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[Qemu-devel] [PATCH 03/26] target/arm: Implement dummy versions of M-pro
From: |
Peter Maydell |
Subject: |
[Qemu-devel] [PATCH 03/26] target/arm: Implement dummy versions of M-profile FP-related registers |
Date: |
Tue, 16 Apr 2019 13:57:21 +0100 |
The M-profile floating point support has three associated config
registers: FPCAR, FPCCR and FPDSCR. It also makes the registers
CPACR and NSACR have behaviour other than reads-as-zero.
Add support for all of these as simple reads-as-written registers.
We will hook up actual functionality later.
The main complexity here is handling the FPCCR register, which
has a mix of banked and unbanked bits.
Note that we don't share storage with the A-profile
cpu->cp15.nsacr and cpu->cp15.cpacr_el1, though the behaviour
is quite similar, for two reasons:
* the M profile CPACR is banked between security states
* it preserves the invariant that M profile uses no state
inside the cp15 substruct
Signed-off-by: Peter Maydell <address@hidden>
---
target/arm/cpu.h | 34 ++++++++++++
hw/intc/armv7m_nvic.c | 125 ++++++++++++++++++++++++++++++++++++++++++
target/arm/cpu.c | 5 ++
target/arm/machine.c | 16 ++++++
4 files changed, 180 insertions(+)
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index d4d2836923d..c8d78bd5b52 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -533,6 +533,11 @@ typedef struct CPUARMState {
uint32_t scr[M_REG_NUM_BANKS];
uint32_t msplim[M_REG_NUM_BANKS];
uint32_t psplim[M_REG_NUM_BANKS];
+ uint32_t fpcar[M_REG_NUM_BANKS];
+ uint32_t fpccr[M_REG_NUM_BANKS];
+ uint32_t fpdscr[M_REG_NUM_BANKS];
+ uint32_t cpacr[M_REG_NUM_BANKS];
+ uint32_t nsacr;
} v7m;
/* Information associated with an exception about to be taken:
@@ -1577,6 +1582,35 @@ FIELD(V7M_CSSELR, LEVEL, 1, 3)
*/
FIELD(V7M_CSSELR, INDEX, 0, 4)
+/* v7M FPCCR bits */
+FIELD(V7M_FPCCR, LSPACT, 0, 1)
+FIELD(V7M_FPCCR, USER, 1, 1)
+FIELD(V7M_FPCCR, S, 2, 1)
+FIELD(V7M_FPCCR, THREAD, 3, 1)
+FIELD(V7M_FPCCR, HFRDY, 4, 1)
+FIELD(V7M_FPCCR, MMRDY, 5, 1)
+FIELD(V7M_FPCCR, BFRDY, 6, 1)
+FIELD(V7M_FPCCR, SFRDY, 7, 1)
+FIELD(V7M_FPCCR, MONRDY, 8, 1)
+FIELD(V7M_FPCCR, SPLIMVIOL, 9, 1)
+FIELD(V7M_FPCCR, UFRDY, 10, 1)
+FIELD(V7M_FPCCR, RES0, 11, 15)
+FIELD(V7M_FPCCR, TS, 26, 1)
+FIELD(V7M_FPCCR, CLRONRETS, 27, 1)
+FIELD(V7M_FPCCR, CLRONRET, 28, 1)
+FIELD(V7M_FPCCR, LSPENS, 29, 1)
+FIELD(V7M_FPCCR, LSPEN, 30, 1)
+FIELD(V7M_FPCCR, ASPEN, 31, 1)
+/* These bits are banked. Others are non-banked and live in the M_REG_S bank */
+#define R_V7M_FPCCR_BANKED_MASK \
+ (R_V7M_FPCCR_LSPACT_MASK | \
+ R_V7M_FPCCR_USER_MASK | \
+ R_V7M_FPCCR_THREAD_MASK | \
+ R_V7M_FPCCR_MMRDY_MASK | \
+ R_V7M_FPCCR_SPLIMVIOL_MASK | \
+ R_V7M_FPCCR_UFRDY_MASK | \
+ R_V7M_FPCCR_ASPEN_MASK)
+
/*
* System register ID fields.
