1 files changed, 480 insertions, 0 deletions
diff --git a/drivers/pci/controller/pci-thunder-pem.c b/drivers/pci/controller/pci-thunder-pem.c
new file mode 100644
index 000000000..06a9855cb
--- /dev/null
+++ b/drivers/pci/controller/pci-thunder-pem.c
@@ -0,0 +1,480 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2015 - 2016 Cavium, Inc.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/of_address.h>
+#include <linux/of_pci.h>
+#include <linux/pci-acpi.h>
+#include <linux/pci-ecam.h>
+#include <linux/platform_device.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
+#include "../pci.h"
+
+#if defined(CONFIG_PCI_HOST_THUNDER_PEM) || (defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS))
+
+#define PEM_CFG_WR 0x28
+#define PEM_CFG_RD 0x30
+
+/*
+ * Enhanced Configuration Access Mechanism (ECAM)
+ *
+ * N.B. This is a non-standard platform-specific ECAM bus shift value.  For
+ * standard values defined in the PCI Express Base Specification see
+ * include/linux/pci-ecam.h.
+ */
+#define THUNDER_PCIE_ECAM_BUS_SHIFT	24
+
+struct thunder_pem_pci {
+	u32		ea_entry[3];
+	void __iomem	*pem_reg_base;
+};
+
+static int thunder_pem_bridge_read(struct pci_bus *bus, unsigned int devfn,
+				   int where, int size, u32 *val)
+{
+	u64 read_val, tmp_val;
+	struct pci_config_window *cfg = bus->sysdata;
+	struct thunder_pem_pci *pem_pci = (struct thunder_pem_pci *)cfg->priv;
+
+	if (devfn != 0 || where >= 2048)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	/*
+	 * 32-bit accesses only.  Write the address to the low order
+	 * bits of PEM_CFG_RD, then trigger the read by reading back.
+	 * The config data lands in the upper 32-bits of PEM_CFG_RD.
+	 */
+	read_val = where & ~3ull;
+	writeq(read_val, pem_pci->pem_reg_base + PEM_CFG_RD);
+	read_val = readq(pem_pci->pem_reg_base + PEM_CFG_RD);
+	read_val >>= 32;
+
+	/*
+	 * The config space contains some garbage, fix it up.  Also
+	 * synthesize an EA capability for the BAR used by MSI-X.
+	 */
+	switch (where & ~3) {
+	case 0x40:
+		read_val &= 0xffff00ff;
+		read_val |= 0x00007000; /* Skip MSI CAP */
+		break;
+	case 0x70: /* Express Cap */
+		/*
+		 * Change PME interrupt to vector 2 on T88 where it
+		 * reads as 0, else leave it alone.
+		 */
+		if (!(read_val & (0x1f << 25)))
+			read_val |= (2u << 25);
+		break;
+	case 0xb0: /* MSI-X Cap */
+		/* TableSize=2 or 4, Next Cap is EA */
+		read_val &= 0xc00000ff;
+		/*
+		 * If Express Cap(0x70) raw PME vector reads as 0 we are on
+		 * T88 and TableSize is reported as 4, else TableSize
+		 * is 2.
+		 */
+		writeq(0x70, pem_pci->pem_reg_base + PEM_CFG_RD);
+		tmp_val = readq(pem_pci->pem_reg_base + PEM_CFG_RD);
+		tmp_val >>= 32;
+		if (!(tmp_val & (0x1f << 25)))
+			read_val |= 0x0003bc00;
+		else
+			read_val |= 0x0001bc00;
+		break;
+	case 0xb4:
+		/* Table offset=0, BIR=0 */
+		read_val = 0x00000000;
+		break;
+	case 0xb8:
+		/* BPA offset=0xf0000, BIR=0 */
+		read_val = 0x000f0000;
+		break;
+	case 0xbc:
+		/* EA, 1 entry, no next Cap */
+		read_val = 0x00010014;
+		break;
+	case 0xc0:
+		/* DW2 for type-1 */
+		read_val = 0x00000000;
+		break;
+	case 0xc4:
+		/* Entry BEI=0, PP=0x00, SP=0xff, ES=3 */
+		read_val = 0x80ff0003;
+		break;
+	case 0xc8:
+		read_val = pem_pci->ea_entry[0];
+		break;
+	case 0xcc:
+		read_val = pem_pci->ea_entry[1];
+		break;
+	case 0xd0:
+		read_val = pem_pci->ea_entry[2];
+		break;
+	default:
+		break;
+	}
+	read_val >>= (8 * (where & 3));
+	switch (size) {
+	case 1:
+		read_val &= 0xff;
+		break;
+	case 2:
+		read_val &= 0xffff;
+		break;
+	default:
+		break;
+	}
+	*val = read_val;
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int thunder_pem_config_read(struct pci_bus *bus, unsigned int devfn,
+				   int where, int size, u32 *val)
+{
+	struct pci_config_window *cfg = bus->sysdata;
+
+	if (bus->number < cfg->busr.start ||
+	    bus->number > cfg->busr.end)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	/*
+	 * The first device on the bus is the PEM PCIe bridge.
