[ARM] 4184/1: iop: cp6 access handler (undef_hook)

Enable svc access to cp6 via an undefined instruction hook.  Do not enable
access for usr code.

This patch also makes iop13xx select PLAT_IOP, this requires a small change
to drivers/i2c/busses/i2c-iop3xx.c.

Per Lennert Buytenhek's note, the cp6 trap routine is moved to arch/arm/plat-iop
Per Nicolas Pitre's note, the cp_wait is skipped since the latency to
return to the faulting function is longer than cp_wait.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Dan Williams 2007-02-13 17:12:04 +01:00 committed by Russell King
parent dfc544c721
commit 588ef76935
8 changed files with 87 additions and 5 deletions

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@ -233,6 +233,8 @@ config ARCH_IOP33X
config ARCH_IOP13XX
bool "IOP13xx-based"
depends on MMU
select PLAT_IOP
select PCI
help
Support for Intel's IOP13XX (XScale) family of processors.

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@ -250,11 +250,14 @@ static struct irq_chip iop13xx_irqchip4 = {
.unmask = iop13xx_irq_unmask3,
};
extern void iop_init_cp6_handler(void);
void __init iop13xx_init_irq(void)
{
unsigned int i;
u32 cp_flags = iop13xx_cp6_save();
iop_init_cp6_handler();
/* disable all interrupts */
write_intctl_0(0);

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@ -60,6 +60,8 @@ void __init iop32x_init_irq(void)
{
int i;
iop_init_cp6_handler();
intctl_write(0);
intstr_write(0);
if (machine_is_glantank() ||

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@ -110,6 +110,8 @@ void __init iop33x_init_irq(void)
{
int i;
iop_init_cp6_handler();
intctl0_write(0);
intctl1_write(0);
intstr0_write(0);

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@ -2,7 +2,29 @@
# Makefile for the linux kernel.
#
obj-y := gpio.o i2c.o pci.o setup.o time.o io.o
obj-m :=
obj-n :=
obj- :=
obj-y :=
# IOP32X
obj-$(CONFIG_ARCH_IOP32X) += gpio.o
obj-$(CONFIG_ARCH_IOP32X) += i2c.o
obj-$(CONFIG_ARCH_IOP32X) += pci.o
obj-$(CONFIG_ARCH_IOP32X) += setup.o
obj-$(CONFIG_ARCH_IOP32X) += time.o
obj-$(CONFIG_ARCH_IOP32X) += io.o
obj-$(CONFIG_ARCH_IOP32X) += cp6.o
# IOP33X
obj-$(CONFIG_ARCH_IOP33X) += gpio.o
obj-$(CONFIG_ARCH_IOP33X) += i2c.o
obj-$(CONFIG_ARCH_IOP33X) += pci.o
obj-$(CONFIG_ARCH_IOP33X) += setup.o
obj-$(CONFIG_ARCH_IOP33X) += time.o
obj-$(CONFIG_ARCH_IOP33X) += io.o
obj-$(CONFIG_ARCH_IOP33X) += cp6.o
# IOP13XX
obj-$(CONFIG_ARCH_IOP13XX) += cp6.o
obj-m :=
obj-n :=
obj- :=

50
arch/arm/plat-iop/cp6.c Normal file
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@ -0,0 +1,50 @@
/*
* IOP Coprocessor-6 access handler
* Copyright (c) 2006, Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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/init.h>
#include <asm/traps.h>
static int cp6_trap(struct pt_regs *regs, unsigned int instr)
{
u32 temp;
/* enable cp6 access */
asm volatile (
"mrc p15, 0, %0, c15, c1, 0\n\t"
"orr %0, %0, #(1 << 6)\n\t"
"mcr p15, 0, %0, c15, c1, 0\n\t"
: "=r"(temp));
return 0;
}
/* permit kernel space cp6 access
* deny user space cp6 access
*/
static struct undef_hook cp6_hook = {
.instr_mask = 0x0f000ff0,
.instr_val = 0x0e000610,
.cpsr_mask = MODE_MASK,
.cpsr_val = SVC_MODE,
.fn = cp6_trap,
};
void __init iop_init_cp6_handler(void)
{
register_undef_hook(&cp6_hook);
}

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@ -84,7 +84,7 @@ iop3xx_i2c_enable(struct i2c_algo_iop3xx_data *iop3xx_adap)
* Every time unit enable is asserted, GPOD needs to be cleared
* on IOP3XX to avoid data corruption on the bus.
*/
#ifdef CONFIG_PLAT_IOP
#if defined(CONFIG_ARCH_IOP32X) || defined(CONFIG_ARCH_IOP33X)
if (iop3xx_adap->id == 0) {
gpio_line_set(IOP3XX_GPIO_LINE(7), GPIO_LOW);
gpio_line_set(IOP3XX_GPIO_LINE(6), GPIO_LOW);

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@ -278,6 +278,7 @@ extern void gpio_line_set(int line, int value);
void iop3xx_map_io(void);
void iop3xx_init_time(unsigned long);
unsigned long iop3xx_gettimeoffset(void);
void iop_init_cp6_handler(void);
extern struct platform_device iop3xx_i2c0_device;
extern struct platform_device iop3xx_i2c1_device;