target-arm: Implement NSACR trapping behaviour

Implement some corner cases of the behaviour of the NSACR
register on ARMv8:
 * if EL3 is AArch64 then accessing the NSACR from Secure EL1
   with AArch32 should trap to EL3
 * if EL3 is not present or is AArch64 then reads from NS EL1 and
   NS EL2 return constant 0xc00

It would in theory be possible to implement all these with
a single reginfo definition, but for clarity we use three
separate definitions for the three cases and install the
right one based on the CPU feature flags.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 1454506721-11843-7-git-send-email-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2016-02-11 11:17:31 +00:00
parent 3f208fd76b
commit 2f027fc52d
1 changed files with 58 additions and 4 deletions

View File

@ -3563,6 +3563,25 @@ static const ARMCPRegInfo el2_cp_reginfo[] = {
REGINFO_SENTINEL
};
static CPAccessResult nsacr_access(CPUARMState *env, const ARMCPRegInfo *ri,
bool isread)
{
/* The NSACR is RW at EL3, and RO for NS EL1 and NS EL2.
* At Secure EL1 it traps to EL3.
*/
if (arm_current_el(env) == 3) {
return CP_ACCESS_OK;
}
if (arm_is_secure_below_el3(env)) {
return CP_ACCESS_TRAP_EL3;
}
/* Accesses from EL1 NS and EL2 NS are UNDEF for write but allow reads. */
if (isread) {
return CP_ACCESS_OK;
}
return CP_ACCESS_TRAP_UNCATEGORIZED;
}
static const ARMCPRegInfo el3_cp_reginfo[] = {
{ .name = "SCR_EL3", .state = ARM_CP_STATE_AA64,
.opc0 = 3, .opc1 = 6, .crn = 1, .crm = 1, .opc2 = 0,
@ -3589,10 +3608,6 @@ static const ARMCPRegInfo el3_cp_reginfo[] = {
.cp = 15, .opc1 = 0, .crn = 1, .crm = 1, .opc2 = 1,
.access = PL3_RW, .resetvalue = 0,
.fieldoffset = offsetoflow32(CPUARMState, cp15.sder) },
/* TODO: Implement NSACR trapping of secure EL1 accesses to EL3 */
{ .name = "NSACR", .cp = 15, .opc1 = 0, .crn = 1, .crm = 1, .opc2 = 2,
.access = PL3_W | PL1_R, .resetvalue = 0,
.fieldoffset = offsetof(CPUARMState, cp15.nsacr) },
{ .name = "MVBAR", .cp = 15, .opc1 = 0, .crn = 12, .crm = 0, .opc2 = 1,
.access = PL1_RW, .accessfn = access_trap_aa32s_el1,
.writefn = vbar_write, .resetvalue = 0,
@ -4363,6 +4378,45 @@ void register_cp_regs_for_features(ARMCPU *cpu)
};
define_one_arm_cp_reg(cpu, &rvbar);
}
/* The behaviour of NSACR is sufficiently various that we don't
* try to describe it in a single reginfo:
* if EL3 is 64 bit, then trap to EL3 from S EL1,
* reads as constant 0xc00 from NS EL1 and NS EL2
* if EL3 is 32 bit, then RW at EL3, RO at NS EL1 and NS EL2
* if v7 without EL3, register doesn't exist
* if v8 without EL3, reads as constant 0xc00 from NS EL1 and NS EL2
*/
if (arm_feature(env, ARM_FEATURE_EL3)) {
if (arm_feature(env, ARM_FEATURE_AARCH64)) {
ARMCPRegInfo nsacr = {
.name = "NSACR", .type = ARM_CP_CONST,
.cp = 15, .opc1 = 0, .crn = 1, .crm = 1, .opc2 = 2,
.access = PL1_RW, .accessfn = nsacr_access,
.resetvalue = 0xc00
};
define_one_arm_cp_reg(cpu, &nsacr);
} else {
ARMCPRegInfo nsacr = {
.name = "NSACR",
.cp = 15, .opc1 = 0, .crn = 1, .crm = 1, .opc2 = 2,
.access = PL3_RW | PL1_R,
.resetvalue = 0,
.fieldoffset = offsetof(CPUARMState, cp15.nsacr)
};
define_one_arm_cp_reg(cpu, &nsacr);
}
} else {
if (arm_feature(env, ARM_FEATURE_V8)) {
ARMCPRegInfo nsacr = {
.name = "NSACR", .type = ARM_CP_CONST,
.cp = 15, .opc1 = 0, .crn = 1, .crm = 1, .opc2 = 2,
.access = PL1_R,
.resetvalue = 0xc00
};
define_one_arm_cp_reg(cpu, &nsacr);
}
}
if (arm_feature(env, ARM_FEATURE_MPU)) {
if (arm_feature(env, ARM_FEATURE_V6)) {
/* PMSAv6 not implemented */