drivers: pcie: reintroduce support for I/O BARs

Reintroduce support for accessing I/O BARs which was removed in
43d84147d9.

Signed-off-by: Henrik Brix Andersen <henrik@brixandersen.dk>

arch/x86/core/early_serial.c

@@ -88,7 +88,7 @@ void z_x86_early_serial_init(void)
 {
 #if defined(DEVICE_MMIO_IS_IN_RAM) && !defined(CONFIG_UART_NS16550_ACCESS_IOPORT)
 #ifdef X86_SOC_EARLY_SERIAL_PCIDEV
-	struct pcie_mbar mbar;
+	struct pcie_bar mbar;
 	pcie_get_mbar(X86_SOC_EARLY_SERIAL_PCIDEV, 0, &mbar);
 	pcie_set_cmd(X86_SOC_EARLY_SERIAL_PCIDEV, PCIE_CONF_CMDSTAT_MEM, true);
 	device_map(&mmio, mbar.phys_addr, mbar.size, K_MEM_CACHE_NONE);

doc/kernel/drivers/index.rst

@@ -606,7 +606,7 @@ may be used directly:
    void some_init_code(...)
    {
       ...
-      struct pcie_mbar mbar;
+      struct pcie_bar mbar;
       bool bar_found = pcie_get_mbar(bdf, index, &mbar);
 
       device_map(DEVICE_MMIO_RAM_PTR(dev), mbar.phys_addr, mbar.size, K_MEM_CACHE_NONE);

drivers/ethernet/eth_e1000.c

@@ -238,7 +238,7 @@ int e1000_probe(const struct device *ddev)
 	const pcie_bdf_t bdf = PCIE_BDF(0, 3, 0);
 	struct e1000_dev *dev = ddev->data;
 	uint32_t ral, rah;
-	struct pcie_mbar mbar;
+	struct pcie_bar mbar;
 
 	if (!pcie_probe(bdf, PCIE_ID(PCI_VENDOR_ID_INTEL,
 				     PCI_DEVICE_ID_I82540EM))) {

drivers/i2c/i2c_dw.c

@@ -849,7 +849,7 @@ static int i2c_dw_initialize(const struct device *dev)
 
 #if DT_ANY_INST_ON_BUS_STATUS_OKAY(pcie)
 	if (rom->pcie) {
-		struct pcie_mbar mbar;
+		struct pcie_bar mbar;
 
 		if (!pcie_probe(rom->pcie_bdf, rom->pcie_id)) {
 			return -EINVAL;

drivers/pcie/host/msi.c

@@ -84,7 +84,7 @@ static bool map_msix_table_entries(pcie_bdf_t bdf,
 {
 	uint32_t table_offset;
 	uint8_t table_bir;
-	struct pcie_mbar bar;
+	struct pcie_bar bar;
 	uintptr_t mapped_table;
 	int i;
 

drivers/pcie/host/pcie.c

@@ -103,9 +103,19 @@ uint32_t pcie_get_ext_cap(pcie_bdf_t bdf, uint32_t cap_id)
 	return reg;
 }
 
-bool pcie_get_mbar(pcie_bdf_t bdf,
+/**
+ * @brief Get the BAR at a specific BAR index
+ *
+ * @param bdf the PCI(e) endpoint
+ * @param bar_index 0-based BAR index
+ * @param bar Pointer to struct pcie_bar
+ * @param io true for I/O BARs, false otherwise
+ * @return true if the BAR was found and is valid, false otherwise
+ */
+static bool pcie_get_bar(pcie_bdf_t bdf,
 			 unsigned int bar_index,
-		   struct pcie_mbar *mbar)
+			 struct pcie_bar *bar,
+			 bool io)
 {
 	uint32_t reg = bar_index + PCIE_CONF_BAR0;
 #ifdef CONFIG_PCIE_CONTROLLER
@@ -128,8 +138,7 @@ bool pcie_get_mbar(pcie_bdf_t bdf,
 
