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authorCatalin Marinas <catalin.marinas@arm.com>2008-04-18 17:43:06 -0400
committerCatalin Marinas <catalin.marinas@arm.com>2008-04-18 17:43:06 -0400
commitd7f864be8323e5394040e2877594645b0e7da85d (patch)
tree55ecf960706be9a4ee0c7804c57c7f5d30e0f1f7 /arch/arm/kernel
parent05dda977f2574c3341abef9b74c27d2b362e1e3a (diff)
ARMv7: Add support for the ThumbEE state saving/restoring
This patch adds the detection and handling of the ThumbEE extension on ARMv7 CPUs. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r--arch/arm/kernel/Makefile1
-rw-r--r--arch/arm/kernel/asm-offsets.c3
-rw-r--r--arch/arm/kernel/thumbee.c81
3 files changed, 85 insertions, 0 deletions
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index 00d44c6fbfe9..d5be3f7ac0e3 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o
22obj-$(CONFIG_KPROBES) += kprobes.o kprobes-decode.o 22obj-$(CONFIG_KPROBES) += kprobes.o kprobes-decode.o
23obj-$(CONFIG_ATAGS_PROC) += atags.o 23obj-$(CONFIG_ATAGS_PROC) += atags.o
24obj-$(CONFIG_OABI_COMPAT) += sys_oabi-compat.o 24obj-$(CONFIG_OABI_COMPAT) += sys_oabi-compat.o
25obj-$(CONFIG_ARM_THUMBEE) += thumbee.o
25 26
26obj-$(CONFIG_CRUNCH) += crunch.o crunch-bits.o 27obj-$(CONFIG_CRUNCH) += crunch.o crunch-bits.o
27AFLAGS_crunch-bits.o := -Wa,-mcpu=ep9312 28AFLAGS_crunch-bits.o := -Wa,-mcpu=ep9312
diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c
index 3278e713c32a..6604b474cfd7 100644
--- a/arch/arm/kernel/asm-offsets.c
+++ b/arch/arm/kernel/asm-offsets.c
@@ -58,6 +58,9 @@ int main(void)
58 DEFINE(TI_TP_VALUE, offsetof(struct thread_info, tp_value)); 58 DEFINE(TI_TP_VALUE, offsetof(struct thread_info, tp_value));
59 DEFINE(TI_FPSTATE, offsetof(struct thread_info, fpstate)); 59 DEFINE(TI_FPSTATE, offsetof(struct thread_info, fpstate));
60 DEFINE(TI_VFPSTATE, offsetof(struct thread_info, vfpstate)); 60 DEFINE(TI_VFPSTATE, offsetof(struct thread_info, vfpstate));
61#ifdef CONFIG_ARM_THUMBEE
62 DEFINE(TI_THUMBEE_STATE, offsetof(struct thread_info, thumbee_state));
63#endif
61#ifdef CONFIG_IWMMXT 64#ifdef CONFIG_IWMMXT
62 DEFINE(TI_IWMMXT_STATE, offsetof(struct thread_info, fpstate.iwmmxt)); 65 DEFINE(TI_IWMMXT_STATE, offsetof(struct thread_info, fpstate.iwmmxt));
63#endif 66#endif
diff --git a/arch/arm/kernel/thumbee.c b/arch/arm/kernel/thumbee.c
new file mode 100644
index 000000000000..df3f6b7ebcea
--- /dev/null
+++ b/arch/arm/kernel/thumbee.c
@@ -0,0 +1,81 @@
1/*
2 * arch/arm/kernel/thumbee.c
3 *
4 * Copyright (C) 2008 ARM Limited
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20#include <linux/kernel.h>
21#include <linux/init.h>
22
23#include <asm/thread_notify.h>
24
25/*
26 * Access to the ThumbEE Handler Base register
27 */
28static inline unsigned long teehbr_read()
29{
30 unsigned long v;
31 asm("mrc p14, 6, %0, c1, c0, 0\n" : "=r" (v));
32 return v;
33}
34
35static inline void teehbr_write(unsigned long v)
36{
37 asm("mcr p14, 6, %0, c1, c0, 0\n" : : "r" (v));
38}
39
40static int thumbee_notifier(struct notifier_block *self, unsigned long cmd, void *t)
41{
42 struct thread_info *thread = t;
43
44 switch (cmd) {
45 case THREAD_NOTIFY_FLUSH:
46 thread->thumbee_state = 0;
47 break;
48 case THREAD_NOTIFY_SWITCH:
49 current_thread_info()->thumbee_state = teehbr_read();
50 teehbr_write(thread->thumbee_state);
51 break;
52 }
53
54 return NOTIFY_DONE;
55}
56
57static struct notifier_block thumbee_notifier_block = {
58 .notifier_call = thumbee_notifier,
59};
60
61static int __init thumbee_init(void)
62{
63 unsigned long pfr0;
64 unsigned int cpu_arch = cpu_architecture();
65
66 if (cpu_arch < CPU_ARCH_ARMv7)
67 return 0;
68
69 /* processor feature register 0 */
70 asm("mrc p15, 0, %0, c0, c1, 0\n" : "=r" (pfr0));
71 if ((pfr0 & 0x0000f000) != 0x00001000)
72 return 0;
73
74 printk(KERN_INFO "ThumbEE CPU extension supported.\n");
75 elf_hwcap |= HWCAP_THUMBEE;
76 thread_register_notifier(&thumbee_notifier_block);
77
78 return 0;
79}
80
81late_initcall(thumbee_init);