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Enter a critical section when storing the vfp registers, we don't want to

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be preempted here as this will enter back into this function, but the
hardware could be in an inconsistant state, and the vfp unit will be off
when switced back to this function.

Sponsored by:	The FreeBSD Foundation
This commit is contained in:
Andrew Turner 2015-04-15 14:30:07 +00:00
parent 899b27a318
commit 731b28fb31
1 changed files with 29 additions and 28 deletions
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57
sys/arm64/arm64/vfp.c
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@ -88,41 +88,42 @@ vfp_save_state(struct thread *td)
uint64_t fpcr, fpsr;
uint32_t cpacr;
critical_enter();
/*
* Only store the registers if the VFP is enabled,
* i.e. return if we are trapping on FP access.
*/
cpacr = READ_SPECIALREG(cpacr_el1);
if ((cpacr & CPACR_FPEN_MASK) != CPACR_FPEN_TRAP_NONE)
return;
if ((cpacr & CPACR_FPEN_MASK) == CPACR_FPEN_TRAP_NONE) {
vfp_state = td->td_pcb->pcb_vfp;
__asm __volatile(
"mrs %0, fpcr \n"
"mrs %1, fpsr \n"
"stp q0, q1, [%2, #16 * 0]\n"
"stp q2, q3, [%2, #16 * 2]\n"
"stp q4, q5, [%2, #16 * 4]\n"
"stp q6, q7, [%2, #16 * 6]\n"
"stp q8, q9, [%2, #16 * 8]\n"
"stp q10, q11, [%2, #16 * 10]\n"
"stp q12, q13, [%2, #16 * 12]\n"
"stp q14, q15, [%2, #16 * 14]\n"
"stp q16, q17, [%2, #16 * 16]\n"
"stp q18, q19, [%2, #16 * 18]\n"
"stp q20, q21, [%2, #16 * 20]\n"
"stp q22, q23, [%2, #16 * 22]\n"
"stp q24, q25, [%2, #16 * 24]\n"
"stp q26, q27, [%2, #16 * 26]\n"
"stp q28, q29, [%2, #16 * 28]\n"
"stp q30, q31, [%2, #16 * 30]\n"
: "=&r"(fpcr), "=&r"(fpsr) : "r"(vfp_state));
vfp_state = td->td_pcb->pcb_vfp;
__asm __volatile(
"mrs %0, fpcr \n"
"mrs %1, fpsr \n"
"stp q0, q1, [%2, #16 * 0]\n"
"stp q2, q3, [%2, #16 * 2]\n"
"stp q4, q5, [%2, #16 * 4]\n"
"stp q6, q7, [%2, #16 * 6]\n"
"stp q8, q9, [%2, #16 * 8]\n"
"stp q10, q11, [%2, #16 * 10]\n"
"stp q12, q13, [%2, #16 * 12]\n"
"stp q14, q15, [%2, #16 * 14]\n"
"stp q16, q17, [%2, #16 * 16]\n"
"stp q18, q19, [%2, #16 * 18]\n"
"stp q20, q21, [%2, #16 * 20]\n"
"stp q22, q23, [%2, #16 * 22]\n"
"stp q24, q25, [%2, #16 * 24]\n"
"stp q26, q27, [%2, #16 * 26]\n"
"stp q28, q29, [%2, #16 * 28]\n"
"stp q30, q31, [%2, #16 * 30]\n"
: "=&r"(fpcr), "=&r"(fpsr) : "r"(vfp_state));
td->td_pcb->pcb_fpcr = fpcr;
td->td_pcb->pcb_fpsr = fpsr;
td->td_pcb->pcb_fpcr = fpcr;
td->td_pcb->pcb_fpsr = fpsr;
dsb();
vfp_disable();
dsb();
vfp_disable();
}
critical_exit();
}
void