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authorPeter Maydell <peter.maydell@linaro.org>2020-02-14 17:05:52 +0000
committerPeter Maydell <peter.maydell@linaro.org>2020-02-14 17:18:10 +0000
commit3cc7ab57cac41b1075597d915821355ba7ed3aea (patch)
tree4eded69353f3ed18ee44eb1053348d02a3b625fb
parented0e2179ae9b23d4038e14ee8144c60cb8666207 (diff)
downloadqemu-arm-3cc7ab57cac41b1075597d915821355ba7ed3aea.tar.gz
target/arm: Correct handling of PMCR_EL0.LC bit
The LC bit in the PMCR_EL0 register is supposed to be: * read/write * RES1 on an AArch64-only implementation * an architecturally UNKNOWN value on reset (and use of LC==0 by software is deprecated). We were implementing it incorrectly as read-only always zero, though we do have all the code needed to test it and behave accordingly. Instead make it a read-write bit which resets to 1 always, which satisfies all the architectural requirements above. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
-rw-r--r--target/arm/helper.c13
1 files changed, 9 insertions, 4 deletions
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 2ebfa6c654..468e4e8984 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -1023,6 +1023,11 @@ static const ARMCPRegInfo v6_cp_reginfo[] = {
#define PMCRC 0x4
#define PMCRP 0x2
#define PMCRE 0x1
+/*
+ * Mask of PMCR bits writeable by guest (not including WO bits like C, P,
+ * which can be written as 1 to trigger behaviour but which stay RAZ).
+ */
+#define PMCR_WRITEABLE_MASK (PMCRLC | PMCRDP | PMCRX | PMCRD | PMCRE)
#define PMXEVTYPER_P 0x80000000
#define PMXEVTYPER_U 0x40000000
@@ -1577,9 +1582,8 @@ static void pmcr_write(CPUARMState *env, const ARMCPRegInfo *ri,
}
}
- /* only the DP, X, D and E bits are writable */
- env->cp15.c9_pmcr &= ~0x39;
- env->cp15.c9_pmcr |= (value & 0x39);
+ env->cp15.c9_pmcr &= ~PMCR_WRITEABLE_MASK;
+ env->cp15.c9_pmcr |= (value & PMCR_WRITEABLE_MASK);
pmu_op_finish(env);
}
@@ -6370,7 +6374,8 @@ static void define_pmu_regs(ARMCPU *cpu)
.access = PL0_RW, .accessfn = pmreg_access,
.type = ARM_CP_IO,
.fieldoffset = offsetof(CPUARMState, cp15.c9_pmcr),
- .resetvalue = (cpu->midr & 0xff000000) | (pmcrn << PMCRN_SHIFT),
+ .resetvalue = (cpu->midr & 0xff000000) | (pmcrn << PMCRN_SHIFT) |
+ PMCRLC,
.writefn = pmcr_write, .raw_writefn = raw_write,
};
define_one_arm_cp_reg(cpu, &pmcr);