PCI: dwc: Validate iATU outbound mappings against hardware constraints

Make __dw_pcie_prog_outbound_atu() check the requested region base and size
against what the hardware can support.  Return error if the region is not
correctly aligned or of a supported size.

[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20220624143947.8991-14-Sergey.Semin@baikalelectronics.ruSigned-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

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

@@ -8,6 +8,7 @@
  * Author: Jingoo Han <jg1.han@samsung.com>
  */
 
+#include <linux/align.h>
 #include <linux/bitops.h>
 #include <linux/delay.h>
 #include <linux/of.h>
@@ -305,7 +306,7 @@ static inline u32 dw_pcie_enable_ecrc(u32 val)
 	return val | PCIE_ATU_TD;
 }
 
-static void __dw_pcie_prog_outbound_atu(struct dw_pcie *pci, u8 func_no,
+static int __dw_pcie_prog_outbound_atu(struct dw_pcie *pci, u8 func_no,
 				       int index, int type, u64 cpu_addr,
 				       u64 pci_addr, u64 size)
 {
@@ -317,6 +318,12 @@ static void __dw_pcie_prog_outbound_atu(struct dw_pcie *pci, u8 func_no,
 
 	limit_addr = cpu_addr + size - 1;
 
+	if ((limit_addr & ~pci->region_limit) != (cpu_addr & ~pci->region_limit) ||
+	    !IS_ALIGNED(cpu_addr, pci->region_align) ||
+	    !IS_ALIGNED(pci_addr, pci->region_align) || !size) {
+		return -EINVAL;
+	}
+
 	dw_pcie_writel_atu_ob(pci, index, PCIE_ATU_LOWER_BASE,
 			      lower_32_bits(cpu_addr));
 	dw_pcie_writel_atu_ob(pci, index, PCIE_ATU_UPPER_BASE,
@@ -350,26 +357,28 @@ static void __dw_pcie_prog_outbound_atu(struct dw_pcie *pci, u8 func_no,
 	for (retries = 0; retries < LINK_WAIT_MAX_IATU_RETRIES; retries++) {
 		val = dw_pcie_readl_atu_ob(pci, index, PCIE_ATU_REGION_CTRL2);
 		if (val & PCIE_ATU_ENABLE)
-			return;
+			return 0;
 
 		mdelay(LINK_WAIT_IATU);
 	}
 
 	dev_err(pci->dev, "Outbound iATU is not being enabled\n");
+
+	return -ETIMEDOUT;
 }
 
-void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int index, int type,
+int dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int index, int type,
 			      u64 cpu_addr, u64 pci_addr, u64 size)
 {
-	__dw_pcie_prog_outbound_atu(pci, 0, index, type,
+	return __dw_pcie_prog_outbound_atu(pci, 0, index, type,
 					   cpu_addr, pci_addr, size);
 }
 
-void dw_pcie_prog_ep_outbound_atu(struct dw_pcie *pci, u8 func_no, int index,
+int dw_pcie_prog_ep_outbound_atu(struct dw_pcie *pci, u8 func_no, int index,
 				 int type, u64 cpu_addr, u64 pci_addr,
 				 u64 size)
 {
-	__dw_pcie_prog_outbound_atu(pci, func_no, index, type,
+	return __dw_pcie_prog_outbound_atu(pci, func_no, index, type,
 					   cpu_addr, pci_addr, size);
 }
 
@@ -389,6 +398,9 @@ int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, u8 func_no, int index,
 {
 	u32 retries, val;
 
+	if (!IS_ALIGNED(cpu_addr, pci->region_align))
+		return -EINVAL;
+
 	dw_pcie_writel_atu_ib(pci, index, PCIE_ATU_LOWER_TARGET,
 			      lower_32_bits(cpu_addr));
 	dw_pcie_writel_atu_ib(pci, index, PCIE_ATU_UPPER_TARGET,

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

@@ -304,12 +304,10 @@ void dw_pcie_write_dbi2(struct dw_pcie *pci, u32 reg, size_t size, u32 val);
 int dw_pcie_link_up(struct dw_pcie *pci);
 void dw_pcie_upconfig_setup(struct dw_pcie *pci);
 int dw_pcie_wait_for_link(struct dw_pcie *pci);
-void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int index,
-			       int type, u64 cpu_addr, u64 pci_addr,
-			       u64 size);
-void dw_pcie_prog_ep_outbound_atu(struct dw_pcie *pci, u8 func_no, int index,
-				  int type, u64 cpu_addr, u64 pci_addr,
-				  u64 size);
+int dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int index, int type,
+			      u64 cpu_addr, u64 pci_addr, u64 size);
+int dw_pcie_prog_ep_outbound_atu(struct dw_pcie *pci, u8 func_no, int index,
+				 int type, u64 cpu_addr, u64 pci_addr, u64 size);
 int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, u8 func_no, int index,
 			     int type, u64 cpu_addr, u8 bar);
 void dw_pcie_disable_atu(struct dw_pcie *pci, u32 dir, int index);