PCI: mvebu: Convert to PCI emulated bridge config space

Convert the pci-mvebu driver to use the pci-bridge-emul logic, that
helps emulating a root port PCI bridge configuration space.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
[lorenzo.pieralisi@arm.com: updated commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

drivers/pci/controller/Kconfig

@@ -9,6 +9,7 @@ config PCI_MVEBU
 	depends on MVEBU_MBUS
 	depends on ARM
 	depends on OF
+	select PCI_BRIDGE_EMUL
 
 config PCI_AARDVARK
 	bool "Aardvark PCIe controller"

drivers/pci/controller/pci-mvebu.c

@@ -22,6 +22,7 @@
 #include <linux/of_platform.h>
 
 #include "../pci.h"
+#include "../pci-bridge-emul.h"
 
 /*
  * PCIe unit register offsets.
@@ -63,56 +64,6 @@
 #define PCIE_DEBUG_CTRL         0x1a60
 #define  PCIE_DEBUG_SOFT_RESET		BIT(20)
 
-enum {
-	PCISWCAP = PCI_BRIDGE_CONTROL + 2,
-	PCISWCAP_EXP_LIST_ID	= PCISWCAP + PCI_CAP_LIST_ID,
-	PCISWCAP_EXP_DEVCAP	= PCISWCAP + PCI_EXP_DEVCAP,
-	PCISWCAP_EXP_DEVCTL	= PCISWCAP + PCI_EXP_DEVCTL,
-	PCISWCAP_EXP_LNKCAP	= PCISWCAP + PCI_EXP_LNKCAP,
-	PCISWCAP_EXP_LNKCTL	= PCISWCAP + PCI_EXP_LNKCTL,
-	PCISWCAP_EXP_SLTCAP	= PCISWCAP + PCI_EXP_SLTCAP,
-	PCISWCAP_EXP_SLTCTL	= PCISWCAP + PCI_EXP_SLTCTL,
-	PCISWCAP_EXP_RTCTL	= PCISWCAP + PCI_EXP_RTCTL,
-	PCISWCAP_EXP_RTSTA	= PCISWCAP + PCI_EXP_RTSTA,
-	PCISWCAP_EXP_DEVCAP2	= PCISWCAP + PCI_EXP_DEVCAP2,
-	PCISWCAP_EXP_DEVCTL2	= PCISWCAP + PCI_EXP_DEVCTL2,
-	PCISWCAP_EXP_LNKCAP2	= PCISWCAP + PCI_EXP_LNKCAP2,
-	PCISWCAP_EXP_LNKCTL2	= PCISWCAP + PCI_EXP_LNKCTL2,
-	PCISWCAP_EXP_SLTCAP2	= PCISWCAP + PCI_EXP_SLTCAP2,
-	PCISWCAP_EXP_SLTCTL2	= PCISWCAP + PCI_EXP_SLTCTL2,
-};
-
-/* PCI configuration space of a PCI-to-PCI bridge */
-struct mvebu_sw_pci_bridge {
-	u16 vendor;
-	u16 device;
-	u16 command;
-	u16 status;
-	u16 class;
-	u8 interface;
-	u8 revision;
-	u8 bist;
-	u8 header_type;
-	u8 latency_timer;
-	u8 cache_line_size;
-	u32 bar[2];
-	u8 primary_bus;
-	u8 secondary_bus;
-	u8 subordinate_bus;
-	u8 secondary_latency_timer;
-	u8 iobase;
-	u8 iolimit;
-	u16 secondary_status;
-	u16 membase;
-	u16 memlimit;
-	u16 iobaseupper;
-	u16 iolimitupper;
-	u32 romaddr;
-	u8 intline;
-	u8 intpin;
-	u16 bridgectrl;
-};
-
 struct mvebu_pcie_port;
 
