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[PULL 25/36] hw/intc/armv7m_nvic: Update FPDSCR masking for v8.1M
From: |
Peter Maydell |
Subject: |
[PULL 25/36] hw/intc/armv7m_nvic: Update FPDSCR masking for v8.1M |
Date: |
Thu, 10 Dec 2020 11:47:45 +0000 |
The FPDSCR register has a similar layout to the FPSCR. In v8.1M it
gains new fields FZ16 (if half-precision floating point is supported)
and LTPSIZE (always reads as 4). Update the reset value and the code
that handles writes to this register accordingly.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201119215617.29887-16-peter.maydell@linaro.org
---
target/arm/cpu.h | 5 +++++
hw/intc/armv7m_nvic.c | 9 ++++++++-
target/arm/cpu.c | 3 +++
3 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 04f6220b2f7..47cb5032ce9 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -1521,14 +1521,19 @@ void vfp_set_fpscr(CPUARMState *env, uint32_t val);
#define FPCR_IXE (1 << 12) /* Inexact exception trap enable */
#define FPCR_IDE (1 << 15) /* Input Denormal exception trap enable */
#define FPCR_FZ16 (1 << 19) /* ARMv8.2+, FP16 flush-to-zero */
+#define FPCR_RMODE_MASK (3 << 22) /* Rounding mode */
#define FPCR_FZ (1 << 24) /* Flush-to-zero enable bit */
#define FPCR_DN (1 << 25) /* Default NaN enable bit */
+#define FPCR_AHP (1 << 26) /* Alternative half-precision */
#define FPCR_QC (1 << 27) /* Cumulative saturation bit */
#define FPCR_V (1 << 28) /* FP overflow flag */
#define FPCR_C (1 << 29) /* FP carry flag */
#define FPCR_Z (1 << 30) /* FP zero flag */
#define FPCR_N (1 << 31) /* FP negative flag */
+#define FPCR_LTPSIZE_SHIFT 16 /* LTPSIZE, M-profile only */
+#define FPCR_LTPSIZE_MASK (7 << FPCR_LTPSIZE_SHIFT)
+
#define FPCR_NZCV_MASK (FPCR_N | FPCR_Z | FPCR_C | FPCR_V)
#define FPCR_NZCVQC_MASK (FPCR_NZCV_MASK | FPCR_QC)
diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c
index 9628ce876e0..be3bc1f1f45 100644
--- a/hw/intc/armv7m_nvic.c
+++ b/hw/intc/armv7m_nvic.c
@@ -2068,7 +2068,14 @@ static void nvic_writel(NVICState *s, uint32_t offset,
uint32_t value,
break;
case 0xf3c: /* FPDSCR */
if (cpu_isar_feature(aa32_vfp_simd, cpu)) {
- value &= 0x07c00000;
+ uint32_t mask = FPCR_AHP | FPCR_DN | FPCR_FZ | FPCR_RMODE_MASK;
+ if (cpu_isar_feature(any_fp16, cpu)) {
+ mask |= FPCR_FZ16;
+ }
+ value &= mask;
+ if (cpu_isar_feature(aa32_lob, cpu)) {
+ value |= 4 << FPCR_LTPSIZE_SHIFT;
+ }
cpu->env.v7m.fpdscr[attrs.secure] = value;
}
break;
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 40f3f798b2b..d6188f6566a 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -262,6 +262,9 @@ static void arm_cpu_reset(DeviceState *dev)
* always reset to 4.
*/
env->v7m.ltpsize = 4;
+ /* The LTPSIZE field in FPDSCR is constant and reads as 4. */
+ env->v7m.fpdscr[M_REG_NS] = 4 << FPCR_LTPSIZE_SHIFT;
+ env->v7m.fpdscr[M_REG_S] = 4 << FPCR_LTPSIZE_SHIFT;
}
if (arm_feature(env, ARM_FEATURE_M_SECURITY)) {
--
2.20.1
- [PULL 07/36] tests/qtest/npcm7xx_rng-test: dump random data on failure, (continued)
- [PULL 07/36] tests/qtest/npcm7xx_rng-test: dump random data on failure, Peter Maydell, 2020/12/10
- [PULL 14/36] target/arm: Don't clobber ID_PFR1.Security on M-profile cores, Peter Maydell, 2020/12/10
- [PULL 08/36] i.MX25: Fix bad printf format specifiers, Peter Maydell, 2020/12/10
- [PULL 10/36] i.MX6: Fix bad printf format specifiers, Peter Maydell, 2020/12/10
- [PULL 16/36] target/arm: Implement CLRM instruction, Peter Maydell, 2020/12/10
- [PULL 17/36] target/arm: Enforce M-profile VMRS/VMSR register restrictions, Peter Maydell, 2020/12/10
- [PULL 11/36] i.MX6ul: Fix bad printf format specifiers, Peter Maydell, 2020/12/10
- [PULL 13/36] target/arm: Implement v8.1M PXN extension, Peter Maydell, 2020/12/10
- [PULL 15/36] target/arm: Implement VSCCLRM insn, Peter Maydell, 2020/12/10
- [PULL 21/36] target/arm: Implement M-profile FPSCR_nzcvqc, Peter Maydell, 2020/12/10
- [PULL 25/36] hw/intc/armv7m_nvic: Update FPDSCR masking for v8.1M,
Peter Maydell <=
- [PULL 22/36] target/arm: Use new FPCR_NZCV_MASK constant, Peter Maydell, 2020/12/10
- [PULL 19/36] target/arm: Move general-use constant expanders up in translate.c, Peter Maydell, 2020/12/10
- [PULL 18/36] target/arm: Refactor M-profile VMSR/VMRS handling, Peter Maydell, 2020/12/10
- [PULL 28/36] target/arm: Implement v8.1M REVIDR register, Peter Maydell, 2020/12/10
- [PULL 26/36] target/arm: For v8.1M, always clear R0-R3, R12, APSR, EPSR on exception entry, Peter Maydell, 2020/12/10
- [PULL 30/36] target/arm: Implement new v8.1M VLLDM and VLSTM encodings, Peter Maydell, 2020/12/10
- [PULL 34/36] target/arm: Implement M-profile "minimal RAS implementation", Peter Maydell, 2020/12/10
- [PULL 12/36] hw/intc/armv7m_nvic: Make all of system PPB range be RAZWI/BusFault, Peter Maydell, 2020/12/10
- [PULL 20/36] target/arm: Implement VLDR/VSTR system register, Peter Maydell, 2020/12/10
- [PULL 31/36] hw/intc/armv7m_nvic: Support v8.1M CCR.TRD bit, Peter Maydell, 2020/12/10