diff options
| -rw-r--r-- | arch/arm/common/Kconfig | 4 | ||||
| -rw-r--r-- | arch/arm/common/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm/common/fiq_glue.S | 111 | ||||
| -rw-r--r-- | arch/arm/common/fiq_glue_setup.c | 92 | ||||
| -rw-r--r-- | arch/arm/include/asm/fiq_glue.h | 30 |
5 files changed, 238 insertions, 0 deletions
diff --git a/arch/arm/common/Kconfig b/arch/arm/common/Kconfig index 4b71766fb21d..897b3fbe6e33 100644 --- a/arch/arm/common/Kconfig +++ b/arch/arm/common/Kconfig @@ -39,3 +39,7 @@ config SHARP_PARAM config SHARP_SCOOP bool + +config FIQ_GLUE + bool + select FIQ diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile index 6ea9b6f3607a..0ca99bbe9d84 100644 --- a/arch/arm/common/Makefile +++ b/arch/arm/common/Makefile @@ -17,3 +17,4 @@ obj-$(CONFIG_ARCH_IXP2000) += uengine.o obj-$(CONFIG_ARCH_IXP23XX) += uengine.o obj-$(CONFIG_PCI_HOST_ITE8152) += it8152.o obj-$(CONFIG_ARM_TIMER_SP804) += timer-sp.o +obj-$(CONFIG_FIQ_GLUE) += fiq_glue.o fiq_glue_setup.o diff --git a/arch/arm/common/fiq_glue.S b/arch/arm/common/fiq_glue.S new file mode 100644 index 000000000000..9e3455a09f8f --- /dev/null +++ b/arch/arm/common/fiq_glue.S @@ -0,0 +1,111 @@ +/* + * Copyright (C) 2008 Google, Inc. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * 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. + * + */ + +#include <linux/linkage.h> +#include <asm/assembler.h> + + .text + + .global fiq_glue_end + + /* fiq stack: r0-r15,cpsr,spsr of interrupted mode */ + +ENTRY(fiq_glue) + /* store pc, cpsr from previous mode */ + mrs r12, spsr + sub r11, lr, #4 + subs r10, #1 + bne nested_fiq + + stmfd sp!, {r11-r12, lr} + + /* store r8-r14 from previous mode */ + sub sp, sp, #(7 * 4) + stmia sp, {r8-r14}^ + nop + + /* store r0-r7 from previous mode */ + stmfd sp!, {r0-r7} + + /* setup func(data,regs) arguments */ + mov r0, r9 + mov r1, sp + mov r3, r8 + + mov r7, sp + + /* Get sp and lr from non-user modes */ + and r4, r12, #MODE_MASK + cmp r4, #USR_MODE + beq fiq_from_usr_mode + + mov r7, sp + orr r4, r4, #(PSR_I_BIT | PSR_F_BIT) + msr cpsr_c, r4 + str sp, [r7, #(4 * 13)] + str lr, [r7, #(4 * 14)] + mrs r5, spsr + str r5, [r7, #(4 * 17)] + + cmp r4, #(SVC_MODE | PSR_I_BIT | PSR_F_BIT) + /* use fiq stack if we reenter this mode */ + subne sp, r7, #(4 * 3) + +fiq_from_usr_mode: + msr cpsr_c, #(SVC_MODE | PSR_I_BIT | PSR_F_BIT) + mov r2, sp + sub sp, r7, #12 + stmfd sp!, {r2, ip, lr} + /* call func(data,regs) */ + blx r3 + ldmfd sp, {r2, ip, lr} + mov sp, r2 + + /* restore/discard saved state */ + cmp r4, #USR_MODE + beq fiq_from_usr_mode_exit + + msr cpsr_c, r4 + ldr sp, [r7, #(4 * 13)] + ldr lr, [r7, #(4 * 14)] + msr spsr_cxsf, r5 + +fiq_from_usr_mode_exit: + msr cpsr_c, #(FIQ_MODE | PSR_I_BIT | PSR_F_BIT) + + ldmfd sp!, {r0-r7} + add sp, sp, #(7 * 4) + ldmfd sp!, {r11-r12, lr} +exit_fiq: + msr spsr_cxsf, r12 + add r10, #1 + movs pc, r11 + +nested_fiq: + orr r12, r12, #(PSR_F_BIT) + b exit_fiq + +fiq_glue_end: + +ENTRY(fiq_glue_setup) /* func, data, sp */ + mrs r3, cpsr + msr cpsr_c, #(FIQ_MODE | PSR_I_BIT | PSR_F_BIT) + movs r8, r0 + mov r9, r1 + mov sp, r2 + moveq r10, #0 + movne r10, #1 + msr cpsr_c, r3 + bx lr + diff --git a/arch/arm/common/fiq_glue_setup.c b/arch/arm/common/fiq_glue_setup.c new file mode 100644 index 000000000000..f878ea079b4d --- /dev/null +++ b/arch/arm/common/fiq_glue_setup.c @@ -0,0 +1,92 @@ +/* + * Copyright (C) 2010 Google, Inc. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * 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. + */ + +#include <linux/kernel.h> +#include <linux/percpu.h> +#include <linux/slab.h> +#include <asm/fiq.h> +#include <asm/fiq_glue.h> + +extern unsigned char fiq_glue, fiq_glue_end; +extern void fiq_glue_setup(void *func, void *data, void *sp); + +static struct fiq_handler fiq_debbuger_fiq_handler = { + .name = "fiq_glue", +}; +static __percpu void *fiq_stack; +static struct fiq_glue_handler *current_handler; +static DEFINE_MUTEX(fiq_glue_lock); + +static void fiq_glue_setup_helper(void *info) +{ + struct fiq_glue_handler *handler = info; + fiq_glue_setup(handler->fiq, handler, + __this_cpu_ptr(fiq_stack) + THREAD_START_SP); +} + +int fiq_glue_register_handler(struct fiq_glue_handler *handler) +{ + int ret; + + if (!handler || !handler->fiq) + return -EINVAL; + + mutex_lock(&fiq_glue_lock); + if (fiq_stack) { + ret = -EBUSY; + goto err_busy; + } + + fiq_stack = __alloc_percpu(THREAD_SIZE, L1_CACHE_BYTES); + if (WARN_ON(!fiq_stack)) { + ret = -ENOMEM; + goto err_alloc_fiq_stack; + } + + ret = claim_fiq(&fiq_debbuger_fiq_handler); + if (WARN_ON(ret)) + goto err_claim_fiq; + + current_handler = handler; + on_each_cpu(fiq_glue_setup_helper, handler, true); + set_fiq_handler(&fiq_glue, &fiq_glue_end - &fiq_glue); + +err_claim_fiq: + if (ret) { + free_percpu(fiq_stack); + fiq_stack = NULL; + } +err_alloc_fiq_stack: +err_busy: + mutex_unlock(&fiq_glue_lock); + return ret; +} + +/** + * fiq_glue_resume - Restore fiqs after suspend or low power idle states + * + * This must be called before calling local_fiq_enable after returning from a + * power state where the fiq mode registers were lost. If a driver provided + * a resume hook when it registered the handler it will be called. + */ + +void fiq_glue_resume(void) +{ + if (!current_handler) + return; + fiq_glue_setup(current_handler->fiq, current_handler, + __this_cpu_ptr(fiq_stack) + THREAD_START_SP); + if (current_handler->resume) + current_handler->resume(current_handler); +} + diff --git a/arch/arm/include/asm/fiq_glue.h b/arch/arm/include/asm/fiq_glue.h new file mode 100644 index 000000000000..d54c29db97a8 --- /dev/null +++ b/arch/arm/include/asm/fiq_glue.h @@ -0,0 +1,30 @@ +/* + * Copyright (C) 2010 Google, Inc. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * 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. + */ + +#ifndef __ASM_FIQ_GLUE_H +#define __ASM_FIQ_GLUE_H + +struct fiq_glue_handler { + void (*fiq)(struct fiq_glue_handler *h, void *regs, void *svc_sp); + void (*resume)(struct fiq_glue_handler *h); +}; + +int fiq_glue_register_handler(struct fiq_glue_handler *handler); + +#ifdef CONFIG_FIQ_GLUE +void fiq_glue_resume(void); +#else +static inline void fiq_glue_resume(void) {} +#endif + +#endif |