+	 * Special case its config access.
+	 */
+	if (bus->number == cfg->busr.start)
+		return thunder_pem_bridge_read(bus, devfn, where, size, val);
+
+	return pci_generic_config_read(bus, devfn, where, size, val);
+}
+
+/*
+ * Some of the w1c_bits below also include read-only or non-writable
+ * reserved bits, this makes the code simpler and is OK as the bits
+ * are not affected by writing zeros to them.
+ */
+static u32 thunder_pem_bridge_w1c_bits(u64 where_aligned)
+{
+	u32 w1c_bits = 0;
+
+	switch (where_aligned) {
+	case 0x04: /* Command/Status */
+	case 0x1c: /* Base and I/O Limit/Secondary Status */
+		w1c_bits = 0xff000000;
+		break;
+	case 0x44: /* Power Management Control and Status */
+		w1c_bits = 0xfffffe00;
+		break;
+	case 0x78: /* Device Control/Device Status */
+	case 0x80: /* Link Control/Link Status */
+	case 0x88: /* Slot Control/Slot Status */
+	case 0x90: /* Root Status */
+	case 0xa0: /* Link Control 2 Registers/Link Status 2 */
+		w1c_bits = 0xffff0000;
+		break;
+	case 0x104: /* Uncorrectable Error Status */
+	case 0x110: /* Correctable Error Status */
+	case 0x130: /* Error Status */
+	case 0x160: /* Link Control 4 */
+		w1c_bits = 0xffffffff;
+		break;
+	default:
+		break;
+	}
+	return w1c_bits;
+}
+
+/* Some bits must be written to one so they appear to be read-only. */
+static u32 thunder_pem_bridge_w1_bits(u64 where_aligned)
+{
+	u32 w1_bits;
+
+	switch (where_aligned) {
+	case 0x1c: /* I/O Base / I/O Limit, Secondary Status */
+		/* Force 32-bit I/O addressing. */
+		w1_bits = 0x0101;
+		break;
+	case 0x24: /* Prefetchable Memory Base / Prefetchable Memory Limit */
+		/* Force 64-bit addressing */
+		w1_bits = 0x00010001;
+		break;
+	default:
+		w1_bits = 0;
+		break;
+	}
+	return w1_bits;
+}
+
+static int thunder_pem_bridge_write(struct pci_bus *bus, unsigned int devfn,
+				    int where, int size, u32 val)
+{
+	struct pci_config_window *cfg = bus->sysdata;
+	struct thunder_pem_pci *pem_pci = (struct thunder_pem_pci *)cfg->priv;
+	u64 write_val, read_val;
+	u64 where_aligned = where & ~3ull;
+	u32 mask = 0;
+
+
+	if (devfn != 0 || where >= 2048)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	/*
+	 * 32-bit accesses only.  If the write is for a size smaller
+	 * than 32-bits, we must first read the 32-bit value and merge
+	 * in the desired bits and then write the whole 32-bits back
+	 * out.
