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linux/arch/arm/mach-pxa/pm.c
Lennert Buytenhek afe4b25e7d [ARM] 3881/4: xscale: clean up cp0/cp1 handling
XScale cores either have a DSP coprocessor (which contains a single
40 bit accumulator register), or an iWMMXt coprocessor (which contains
eight 64 bit registers.)

Because of the small amount of state in the DSP coprocessor, access to
the DSP coprocessor (CP0) is always enabled, and DSP context switching
is done unconditionally on every task switch.  Access to the iWMMXt
coprocessor (CP0/CP1) is enabled only when an iWMMXt instruction is
first issued, and iWMMXt context switching is done lazily.

CONFIG_IWMMXT is supposed to mean 'the cpu we will be running on will
have iWMMXt support', but boards are supposed to select this config
symbol by hand, and at least one pxa27x board doesn't get this right,
so on that board, proc-xscale.S will incorrectly assume that we have a
DSP coprocessor, enable CP0 on boot, and we will then only save the
first iWMMXt register (wR0) on context switches, which is Bad.

This patch redefines CONFIG_IWMMXT as 'the cpu we will be running on
might have iWMMXt support, and we will enable iWMMXt context switching
if it does.'  This means that with this patch, running a CONFIG_IWMMXT=n
kernel on an iWMMXt-capable CPU will no longer potentially corrupt iWMMXt
state over context switches, and running a CONFIG_IWMMXT=y kernel on a
non-iWMMXt capable CPU will still do DSP context save/restore.

These changes should make iWMMXt work on PXA3xx, and as a side effect,
enable proper acc0 save/restore on non-iWMMXt capable xsc3 cores such
as IOP13xx and IXP23xx (which will not have CONFIG_CPU_XSCALE defined),
as well as setting and using HWCAP_IWMMXT properly.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-12-03 17:52:22 +00:00