 	phys_addr = pcie_conf_read(bdf, reg);
 #ifndef CONFIG_PCIE_CONTROLLER
-	if (PCIE_CONF_BAR_IO(phys_addr)) {
+	if ((PCIE_CONF_BAR_MEM(phys_addr) && io) || (PCIE_CONF_BAR_IO(phys_addr) && !io)) {
-		/* Discard I/O bars */
 		return false;
 	}
 #endif
@@ -183,20 +192,36 @@ bool pcie_get_mbar(pcie_bdf_t bdf,
 					PCIE_CONF_BAR_MEM(phys_addr) ?
 						PCIE_CONF_BAR_ADDR(phys_addr)
 						: PCIE_CONF_BAR_IO_ADDR(phys_addr),
-					&mbar->phys_addr)) {
+					&bar->phys_addr)) {
 		return false;
 	}
 #else
-	mbar->phys_addr = PCIE_CONF_BAR_ADDR(phys_addr);
+	bar->phys_addr = PCIE_CONF_BAR_ADDR(phys_addr);
 #endif /* CONFIG_PCIE_CONTROLLER */
-	mbar->size = size & ~(size-1);
+	bar->size = size & ~(size-1);
 
 	return true;
 }
 
-bool pcie_probe_mbar(pcie_bdf_t bdf,
+/**
+ * @brief Probe the nth BAR assigned to an endpoint.
+ *
+ * A PCI(e) endpoint has 0 or more BARs. This function
+ * allows the caller to enumerate them by calling with index=0..n.
+ * Value of n has to be below 6, as there is a maximum of 6 BARs. The indices
+ * are order-preserving with respect to the endpoint BARs: e.g., index 0
+ * will return the lowest-numbered BAR on the endpoint.
+ *
+ * @param bdf the PCI(e) endpoint
+ * @param index (0-based) index
+ * @param bar Pointer to struct pcie_bar
+ * @param io true for I/O BARs, false otherwise
+ * @return true if the BAR was found and is valid, false otherwise
+ */
+static bool pcie_probe_bar(pcie_bdf_t bdf,
 			   unsigned int index,
-		     struct pcie_mbar *mbar)
+			   struct pcie_bar *bar,
+			   bool io)
 {
 	uint32_t reg;
 
@@ -213,7 +238,35 @@ bool pcie_probe_mbar(pcie_bdf_t bdf,
 		return false;
 	}
 
-	return pcie_get_mbar(bdf, reg - PCIE_CONF_BAR0, mbar);
+	return pcie_get_bar(bdf, reg - PCIE_CONF_BAR0, bar, io);
+}
+
+bool pcie_get_mbar(pcie_bdf_t bdf,
+		   unsigned int bar_index,
+		   struct pcie_bar *mbar)
+{
+	return pcie_get_bar(bdf, bar_index, mbar, false);
+}
+
+bool pcie_probe_mbar(pcie_bdf_t bdf,
+		     unsigned int index,
+		     struct pcie_bar *mbar)
+{
+	return pcie_probe_bar(bdf, index, mbar, false);
+}
+
+bool pcie_get_iobar(pcie_bdf_t bdf,
+		    unsigned int bar_index,
+		    struct pcie_bar *iobar)
+{
+	return pcie_get_bar(bdf, bar_index, iobar, true);
+}
+
+bool pcie_probe_iobar(pcie_bdf_t bdf,
+		      unsigned int index,
+		      struct pcie_bar *iobar)
+{
+	return pcie_probe_bar(bdf, index, iobar, true);
 }
 