+	 */
+	switch (size) {
+	case 1:
+		writeq(where_aligned, pem_pci->pem_reg_base + PEM_CFG_RD);
+		read_val = readq(pem_pci->pem_reg_base + PEM_CFG_RD);
+		read_val >>= 32;
+		mask = ~(0xff << (8 * (where & 3)));
+		read_val &= mask;
+		val = (val & 0xff) << (8 * (where & 3));
+		val |= (u32)read_val;
+		break;
+	case 2:
+		writeq(where_aligned, pem_pci->pem_reg_base + PEM_CFG_RD);
+		read_val = readq(pem_pci->pem_reg_base + PEM_CFG_RD);
+		read_val >>= 32;
+		mask = ~(0xffff << (8 * (where & 3)));
+		read_val &= mask;
+		val = (val & 0xffff) << (8 * (where & 3));
+		val |= (u32)read_val;
+		break;
+	default:
+		break;
+	}
+
+	/*
+	 * By expanding the write width to 32 bits, we may
+	 * inadvertently hit some W1C bits that were not intended to
+	 * be written.  Calculate the mask that must be applied to the
+	 * data to be written to avoid these cases.
+	 */
+	if (mask) {
+		u32 w1c_bits = thunder_pem_bridge_w1c_bits(where);
+
+		if (w1c_bits) {
+			mask &= w1c_bits;
+			val &= ~mask;
+		}
+	}
+
+	/*
+	 * Some bits must be read-only with value of one.  Since the
+	 * access method allows these to be cleared if a zero is
+	 * written, force them to one before writing.
+	 */
+	val |= thunder_pem_bridge_w1_bits(where_aligned);
+
+	/*
+	 * Low order bits are the config address, the high order 32
+	 * bits are the data to be written.
+	 */
+	write_val = (((u64)val) << 32) | where_aligned;
+	writeq(write_val, pem_pci->pem_reg_base + PEM_CFG_WR);
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int thunder_pem_config_write(struct pci_bus *bus, unsigned int devfn,
+				    int where, int size, u32 val)
+{
+	struct pci_config_window *cfg = bus->sysdata;
+
+	if (bus->number < cfg->busr.start ||
+	    bus->number > cfg->busr.end)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+	/*
+	 * The first device on the bus is the PEM PCIe bridge.
+	 * Special case its config access.
+	 */
+	if (bus->number == cfg->busr.start)
+		return thunder_pem_bridge_write(bus, devfn, where, size, val);
+
+
+	return pci_generic_config_write(bus, devfn, where, size, val);
+}
+
+static int thunder_pem_init(struct device *dev, struct pci_config_window *cfg,
+			    struct resource *res_pem)
+{
+	struct thunder_pem_pci *pem_pci;
+	resource_size_t bar4_start;
+
+	pem_pci = devm_kzalloc(dev, sizeof(*pem_pci), GFP_KERNEL);
+	if (!pem_pci)
+		return -ENOMEM;
+
+	pem_pci->pem_reg_base = devm_ioremap(dev, res_pem->start, 0x10000);
+	if (!pem_pci->pem_reg_base)
+		return -ENOMEM;
+
+	/*
+	 * The MSI-X BAR for the PEM and AER interrupts is located at
+	 * a fixed offset from the PEM register base.  Generate a
+	 * fragment of the synthesized Enhanced Allocation capability
+	 * structure here for the BAR.
+	 */
+	bar4_start = res_pem->start + 0xf00000;
+	pem_pci->ea_entry[0] = lower_32_bits(bar4_start) | 2;
+	pem_pci->ea_entry[1] = lower_32_bits(res_pem->end - bar4_start) & ~3u;
+	pem_pci->ea_entry[2] = upper_32_bits(bar4_start);
+
+	cfg->priv = pem_pci;
+	return 0;
+}
+
+#if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS)
+
+#define PEM_RES_BASE		0x87e0c0000000ULL
+#define PEM_NODE_MASK		GENMASK_ULL(45, 44)
+#define PEM_INDX_MASK		GENMASK_ULL(26, 24)
+#define PEM_MIN_DOM_IN_NODE	4
+#define PEM_MAX_DOM_IN_NODE	10
+
+static void thunder_pem_reserve_range(struct device *dev, int seg,
+				      struct resource *r)
+{
+	resource_size_t start = r->start, end = r->end;
+	struct resource *res;
+	const char *regionid;
+