 /* Structure representing all PCIe interfaces */
@@ -148,7 +99,7 @@ struct mvebu_pcie_port {
 	struct clk *clk;
 	struct gpio_desc *reset_gpio;
 	char *reset_name;
-	struct mvebu_sw_pci_bridge bridge;
+	struct pci_bridge_emul bridge;
 	struct device_node *dn;
 	struct mvebu_pcie *pcie;
 	struct mvebu_pcie_window memwin;
@@ -410,11 +361,12 @@ static void mvebu_pcie_set_window(struct mvebu_pcie_port *port,
 static void mvebu_pcie_handle_iobase_change(struct mvebu_pcie_port *port)
 {
 	struct mvebu_pcie_window desired = {};
+	struct pci_bridge_emul_conf *conf = &port->bridge.conf;
 
 	/* Are the new iobase/iolimit values invalid? */
-	if (port->bridge.iolimit < port->bridge.iobase ||
-	    port->bridge.iolimitupper < port->bridge.iobaseupper ||
-	    !(port->bridge.command & PCI_COMMAND_IO)) {
+	if (conf->iolimit < conf->iobase ||
+	    conf->iolimitupper < conf->iobaseupper ||
+	    !(conf->command & PCI_COMMAND_IO)) {
 		mvebu_pcie_set_window(port, port->io_target, port->io_attr,
 				      &desired, &port->iowin);
 		return;
@@ -433,11 +385,11 @@ static void mvebu_pcie_handle_iobase_change(struct mvebu_pcie_port *port)
 	 * specifications. iobase is the bus address, port->iowin_base
 	 * is the CPU address.
 	 */
-	desired.remap = ((port->bridge.iobase & 0xF0) << 8) |
-			(port->bridge.iobaseupper << 16);
+	desired.remap = ((conf->iobase & 0xF0) << 8) |
+			(conf->iobaseupper << 16);
 	desired.base = port->pcie->io.start + desired.remap;
-	desired.size = ((0xFFF | ((port->bridge.iolimit & 0xF0) << 8) |
-			 (port->bridge.iolimitupper << 16)) -
+	desired.size = ((0xFFF | ((conf->iolimit & 0xF0) << 8) |
+			 (conf->iolimitupper << 16)) -
 			desired.remap) +
 		       1;
 
@@ -448,10 +400,11 @@ static void mvebu_pcie_handle_iobase_change(struct mvebu_pcie_port *port)
 static void mvebu_pcie_handle_membase_change(struct mvebu_pcie_port *port)
 {
 	struct mvebu_pcie_window desired = {.remap = MVEBU_MBUS_NO_REMAP};
+	struct pci_bridge_emul_conf *conf = &port->bridge.conf;
 
 	/* Are the new membase/memlimit values invalid? */
-	if (port->bridge.memlimit < port->bridge.membase ||
-	    !(port->bridge.command & PCI_COMMAND_MEMORY)) {
+	if (conf->memlimit < conf->membase ||
+	    !(conf->command & PCI_COMMAND_MEMORY)) {
 		mvebu_pcie_set_window(port, port->mem_target, port->mem_attr,
 				      &desired, &port->memwin);
 		return;
@@ -463,129 +416,32 @@ static void mvebu_pcie_handle_membase_change(struct mvebu_pcie_port *port)
 	 * window to setup, according to the PCI-to-PCI bridge
 	 * specifications.
 	 */
-	desired.base = ((port->bridge.membase & 0xFFF0) << 16);
-	desired.size = (((port->bridge.memlimit & 0xFFF0) << 16) | 0xFFFFF) -
+	desired.base = ((conf->membase & 0xFFF0) << 16);
+	desired.size = (((conf->memlimit & 0xFFF0) << 16) | 0xFFFFF) -
 		       desired.base + 1;
 
 	mvebu_pcie_set_window(port, port->mem_target, port->mem_attr, &desired,
 			      &port->memwin);
 }
 
