[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [Qemu-arm] [PATCH 08/15] target/arm: Define and use XPS
From: |
Edgar E. Iglesias |
Subject: |
Re: [Qemu-devel] [Qemu-arm] [PATCH 08/15] target/arm: Define and use XPSR bit masks |
Date: |
Thu, 3 Aug 2017 17:32:27 +0200 |
User-agent: |
Mutt/1.5.24 (2015-08-30) |
On Wed, Aug 02, 2017 at 05:43:54PM +0100, Peter Maydell wrote:
> The M profile XPSR is almost the same format as the A profile CPSR,
> but not quite. Define some XPSR_* macros and use them where we
> definitely dealing with an XPSR rather than reusing the CPSR ones.
>
> Signed-off-by: Peter Maydell <address@hidden>
Reviewed-by: Edgar E. Iglesias <address@hidden>
> ---
> target/arm/cpu.h | 38 ++++++++++++++++++++++++++++----------
> target/arm/helper.c | 15 ++++++++-------
> 2 files changed, 36 insertions(+), 17 deletions(-)
>
> diff --git a/target/arm/cpu.h b/target/arm/cpu.h
> index b64474c..1f06de0 100644
> --- a/target/arm/cpu.h
> +++ b/target/arm/cpu.h
> @@ -883,6 +883,22 @@ void pmccntr_sync(CPUARMState *env);
> /* Mask of bits which may be set by exception return copying them from SPSR
> */
> #define CPSR_ERET_MASK (~CPSR_RESERVED)
>
> +/* Bit definitions for M profile XPSR. Most are the same as CPSR. */
> +#define XPSR_EXCP 0x1ffU
> +#define XPSR_SPREALIGN (1U << 9) /* Only set in exception stack frames */
> +#define XPSR_IT_2_7 CPSR_IT_2_7
> +#define XPSR_GE CPSR_GE
> +#define XPSR_SFPA (1U << 20) /* Only set in exception stack frames */
> +#define XPSR_T (1U << 24) /* Not the same as CPSR_T ! */
> +#define XPSR_IT_0_1 CPSR_IT_0_1
> +#define XPSR_Q CPSR_Q
> +#define XPSR_V CPSR_V
> +#define XPSR_C CPSR_C
> +#define XPSR_Z CPSR_Z
> +#define XPSR_N CPSR_N
> +#define XPSR_NZCV CPSR_NZCV
> +#define XPSR_IT CPSR_IT
> +
> #define TTBCR_N (7U << 0) /* TTBCR.EAE==0 */
> #define TTBCR_T0SZ (7U << 0) /* TTBCR.EAE==1 */
> #define TTBCR_PD0 (1U << 4)
> @@ -987,26 +1003,28 @@ static inline uint32_t xpsr_read(CPUARMState *env)
> /* Set the xPSR. Note that some bits of mask must be all-set or all-clear.