+	regionid = kasprintf(GFP_KERNEL, "PEM RC:%d", seg);
+	if (!regionid)
+		return;
+
+	res = request_mem_region(start, end - start + 1, regionid);
+	if (res)
+		res->flags &= ~IORESOURCE_BUSY;
+	else
+		kfree(regionid);
+
+	dev_info(dev, "%pR %s reserved\n", r,
+		 res ? "has been" : "could not be");
+}
+
+static void thunder_pem_legacy_fw(struct acpi_pci_root *root,
+				 struct resource *res_pem)
+{
+	int node = acpi_get_node(root->device->handle);
+	int index;
+
+	if (node == NUMA_NO_NODE)
+		node = 0;
+
+	index = root->segment - PEM_MIN_DOM_IN_NODE;
+	index -= node * PEM_MAX_DOM_IN_NODE;
+	res_pem->start = PEM_RES_BASE | FIELD_PREP(PEM_NODE_MASK, node) |
+					FIELD_PREP(PEM_INDX_MASK, index);
+	res_pem->flags = IORESOURCE_MEM;
+}
+
+static int thunder_pem_acpi_init(struct pci_config_window *cfg)
+{
+	struct device *dev = cfg->parent;
+	struct acpi_device *adev = to_acpi_device(dev);
+	struct acpi_pci_root *root = acpi_driver_data(adev);
+	struct resource *res_pem;
+	int ret;
+
+	res_pem = devm_kzalloc(&adev->dev, sizeof(*res_pem), GFP_KERNEL);
+	if (!res_pem)
+		return -ENOMEM;
+
+	ret = acpi_get_rc_resources(dev, "CAVA02B", root->segment, res_pem);
+
+	/*
+	 * If we fail to gather resources it means that we run with old
+	 * FW where we need to calculate PEM-specific resources manually.
+	 */
+	if (ret) {
+		thunder_pem_legacy_fw(root, res_pem);
+		/*
+		 * Reserve 64K size PEM specific resources. The full 16M range
+		 * size is required for thunder_pem_init() call.
+		 */
+		res_pem->end = res_pem->start + SZ_64K - 1;
+		thunder_pem_reserve_range(dev, root->segment, res_pem);
+		res_pem->end = res_pem->start + SZ_16M - 1;
+
+		/* Reserve PCI configuration space as well. */
+		thunder_pem_reserve_range(dev, root->segment, &cfg->res);
+	}
+
+	return thunder_pem_init(dev, cfg, res_pem);
+}
+
+const struct pci_ecam_ops thunder_pem_ecam_ops = {
+	.bus_shift	= THUNDER_PCIE_ECAM_BUS_SHIFT,
+	.init		= thunder_pem_acpi_init,
+	.pci_ops	= {
+		.map_bus	= pci_ecam_map_bus,
+		.read		= thunder_pem_config_read,
+		.write		= thunder_pem_config_write,
+	}
+};
+
+#endif
+
+#ifdef CONFIG_PCI_HOST_THUNDER_PEM
+
+static int thunder_pem_platform_init(struct pci_config_window *cfg)
+{
+	struct device *dev = cfg->parent;
+	struct platform_device *pdev = to_platform_device(dev);
+	struct resource *res_pem;
+
+	if (!dev->of_node)
+		return -EINVAL;
+
+	/*
+	 * The second register range is the PEM bridge to the PCIe
+	 * bus.  It has a different config access method than those
+	 * devices behind the bridge.
+	 */
+	res_pem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!res_pem) {
+		dev_err(dev, "missing \"reg[1]\"property\n");
+		return -EINVAL;
+	}
+
+	return thunder_pem_init(dev, cfg, res_pem);
+}
+
+static const struct pci_ecam_ops pci_thunder_pem_ops = {
+	.bus_shift	= THUNDER_PCIE_ECAM_BUS_SHIFT,
+	.init		= thunder_pem_platform_init,
+	.pci_ops	= {
+		.map_bus	= pci_ecam_map_bus,
+		.read		= thunder_pem_config_read,
+		.write		= thunder_pem_config_write,
+	}
+};
+
+static const struct of_device_id thunder_pem_of_match[] = {
+	{
+		.compatible = "cavium,pci-host-thunder-pem",
+		.data = &pci_thunder_pem_ops,
+	},
+	{ },
+};
+
+static struct platform_driver thunder_pem_driver = {
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.of_match_table = thunder_pem_of_match,
+		.suppress_bind_attrs = true,
+	},
+	.probe = pci_host_common_probe,
+};
+builtin_platform_driver(thunder_pem_driver);
+
+#endif
+#endif