-/*
- * Initialize the configuration space of the PCI-to-PCI bridge
- * associated with the given PCIe interface.
- */
-static void mvebu_sw_pci_bridge_init(struct mvebu_pcie_port *port)
+static pci_bridge_emul_read_status_t
+mvebu_pci_bridge_emul_pcie_conf_read(struct pci_bridge_emul *bridge,
+				     int reg, u32 *value)
 {
-	struct mvebu_sw_pci_bridge *bridge = &port->bridge;
-
-	memset(bridge, 0, sizeof(struct mvebu_sw_pci_bridge));
-
-	bridge->class = PCI_CLASS_BRIDGE_PCI;
-	bridge->vendor = PCI_VENDOR_ID_MARVELL;
-	bridge->device = mvebu_readl(port, PCIE_DEV_ID_OFF) >> 16;
-	bridge->revision = mvebu_readl(port, PCIE_DEV_REV_OFF) & 0xff;
-	bridge->header_type = PCI_HEADER_TYPE_BRIDGE;
-	bridge->cache_line_size = 0x10;
-
-	/* We support 32 bits I/O addressing */
-	bridge->iobase = PCI_IO_RANGE_TYPE_32;
-	bridge->iolimit = PCI_IO_RANGE_TYPE_32;
-
-	/* Add capabilities */
-	bridge->status = PCI_STATUS_CAP_LIST;
-}
-
-/*
- * Read the configuration space of the PCI-to-PCI bridge associated to
- * the given PCIe interface.
- */
-static int mvebu_sw_pci_bridge_read(struct mvebu_pcie_port *port,
-				  unsigned int where, int size, u32 *value)
-{
-	struct mvebu_sw_pci_bridge *bridge = &port->bridge;
-
-	switch (where & ~3) {
-	case PCI_VENDOR_ID:
-		*value = bridge->device << 16 | bridge->vendor;
-		break;
-
-	case PCI_COMMAND:
-		*value = bridge->command | bridge->status << 16;
-		break;
-
-	case PCI_CLASS_REVISION:
-		*value = bridge->class << 16 | bridge->interface << 8 |
-			 bridge->revision;
-		break;
-
-	case PCI_CACHE_LINE_SIZE:
-		*value = bridge->bist << 24 | bridge->header_type << 16 |
-			 bridge->latency_timer << 8 | bridge->cache_line_size;
-		break;
-
-	case PCI_BASE_ADDRESS_0 ... PCI_BASE_ADDRESS_1:
-		*value = bridge->bar[((where & ~3) - PCI_BASE_ADDRESS_0) / 4];
-		break;
-
-	case PCI_PRIMARY_BUS:
-		*value = (bridge->secondary_latency_timer << 24 |
-			  bridge->subordinate_bus         << 16 |
-			  bridge->secondary_bus           <<  8 |
-			  bridge->primary_bus);
-		break;
-
-	case PCI_IO_BASE:
-		if (!mvebu_has_ioport(port))
-			*value = bridge->secondary_status << 16;
-		else
-			*value = (bridge->secondary_status << 16 |
-				  bridge->iolimit          <<  8 |
-				  bridge->iobase);
-		break;
-
-	case PCI_MEMORY_BASE:
-		*value = (bridge->memlimit << 16 | bridge->membase);
-		break;
-
-	case PCI_PREF_MEMORY_BASE:
-		*value = 0;
-		break;
-
-	case PCI_IO_BASE_UPPER16:
-		*value = (bridge->iolimitupper << 16 | bridge->iobaseupper);
-		break;
-
-	case PCI_CAPABILITY_LIST:
-		*value = PCISWCAP;
-		break;
+	struct mvebu_pcie_port *port = bridge->data;
 
-	case PCI_ROM_ADDRESS1:
-		*value = 0;
-		break;
-
-	case PCI_INTERRUPT_LINE:
-		/* LINE PIN MIN_GNT MAX_LAT */
-		*value = 0;
-		break;
-
-	case PCISWCAP_EXP_LIST_ID:
-		/* Set PCIe v2, root port, slot support */
-		*value = (PCI_EXP_TYPE_ROOT_PORT << 4 | 2 |
-			  PCI_EXP_FLAGS_SLOT) << 16 | PCI_CAP_ID_EXP;
-		break;
-
-	case PCISWCAP_EXP_DEVCAP:
+	switch (reg) {
+	case PCI_EXP_DEVCAP:
 		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_DEVCAP);
 		break;
 
-	case PCISWCAP_EXP_DEVCTL:
+	case PCI_EXP_DEVCTL:
 		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_DEVCTL) &
 				 ~(PCI_EXP_DEVCTL_URRE | PCI_EXP_DEVCTL_FERE |
 				   PCI_EXP_DEVCTL_NFERE | PCI_EXP_DEVCTL_CERE);
 		break;
 
