diff options
Diffstat (limited to 'arch/tile/kernel/regs_32.S')
| -rw-r--r-- | arch/tile/kernel/regs_32.S | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/arch/tile/kernel/regs_32.S b/arch/tile/kernel/regs_32.S new file mode 100644 index 000000000..542cae17a --- /dev/null +++ b/arch/tile/kernel/regs_32.S @@ -0,0 +1,145 @@ +/* + * Copyright 2010 Tilera Corporation. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, version 2. + * + * 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, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for + * more details. + */ + +#include <linux/linkage.h> +#include <asm/ptrace.h> +#include <asm/asm-offsets.h> +#include <arch/spr_def.h> +#include <asm/processor.h> +#include <asm/switch_to.h> + +/* + * See <asm/switch_to.h>; called with prev and next task_struct pointers. + * "prev" is returned in r0 for _switch_to and also for ret_from_fork. + * + * We want to save pc/sp in "prev", and get the new pc/sp from "next". + * We also need to save all the callee-saved registers on the stack. + * + * Intel enables/disables access to the hardware cycle counter in + * seccomp (secure computing) environments if necessary, based on + * has_secure_computing(). We might want to do this at some point, + * though it would require virtualizing the other SPRs under WORLD_ACCESS. + * + * Since we're saving to the stack, we omit sp from this list. + * And for parallels with other architectures, we save lr separately, + * in the thread_struct itself (as the "pc" field). + * + * This code also needs to be aligned with process.c copy_thread() + */ + +#if CALLEE_SAVED_REGS_COUNT != 24 +# error Mismatch between <asm/switch_to.h> and kernel/entry.S +#endif +#define FRAME_SIZE ((2 + CALLEE_SAVED_REGS_COUNT) * 4) + +#define SAVE_REG(r) { sw r12, r; addi r12, r12, 4 } +#define LOAD_REG(r) { lw r, r12; addi r12, r12, 4 } +#define FOR_EACH_CALLEE_SAVED_REG(f) \ + f(r30); f(r31); \ + f(r32); f(r33); f(r34); f(r35); f(r36); f(r37); f(r38); f(r39); \ + f(r40); f(r41); f(r42); f(r43); f(r44); f(r45); f(r46); f(r47); \ + f(r48); f(r49); f(r50); f(r51); f(r52); + +STD_ENTRY_SECTION(__switch_to, .sched.text) + { + move r10, sp + sw sp, lr + addi sp, sp, -FRAME_SIZE + } + { + addi r11, sp, 4 + addi r12, sp, 8 + } + { + sw r11, r10 + addli r4, r1, TASK_STRUCT_THREAD_KSP_OFFSET + } + { + lw r13, r4 /* Load new sp to a temp register early. */ + addli r3, r0, TASK_STRUCT_THREAD_KSP_OFFSET + } + FOR_EACH_CALLEE_SAVED_REG(SAVE_REG) + { + sw r3, sp + addli r3, r0, TASK_STRUCT_THREAD_PC_OFFSET + } + { + sw r3, lr + addli r4, r1, TASK_STRUCT_THREAD_PC_OFFSET + } + { + lw lr, r4 + addi r12, r13, 8 + } + { + /* Update sp and ksp0 simultaneously to avoid backtracer warnings. */ + move sp, r13 + mtspr SPR_SYSTEM_SAVE_K_0, r2 + } + FOR_EACH_CALLEE_SAVED_REG(LOAD_REG) +.L__switch_to_pc: + { + addi sp, sp, FRAME_SIZE + jrp lr /* r0 is still valid here, so return it */ + } + STD_ENDPROC(__switch_to) + +/* Return a suitable address for the backtracer for suspended threads */ +STD_ENTRY_SECTION(get_switch_to_pc, .sched.text) + lnk r0 + { + addli r0, r0, .L__switch_to_pc - . + jrp lr + } + STD_ENDPROC(get_switch_to_pc) + +STD_ENTRY(get_pt_regs) + .irp reg, r0, r1, r2, r3, r4, r5, r6, r7, \ + r8, r9, r10, r11, r12, r13, r14, r15, \ + r16, r17, r18, r19, r20, r21, r22, r23, \ + r24, r25, r26, r27, r28, r29, r30, r31, \ + r32, r33, r34, r35, r36, r37, r38, r39, \ + r40, r41, r42, r43, r44, r45, r46, r47, \ + r48, r49, r50, r51, r52, tp, sp + { + sw r0, \reg + addi r0, r0, 4 + } + .endr + { + sw r0, lr + addi r0, r0, PTREGS_OFFSET_PC - PTREGS_OFFSET_LR + } + lnk r1 + { + sw r0, r1 + addi r0, r0, PTREGS_OFFSET_EX1 - PTREGS_OFFSET_PC + } + mfspr r1, INTERRUPT_CRITICAL_SECTION + shli r1, r1, SPR_EX_CONTEXT_1_1__ICS_SHIFT + ori r1, r1, KERNEL_PL + { + sw r0, r1 + addi r0, r0, PTREGS_OFFSET_FAULTNUM - PTREGS_OFFSET_EX1 + } + { + sw r0, zero /* clear faultnum */ + addi r0, r0, PTREGS_OFFSET_ORIG_R0 - PTREGS_OFFSET_FAULTNUM + } + { + sw r0, zero /* clear orig_r0 */ + addli r0, r0, -PTREGS_OFFSET_ORIG_R0 /* restore r0 to base */ + } + jrp lr + STD_ENDPROC(get_pt_regs) |