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[Qemu-devel] [PATCH] target-arm: Implement FPEXC32_EL2 system register
From: |
Peter Maydell |
Subject: |
[Qemu-devel] [PATCH] target-arm: Implement FPEXC32_EL2 system register |
Date: |
Mon, 18 Jan 2016 15:53:34 +0000 |
The AArch64 FPEXC32_EL2 system register is visible at EL2 and EL3,
and allows those exception levels to read and write the FPEXC
register for a lower exception level that is using AArch32.
Signed-off-by: Peter Maydell <address@hidden>
---
ARM Trusted Firmware expects this to exist (as does your average
hypervisor, I expect).
target-arm/helper.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/target-arm/helper.c b/target-arm/helper.c
index 196c111..e8ede3f 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -2890,6 +2890,17 @@ static void sctlr_write(CPUARMState *env, const
ARMCPRegInfo *ri,
tlb_flush(CPU(cpu), 1);
}
+static CPAccessResult fpexc32_access(CPUARMState *env, const ARMCPRegInfo *ri)
+{
+ if ((env->cp15.cptr_el[2] & CPTR_TFP) && arm_current_el(env) == 2) {
+ return CP_ACCESS_TRAP_EL2;
+ }
+ if (env->cp15.cptr_el[3] & CPTR_TFP) {
+ return CP_ACCESS_TRAP_EL3;
+ }
+ return CP_ACCESS_OK;
+}
+
static const ARMCPRegInfo v8_cp_reginfo[] = {
/* Minimal set of EL0-visible registers. This will need to be expanded
* significantly for system emulation of AArch64 CPUs.
@@ -3150,6 +3161,11 @@ static const ARMCPRegInfo v8_cp_reginfo[] = {
.opc0 = 3, .opc1 = 0, .crn = 4, .crm = 2, .opc2 = 0,
.type = ARM_CP_NO_RAW,
.access = PL1_RW, .readfn = spsel_read, .writefn = spsel_write },
+ { .name = "FPEXC32_EL2", .state = ARM_CP_STATE_AA64,
+ .opc0 = 3, .opc1 = 4, .crn = 5, .crm = 3, .opc2 = 0,
+ .type = ARM_CP_ALIAS,
+ .fieldoffset = offsetof(CPUARMState, vfp.xregs[ARM_VFP_FPEXC]),
+ .access = PL2_RW, .accessfn = fpexc32_access },
REGINFO_SENTINEL
};
--
1.9.1
- [Qemu-devel] [PATCH] target-arm: Implement FPEXC32_EL2 system register,
Peter Maydell <=