> */
> static inline void xpsr_write(CPUARMState *env, uint32_t val, uint32_t mask)
> {
> - if (mask & CPSR_NZCV) {
> - env->ZF = (~val) & CPSR_Z;
> + if (mask & XPSR_NZCV) {
> + env->ZF = (~val) & XPSR_Z;
> env->NF = val;
> env->CF = (val >> 29) & 1;
> env->VF = (val << 3) & 0x80000000;
> }
> - if (mask & CPSR_Q)
> - env->QF = ((val & CPSR_Q) != 0);
> - if (mask & (1 << 24))
> - env->thumb = ((val & (1 << 24)) != 0);
> - if (mask & CPSR_IT_0_1) {
> + if (mask & XPSR_Q) {
> + env->QF = ((val & XPSR_Q) != 0);
> + }
> + if (mask & XPSR_T) {
> + env->thumb = ((val & XPSR_T) != 0);
> + }
> + if (mask & XPSR_IT_0_1) {
> env->condexec_bits &= ~3;
> env->condexec_bits |= (val >> 25) & 3;
> }
> - if (mask & CPSR_IT_2_7) {
> + if (mask & XPSR_IT_2_7) {
> env->condexec_bits &= 3;
> env->condexec_bits |= (val >> 8) & 0xfc;
> }
> - if (mask & 0x1ff) {
> - env->v7m.exception = val & 0x1ff;
> + if (mask & XPSR_EXCP) {
> + env->v7m.exception = val & XPSR_EXCP;
> }
> }
>
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index cb88c66..f087d42 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -6119,7 +6119,7 @@ static void v7m_push_stack(ARMCPU *cpu)
> /* Align stack pointer if the guest wants that */
> if ((env->regs[13] & 4) && (env->v7m.ccr & R_V7M_CCR_STKALIGN_MASK)) {
> env->regs[13] -= 4;
> - xpsr |= 0x200;
> + xpsr |= XPSR_SPREALIGN;
> }
> /* Switch to the handler mode. */
> v7m_push(env, xpsr);
> @@ -6244,10 +6244,11 @@ static void do_v7m_exception_exit(ARMCPU *cpu)
> env->regs[15] &= ~1U;
> }
> xpsr = v7m_pop(env);
> - xpsr_write(env, xpsr, 0xfffffdff);
> + xpsr_write(env, xpsr, ~XPSR_SPREALIGN);
> /* Undo stack alignment. */
> - if (xpsr & 0x200)
> + if (xpsr & XPSR_SPREALIGN) {
> env->regs[13] |= 4;
> + }
>
> /* The restored xPSR exception field will be zero if we're
> * resuming in Thread mode. If that doesn't match what the
> @@ -8693,10 +8694,10 @@ uint32_t HELPER(v7m_mrs)(CPUARMState *env, uint32_t
> reg)
> case 0 ... 7: /* xPSR sub-fields */
> mask = 0;
> if ((reg & 1) && el) {
> - mask |= 0x000001ff; /* IPSR (unpriv. reads as zero) */
> + mask |= XPSR_EXCP; /* IPSR (unpriv. reads as zero) */
> }
> if (!(reg & 4)) {
> - mask |= 0xf8000000; /* APSR */
> + mask |= XPSR_NZCV | XPSR_Q; /* APSR */
> }
> /* EPSR reads as zero */
> return xpsr_read(env) & mask;
> @@ -8754,10 +8755,10 @@ void HELPER(v7m_msr)(CPUARMState *env, uint32_t
> maskreg, uint32_t val)
> uint32_t apsrmask = 0;
>
> if (mask & 8) {
> - apsrmask |= 0xf8000000; /* APSR NZCVQ */
> + apsrmask |= XPSR_NZCV | XPSR_Q;
> }
> if ((mask & 4) && arm_feature(env, ARM_FEATURE_THUMB_DSP)) {
> - apsrmask |= 0x000f0000; /* APSR GE[3:0] */
> + apsrmask |= XPSR_GE;
> }
> xpsr_write(env, val, apsrmask);
> }
> --
> 2.7.4
>
>
- [Qemu-devel] [PATCH 00/15] v7M: cleanups and bugfixes prior to v8M, Peter Maydell, 2017/08/02
- [Qemu-devel] [PATCH 13/15] target/arm: Create and use new function arm_v7m_is_handler_mode(), Peter Maydell, 2017/08/02
- [Qemu-devel] [PATCH 11/15] target/arm: Make arm_cpu_dump_state() handle the M-profile XPSR, Peter Maydell, 2017/08/02
- [Qemu-devel] [PATCH 08/15] target/arm: Define and use XPSR bit masks, Peter Maydell, 2017/08/02
- [Qemu-devel] [PATCH 14/15] armv7m_nvic.h: Move from include/hw/arm to include/hw/intc, Peter Maydell, 2017/08/02
- [Qemu-devel] [PATCH 01/15] target/arm: Use MMUAccessType enum rather than int, Peter Maydell, 2017/08/02
- [Qemu-devel] [PATCH 15/15] nvic: Implement "user accesses BusFault" SCS region behaviour, Peter Maydell, 2017/08/02