*/
diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c
index 45d72f86bdf..5eb438f5409 100644
--- a/hw/intc/armv7m_nvic.c
+++ b/hw/intc/armv7m_nvic.c
@@ -1077,6 +1077,16 @@ static uint32_t nvic_readl(NVICState *s, uint32_t
offset, MemTxAttrs attrs)
}
case 0xd84: /* CSSELR */
return cpu->env.v7m.csselr[attrs.secure];
+ case 0xd88: /* CPACR */
+ if (!arm_feature(&cpu->env, ARM_FEATURE_VFP)) {
+ return 0;
+ }
+ return cpu->env.v7m.cpacr[attrs.secure];
+ case 0xd8c: /* NSACR */
+ if (!attrs.secure || !arm_feature(&cpu->env, ARM_FEATURE_VFP)) {
+ return 0;
+ }
+ return cpu->env.v7m.nsacr;
/* TODO: Implement debug registers. */
case 0xd90: /* MPU_TYPE */
/* Unified MPU; if the MPU is not present this value is zero */
@@ -1222,6 +1232,43 @@ static uint32_t nvic_readl(NVICState *s, uint32_t
offset, MemTxAttrs attrs)
return 0;
}
return cpu->env.v7m.sfar;
+ case 0xf34: /* FPCCR */
+ if (!arm_feature(&cpu->env, ARM_FEATURE_VFP)) {
+ return 0;
+ }
+ if (attrs.secure) {
+ return cpu->env.v7m.fpccr[M_REG_S];
+ } else {
+ /*
+ * NS can read LSPEN, CLRONRET and MONRDY. It can read
+ * BFRDY and HFRDY if AIRCR.BFHFNMINS != 0;
+ * other non-banked bits RAZ.
+ * TODO: MONRDY should RAZ/WI if DEMCR.SDME is set.
+ */
+ uint32_t value = cpu->env.v7m.fpccr[M_REG_S];
+ uint32_t mask = R_V7M_FPCCR_LSPEN_MASK |
+ R_V7M_FPCCR_CLRONRET_MASK |
+ R_V7M_FPCCR_MONRDY_MASK;
+
+ if (s->cpu->env.v7m.aircr & R_V7M_AIRCR_BFHFNMINS_MASK) {
+ mask |= R_V7M_FPCCR_BFRDY_MASK | R_V7M_FPCCR_HFRDY_MASK;
+ }
+
+ value &= mask;
+
+ value |= cpu->env.v7m.fpccr[M_REG_NS];
+ return value;
+ }
+ case 0xf38: /* FPCAR */
+ if (!arm_feature(&cpu->env, ARM_FEATURE_VFP)) {
+ return 0;
+ }
+ return cpu->env.v7m.fpcar[attrs.secure];
+ case 0xf3c: /* FPDSCR */
+ if (!arm_feature(&cpu->env, ARM_FEATURE_VFP)) {
+ return 0;
+ }
+ return cpu->env.v7m.fpdscr[attrs.secure];
case 0xf40: /* MVFR0 */
return cpu->isar.mvfr0;
case 0xf44: /* MVFR1 */
@@ -1475,6 +1522,18 @@ static void nvic_writel(NVICState *s, uint32_t offset,
uint32_t value,
cpu->env.v7m.csselr[attrs.secure] = value &
R_V7M_CSSELR_INDEX_MASK;
}
break;
+ case 0xd88: /* CPACR */
