diff options
Diffstat (limited to 'arch/arm/kernel/entry-header.S')
| -rw-r--r-- | arch/arm/kernel/entry-header.S | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S new file mode 100644 index 00000000000..4039d8c120b --- /dev/null +++ b/arch/arm/kernel/entry-header.S @@ -0,0 +1,182 @@ +#include <linux/config.h> /* for CONFIG_ARCH_xxxx */ +#include <linux/linkage.h> + +#include <asm/assembler.h> +#include <asm/constants.h> +#include <asm/errno.h> +#include <asm/hardware.h> +#include <asm/arch/irqs.h> +#include <asm/arch/entry-macro.S> + +#ifndef MODE_SVC +#define MODE_SVC 0x13 +#endif + + .macro zero_fp +#ifdef CONFIG_FRAME_POINTER + mov fp, #0 +#endif + .endm + + .text + +@ Bad Abort numbers +@ ----------------- +@ +#define BAD_PREFETCH 0 +#define BAD_DATA 1 +#define BAD_ADDREXCPTN 2 +#define BAD_IRQ 3 +#define BAD_UNDEFINSTR 4 + +#define PT_TRACESYS 0x00000002 + +@ OS version number used in SWIs +@ RISC OS is 0 +@ RISC iX is 8 +@ +#define OS_NUMBER 9 +#define ARMSWI_OFFSET 0x000f0000 + +@ +@ Stack format (ensured by USER_* and SVC_*) +@ +#define S_FRAME_SIZE 72 +#define S_OLD_R0 68 +#define S_PSR 64 + +#define S_PC 60 +#define S_LR 56 +#define S_SP 52 +#define S_IP 48 +#define S_FP 44 +#define S_R10 40 +#define S_R9 36 +#define S_R8 32 +#define S_R7 28 +#define S_R6 24 +#define S_R5 20 +#define S_R4 16 +#define S_R3 12 +#define S_R2 8 +#define S_R1 4 +#define S_R0 0 +#define S_OFF 8 + + .macro set_cpsr_c, reg, mode + msr cpsr_c, \mode + .endm + +#if __LINUX_ARM_ARCH__ >= 6 + .macro disable_irq, temp + cpsid i + .endm + + .macro enable_irq, temp + cpsie i + .endm +#else + .macro disable_irq, temp + set_cpsr_c \temp, #PSR_I_BIT | MODE_SVC + .endm + + .macro enable_irq, temp + set_cpsr_c \temp, #MODE_SVC + .endm +#endif + + .macro save_user_regs + sub sp, sp, #S_FRAME_SIZE + stmia sp, {r0 - r12} @ Calling r0 - r12 + add r8, sp, #S_PC + stmdb r8, {sp, lr}^ @ Calling sp, lr + mrs r8, spsr @ called from non-FIQ mode, so ok. + str lr, [sp, #S_PC] @ Save calling PC + str r8, [sp, #S_PSR] @ Save CPSR + str r0, [sp, #S_OLD_R0] @ Save OLD_R0 + .endm + + .macro restore_user_regs + ldr r1, [sp, #S_PSR] @ Get calling cpsr + disable_irq ip @ disable IRQs + ldr lr, [sp, #S_PC]! @ Get PC + msr spsr_cxsf, r1 @ save in spsr_svc + ldmdb sp, {r0 - lr}^ @ Get calling r0 - lr + mov r0, r0 + add sp, sp, #S_FRAME_SIZE - S_PC + movs pc, lr @ return & move spsr_svc into cpsr + .endm + +/* + * Must be called with IRQs already disabled. + */ + .macro fast_restore_user_regs + ldr r1, [sp, #S_OFF + S_PSR] @ get calling cpsr + ldr lr, [sp, #S_OFF + S_PC]! @ get pc + msr spsr_cxsf, r1 @ save in spsr_svc + ldmdb sp, {r1 - lr}^ @ get calling r1 - lr + mov r0, r0 + add sp, sp, #S_FRAME_SIZE - S_PC + movs pc, lr @ return & move spsr_svc into cpsr + .endm + +/* + * Must be called with IRQs already disabled. + */ + .macro slow_restore_user_regs + ldr r1, [sp, #S_PSR] @ get calling cpsr + ldr lr, [sp, #S_PC]! @ get pc + msr spsr_cxsf, r1 @ save in spsr_svc + ldmdb sp, {r0 - lr}^ @ get calling r1 - lr + mov r0, r0 + add sp, sp, #S_FRAME_SIZE - S_PC + movs pc, lr @ return & move spsr_svc into cpsr + .endm + + .macro mask_pc, rd, rm + .endm + + .macro get_thread_info, rd + mov \rd, sp, lsr #13 + mov \rd, \rd, lsl #13 + .endm + + .macro alignment_trap, rbase, rtemp, sym +#ifdef CONFIG_ALIGNMENT_TRAP +#define OFF_CR_ALIGNMENT(x) cr_alignment - x + + ldr \rtemp, [\rbase, #OFF_CR_ALIGNMENT(\sym)] + mcr p15, 0, \rtemp, c1, c0 +#endif + .endm + + +/* + * These are the registers used in the syscall handler, and allow us to + * have in theory up to 7 arguments to a function - r0 to r6. + * + * r7 is reserved for the system call number for thumb mode. + * + * Note that tbl == why is intentional. + * + * We must set at least "tsk" and "why" when calling ret_with_reschedule. + */ +scno .req r7 @ syscall number +tbl .req r8 @ syscall table pointer +why .req r8 @ Linux syscall (!= 0) +tsk .req r9 @ current thread_info + +/* + * Get the system call number. + */ + .macro get_scno +#ifdef CONFIG_ARM_THUMB + tst r8, #PSR_T_BIT @ this is SPSR from save_user_regs + addne scno, r7, #OS_NUMBER << 20 @ put OS number in + ldreq scno, [lr, #-4] + +#else + mask_pc lr, lr + ldr scno, [lr, #-4] @ get SWI instruction +#endif + .endm |