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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /drivers/pci/controller/pci-thunder-pem.c | |
parent | Initial commit. (diff) | |
download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip |
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/pci/controller/pci-thunder-pem.c')
-rw-r--r-- | drivers/pci/controller/pci-thunder-pem.c | 474 |
1 files changed, 474 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..1650ec2c3 --- /dev/null +++ b/drivers/pci/controller/pci-thunder-pem.c @@ -0,0 +1,474 @@ +// 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/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 + +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) { + *val = ~0; + 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); +} + +struct pci_ecam_ops thunder_pem_ecam_ops = { + .bus_shift = 24, + .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 struct pci_ecam_ops pci_thunder_pem_ops = { + .bus_shift = 24, + .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" }, + { }, +}; + +static int thunder_pem_probe(struct platform_device *pdev) +{ + return pci_host_common_probe(pdev, &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 = thunder_pem_probe, +}; +builtin_platform_driver(thunder_pem_driver); + +#endif +#endif |