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| #include <linux/types.h> |
| #include <linux/kernel.h> |
| #include <linux/signal.h> |
| #include <linux/sched.h> |
| #include <linux/init.h> |
| #include <linux/io.h> |
| #include <asm/thread_notify.h> |
| #include <asm/cputype.h> |
| |
| asm(" .arch armv5te\n"); |
| |
| static inline void dsp_save_state(u32 *state) |
| { |
| <------>__asm__ __volatile__ ( |
| <------><------>"mrrc p0, 0, %0, %1, c0\n" |
| <------><------>: "=r" (state[0]), "=r" (state[1])); |
| } |
| |
| static inline void dsp_load_state(u32 *state) |
| { |
| <------>__asm__ __volatile__ ( |
| <------><------>"mcrr p0, 0, %0, %1, c0\n" |
| <------><------>: : "r" (state[0]), "r" (state[1])); |
| } |
| |
| static int dsp_do(struct notifier_block *self, unsigned long cmd, void *t) |
| { |
| <------>struct thread_info *thread = t; |
| |
| <------>switch (cmd) { |
| <------>case THREAD_NOTIFY_FLUSH: |
| <------><------>thread->cpu_context.extra[0] = 0; |
| <------><------>thread->cpu_context.extra[1] = 0; |
| <------><------>break; |
| |
| <------>case THREAD_NOTIFY_SWITCH: |
| <------><------>dsp_save_state(current_thread_info()->cpu_context.extra); |
| <------><------>dsp_load_state(thread->cpu_context.extra); |
| <------><------>break; |
| <------>} |
| |
| <------>return NOTIFY_DONE; |
| } |
| |
| static struct notifier_block dsp_notifier_block = { |
| <------>.notifier_call = dsp_do, |
| }; |
| |
| |
| #ifdef CONFIG_IWMMXT |
| static int iwmmxt_do(struct notifier_block *self, unsigned long cmd, void *t) |
| { |
| <------>struct thread_info *thread = t; |
| |
| <------>switch (cmd) { |
| <------>case THREAD_NOTIFY_FLUSH: |
| <------><------> |
| <------><------> * flush_thread() zeroes thread->fpstate, so no need |
| <------><------> * to do anything here. |
| <------><------> * |
| <------><------> * FALLTHROUGH: Ensure we don't try to overwrite our newly |
| <------><------> * initialised state information on the first fault. |
| <------><------> */ |
| |
| <------>case THREAD_NOTIFY_EXIT: |
| <------><------>iwmmxt_task_release(thread); |
| <------><------>break; |
| |
| <------>case THREAD_NOTIFY_SWITCH: |
| <------><------>iwmmxt_task_switch(thread); |
| <------><------>break; |
| <------>} |
| |
| <------>return NOTIFY_DONE; |
| } |
| |
| static struct notifier_block iwmmxt_notifier_block = { |
| <------>.notifier_call = iwmmxt_do, |
| }; |
| #endif |
| |
| |
| static u32 __init xscale_cp_access_read(void) |
| { |
| <------>u32 value; |
| |
| <------>__asm__ __volatile__ ( |
| <------><------>"mrc p15, 0, %0, c15, c1, 0\n\t" |
| <------><------>: "=r" (value)); |
| |
| <------>return value; |
| } |
| |
| static void __init xscale_cp_access_write(u32 value) |
| { |
| <------>u32 temp; |
| |
| <------>__asm__ __volatile__ ( |
| <------><------>"mcr p15, 0, %1, c15, c1, 0\n\t" |
| <------><------>"mrc p15, 0, %0, c15, c1, 0\n\t" |
| <------><------>"mov %0, %0\n\t" |
| <------><------>"sub pc, pc, #4\n\t" |
| <------><------>: "=r" (temp) : "r" (value)); |
| } |
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| static int __init cpu_has_iwmmxt(void) |
| { |
| <------>u32 lo; |
| <------>u32 hi; |
| |
| <------> |
| <------> * This sequence is interpreted by the DSP coprocessor as: |
| <------> * mar acc0, %2, %3 |
| <------> * mra %0, %1, acc0 |
| <------> * |
| <------> * And by the iWMMXt coprocessor as: |
| <------> * tmcrr wR0, %2, %3 |
| <------> * tmrrc %0, %1, wR0 |
| <------> */ |
| <------>__asm__ __volatile__ ( |
| <------><------>"mcrr p0, 0, %2, %3, c0\n" |
| <------><------>"mrrc p0, 0, %0, %1, c0\n" |
| <------><------>: "=r" (lo), "=r" (hi) |
| <------><------>: "r" (0), "r" (0x100)); |
| |
| <------>return !!hi; |
| } |
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| static int __init xscale_cp0_init(void) |
| { |
| <------>u32 cp_access; |
| |
| <------> |
| <------>if (!cpu_is_xscale_family()) |
| <------><------>return 0; |
| |
| <------>cp_access = xscale_cp_access_read() & ~3; |
| <------>xscale_cp_access_write(cp_access | 1); |
| |
| <------>if (cpu_has_iwmmxt()) { |
| #ifndef CONFIG_IWMMXT |
| <------><------>pr_warn("CAUTION: XScale iWMMXt coprocessor detected, but kernel support is missing.\n"); |
| #else |
| <------><------>pr_info("XScale iWMMXt coprocessor detected.\n"); |
| <------><------>elf_hwcap |= HWCAP_IWMMXT; |
| <------><------>thread_register_notifier(&iwmmxt_notifier_block); |
| #endif |
| <------>} else { |
| <------><------>pr_info("XScale DSP coprocessor detected.\n"); |
| <------><------>thread_register_notifier(&dsp_notifier_block); |
| <------><------>cp_access |= 1; |
| <------>} |
| |
| <------>xscale_cp_access_write(cp_access); |
| |
| <------>return 0; |
| } |
| |
| late_initcall(xscale_cp0_init); |
| |