| /* |
| * linux/arch/arm/kernel/iwmmxt.S |
| * |
| * XScale iWMMXt (Concan) context switching and handling |
| * |
| * Initial code: |
| * Copyright (c) 2003, Intel Corporation |
| * |
| * Full lazy switching support, optimizations and more, by Nicolas Pitre |
| * Copyright (c) 2003-2004, MontaVista Software, Inc. |
| * |
| * 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. |
| */ |
| |
| #include <linux/linkage.h> |
| #include <asm/ptrace.h> |
| #include <asm/thread_info.h> |
| #include <asm/asm-offsets.h> |
| |
| #define MMX_WR0 (0x00) |
| #define MMX_WR1 (0x08) |
| #define MMX_WR2 (0x10) |
| #define MMX_WR3 (0x18) |
| #define MMX_WR4 (0x20) |
| #define MMX_WR5 (0x28) |
| #define MMX_WR6 (0x30) |
| #define MMX_WR7 (0x38) |
| #define MMX_WR8 (0x40) |
| #define MMX_WR9 (0x48) |
| #define MMX_WR10 (0x50) |
| #define MMX_WR11 (0x58) |
| #define MMX_WR12 (0x60) |
| #define MMX_WR13 (0x68) |
| #define MMX_WR14 (0x70) |
| #define MMX_WR15 (0x78) |
| #define MMX_WCSSF (0x80) |
| #define MMX_WCASF (0x84) |
| #define MMX_WCGR0 (0x88) |
| #define MMX_WCGR1 (0x8C) |
| #define MMX_WCGR2 (0x90) |
| #define MMX_WCGR3 (0x94) |
| |
| #define MMX_SIZE (0x98) |
| |
| .text |
| |
| /* |
| * Lazy switching of Concan coprocessor context |
| * |
| * r10 = struct thread_info pointer |
| * r9 = ret_from_exception |
| * lr = undefined instr exit |
| * |
| * called from prefetch exception handler with interrupts disabled |
| */ |
| |
| ENTRY(iwmmxt_task_enable) |
| |
| mrc p15, 0, r2, c15, c1, 0 |
| tst r2, #0x3 @ CP0 and CP1 accessible? |
| movne pc, lr @ if so no business here |
| orr r2, r2, #0x3 @ enable access to CP0 and CP1 |
| mcr p15, 0, r2, c15, c1, 0 |
| |
| ldr r3, =concan_owner |
| add r0, r10, #TI_IWMMXT_STATE @ get task Concan save area |
| ldr r2, [sp, #60] @ current task pc value |
| ldr r1, [r3] @ get current Concan owner |
| str r0, [r3] @ this task now owns Concan regs |
| sub r2, r2, #4 @ adjust pc back |
| str r2, [sp, #60] |
| |
| mrc p15, 0, r2, c2, c0, 0 |
| mov r2, r2 @ cpwait |
| |
| teq r1, #0 @ test for last ownership |
| mov lr, r9 @ normal exit from exception |
| beq concan_load @ no owner, skip save |
| |
| concan_save: |
| |
| tmrc r2, wCon |
| |
| @ CUP? wCx |
| tst r2, #0x1 |
| beq 1f |
| |
| concan_dump: |
| |
| wstrw wCSSF, [r1, #MMX_WCSSF] |
| wstrw wCASF, [r1, #MMX_WCASF] |
| wstrw wCGR0, [r1, #MMX_WCGR0] |
| wstrw wCGR1, [r1, #MMX_WCGR1] |
| wstrw wCGR2, [r1, #MMX_WCGR2] |
| wstrw wCGR3, [r1, #MMX_WCGR3] |
| |
| 1: @ MUP? wRn |
| tst r2, #0x2 |
| beq 2f |
| |
| wstrd wR0, [r1, #MMX_WR0] |
| wstrd wR1, [r1, #MMX_WR1] |
| wstrd wR2, [r1, #MMX_WR2] |
| wstrd wR3, [r1, #MMX_WR3] |
| wstrd wR4, [r1, #MMX_WR4] |
| wstrd wR5, [r1, #MMX_WR5] |
| wstrd wR6, [r1, #MMX_WR6] |
| wstrd wR7, [r1, #MMX_WR7] |
| wstrd wR8, [r1, #MMX_WR8] |
| wstrd wR9, [r1, #MMX_WR9] |
