// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2001,2002,2003 Broadcom Corporation
* Copyright (C) 2004 by Ralf Baechle (ralf@linux-mips.org)
*/
/*
* BCM1250-specific PCI support
*
* This module provides the glue between Linux's PCI subsystem
* and the hardware. We basically provide glue for accessing
* configuration space, and set up the translation for I/O
* space accesses.
*
* To access configuration space, we use ioremap. In the 32-bit
* kernel, this consumes either 4 or 8 page table pages, and 16MB of
* kernel mapped memory. Hopefully neither of these should be a huge
* problem.
*/
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/console.h>
#include <linux/tty.h>
#include <linux/vt.h>
#include <asm/io.h>
#include <asm/sibyte/sb1250_defs.h>
#include <asm/sibyte/sb1250_regs.h>
#include <asm/sibyte/sb1250_scd.h>
#include <asm/sibyte/board.h>
/*
* Macros for calculating offsets into config space given a device
* structure or dev/fun/reg
*/
#define CFGOFFSET(bus, devfn, where) (((bus)<<16) + ((devfn)<<8) + (where))
#define CFGADDR(bus, devfn, where) CFGOFFSET((bus)->number, (devfn), where)
static void *cfg_space;
#define PCI_BUS_ENABLED 1
#define LDT_BUS_ENABLED 2
#define PCI_DEVICE_MODE 4
static int sb1250_bus_status;
#define PCI_BRIDGE_DEVICE 0
#define LDT_BRIDGE_DEVICE 1
#ifdef CONFIG_SIBYTE_HAS_LDT
/*
* HT's level-sensitive interrupts require EOI, which is generated
* through a 4MB memory-mapped region
*/
unsigned long ldt_eoi_space;
#endif
/*
* Read/write 32-bit values in config space.
*/
static inline u32 READCFG32(u32 addr)
{
return *(u32 *) (cfg_space + (addr & ~3));
}
static inline void WRITECFG32(u32 addr, u32 data)
{
*(u32 *) (cfg_space + (addr & ~3)) = data;
}
int pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
{
return dev->irq;
}
/* Do platform specific device initialization at pci_enable_device() time */
int pcibios_plat_dev_init(struct pci_dev *dev)
{
return 0;
}
/*
* Some checks before doing config cycles:
* In PCI Device Mode, hide everything on bus 0 except the LDT host
* bridge. Otherwise, access is controlled by bridge MasterEn bits.
*/
static int sb1250_pci_can_access(struct pci_bus *bus, int devfn)
{
u32 devno;
if (!(sb1250_bus_status & (PCI_BUS_ENABLED | PCI_DEVICE_MODE)))
return 0;
if (bus->number == 0) {
devno = PCI_SLOT(devfn);
if (devno == LDT_BRIDGE_DEVICE)
return (sb1250_bus_status & LDT_BUS_ENABLED) != 0;
else if (sb1250_bus_status & PCI_DEVICE_MODE)
return 0;
else
return 1;
} else
return 1;
}
/*
* Read/write access functions for various sizes of values
* in config space. Return all 1's for disallowed accesses
* for a kludgy but adequate simulation of master aborts.
