/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Copyright (C) 2015 - 2016 Cavium, Inc.
*/
#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 "../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] = (u32)bar4_start | 2;
pem_pci->ea_entry[1] = (u32)(res_pem->end - bar4_start) & ~3u;
pem_pci->ea_entry[2] = (u32)(bar4_start >> 32);
cfg->priv = pem_pci;
return 0;
}
#if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS)
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 (ret) {
dev_err(dev, "can't get rc base address\n");
return ret;
}
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,
},
.probe = thunder_pem_probe,
};
builtin_platform_driver(thunder_pem_driver);
#endif
#endif