-	case PCISWCAP_EXP_LNKCAP:
+	case PCI_EXP_LNKCAP:
 		/*
 		 * PCIe requires the clock power management capability to be
 		 * hard-wired to zero for downstream ports
@@ -594,168 +450,140 @@ static int mvebu_sw_pci_bridge_read(struct mvebu_pcie_port *port,
 			 ~PCI_EXP_LNKCAP_CLKPM;
 		break;
 
-	case PCISWCAP_EXP_LNKCTL:
+	case PCI_EXP_LNKCTL:
 		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_LNKCTL);
 		break;
 
-	case PCISWCAP_EXP_SLTCTL:
+	case PCI_EXP_SLTCTL:
 		*value = PCI_EXP_SLTSTA_PDS << 16;
 		break;
 
-	case PCISWCAP_EXP_RTSTA:
+	case PCI_EXP_RTSTA:
 		*value = mvebu_readl(port, PCIE_RC_RTSTA);
 		break;
 
-	/* PCIe requires the v2 fields to be hard-wired to zero */
-	case PCISWCAP_EXP_DEVCAP2:
-	case PCISWCAP_EXP_DEVCTL2:
-	case PCISWCAP_EXP_LNKCAP2:
-	case PCISWCAP_EXP_LNKCTL2:
-	case PCISWCAP_EXP_SLTCAP2:
-	case PCISWCAP_EXP_SLTCTL2:
 	default:
-		/*
-		 * PCI defines configuration read accesses to reserved or
-		 * unimplemented registers to read as zero and complete
-		 * normally.
-		 */
-		*value = 0;
-		return PCIBIOS_SUCCESSFUL;
+		return PCI_BRIDGE_EMUL_NOT_HANDLED;
 	}
 
-	if (size == 2)
-		*value = (*value >> (8 * (where & 3))) & 0xffff;
-	else if (size == 1)
-		*value = (*value >> (8 * (where & 3))) & 0xff;
-
-	return PCIBIOS_SUCCESSFUL;
+	return PCI_BRIDGE_EMUL_HANDLED;
 }
 
-/* Write to the PCI-to-PCI bridge configuration space */
-static int mvebu_sw_pci_bridge_write(struct mvebu_pcie_port *port,
-				     unsigned int where, int size, u32 value)
+static void
+mvebu_pci_bridge_emul_base_conf_write(struct pci_bridge_emul *bridge,
+				      int reg, u32 old, u32 new, u32 mask)
 {
-	struct mvebu_sw_pci_bridge *bridge = &port->bridge;
-	u32 mask, reg;
-	int err;
-
-	if (size == 4)
-		mask = 0x0;
-	else if (size == 2)
-		mask = ~(0xffff << ((where & 3) * 8));
-	else if (size == 1)
-		mask = ~(0xff << ((where & 3) * 8));
-	else
-		return PCIBIOS_BAD_REGISTER_NUMBER;
+	struct mvebu_pcie_port *port = bridge->data;
+	struct pci_bridge_emul_conf *conf = &bridge->conf;
 
-	err = mvebu_sw_pci_bridge_read(port, where & ~3, 4, &reg);
-	if (err)
-		return err;
-
-	value = (reg & mask) | value << ((where & 3) * 8);
-
-	switch (where & ~3) {
+	switch (reg) {
 	case PCI_COMMAND:
 	{
-		u32 old = bridge->command;
-
 		if (!mvebu_has_ioport(port))
-			value &= ~PCI_COMMAND_IO;
+			conf->command &= ~PCI_COMMAND_IO;
 
-		bridge->command = value & 0xffff;
-		if ((old ^ bridge->command) & PCI_COMMAND_IO)
+		if ((old ^ new) & PCI_COMMAND_IO)
 			mvebu_pcie_handle_iobase_change(port);
-		if ((old ^ bridge->command) & PCI_COMMAND_MEMORY)
+		if ((old ^ new) & PCI_COMMAND_MEMORY)
 			mvebu_pcie_handle_membase_change(port);
-		break;
-	}
 