 #ifndef CONFIG_PCIE_CONTROLLER

drivers/serial/uart_ns16550.c

@@ -333,7 +333,7 @@ static int uart_ns16550_configure(const struct device *dev,
 #ifndef CONFIG_UART_NS16550_ACCESS_IOPORT
 #if DT_ANY_INST_ON_BUS_STATUS_OKAY(pcie)
 	if (dev_cfg->pcie) {
-		struct pcie_mbar mbar;
+		struct pcie_bar mbar;
 
 		if (!pcie_probe(dev_cfg->pcie_bdf, dev_cfg->pcie_id)) {
 			ret = -EINVAL;

drivers/virtualization/virt_ivshmem.c

@@ -108,7 +108,7 @@ static const struct ivshmem_reg no_reg;
 static bool ivshmem_configure(const struct device *dev)
 {
 	struct ivshmem *data = dev->data;
-	struct pcie_mbar mbar_regs, mbar_mem;
+	struct pcie_bar mbar_regs, mbar_mem;
 
 	if (!pcie_get_mbar(data->bdf, IVSHMEM_PCIE_REG_BAR_IDX, &mbar_regs)) {
 #ifdef CONFIG_IVSHMEM_DOORBELL

include/zephyr/drivers/pcie/pcie.h

@@ -36,7 +36,7 @@ typedef uint32_t pcie_bdf_t;
  */
 typedef uint32_t pcie_id_t;
 
-struct pcie_mbar {
+struct pcie_bar {
 	uintptr_t phys_addr;
 	size_t size;
 };
@@ -91,18 +91,18 @@ extern bool pcie_probe(pcie_bdf_t bdf, pcie_id_t id);
  * @brief Get the MBAR at a specific BAR index
  * @param bdf the PCI(e) endpoint
  * @param bar_index 0-based BAR index
- * @param mbar Pointer to struct pcie_mbar
+ * @param mbar Pointer to struct pcie_bar
  * @return true if the mbar was found and is valid, false otherwise
  */
 extern bool pcie_get_mbar(pcie_bdf_t bdf,
 			  unsigned int bar_index,
-			  struct pcie_mbar *mbar);
+			  struct pcie_bar *mbar);
 
 /**
  * @brief Probe the nth MMIO address assigned to an endpoint.
  * @param bdf the PCI(e) endpoint
  * @param index (0-based) index
- * @param mbar Pointer to struct pcie_mbar
+ * @param mbar Pointer to struct pcie_bar
  * @return true if the mbar was found and is valid, false otherwise
  *
  * A PCI(e) endpoint has 0 or more memory-mapped regions. This function
@@ -113,7 +113,35 @@ extern bool pcie_get_mbar(pcie_bdf_t bdf,
  */
 extern bool pcie_probe_mbar(pcie_bdf_t bdf,
 			    unsigned int index,
-			    struct pcie_mbar *mbar);
+			    struct pcie_bar *mbar);
+
+/**
+ * @brief Get the I/O BAR at a specific BAR index
+ * @param bdf the PCI(e) endpoint
+ * @param bar_index 0-based BAR index
+ * @param iobar Pointer to struct pcie_bar
+ * @return true if the I/O BAR was found and is valid, false otherwise
+ */
+extern bool pcie_get_iobar(pcie_bdf_t bdf,
+			   unsigned int bar_index,
+			   struct pcie_bar *iobar);
+
+/**
+ * @brief Probe the nth I/O BAR address assigned to an endpoint.
+ * @param bdf the PCI(e) endpoint
+ * @param index (0-based) index
+ * @param iobar Pointer to struct pcie_bar
+ * @return true if the I/O BAR was found and is valid, false otherwise
+ *
+ * A PCI(e) endpoint has 0 or more I/O regions. This function
+ * allows the caller to enumerate them by calling with index=0..n.
+ * Value of n has to be below 6, as there is a maximum of 6 BARs. The indices
+ * are order-preserving with respect to the endpoint BARs: e.g., index 0
+ * will return the lowest-numbered I/O BAR on the endpoint.
+ */
+extern bool pcie_probe_iobar(pcie_bdf_t bdf,
+			     unsigned int index,
+			     struct pcie_bar *iobar);
 
 /**
  * @brief Set or reset bits in the endpoint command/status register.