https://github.com/torvalds/linux
Tip revision: 085b7755808aa11f78ab9377257e1dad2e6fa4bb authored by Linus Torvalds on 21 April 2019, 17:45:57 UTC
Linux 5.1-rc6
Linux 5.1-rc6
Tip revision: 085b775
rtas_pci.c
/*
* Copyright (C) 2001 Dave Engebretsen, IBM Corporation
* Copyright (C) 2003 Anton Blanchard <anton@au.ibm.com>, IBM
*
* RTAS specific routines for PCI.
*
* Based on code from pci.c, chrp_pci.c and pSeries_pci.c
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/kernel.h>
#include <linux/threads.h>
#include <linux/pci.h>
#include <linux/string.h>
#include <linux/init.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/irq.h>
#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/pci-bridge.h>
#include <asm/iommu.h>
#include <asm/rtas.h>
#include <asm/mpic.h>
#include <asm/ppc-pci.h>
#include <asm/eeh.h>
/* RTAS tokens */
static int read_pci_config;
static int write_pci_config;
static int ibm_read_pci_config;
static int ibm_write_pci_config;
static inline int config_access_valid(struct pci_dn *dn, int where)
{
if (where < 256)
return 1;
if (where < 4096 && dn->pci_ext_config_space)
return 1;
return 0;
}
int rtas_read_config(struct pci_dn *pdn, int where, int size, u32 *val)
{
int returnval = -1;
unsigned long buid, addr;
int ret;
if (!pdn)
return PCIBIOS_DEVICE_NOT_FOUND;
if (!config_access_valid(pdn, where))
return PCIBIOS_BAD_REGISTER_NUMBER;
#ifdef CONFIG_EEH
if (pdn->edev && pdn->edev->pe &&
(pdn->edev->pe->state & EEH_PE_CFG_BLOCKED))
return PCIBIOS_SET_FAILED;
#endif
addr = rtas_config_addr(pdn->busno, pdn->devfn, where);
buid = pdn->phb->buid;
if (buid) {
ret = rtas_call(ibm_read_pci_config, 4, 2, &returnval,
addr, BUID_HI(buid), BUID_LO(buid), size);
} else {
ret = rtas_call(read_pci_config, 2, 2, &returnval, addr, size);
}
*val = returnval;
if (ret)
return PCIBIOS_DEVICE_NOT_FOUND;
return PCIBIOS_SUCCESSFUL;
}
static int rtas_pci_read_config(struct pci_bus *bus,
unsigned int devfn,
int where, int size, u32 *val)
{
struct pci_dn *pdn;
int ret;
*val = 0xFFFFFFFF;
pdn = pci_get_pdn_by_devfn(bus, devfn);
/* Validity of pdn is checked in here */
ret = rtas_read_config(pdn, where, size, val);
if (*val == EEH_IO_ERROR_VALUE(size) &&
eeh_dev_check_failure(pdn_to_eeh_dev(pdn)))
return PCIBIOS_DEVICE_NOT_FOUND;
return ret;
}
int rtas_write_config(struct pci_dn *pdn, int where, int size, u32 val)
{
unsigned long buid, addr;
int ret;
if (!pdn)
return PCIBIOS_DEVICE_NOT_FOUND;
if (!config_access_valid(pdn, where))
return PCIBIOS_BAD_REGISTER_NUMBER;
#ifdef CONFIG_EEH
if (pdn->edev && pdn->edev->pe &&
(pdn->edev->pe->state & EEH_PE_CFG_BLOCKED))
return PCIBIOS_SET_FAILED;
#endif
addr = rtas_config_addr(pdn->busno, pdn->devfn, where);
buid = pdn->phb->buid;
if (buid) {
ret = rtas_call(ibm_write_pci_config, 5, 1, NULL, addr,
BUID_HI(buid), BUID_LO(buid), size, (ulong) val);
} else {
ret = rtas_call(write_pci_config, 3, 1, NULL, addr, size, (ulong)val);
}
if (ret)
return PCIBIOS_DEVICE_NOT_FOUND;
return PCIBIOS_SUCCESSFUL;
}
static int rtas_pci_write_config(struct pci_bus *bus,
unsigned int devfn,
int where, int size, u32 val)
{
struct pci_dn *pdn;
pdn = pci_get_pdn_by_devfn(bus, devfn);
/* Validity of pdn is checked in here. */
return rtas_write_config(pdn, where, size, val);
}
static struct pci_ops rtas_pci_ops = {
.read = rtas_pci_read_config,
.write = rtas_pci_write_config,
};
static int is_python(struct device_node *dev)
{
const char *model = of_get_property(dev, "model", NULL);
if (model && strstr(model, "Python"))
return 1;
return 0;
}
static void python_countermeasures(struct device_node *dev)
{
struct resource registers;
void __iomem *chip_regs;
volatile u32 val;
if (of_address_to_resource(dev, 0, ®isters)) {
printk(KERN_ERR "Can't get address for Python workarounds !\n");
return;
}
/* Python's register file is 1 MB in size. */
chip_regs = ioremap(registers.start & ~(0xfffffUL), 0x100000);
/*
* Firmware doesn't always clear this bit which is critical
* for good performance - Anton
*/
#define PRG_CL_RESET_VALID 0x00010000
val = in_be32(chip_regs + 0xf6030);
if (val & PRG_CL_RESET_VALID) {
printk(KERN_INFO "Python workaround: ");
val &= ~PRG_CL_RESET_VALID;
out_be32(chip_regs + 0xf6030, val);
/*
* We must read it back for changes to
* take effect
*/
val = in_be32(chip_regs + 0xf6030);
printk("reg0: %x\n", val);
}
iounmap(chip_regs);
}
void __init init_pci_config_tokens(void)
{
read_pci_config = rtas_token("read-pci-config");
write_pci_config = rtas_token("write-pci-config");
ibm_read_pci_config = rtas_token("ibm,read-pci-config");
ibm_write_pci_config = rtas_token("ibm,write-pci-config");
}
unsigned long get_phb_buid(struct device_node *phb)
{
struct resource r;
if (ibm_read_pci_config == -1)
return 0;
if (of_address_to_resource(phb, 0, &r))
return 0;
return r.start;
}
static int phb_set_bus_ranges(struct device_node *dev,
struct pci_controller *phb)
{
const __be32 *bus_range;
unsigned int len;
bus_range = of_get_property(dev, "bus-range", &len);
if (bus_range == NULL || len < 2 * sizeof(int)) {
return 1;
}
phb->first_busno = be32_to_cpu(bus_range[0]);
phb->last_busno = be32_to_cpu(bus_range[1]);
return 0;
}
int rtas_setup_phb(struct pci_controller *phb)
{
struct device_node *dev = phb->dn;
if (is_python(dev))
python_countermeasures(dev);
if (phb_set_bus_ranges(dev, phb))
return 1;
phb->ops = &rtas_pci_ops;
phb->buid = get_phb_buid(dev);
return 0;
}