[PATCH 8/8] ARM: pxa: add iwmmx support for PJ4
Haojian Zhuang
haojian.zhuang at marvell.com
Tue Nov 23 22:54:25 EST 2010
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 at marvell.com>
Signed-off-by: Haojian Zhuang <haojian.zhuang at marvell.com>
Cc: Eric Miao <eric.y.miao at gmail.com>
Cc: Nicolas Pitre <nico at fluxnic.net>
---
arch/arm/Kconfig | 4 +-
arch/arm/kernel/Makefile | 1 +
arch/arm/kernel/iwmmxt.S | 55 ++++++++++++++++++++------
arch/arm/kernel/pj4-cp0.c | 94 +++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 139 insertions(+), 15 deletions(-)
create mode 100644 arch/arm/kernel/pj4-cp0.c
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index a19a526..b0f25b0 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -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.
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index 5b9b268..b0f11fa 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -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
diff --git a/arch/arm/kernel/iwmmxt.S b/arch/arm/kernel/iwmmxt.S
index b63b528..7fa3bb0 100644
--- a/arch/arm/kernel/iwmmxt.S
+++ b/arch/arm/kernel/iwmmxt.S
@@ -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
diff --git a/arch/arm/kernel/pj4-cp0.c b/arch/arm/kernel/pj4-cp0.c
new file mode 100644
index 0000000..a4b1b07
--- /dev/null
+++ b/arch/arm/kernel/pj4-cp0.c
@@ -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);
--
1.5.6.5
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