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target-arm: implement CPACR register logic for ARMv7 

In ARMv7 the CPACR register allows to control access rights to
coprocessor 0-13 interfaces. Bits corresponding to unimplemented
coprocessors should be RAZ/WI. Bits ASEDIS, D32DIS, TRCDIS are
UNK/SBZP if VFP is not implemented and RAO/WI in some cases.
Treating TRCDIS as RAZ/WI since we neither implement a trace
macrocell nor a CP14 interface to the trace macrocell registers.

Since CPACR bits for VFP/Neon access are honoured with the CPACR_FPEN
bit in the TB flags, flushing the TLB is not necessary anymore.

Signed-off-by: Fabian Aggeler <aggelerf@ethz.ch>
Message-id: 1400532968-30668-1-git-send-email-aggelerf@ethz.ch
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Fabian Aggeler 2014-05-27 17:09:49 +01:00 committed by Peter Maydell
parent fc37b7a0b0
commit f0aff25570
1 changed files with 28 additions and 4 deletions
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32
target-arm/helper.c
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@ -477,11 +477,35 @@ static const ARMCPRegInfo not_v7_cp_reginfo[] = {
static void cpacr_write(CPUARMState *env, const ARMCPRegInfo *ri,
uint64_t value)
{
if (env->cp15.c1_coproc != value) {
env->cp15.c1_coproc = value;
/* ??? Is this safe when called from within a TB? */
tb_flush(env);
uint32_t mask = 0;
/* In ARMv8 most bits of CPACR_EL1 are RES0. */
if (!arm_feature(env, ARM_FEATURE_V8)) {
/* ARMv7 defines bits for unimplemented coprocessors as RAZ/WI.
* ASEDIS [31] and D32DIS [30] are both UNK/SBZP without VFP.
* TRCDIS [28] is RAZ/WI since we do not implement a trace macrocell.
*/
if (arm_feature(env, ARM_FEATURE_VFP)) {
/* VFP coprocessor: cp10 & cp11 [23:20] */
mask |= (1 << 31) | (1 << 30) | (0xf << 20);
if (!arm_feature(env, ARM_FEATURE_NEON)) {
/* ASEDIS [31] bit is RAO/WI */
value |= (1 << 31);
}
/* VFPv3 and upwards with NEON implement 32 double precision
* registers (D0-D31).
*/
if (!arm_feature(env, ARM_FEATURE_NEON) ||
!arm_feature(env, ARM_FEATURE_VFP3)) {
/* D32DIS [30] is RAO/WI if D16-31 are not implemented. */
value |= (1 << 30);
}
}
value &= mask;
}
env->cp15.c1_coproc = value;
}
static const ARMCPRegInfo v6_cp_reginfo[] = {