| wstrd wR10, [r1, #MMX_WR10] |
| wstrd wR11, [r1, #MMX_WR11] |
| wstrd wR12, [r1, #MMX_WR12] |
| wstrd wR13, [r1, #MMX_WR13] |
| wstrd wR14, [r1, #MMX_WR14] |
| wstrd wR15, [r1, #MMX_WR15] |
| |
| 2: teq r0, #0 @ anything to load? |
| moveq pc, lr |
| |
| concan_load: |
| |
| @ Load wRn |
| wldrd wR0, [r0, #MMX_WR0] |
| wldrd wR1, [r0, #MMX_WR1] |
| wldrd wR2, [r0, #MMX_WR2] |
| wldrd wR3, [r0, #MMX_WR3] |
| wldrd wR4, [r0, #MMX_WR4] |
| wldrd wR5, [r0, #MMX_WR5] |
| wldrd wR6, [r0, #MMX_WR6] |
| wldrd wR7, [r0, #MMX_WR7] |
| wldrd wR8, [r0, #MMX_WR8] |
| wldrd wR9, [r0, #MMX_WR9] |
| wldrd wR10, [r0, #MMX_WR10] |
| wldrd wR11, [r0, #MMX_WR11] |
| wldrd wR12, [r0, #MMX_WR12] |
| wldrd wR13, [r0, #MMX_WR13] |
| wldrd wR14, [r0, #MMX_WR14] |
| wldrd wR15, [r0, #MMX_WR15] |
| |
| @ Load wCx |
| wldrw wCSSF, [r0, #MMX_WCSSF] |
| wldrw wCASF, [r0, #MMX_WCASF] |
| wldrw wCGR0, [r0, #MMX_WCGR0] |
| wldrw wCGR1, [r0, #MMX_WCGR1] |
| wldrw wCGR2, [r0, #MMX_WCGR2] |
| wldrw wCGR3, [r0, #MMX_WCGR3] |
| |
| @ clear CUP/MUP (only if r1 != 0) |
| teq r1, #0 |
| mov r2, #0 |
| moveq pc, lr |
| tmcr wCon, r2 |
| mov pc, lr |
| |
| /* |
| * Back up Concan regs to save area and disable access to them |
| * (mainly for gdb or sleep mode usage) |
| * |
| * r0 = struct thread_info pointer of target task or NULL for any |
| */ |
| |
| ENTRY(iwmmxt_task_disable) |
| |
| stmfd sp!, {r4, lr} |
| |
| mrs ip, cpsr |
| orr r2, ip, #PSR_I_BIT @ disable interrupts |
| msr cpsr_c, r2 |
| |
| ldr r3, =concan_owner |
| add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area |
| ldr r1, [r3] @ get current Concan owner |
| teq r1, #0 @ any current owner? |
| beq 1f @ no: quit |
| teq r0, #0 @ any owner? |
| teqne r1, r2 @ or specified one? |
| bne 1f @ no: quit |
| |
| mrc p15, 0, r4, c15, c1, 0 |
| orr r4, r4, #0x3 @ enable access to CP0 and CP1 |
| mcr p15, 0, r4, c15, c1, 0 |
| mov r0, #0 @ nothing to load |
| str r0, [r3] @ no more current owner |
| mrc p15, 0, r2, c2, c0, 0 |
| mov r2, r2 @ cpwait |
| bl concan_save |
| |
| bic r4, r4, #0x3 @ disable access to CP0 and CP1 |
| mcr p15, 0, r4, c15, c1, 0 |
| mrc p15, 0, r2, c2, c0, 0 |
| mov r2, r2 @ cpwait |
| |
| 1: msr cpsr_c, ip @ restore interrupt mode |
| ldmfd sp!, {r4, pc} |
| |
| /* |
| * Copy Concan state to given memory address |
| * |
| * r0 = struct thread_info pointer of target task |
| * r1 = memory address where to store Concan state |
| * |
| * this is called mainly in the creation of signal stack frames |
| */ |
| |
| ENTRY(iwmmxt_task_copy) |
| |
| mrs ip, cpsr |
| orr r2, ip, #PSR_I_BIT @ disable interrupts |
| msr cpsr_c, r2 |
| |
| ldr r3, =concan_owner |
| add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area |
| ldr r3, [r3] @ get current Concan owner |
| teq r2, r3 @ does this task own it... |
| beq 1f |
| |