-	case PCI_BASE_ADDRESS_0 ... PCI_BASE_ADDRESS_1:
-		bridge->bar[((where & ~3) - PCI_BASE_ADDRESS_0) / 4] = value;
 		break;
+	}
 
 	case PCI_IO_BASE:
 		/*
-		 * We also keep bit 1 set, it is a read-only bit that
+		 * We keep bit 1 set, it is a read-only bit that
 		 * indicates we support 32 bits addressing for the
 		 * I/O
 		 */
-		bridge->iobase = (value & 0xff) | PCI_IO_RANGE_TYPE_32;
-		bridge->iolimit = ((value >> 8) & 0xff) | PCI_IO_RANGE_TYPE_32;
+		conf->iobase |= PCI_IO_RANGE_TYPE_32;
+		conf->iolimit |= PCI_IO_RANGE_TYPE_32;
 		mvebu_pcie_handle_iobase_change(port);
 		break;
 
 	case PCI_MEMORY_BASE:
-		bridge->membase = value & 0xffff;
-		bridge->memlimit = value >> 16;
 		mvebu_pcie_handle_membase_change(port);
 		break;
 
 	case PCI_IO_BASE_UPPER16:
-		bridge->iobaseupper = value & 0xffff;
-		bridge->iolimitupper = value >> 16;
 		mvebu_pcie_handle_iobase_change(port);
 		break;
 
 	case PCI_PRIMARY_BUS:
-		bridge->primary_bus             = value & 0xff;
-		bridge->secondary_bus           = (value >> 8) & 0xff;
-		bridge->subordinate_bus         = (value >> 16) & 0xff;
-		bridge->secondary_latency_timer = (value >> 24) & 0xff;
-		mvebu_pcie_set_local_bus_nr(port, bridge->secondary_bus);
+		mvebu_pcie_set_local_bus_nr(port, conf->secondary_bus);
 		break;
 
-	case PCISWCAP_EXP_DEVCTL:
+	default:
+		break;
+	}
+}
+
+static void
+mvebu_pci_bridge_emul_pcie_conf_write(struct pci_bridge_emul *bridge,
+				      int reg, u32 old, u32 new, u32 mask)
+{
+	struct mvebu_pcie_port *port = bridge->data;
+
+	switch (reg) {
+	case PCI_EXP_DEVCTL:
 		/*
 		 * Armada370 data says these bits must always
 		 * be zero when in root complex mode.
 		 */
-		value &= ~(PCI_EXP_DEVCTL_URRE | PCI_EXP_DEVCTL_FERE |
-			   PCI_EXP_DEVCTL_NFERE | PCI_EXP_DEVCTL_CERE);
-
-		/*
-		 * If the mask is 0xffff0000, then we only want to write
-		 * the device control register, rather than clearing the
-		 * RW1C bits in the device status register.  Mask out the
-		 * status register bits.
-		 */
-		if (mask == 0xffff0000)
-			value &= 0xffff;
+		new &= ~(PCI_EXP_DEVCTL_URRE | PCI_EXP_DEVCTL_FERE |
+			 PCI_EXP_DEVCTL_NFERE | PCI_EXP_DEVCTL_CERE);
 
-		mvebu_writel(port, value, PCIE_CAP_PCIEXP + PCI_EXP_DEVCTL);
+		mvebu_writel(port, new, PCIE_CAP_PCIEXP + PCI_EXP_DEVCTL);
 		break;
 
-	case PCISWCAP_EXP_LNKCTL:
+	case PCI_EXP_LNKCTL:
 		/*
 		 * If we don't support CLKREQ, we must ensure that the
 		 * CLKREQ enable bit always reads zero.  Since we haven't
 		 * had this capability, and it's dependent on board wiring,
 		 * disable it for the time being.
 		 */
-		value &= ~PCI_EXP_LNKCTL_CLKREQ_EN;
-
-		/*
-		 * If the mask is 0xffff0000, then we only want to write
-		 * the link control register, rather than clearing the
-		 * RW1C bits in the link status register.  Mask out the
-		 * RW1C status register bits.
-		 */
-		if (mask == 0xffff0000)
-			value &= ~((PCI_EXP_LNKSTA_LABS |
-				    PCI_EXP_LNKSTA_LBMS) << 16);
+		new &= ~PCI_EXP_LNKCTL_CLKREQ_EN;
 
