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linux-next/arch/mips/pci/ops-emma2rh.c
Paul Burton 2dca88da83 MIPS: ops-emma2rh: Drop nonsensical db_assert
The db_assert call checks whether the bus_num pointer is non-NULL, but
does so after said pointer has been dereferenced by the assignment on
the previous line. Thus the check is pointless & likely to have been
optimised out by the compiler anyway. The check_args function is static
& only ever called from the local file with bus_num being a pointer to
an on-stack variable, so the check seems somewhat overzealous anyway.
Simply remove it.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/10692/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-08-26 15:23:35 +02:00

181 lines
4.3 KiB
C

/*
* Copyright (C) NEC Electronics Corporation 2004-2006
*
* This file is based on the arch/mips/pci/ops-vr41xx.c
*
* Copyright 2001 MontaVista Software Inc.
*
* 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/pci.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <asm/addrspace.h>
#include <asm/emma/emma2rh.h>
#define RTABORT (0x1<<9)
#define RMABORT (0x1<<10)
#define EMMA2RH_PCI_SLOT_NUM 9 /* 0000:09.0 is final PCI device */
/*
* access config space
*/
static int check_args(struct pci_bus *bus, u32 devfn, u32 * bus_num)
{
/* check if the bus is top-level */
if (bus->parent != NULL)
*bus_num = bus->number;
else
*bus_num = 0;
if (*bus_num == 0) {
/* Type 0 */
if (PCI_SLOT(devfn) >= 10)
return PCIBIOS_DEVICE_NOT_FOUND;
} else {
/* Type 1 */
if ((*bus_num >= 64) || (PCI_SLOT(devfn) >= 16))
return PCIBIOS_DEVICE_NOT_FOUND;
}
return 0;
}
static inline int set_pci_configuration_address(unsigned char bus_num,
unsigned int devfn, int where)
{
u32 config_win0;
emma2rh_out32(EMMA2RH_PCI_INT, ~RMABORT);
if (bus_num == 0)
/*
* Type 0 configuration
*/
config_win0 = (1 << (22 + PCI_SLOT(devfn))) | (5 << 9);
else
/*
* Type 1 configuration
*/
config_win0 = (bus_num << 26) | (PCI_SLOT(devfn) << 22) |
(1 << 15) | (5 << 9);
emma2rh_out32(EMMA2RH_PCI_IWIN0_CTR, config_win0);
return 0;
}
static int pci_config_read(struct pci_bus *bus, unsigned int devfn, int where,
int size, uint32_t * val)
{
u32 bus_num;
u32 base = KSEG1ADDR(EMMA2RH_PCI_CONFIG_BASE);
u32 backup_win0;
u32 data;
*val = 0xffffffffU;
if (check_args(bus, devfn, &bus_num) == PCIBIOS_DEVICE_NOT_FOUND)
return PCIBIOS_DEVICE_NOT_FOUND;
backup_win0 = emma2rh_in32(EMMA2RH_PCI_IWIN0_CTR);
if (set_pci_configuration_address(bus_num, devfn, where) < 0)
return PCIBIOS_DEVICE_NOT_FOUND;
data =
*(volatile u32 *)(base + (PCI_FUNC(devfn) << 8) +
(where & 0xfffffffc));
switch (size) {
case 1:
*val = (data >> ((where & 3) << 3)) & 0xffU;
break;
case 2:
*val = (data >> ((where & 2) << 3)) & 0xffffU;
break;
case 4:
*val = data;
break;
default:
emma2rh_out32(EMMA2RH_PCI_IWIN0_CTR, backup_win0);
return PCIBIOS_FUNC_NOT_SUPPORTED;
}
emma2rh_out32(EMMA2RH_PCI_IWIN0_CTR, backup_win0);
if (emma2rh_in32(EMMA2RH_PCI_INT) & RMABORT)
return PCIBIOS_DEVICE_NOT_FOUND;
return PCIBIOS_SUCCESSFUL;
}
static int pci_config_write(struct pci_bus *bus, unsigned int devfn, int where,
int size, u32 val)
{
u32 bus_num;
u32 base = KSEG1ADDR(EMMA2RH_PCI_CONFIG_BASE);
u32 backup_win0;
u32 data;
int shift;
if (check_args(bus, devfn, &bus_num) == PCIBIOS_DEVICE_NOT_FOUND)
return PCIBIOS_DEVICE_NOT_FOUND;
backup_win0 = emma2rh_in32(EMMA2RH_PCI_IWIN0_CTR);
if (set_pci_configuration_address(bus_num, devfn, where) < 0)
return PCIBIOS_DEVICE_NOT_FOUND;
/* read modify write */
data =
*(volatile u32 *)(base + (PCI_FUNC(devfn) << 8) +
(where & 0xfffffffc));
switch (size) {
case 1:
shift = (where & 3) << 3;
data &= ~(0xffU << shift);
data |= ((val & 0xffU) << shift);
break;
case 2:
shift = (where & 2) << 3;
data &= ~(0xffffU << shift);
data |= ((val & 0xffffU) << shift);
break;
case 4:
data = val;
break;
default:
emma2rh_out32(EMMA2RH_PCI_IWIN0_CTR, backup_win0);
return PCIBIOS_FUNC_NOT_SUPPORTED;
}
*(volatile u32 *)(base + (PCI_FUNC(devfn) << 8) +
(where & 0xfffffffc)) = data;
emma2rh_out32(EMMA2RH_PCI_IWIN0_CTR, backup_win0);
if (emma2rh_in32(EMMA2RH_PCI_INT) & RMABORT)
return PCIBIOS_DEVICE_NOT_FOUND;
return PCIBIOS_SUCCESSFUL;
}
struct pci_ops emma2rh_pci_ops = {
.read = pci_config_read,
.write = pci_config_write,
};