| @ current Concan values are in the task save area |
| msr cpsr_c, ip @ restore interrupt mode |
| mov r0, r1 |
| mov r1, r2 |
| mov r2, #MMX_SIZE |
| b memcpy |
| |
| 1: @ this task owns Concan regs -- grab a copy from there |
| mov r0, #0 @ nothing to load |
| mov r2, #3 @ save all regs |
| mov r3, lr @ preserve return address |
| bl concan_dump |
| msr cpsr_c, ip @ restore interrupt mode |
| mov pc, r3 |
| |
| /* |
| * Restore Concan state from given memory address |
| * |
| * r0 = struct thread_info pointer of target task |
| * r1 = memory address where to get Concan state from |
| * |
| * this is used to restore Concan state when unwinding a signal stack frame |
| */ |
| |
| ENTRY(iwmmxt_task_restore) |
| |
| mrs ip, cpsr |
| orr r2, ip, #PSR_I_BIT @ disable interrupts |
| msr cpsr_c, r2 |
| |
| ldr r3, =concan_owner |
| add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area |
| ldr r3, [r3] @ get current Concan owner |
| bic r2, r2, #0x7 @ 64-bit alignment |
| teq r2, r3 @ does this task own it... |
| beq 1f |
| |
| @ this task doesn't own Concan regs -- use its save area |
| msr cpsr_c, ip @ restore interrupt mode |
| mov r0, r2 |
| mov r2, #MMX_SIZE |
| b memcpy |
| |
| 1: @ this task owns Concan regs -- load them directly |
| mov r0, r1 |
| mov r1, #0 @ don't clear CUP/MUP |
| mov r3, lr @ preserve return address |
| bl concan_load |
| msr cpsr_c, ip @ restore interrupt mode |
| mov pc, r3 |
| |
| /* |
| * Concan handling on task switch |
| * |
| * r0 = previous task_struct pointer (must be preserved) |
| * r1 = previous thread_info pointer |
| * r2 = next thread_info pointer (must be preserved) |
| * |
| * Called only from __switch_to with task preemption disabled. |
| * No need to care about preserving r4 and above. |
| */ |
| ENTRY(iwmmxt_task_switch) |
| |
| mrc p15, 0, r4, c15, c1, 0 |
| tst r4, #0x3 @ CP0 and CP1 accessible? |
| bne 1f @ yes: block them for next task |
| |
| ldr r5, =concan_owner |
| add r6, r2, #TI_IWMMXT_STATE @ get next task Concan save area |
| ldr r5, [r5] @ get current Concan owner |
| teq r5, r6 @ next task owns it? |
| movne pc, lr @ no: leave Concan disabled |
| |
| 1: eor r4, r4, #3 @ flip Concan access |
| mcr p15, 0, r4, c15, c1, 0 |
| |
| mrc p15, 0, r4, c2, c0, 0 |
| sub pc, lr, r4, lsr #32 @ cpwait and return |
| |
| /* |
| * Remove Concan ownership of given task |
| * |
| * r0 = struct thread_info pointer |
| */ |
| ENTRY(iwmmxt_task_release) |
| |
| mrs r2, cpsr |
| orr ip, r2, #PSR_I_BIT @ disable interrupts |
| msr cpsr_c, ip |
| ldr r3, =concan_owner |
| add r0, r0, #TI_IWMMXT_STATE @ get task Concan save area |
| ldr r1, [r3] @ get current Concan owner |
| eors r0, r0, r1 @ if equal... |
| streq r0, [r3] @ then clear ownership |
| msr cpsr_c, r2 @ restore interrupts |
| mov pc, lr |
| |
| .data |
| concan_owner: |
| .word 0 |
| |