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ARM: pxa: add iwmmx support for PJ4 

iwmmxt is used in XScale, XScale3, Mohawk and PJ4 core. But the instructions
of accessing CP0 and CP1 is changed in PJ4. Append more files to support
iwmmxt in PJ4 core.

Signed-off-by: Zhou Zhu <zzhu3@marvell.com>
Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
This commit is contained in:
Haojian Zhuang 2010-11-24 11:54:25 +08:00 committed by Eric Miao
parent a79a9ad94a
commit ef6c84454f
4 changed files with 139 additions and 15 deletions
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4
arch/arm/Kconfig
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@ -999,8 +999,8 @@ source arch/arm/mm/Kconfig
config IWMMXT
bool "Enable iWMMXt support"
depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK
default y if PXA27x || PXA3xx || ARCH_MMP
depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4
default y if PXA27x || PXA3xx || PXA95x || ARCH_MMP
help
Enable support for iWMMXt context switching at run time if
running on a CPU that supports it.

1
arch/arm/kernel/Makefile
View File

@ -50,6 +50,7 @@ AFLAGS_crunch-bits.o := -Wa,-mcpu=ep9312
obj-$(CONFIG_CPU_XSCALE) += xscale-cp0.o
obj-$(CONFIG_CPU_XSC3) += xscale-cp0.o
obj-$(CONFIG_CPU_MOHAWK) += xscale-cp0.o
obj-$(CONFIG_CPU_PJ4) += pj4-cp0.o
obj-$(CONFIG_IWMMXT) += iwmmxt.o
obj-$(CONFIG_CPU_HAS_PMU) += pmu.o
obj-$(CONFIG_HW_PERF_EVENTS) += perf_event.o

55
arch/arm/kernel/iwmmxt.S
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@ -19,6 +19,14 @@
#include <asm/thread_info.h>
#include <asm/asm-offsets.h>
#if defined(CONFIG_CPU_PJ4)
#define PJ4(code...) code
#define XSC(code...)
#else
#define PJ4(code...)
#define XSC(code...) code
#endif
#define MMX_WR0 (0x00)
#define MMX_WR1 (0x08)
#define MMX_WR2 (0x10)
@ -58,11 +66,17 @@
ENTRY(iwmmxt_task_enable)
mrc p15, 0, r2, c15, c1, 0
tst r2, #0x3 @ CP0 and CP1 accessible?
XSC(mrc p15, 0, r2, c15, c1, 0)
PJ4(mrc p15, 0, r2, c1, c0, 2)
@ CP0 and CP1 accessible?
XSC(tst r2, #0x3)
PJ4(tst r2, #0xf)
movne pc, lr @ if so no business here
orr r2, r2, #0x3 @ enable access to CP0 and CP1
mcr p15, 0, r2, c15, c1, 0
@ enable access to CP0 and CP1
XSC(orr r2, r2, #0x3)
XSC(mcr p15, 0, r2, c15, c1, 0)
PJ4(orr r2, r2, #0xf)
PJ4(mcr p15, 0, r2, c1, c0, 2)
ldr r3, =concan_owner
add r0, r10, #TI_IWMMXT_STATE @ get task Concan save area
@ -179,17 +193,26 @@ ENTRY(iwmmxt_task_disable)
teqne r1, r2 @ or specified one?
bne 1f @ no: quit
mrc p15, 0, r4, c15, c1, 0
orr r4, r4, #0x3 @ enable access to CP0 and CP1
mcr p15, 0, r4, c15, c1, 0
@ enable access to CP0 and CP1
XSC(mrc p15, 0, r4, c15, c1, 0)
XSC(orr r4, r4, #0xf)
XSC(mcr p15, 0, r4, c15, c1, 0)
PJ4(mrc p15, 0, r4, c1, c0, 2)
PJ4(orr r4, r4, #0x3)
PJ4(mcr p15, 0, r4, c1, c0, 2)
mov r0, #0 @ nothing to load
str r0, [r3] @ no more current owner
mrc p15, 0, r2, c2, c0, 0
mov r2, r2 @ cpwait
bl concan_save
bic r4, r4, #0x3 @ disable access to CP0 and CP1
mcr p15, 0, r4, c15, c1, 0
@ disable access to CP0 and CP1
XSC(bic r4, r4, #0x3)
XSC(mcr p15, 0, r4, c15, c1, 0)
PJ4(bic r4, r4, #0xf)
PJ4(mcr p15, 0, r4, c1, c0, 2)
mrc p15, 0, r2, c2, c0, 0
mov r2, r2 @ cpwait
@ -277,8 +300,11 @@ ENTRY(iwmmxt_task_restore)
*/
ENTRY(iwmmxt_task_switch)
mrc p15, 0, r1, c15, c1, 0
tst r1, #0x3 @ CP0 and CP1 accessible?
XSC(mrc p15, 0, r1, c15, c1, 0)
PJ4(mrc p15, 0, r1, c1, c0, 2)
@ CP0 and CP1 accessible?
XSC(tst r1, #0x3)
PJ4(tst r1, #0xf)
bne 1f @ yes: block them for next task
ldr r2, =concan_owner
@ -287,8 +313,11 @@ ENTRY(iwmmxt_task_switch)
teq r2, r3 @ next task owns it?
movne pc, lr @ no: leave Concan disabled
1: eor r1, r1, #3 @ flip Concan access
mcr p15, 0, r1, c15, c1, 0
1: @ flip Conan access
XSC(eor r1, r1, #0x3)
XSC(mcr p15, 0, r1, c15, c1, 0)
PJ4(eor r1, r1, #0xf)
PJ4(mcr p15, 0, r1, c1, c0, 2)
mrc p15, 0, r1, c2, c0, 0
sub pc, lr, r1, lsr #32 @ cpwait and return