*/
static int sb1250_pcibios_read(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 * val)
{
u32 data = 0;
if ((size == 2) && (where & 1))
return PCIBIOS_BAD_REGISTER_NUMBER;
else if ((size == 4) && (where & 3))
return PCIBIOS_BAD_REGISTER_NUMBER;
if (sb1250_pci_can_access(bus, devfn))
data = READCFG32(CFGADDR(bus, devfn, where));
else
data = 0xFFFFFFFF;
if (size == 1)
*val = (data >> ((where & 3) << 3)) & 0xff;
else if (size == 2)
*val = (data >> ((where & 3) << 3)) & 0xffff;
else
*val = data;
return PCIBIOS_SUCCESSFUL;
}
static int sb1250_pcibios_write(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 val)
{
u32 cfgaddr = CFGADDR(bus, devfn, where);
u32 data = 0;
if ((size == 2) && (where & 1))
return PCIBIOS_BAD_REGISTER_NUMBER;
else if ((size == 4) && (where & 3))
return PCIBIOS_BAD_REGISTER_NUMBER;
if (!sb1250_pci_can_access(bus, devfn))
return PCIBIOS_BAD_REGISTER_NUMBER;
data = READCFG32(cfgaddr);
if (size == 1)
data = (data & ~(0xff << ((where & 3) << 3))) |
(val << ((where & 3) << 3));
else if (size == 2)
data = (data & ~(0xffff << ((where & 3) << 3))) |
(val << ((where & 3) << 3));
else
data = val;
WRITECFG32(cfgaddr, data);
return PCIBIOS_SUCCESSFUL;
}
struct pci_ops sb1250_pci_ops = {
.read = sb1250_pcibios_read,
.write = sb1250_pcibios_write,
};
static struct resource sb1250_mem_resource = {
.name = "SB1250 PCI MEM",
.start = 0x40000000UL,
.end = 0x5fffffffUL,
.flags = IORESOURCE_MEM,
};
static struct resource sb1250_io_resource = {
.name = "SB1250 PCI I/O",
.start = 0x00000000UL,
.end = 0x01ffffffUL,
.flags = IORESOURCE_IO,
};
struct pci_controller sb1250_controller = {
.pci_ops = &sb1250_pci_ops,
.mem_resource = &sb1250_mem_resource,
.io_resource = &sb1250_io_resource,
};
static int __init sb1250_pcibios_init(void)
{
void __iomem *io_map_base;
uint32_t cmdreg;
uint64_t reg;
/* CFE will assign PCI resources */
pci_set_flags(PCI_PROBE_ONLY);
/* Avoid ISA compat ranges. */
PCIBIOS_MIN_IO = 0x00008000UL;
PCIBIOS_MIN_MEM = 0x01000000UL;
/* Set I/O resource limits. */
ioport_resource.end = 0x01ffffffUL; /* 32MB accessible by sb1250 */
iomem_resource.end = 0xffffffffUL; /* no HT support yet */
cfg_space =
ioremap(A_PHYS_LDTPCI_CFG_MATCH_BITS, 16 * 1024 * 1024);
/*
* See if the PCI bus has been configured by the firmware.
*/
reg = __raw_readq(IOADDR(A_SCD_SYSTEM_CFG));
if (!(reg & M_SYS_PCI_HOST)) {
sb1250_bus_status |= PCI_DEVICE_MODE;
} else {
cmdreg =
READCFG32(CFGOFFSET
(0, PCI_DEVFN(PCI_BRIDGE_DEVICE, 0),
PCI_COMMAND));
if (!(cmdreg & PCI_COMMAND_MASTER)) {
printk
("PCI: Skipping PCI probe. Bus is not initialized.\n");
iounmap(cfg_space);
return 0;
}
sb1250_bus_status |= PCI_BUS_ENABLED;
}
/*
* Establish mappings in KSEG2 (kernel virtual) to PCI I/O
* space. Use "match bytes" policy to make everything look
* little-endian. So, you need to also set
* CONFIG_SWAP_IO_SPACE, but this is the combination that
* works correctly with most of Linux's drivers.
* XXX ehs: Should this happen in PCI Device mode?
*/
io_map_base = ioremap(A_PHYS_LDTPCI_IO_MATCH_BYTES, 1024 * 1024);
sb1250_controller.io_map_base = (unsigned long)io_map_base;
set_io_port_base((unsigned long)io_map_base);
#ifdef CONFIG_SIBYTE_HAS_LDT
/*
* Also check the LDT bridge's enable, just in case we didn't
* initialize that one.
*/
cmdreg = READCFG32(CFGOFFSET(0, PCI_DEVFN(LDT_BRIDGE_DEVICE, 0),
PCI_COMMAND));
if (cmdreg & PCI_COMMAND_MASTER) {
sb1250_bus_status |= LDT_BUS_ENABLED;
/*
* Need bits 23:16 to convey vector number. Note that
* this consumes 4MB of kernel-mapped memory
* (Kseg2/Kseg3) for 32-bit kernel.
*/
ldt_eoi_space = (unsigned long)
ioremap(A_PHYS_LDT_SPECIAL_MATCH_BYTES,
4 * 1024 * 1024);
}
#endif
register_pci_controller(&sb1250_controller);
#ifdef CONFIG_VGA_CONSOLE
console_lock();
do_take_over_console(&vga_con, 0, MAX_NR_CONSOLES - 1, 1);
console_unlock();
#endif
return 0;
}
arch_initcall(sb1250_pcibios_init);