diff options
Diffstat (limited to 'arch/powerpc/kernel/rtas_pci.c')
| -rw-r--r-- | arch/powerpc/kernel/rtas_pci.c | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/rtas_pci.c b/arch/powerpc/kernel/rtas_pci.c new file mode 100644 index 000000000..781c18699 --- /dev/null +++ b/arch/powerpc/kernel/rtas_pci.c @@ -0,0 +1,241 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * 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 + */ + +#include <linux/kernel.h> +#include <linux/threads.h> +#include <linux/pci.h> +#include <linux/string.h> +#include <linux/init.h> +#include <linux/pgtable.h> + +#include <asm/io.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; +} |