94
arch/arm/kernel/pj4-cp0.c Normal file
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@ -0,0 +1,94 @@
/*
* linux/arch/arm/kernel/pj4-cp0.c
*
* PJ4 iWMMXt coprocessor context switching and handling
*
* Copyright (c) 2010 Marvell International Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/io.h>
#include <asm/thread_notify.h>
static int iwmmxt_do(struct notifier_block *self, unsigned long cmd, void *t)
{
struct thread_info *thread = t;
switch (cmd) {
case THREAD_NOTIFY_FLUSH:
/*
* flush_thread() zeroes thread->fpstate, so no need
* to do anything here.
*
* FALLTHROUGH: Ensure we don't try to overwrite our newly
* initialised state information on the first fault.
*/
case THREAD_NOTIFY_EXIT:
iwmmxt_task_release(thread);
break;
case THREAD_NOTIFY_SWITCH:
iwmmxt_task_switch(thread);
break;
}
return NOTIFY_DONE;
}
static struct notifier_block iwmmxt_notifier_block = {
.notifier_call = iwmmxt_do,
};
static u32 __init pj4_cp_access_read(void)
{
u32 value;
__asm__ __volatile__ (
"mrc p15, 0, %0, c1, c0, 2\n\t"
: "=r" (value));
return value;
}
static void __init pj4_cp_access_write(u32 value)
{
u32 temp;
__asm__ __volatile__ (
"mcr p15, 0, %1, c1, c0, 2\n\t"
"mrc p15, 0, %0, c1, c0, 2\n\t"
"mov %0, %0\n\t"
"sub pc, pc, #4\n\t"
: "=r" (temp) : "r" (value));
}
/*
* Disable CP0/CP1 on boot, and let call_fpe() and the iWMMXt lazy
* switch code handle iWMMXt context switching.
*/
static int __init pj4_cp0_init(void)
{
u32 cp_access;
cp_access = pj4_cp_access_read() & ~0xf;
pj4_cp_access_write(cp_access);
printk(KERN_INFO "PJ4 iWMMXt coprocessor enabled.\n");
elf_hwcap |= HWCAP_IWMMXT;
thread_register_notifier(&iwmmxt_notifier_block);
return 0;
}
late_initcall(pj4_cp0_init);