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git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
ARM: iwmmxt: Use undef hook to enable coprocessor for task
Define a undef hook to deal with undef exceptions triggered by iwmmxt
instructions that were issued with the coprocessor disabled. This
removes the dependency on the coprocessor dispatch code in entry-armv.S,
which will be made NWFPE-only in a subsequent patch.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
+33
-4
+16
arch/arm/include/asm/thread_info.h
+16
arch/arm/include/asm/thread_info.h
···
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DECLARE_PER_CPU(struct task_struct *, __entry_task);
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#include <asm/types.h>
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+
#include <asm/traps.h>
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struct cpu_context_save {
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__u32 r4;
···
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extern void iwmmxt_task_restore(struct thread_info *, void *);
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extern void iwmmxt_task_release(struct thread_info *);
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extern void iwmmxt_task_switch(struct thread_info *);
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+
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extern int iwmmxt_undef_handler(struct pt_regs *, u32);
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static inline void register_iwmmxt_undef_handler(void)
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{
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static struct undef_hook iwmmxt_undef_hook = {
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.instr_mask = 0x0c000e00,
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.instr_val = 0x0c000000,
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.cpsr_mask = MODE_MASK | PSR_T_BIT,
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.cpsr_val = USR_MODE,
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.fn = iwmmxt_undef_handler,
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};
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register_undef_hook(&iwmmxt_undef_hook);
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}
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extern void vfp_sync_hwstate(struct thread_info *);
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extern void vfp_flush_hwstate(struct thread_info *);
+1
arch/arm/kernel/entry-armv.S
+1
arch/arm/kernel/entry-armv.S
+14
-4
arch/arm/kernel/iwmmxt.S
+14
-4
arch/arm/kernel/iwmmxt.S
···
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.text
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.arm
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ENTRY(iwmmxt_undef_handler)
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push {r9, r10, lr}
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get_thread_info r10
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mov r9, pc
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b iwmmxt_task_enable
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mov r0, #0
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pop {r9, r10, pc}
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ENDPROC(iwmmxt_undef_handler)
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/*
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* Lazy switching of Concan coprocessor context
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*
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* r0 = struct pt_regs pointer
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* r10 = struct thread_info pointer
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* r9 = ret_from_exception
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* lr = undefined instr exit
···
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PJ4(mcr p15, 0, r2, c1, c0, 2)
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ldr r3, =concan_owner
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-
add r0, r10, #TI_IWMMXT_STATE @ get task Concan save area
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-
ldr r2, [sp, #60] @ current task pc value
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ldr r2, [r0, #S_PC] @ current task pc value
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ldr r1, [r3] @ get current Concan owner
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-
str r0, [r3] @ this task now owns Concan regs
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sub r2, r2, #4 @ adjust pc back
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-
str r2, [sp, #60]
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str r2, [r0, #S_PC]
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add r0, r10, #TI_IWMMXT_STATE @ get task Concan save area
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str r0, [r3] @ this task now owns Concan regs
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mrc p15, 0, r2, c2, c0, 0
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mov r2, r2 @ cpwait
+1
arch/arm/kernel/pj4-cp0.c
+1
arch/arm/kernel/pj4-cp0.c
+1
arch/arm/kernel/xscale-cp0.c
+1
arch/arm/kernel/xscale-cp0.c