+ if (arm_feature(&cpu->env, ARM_FEATURE_VFP)) {
+ /* We implement only the Floating Point extension's CP10/CP11 */
+ cpu->env.v7m.cpacr[attrs.secure] = value & (0xf << 20);
+ }
+ break;
+ case 0xd8c: /* NSACR */
+ if (attrs.secure && arm_feature(&cpu->env, ARM_FEATURE_VFP)) {
+ /* We implement only the Floating Point extension's CP10/CP11 */
+ cpu->env.v7m.nsacr = value & (3 << 10);
+ }
+ break;
case 0xd90: /* MPU_TYPE */
return; /* RO */
case 0xd94: /* MPU_CTRL */
@@ -1703,6 +1762,72 @@ static void nvic_writel(NVICState *s, uint32_t offset,
uint32_t value,
}
break;
}
+ case 0xf34: /* FPCCR */
+ if (arm_feature(&cpu->env, ARM_FEATURE_VFP)) {
+ /* Not all bits here are banked. */
+ uint32_t fpccr_s;
+
+ if (!arm_feature(&cpu->env, ARM_FEATURE_V8)) {
+ /* Don't allow setting of bits not present in v7M */
+ value &= (R_V7M_FPCCR_LSPACT_MASK |
+ R_V7M_FPCCR_USER_MASK |
+ R_V7M_FPCCR_THREAD_MASK |
+ R_V7M_FPCCR_HFRDY_MASK |
+ R_V7M_FPCCR_MMRDY_MASK |
+ R_V7M_FPCCR_BFRDY_MASK |
+ R_V7M_FPCCR_MONRDY_MASK |
+ R_V7M_FPCCR_LSPEN_MASK |
+ R_V7M_FPCCR_ASPEN_MASK);
+ }
+ value &= ~R_V7M_FPCCR_RES0_MASK;
+
+ if (!attrs.secure) {
+ /* Some non-banked bits are configurably writable by NS */
+ fpccr_s = cpu->env.v7m.fpccr[M_REG_S];
+ if (!(fpccr_s & R_V7M_FPCCR_LSPENS_MASK)) {
+ uint32_t lspen = FIELD_EX32(value, V7M_FPCCR, LSPEN);
+ fpccr_s = FIELD_DP32(fpccr_s, V7M_FPCCR, LSPEN, lspen);
+ }
+ if (!(fpccr_s & R_V7M_FPCCR_CLRONRETS_MASK)) {
+ uint32_t cor = FIELD_EX32(value, V7M_FPCCR, CLRONRET);
+ fpccr_s = FIELD_DP32(fpccr_s, V7M_FPCCR, CLRONRET, cor);
+ }
+ if ((s->cpu->env.v7m.aircr & R_V7M_AIRCR_BFHFNMINS_MASK)) {
+ uint32_t hfrdy = FIELD_EX32(value, V7M_FPCCR, HFRDY);
+ uint32_t bfrdy = FIELD_EX32(value, V7M_FPCCR, BFRDY);
+ fpccr_s = FIELD_DP32(fpccr_s, V7M_FPCCR, HFRDY, hfrdy);
+ fpccr_s = FIELD_DP32(fpccr_s, V7M_FPCCR, BFRDY, bfrdy);
+ }
+ /* TODO MONRDY should RAZ/WI if DEMCR.SDME is set */
+ {
+ uint32_t monrdy = FIELD_EX32(value, V7M_FPCCR, MONRDY);
+ fpccr_s = FIELD_DP32(fpccr_s, V7M_FPCCR, MONRDY, monrdy);
+ }
+
+ /*
+ * All other non-banked bits are RAZ/WI from NS; write
+ * just the banked bits to fpccr[M_REG_NS].