243 lines
5.5 KiB
C

/*
* PXA250/210 Power Management Routines
*
* Original code for the SA11x0:
* Copyright (c) 2001 Cliff Brake <cbrake@accelent.com>
*
* Modified for the PXA250 by Nicolas Pitre:
* Copyright (c) 2002 Monta Vista Software, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/suspend.h>
#include <linux/errno.h>
#include <linux/time.h>
#include <asm/hardware.h>
#include <asm/memory.h>
#include <asm/system.h>
#include <asm/arch/pm.h>
#include <asm/arch/pxa-regs.h>
#include <asm/arch/lubbock.h>
#include <asm/mach/time.h>
/*
* Debug macros
*/
#undef DEBUG
#define SAVE(x) sleep_save[SLEEP_SAVE_##x] = x
#define RESTORE(x) x = sleep_save[SLEEP_SAVE_##x]
#define RESTORE_GPLEVEL(n) do { \
GPSR##n = sleep_save[SLEEP_SAVE_GPLR##n]; \
GPCR##n = ~sleep_save[SLEEP_SAVE_GPLR##n]; \
} while (0)
/*
* List of global PXA peripheral registers to preserve.
* More ones like CP and general purpose register values are preserved
* with the stack pointer in sleep.S.
*/
enum { SLEEP_SAVE_START = 0,
SLEEP_SAVE_GPLR0, SLEEP_SAVE_GPLR1, SLEEP_SAVE_GPLR2, SLEEP_SAVE_GPLR3,
SLEEP_SAVE_GPDR0, SLEEP_SAVE_GPDR1, SLEEP_SAVE_GPDR2, SLEEP_SAVE_GPDR3,
SLEEP_SAVE_GRER0, SLEEP_SAVE_GRER1, SLEEP_SAVE_GRER2, SLEEP_SAVE_GRER3,
SLEEP_SAVE_GFER0, SLEEP_SAVE_GFER1, SLEEP_SAVE_GFER2, SLEEP_SAVE_GFER3,
SLEEP_SAVE_PGSR0, SLEEP_SAVE_PGSR1, SLEEP_SAVE_PGSR2, SLEEP_SAVE_PGSR3,
SLEEP_SAVE_GAFR0_L, SLEEP_SAVE_GAFR0_U,
SLEEP_SAVE_GAFR1_L, SLEEP_SAVE_GAFR1_U,
SLEEP_SAVE_GAFR2_L, SLEEP_SAVE_GAFR2_U,
SLEEP_SAVE_GAFR3_L, SLEEP_SAVE_GAFR3_U,
SLEEP_SAVE_PSTR,
SLEEP_SAVE_ICMR,
SLEEP_SAVE_CKEN,
#ifdef CONFIG_PXA27x
SLEEP_SAVE_MDREFR,
SLEEP_SAVE_PWER, SLEEP_SAVE_PCFR, SLEEP_SAVE_PRER,
SLEEP_SAVE_PFER, SLEEP_SAVE_PKWR,
#endif
SLEEP_SAVE_CKSUM,
SLEEP_SAVE_SIZE
};
int pxa_pm_enter(suspend_state_t state)
{
unsigned long sleep_save[SLEEP_SAVE_SIZE];
unsigned long checksum = 0;
struct timespec delta, rtc;
int i;
extern void pxa_cpu_pm_enter(suspend_state_t state);
#ifdef CONFIG_IWMMXT
/* force any iWMMXt context to ram **/
if (elf_hwcap & HWCAP_IWMMXT)
iwmmxt_task_disable(NULL);
#endif
/* preserve current time */
rtc.tv_sec = RCNR;
rtc.tv_nsec = 0;
save_time_delta(&delta, &rtc);
SAVE(GPLR0); SAVE(GPLR1); SAVE(GPLR2);
SAVE(GPDR0); SAVE(GPDR1); SAVE(GPDR2);
SAVE(GRER0); SAVE(GRER1); SAVE(GRER2);
SAVE(GFER0); SAVE(GFER1); SAVE(GFER2);
SAVE(PGSR0); SAVE(PGSR1); SAVE(PGSR2);
SAVE(GAFR0_L); SAVE(GAFR0_U);
SAVE(GAFR1_L); SAVE(GAFR1_U);
SAVE(GAFR2_L); SAVE(GAFR2_U);
#ifdef CONFIG_PXA27x
SAVE(MDREFR);
SAVE(GPLR3); SAVE(GPDR3); SAVE(GRER3); SAVE(GFER3); SAVE(PGSR3);
SAVE(GAFR3_L); SAVE(GAFR3_U);
SAVE(PWER); SAVE(PCFR); SAVE(PRER);
SAVE(PFER); SAVE(PKWR);
#endif
SAVE(ICMR);
ICMR = 0;
SAVE(CKEN);
SAVE(PSTR);
/* Note: wake up source are set up in each machine specific files */
/* clear GPIO transition detect bits */
GEDR0 = GEDR0; GEDR1 = GEDR1; GEDR2 = GEDR2;
#ifdef CONFIG_PXA27x
GEDR3 = GEDR3;
#endif
/* Clear sleep reset status */
RCSR = RCSR_SMR;
/* before sleeping, calculate and save a checksum */
for (i = 0; i < SLEEP_SAVE_SIZE - 1; i++)
checksum += sleep_save[i];
sleep_save[SLEEP_SAVE_CKSUM] = checksum;
/* *** go zzz *** */
pxa_cpu_pm_enter(state);
cpu_init();
/* after sleeping, validate the checksum */
checksum = 0;
for (i = 0; i < SLEEP_SAVE_SIZE - 1; i++)
checksum += sleep_save[i];
/* if invalid, display message and wait for a hardware reset */
if (checksum != sleep_save[SLEEP_SAVE_CKSUM]) {
#ifdef CONFIG_ARCH_LUBBOCK
LUB_HEXLED = 0xbadbadc5;
#endif
while (1)
pxa_cpu_pm_enter(state);
}
/* ensure not to come back here if it wasn't intended */
PSPR = 0;
/* restore registers */
RESTORE_GPLEVEL(0); RESTORE_GPLEVEL(1); RESTORE_GPLEVEL(2);
RESTORE(GPDR0); RESTORE(GPDR1); RESTORE(GPDR2);
RESTORE(GAFR0_L); RESTORE(GAFR0_U);
RESTORE(GAFR1_L); RESTORE(GAFR1_U);
RESTORE(GAFR2_L); RESTORE(GAFR2_U);
RESTORE(GRER0); RESTORE(GRER1); RESTORE(GRER2);
RESTORE(GFER0); RESTORE(GFER1); RESTORE(GFER2);
RESTORE(PGSR0); RESTORE(PGSR1); RESTORE(PGSR2);
#ifdef CONFIG_PXA27x
RESTORE(MDREFR);
RESTORE_GPLEVEL(3); RESTORE(GPDR3);
RESTORE(GAFR3_L); RESTORE(GAFR3_U);
RESTORE(GRER3); RESTORE(GFER3); RESTORE(PGSR3);
RESTORE(PWER); RESTORE(PCFR); RESTORE(PRER);
RESTORE(PFER); RESTORE(PKWR);
#endif
PSSR = PSSR_RDH | PSSR_PH;
RESTORE(CKEN);
ICLR = 0;
ICCR = 1;
RESTORE(ICMR);
RESTORE(PSTR);
/* restore current time */
rtc.tv_sec = RCNR;
restore_time_delta(&delta, &rtc);
#ifdef DEBUG
printk(KERN_DEBUG "*** made it back from resume\n");
#endif
return 0;
}
EXPORT_SYMBOL_GPL(pxa_pm_enter);
unsigned long sleep_phys_sp(void *sp)
{
return virt_to_phys(sp);
}
/*
* Called after processes are frozen, but before we shut down devices.
*/
int pxa_pm_prepare(suspend_state_t state)
{
extern int pxa_cpu_pm_prepare(suspend_state_t state);
return pxa_cpu_pm_prepare(state);
}
EXPORT_SYMBOL_GPL(pxa_pm_prepare);
/*
* Called after devices are re-setup, but before processes are thawed.
*/
int pxa_pm_finish(suspend_state_t state)
{
return 0;
}
EXPORT_SYMBOL_GPL(pxa_pm_finish);
/*
* Set to PM_DISK_FIRMWARE so we can quickly veto suspend-to-disk.
*/
static struct pm_ops pxa_pm_ops = {
.pm_disk_mode = PM_DISK_FIRMWARE,
.prepare = pxa_pm_prepare,
.enter = pxa_pm_enter,
.finish = pxa_pm_finish,
};
static int __init pxa_pm_init(void)
{
pm_set_ops(&pxa_pm_ops);
return 0;
}
device_initcall(pxa_pm_init);