_CTRL_REG +
 				       PCI_MSI_ADDRESS_LO);
-	pci_addr &= GENMASK_ULL(63, 2);
 
 	/* Set the outbound region if needed. */
-	if (unlikely(ep->irq_pci_addr != (pci_addr & ~pci_addr_mask) ||
+	if (unlikely(ep->irq_pci_addr != (pci_addr & PCIE_ADDR_MASK) ||
 		     ep->irq_pci_fn != fn)) {
-		rockchip_pcie_prog_ep_ob_atu(rockchip, fn, ep->max_regions - 1,
-					     AXI_WRAPPER_MEM_WRITE,
+		r = rockchip_ob_region(ep->irq_phys_addr);
+		rockchip_pcie_prog_ep_ob_atu(rockchip, fn, r,
 					     ep->irq_phys_addr,
-					     pci_addr & ~pci_addr_mask,
-					     pci_addr_mask + 1);
-		ep->irq_pci_addr = (pci_addr & ~pci_addr_mask);
+					     pci_addr & PCIE_ADDR_MASK,
+					     ~PCIE_ADDR_MASK + 1);
+		ep->irq_pci_addr = (pci_addr & PCIE_ADDR_MASK);
 		ep->irq_pci_fn = fn;
 	}
 
-	writew(data, ep->irq_cpu_addr + (pci_addr & pci_addr_mask));
+	writew(data, ep->irq_cpu_addr + (pci_addr & ~PCIE_ADDR_MASK));
 	return 0;
 }
 
@@ -516,6 +483,8 @@ static int rockchip_pcie_parse_ep_dt(struct rockchip_pcie *rockchip,
 	if (err < 0 || ep->max_regions > MAX_REGION_LIMIT)
 		ep->max_regions = MAX_REGION_LIMIT;
 
+	ep->ob_region_map = 0;
+
 	err = of_property_read_u8(dev->of_node, "max-functions",
 				  &ep->epc->max_functions);
 	if (err < 0)
@@ -536,7 +505,8 @@ static int rockchip_pcie_ep_probe(struct platform_device *pdev)
 	struct rockchip_pcie *rockchip;
 	struct pci_epc *epc;
 	size_t max_regions;
-	int err;
+	struct pci_epc_mem_window *windows = NULL;
+	int err, i;
 
 	ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL);
 	if (!ep)
@@ -583,15 +553,27 @@ static int rockchip_pcie_ep_probe(struct platform_device *pdev)
 	/* Only enable function 0 by default */
 	rockchip_pcie_write(rockchip, BIT(0), PCIE_CORE_PHY_FUNC_CFG);
 
-	err = pci_epc_mem_init(epc, rockchip->mem_res->start,
-			       resource_size(rockchip->mem_res), PAGE_SIZE);
+	windows = devm_kcalloc(dev, ep->max_regions,
+			       sizeof(struct pci_epc_mem_window), GFP_KERNEL);
+	if (!windows) {
+		err = -ENOMEM;
+		goto err_uninit_port;
+	}
+	for (i = 0; i < ep->max_regions; i++) {
+		windows[i].phys_base = rockchip->mem_res->start + (SZ_1M * i);
+		windows[i].size = SZ_1M;
+		windows[i].page_size = SZ_1M;
+	}
+	err = pci_epc_multi_mem_init(epc, windows, ep->max_regions);
+	devm_kfree(dev, windows);
+
 	if (err < 0) {
 		dev_err(dev, "failed to initialize the memory space\n");
 		goto err_uninit_port;
 	}
 
 	ep->irq_cpu_addr = pci_epc_mem_alloc_addr(epc, &ep->irq_phys_addr,
-						  SZ_128K);
+						  SZ_1M);
 	if (!ep->irq_cpu_addr) {
 		dev_err(dev, "failed to reserve memory space for MSI\n");
 		err = -ENOMEM;