From d7f864be8323e5394040e2877594645b0e7da85d Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Fri, 18 Apr 2008 22:43:06 +0100 Subject: [PATCH] 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 --- arch/arm/kernel/Makefile | 1 + arch/arm/kernel/asm-offsets.c | 3 ++ arch/arm/kernel/thumbee.c | 81 +++++++++++++++++++++++++++++++++++ arch/arm/mm/Kconfig | 7 +++ include/asm-arm/hwcap.h | 1 + include/asm-arm/thread_info.h | 3 ++ 6 files changed, 96 insertions(+) create mode 100644 arch/arm/kernel/thumbee.c 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-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o obj-$(CONFIG_KPROBES) += kprobes.o kprobes-decode.o obj-$(CONFIG_ATAGS_PROC) += atags.o obj-$(CONFIG_OABI_COMPAT) += sys_oabi-compat.o +obj-$(CONFIG_ARM_THUMBEE) += thumbee.o obj-$(CONFIG_CRUNCH) += crunch.o crunch-bits.o AFLAGS_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) DEFINE(TI_TP_VALUE, offsetof(struct thread_info, tp_value)); DEFINE(TI_FPSTATE, offsetof(struct thread_info, fpstate)); DEFINE(TI_VFPSTATE, offsetof(struct thread_info, vfpstate)); +#ifdef CONFIG_ARM_THUMBEE + DEFINE(TI_THUMBEE_STATE, offsetof(struct thread_info, thumbee_state)); +#endif #ifdef CONFIG_IWMMXT DEFINE(TI_IWMMXT_STATE, offsetof(struct thread_info, fpstate.iwmmxt)); #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 @@ +/* + * arch/arm/kernel/thumbee.c + * + * Copyright (C) 2008 ARM Limited + * + * 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. + * + * This program is distributed in the hope that 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 +#include + +#include + +/* + * Access to the ThumbEE Handler Base register + */ +static inline unsigned long teehbr_read() +{ + unsigned long v; + asm("mrc p14, 6, %0, c1, c0, 0\n" : "=r" (v)); + return v; +} + +static inline void teehbr_write(unsigned long v) +{ + asm("mcr p14, 6, %0, c1, c0, 0\n" : : "r" (v)); +} + +static int thumbee_notifier(struct notifier_block *self, unsigned long cmd, void *t) +{ + struct thread_info *thread = t; + + switch (cmd) { + case THREAD_NOTIFY_FLUSH: + thread->thumbee_state = 0; + break; + case THREAD_NOTIFY_SWITCH: + current_thread_info()->thumbee_state = teehbr_read(); + teehbr_write(thread->thumbee_state); + break; + } + + return NOTIFY_DONE; +} + +static struct notifier_block thumbee_notifier_block = { + .notifier_call = thumbee_notifier, +}; + +static int __init thumbee_init(void) +{ + unsigned long pfr0; + unsigned int cpu_arch = cpu_architecture(); + + if (cpu_arch < CPU_ARCH_ARMv7) + return 0; + + /* processor feature register 0 */ + asm("mrc p15, 0, %0, c0, c1, 0\n" : "=r" (pfr0)); + if ((pfr0 & 0x0000f000) != 0x00001000) + return 0; + + printk(KERN_INFO "ThumbEE CPU extension supported.\n"); + elf_hwcap |= HWCAP_THUMBEE; + thread_register_notifier(&thumbee_notifier_block); + + return 0; +} + +late_initcall(thumbee_init); diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig index 76348f060f27..084fe8de3efe 100644 --- a/arch/arm/mm/Kconfig +++ b/arch/arm/mm/Kconfig @@ -572,6 +572,13 @@ config ARM_THUMB If you don't know what this all is, saying Y is a safe choice. +config ARM_THUMBEE + bool "Enable ThumbEE CPU extension" + depends on CPU_V7 + help + Say Y here if you have a CPU with the ThumbEE extension and code to + make use of it. Say N for code that can run on CPUs without ThumbEE. + config CPU_BIG_ENDIAN bool "Build big-endian kernel" depends on ARCH_SUPPORTS_BIG_ENDIAN diff --git a/include/asm-arm/hwcap.h b/include/asm-arm/hwcap.h index 01a1391d3014..81f4c899a555 100644 --- a/include/asm-arm/hwcap.h +++ b/include/asm-arm/hwcap.h @@ -15,6 +15,7 @@ #define HWCAP_JAVA 256 #define HWCAP_IWMMXT 512 #define HWCAP_CRUNCH 1024 +#define HWCAP_THUMBEE 2048 #if defined(__KERNEL__) && !defined(__ASSEMBLY__) /* diff --git a/include/asm-arm/thread_info.h b/include/asm-arm/thread_info.h index 41784357a204..f5a664786311 100644 --- a/include/asm-arm/thread_info.h +++ b/include/asm-arm/thread_info.h @@ -62,6 +62,9 @@ struct thread_info { struct crunch_state crunchstate; union fp_state fpstate __attribute__((aligned(8))); union vfp_state vfpstate; +#ifdef CONFIG_ARM_THUMBEE + unsigned long thumbee_state; /* ThumbEE Handler Base register */ +#endif struct restart_block restart_block; }; -- 2.20.1