+ */
+ value &= R_V7M_FPCCR_BANKED_MASK;
+ cpu->env.v7m.fpccr[M_REG_NS] = value;
+ } else {
+ fpccr_s = value;
+ }
+ cpu->env.v7m.fpccr[M_REG_S] = fpccr_s;
+ }
+ break;
+ case 0xf38: /* FPCAR */
+ if (arm_feature(&cpu->env, ARM_FEATURE_VFP)) {
+ value &= ~7;
+ cpu->env.v7m.fpcar[attrs.secure] = value;
+ }
+ break;
+ case 0xf3c: /* FPDSCR */
+ if (arm_feature(&cpu->env, ARM_FEATURE_VFP)) {
+ value &= 0x07c00000;
+ cpu->env.v7m.fpdscr[attrs.secure] = value;
+ }
+ break;
case 0xf50: /* ICIALLU */
case 0xf58: /* ICIMVAU */
case 0xf5c: /* DCIMVAC */
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 41557821974..3f9c81e7e9e 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -282,6 +282,11 @@ static void arm_cpu_reset(CPUState *s)
env->v7m.ccr[M_REG_S] |= R_V7M_CCR_UNALIGN_TRP_MASK;
}
+ if (arm_feature(env, ARM_FEATURE_VFP)) {
+ env->v7m.fpccr[M_REG_NS] = R_V7M_FPCCR_ASPEN_MASK;
+ env->v7m.fpccr[M_REG_S] = R_V7M_FPCCR_ASPEN_MASK |
+ R_V7M_FPCCR_LSPEN_MASK | R_V7M_FPCCR_S_MASK;
+ }
/* Unlike A/R profile, M profile defines the reset LR value */
env->regs[14] = 0xffffffff;
diff --git a/target/arm/machine.c b/target/arm/machine.c
index b2925496148..09567d4fc66 100644
--- a/target/arm/machine.c
+++ b/target/arm/machine.c
@@ -305,6 +305,21 @@ static const VMStateDescription vmstate_m_v8m = {
}
};
+static const VMStateDescription vmstate_m_fp = {
+ .name = "cpu/m/fp",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .needed = vfp_needed,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT32_ARRAY(env.v7m.fpcar, ARMCPU, M_REG_NUM_BANKS),
+ VMSTATE_UINT32_ARRAY(env.v7m.fpccr, ARMCPU, M_REG_NUM_BANKS),
+ VMSTATE_UINT32_ARRAY(env.v7m.fpdscr, ARMCPU, M_REG_NUM_BANKS),
+ VMSTATE_UINT32_ARRAY(env.v7m.cpacr, ARMCPU, M_REG_NUM_BANKS),
+ VMSTATE_UINT32(env.v7m.nsacr, ARMCPU),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
static const VMStateDescription vmstate_m = {
.name = "cpu/m",
.version_id = 4,
@@ -330,6 +345,7 @@ static const VMStateDescription vmstate_m = {
&vmstate_m_scr,
&vmstate_m_other_sp,
&vmstate_m_v8m,
+ &vmstate_m_fp,
NULL
}
};
--
2.20.1
- [Qemu-devel] [PATCH 00/26] target/arm: Implement M profile floating point, Peter Maydell, 2019/04/16
- [Qemu-devel] [PATCH 01/26] target/arm: Make sure M-profile FPSCR RES0 bits are not settable, Peter Maydell, 2019/04/16
- [Qemu-devel] [PATCH 03/26] target/arm: Implement dummy versions of M-profile FP-related registers,
Peter Maydell <=
- [Qemu-devel] [PATCH 02/26] hw/intc/armv7m_nvic: Allow reading of M-profile MVFR* registers, Peter Maydell, 2019/04/16
- [Qemu-devel] [PATCH 04/26] target/arm: Disable most VFP sysregs for M-profile, Peter Maydell, 2019/04/16
- [Qemu-devel] [PATCH 06/26] target/arm: Decode FP instructions for M profile, Peter Maydell, 2019/04/16
- [Qemu-devel] [PATCH 07/26] target/arm: Clear CONTROL_S.SFPA in SG insn if FPU present, Peter Maydell, 2019/04/16
- [Qemu-devel] [PATCH 09/26] target/arm/helper: don't return early for STKOF faults during stacking, Peter Maydell, 2019/04/16