-		mvebu_writel(port, value, PCIE_CAP_PCIEXP + PCI_EXP_LNKCTL);
+		mvebu_writel(port, new, PCIE_CAP_PCIEXP + PCI_EXP_LNKCTL);
 		break;
 
-	case PCISWCAP_EXP_RTSTA:
-		mvebu_writel(port, value, PCIE_RC_RTSTA);
+	case PCI_EXP_RTSTA:
+		mvebu_writel(port, new, PCIE_RC_RTSTA);
 		break;
+	}
+}
 
-	default:
-		break;
+struct pci_bridge_emul_ops mvebu_pci_bridge_emul_ops = {
+	.write_base = mvebu_pci_bridge_emul_base_conf_write,
+	.read_pcie = mvebu_pci_bridge_emul_pcie_conf_read,
+	.write_pcie = mvebu_pci_bridge_emul_pcie_conf_write,
+};
+
+/*
+ * Initialize the configuration space of the PCI-to-PCI bridge
+ * associated with the given PCIe interface.
+ */
+static void mvebu_pci_bridge_emul_init(struct mvebu_pcie_port *port)
+{
+	struct pci_bridge_emul *bridge = &port->bridge;
+
+	bridge->conf.vendor = PCI_VENDOR_ID_MARVELL;
+	bridge->conf.device = mvebu_readl(port, PCIE_DEV_ID_OFF) >> 16;
+	bridge->conf.class_revision =
+		mvebu_readl(port, PCIE_DEV_REV_OFF) & 0xff;
+
+	if (mvebu_has_ioport(port)) {
+		/* We support 32 bits I/O addressing */
+		bridge->conf.iobase = PCI_IO_RANGE_TYPE_32;
+		bridge->conf.iolimit = PCI_IO_RANGE_TYPE_32;
 	}
 
-	return PCIBIOS_SUCCESSFUL;
+	bridge->has_pcie = true;
+	bridge->data = port;
+	bridge->ops = &mvebu_pci_bridge_emul_ops;
+
+	pci_bridge_emul_init(bridge);
 }
 
 static inline struct mvebu_pcie *sys_to_pcie(struct pci_sys_data *sys)
@@ -775,8 +603,8 @@ static struct mvebu_pcie_port *mvebu_pcie_find_port(struct mvebu_pcie *pcie,
 		if (bus->number == 0 && port->devfn == devfn)
 			return port;
 		if (bus->number != 0 &&
-		    bus->number >= port->bridge.secondary_bus &&
-		    bus->number <= port->bridge.subordinate_bus)
+		    bus->number >= port->bridge.conf.secondary_bus &&
+		    bus->number <= port->bridge.conf.subordinate_bus)
 			return port;
 	}
 
@@ -797,7 +625,8 @@ static int mvebu_pcie_wr_conf(struct pci_bus *bus, u32 devfn,
 
 	/* Access the emulated PCI-to-PCI bridge */
 	if (bus->number == 0)
-		return mvebu_sw_pci_bridge_write(port, where, size, val);
+		return pci_bridge_emul_conf_write(&port->bridge, where,
+						  size, val);
 
 	if (!mvebu_pcie_link_up(port))
 		return PCIBIOS_DEVICE_NOT_FOUND;
@@ -825,7 +654,8 @@ static int mvebu_pcie_rd_conf(struct pci_bus *bus, u32 devfn, int where,
 
 	/* Access the emulated PCI-to-PCI bridge */
 	if (bus->number == 0)
-		return mvebu_sw_pci_bridge_read(port, where, size, val);
+		return pci_bridge_emul_conf_read(&port->bridge, where,
+						 size, val);
 
 	if (!mvebu_pcie_link_up(port)) {
 		*val = 0xffffffff;
@@ -1239,7 +1069,7 @@ static int mvebu_pcie_probe(struct platform_device *pdev)
 
 		mvebu_pcie_setup_hw(port);
 		mvebu_pcie_set_local_dev_nr(port, 1);
-		mvebu_sw_pci_bridge_init(port);
+		mvebu_pci_bridge_emul_init(port);
 	}
 
 	pcie->nports = i;