target/arm: Implement VLSTM for v7M CPUs with an FPU
Implement the VLSTM instruction for v7M for the FPU present case.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190416125744.27770-25-peter.maydell@linaro.org
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 0b10aef..22bc6e0 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -58,6 +58,8 @@
#define EXCP_INVSTATE 18 /* v7M INVSTATE UsageFault */
#define EXCP_STKOF 19 /* v8M STKOF UsageFault */
#define EXCP_LAZYFP 20 /* v7M fault during lazy FP stacking */
+#define EXCP_LSERR 21 /* v8M LSERR SecureFault */
+#define EXCP_UNALIGNED 22 /* v7M UNALIGNED UsageFault */
/* NB: add new EXCP_ defines to the array in arm_log_exception() too */
#define ARMV7M_EXCP_RESET 1
diff --git a/target/arm/helper.c b/target/arm/helper.c
index b11f8aa..b821037 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -7384,6 +7384,12 @@
g_assert_not_reached();
}
+void HELPER(v7m_vlstm)(CPUARMState *env, uint32_t fptr)
+{
+ /* translate.c should never generate calls here in user-only mode */
+ g_assert_not_reached();
+}
+
uint32_t HELPER(v7m_tt)(CPUARMState *env, uint32_t addr, uint32_t op)
{
/* The TT instructions can be used by unprivileged code, but in
@@ -8400,6 +8406,74 @@
}
}
+void HELPER(v7m_vlstm)(CPUARMState *env, uint32_t fptr)
+{
+ /* fptr is the value of Rn, the frame pointer we store the FP regs to */
+ bool s = env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_S_MASK;
+ bool lspact = env->v7m.fpccr[s] & R_V7M_FPCCR_LSPACT_MASK;
+
+ assert(env->v7m.secure);
+
+ if (!(env->v7m.control[M_REG_S] & R_V7M_CONTROL_SFPA_MASK)) {
+ return;
+ }
+
+ /* Check access to the coprocessor is permitted */
+ if (!v7m_cpacr_pass(env, true, arm_current_el(env) != 0)) {
+ raise_exception_ra(env, EXCP_NOCP, 0, 1, GETPC());
+ }
+
+ if (lspact) {
+ /* LSPACT should not be active when there is active FP state */
+ raise_exception_ra(env, EXCP_LSERR, 0, 1, GETPC());
+ }
+
+ if (fptr & 7) {
+ raise_exception_ra(env, EXCP_UNALIGNED, 0, 1, GETPC());
+ }
+
+ /*
+ * Note that we do not use v7m_stack_write() here, because the
+ * accesses should not set the FSR bits for stacking errors if they
+ * fail. (In pseudocode terms, they are AccType_NORMAL, not AccType_STACK
+ * or AccType_LAZYFP). Faults in cpu_stl_data() will throw exceptions
+ * and longjmp out.
+ */
+ if (!(env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_LSPEN_MASK)) {
+ bool ts = env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_TS_MASK;
+ int i;
+
+ for (i = 0; i < (ts ? 32 : 16); i += 2) {
+ uint64_t dn = *aa32_vfp_dreg(env, i / 2);
+ uint32_t faddr = fptr + 4 * i;
+ uint32_t slo = extract64(dn, 0, 32);
+ uint32_t shi = extract64(dn, 32, 32);
+
+ if (i >= 16) {
+ faddr += 8; /* skip the slot for the FPSCR */
+ }
+ cpu_stl_data(env, faddr, slo);
+ cpu_stl_data(env, faddr + 4, shi);
+ }
+ cpu_stl_data(env, fptr + 0x40, vfp_get_fpscr(env));
+
+ /*
+ * If TS is 0 then s0 to s15 and FPSCR are UNKNOWN; we choose to
+ * leave them unchanged, matching our choice in v7m_preserve_fp_state.
+ */
+ if (ts) {
+ for (i = 0; i < 32; i += 2) {
+ *aa32_vfp_dreg(env, i / 2) = 0;
+ }
+ vfp_set_fpscr(env, 0);
+ }
+ } else {
+ v7m_update_fpccr(env, fptr, false);
+ }
+
+ env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_FPCA_MASK;
+}
+
static bool v7m_push_stack(ARMCPU *cpu)
{
/* Do the "set up stack frame" part of exception entry,
@@ -9160,6 +9234,8 @@
[EXCP_INVSTATE] = "v7M INVSTATE UsageFault",
[EXCP_STKOF] = "v8M STKOF UsageFault",
[EXCP_LAZYFP] = "v7M exception during lazy FP stacking",
+ [EXCP_LSERR] = "v8M LSERR UsageFault",
+ [EXCP_UNALIGNED] = "v7M UNALIGNED UsageFault",
};
if (idx >= 0 && idx < ARRAY_SIZE(excnames)) {
@@ -9334,6 +9410,14 @@
armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure);
env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_STKOF_MASK;
break;
+ case EXCP_LSERR:
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false);
+ env->v7m.sfsr |= R_V7M_SFSR_LSERR_MASK;
+ break;
+ case EXCP_UNALIGNED:
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure);
+ env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_UNALIGNED_MASK;
+ break;
case EXCP_SWI:
/* The PC already points to the next instruction. */
armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SVC, env->v7m.secure);
diff --git a/target/arm/helper.h b/target/arm/helper.h
index 0a3a805..62051ae 100644
--- a/target/arm/helper.h
+++ b/target/arm/helper.h
@@ -71,6 +71,8 @@
DEF_HELPER_1(v7m_preserve_fp_state, void, env)
+DEF_HELPER_2(v7m_vlstm, void, env, i32)
+
DEF_HELPER_2(v8m_stackcheck, void, env, i32)
DEF_HELPER_4(access_check_cp_reg, void, env, ptr, i32, i32)
diff --git a/target/arm/translate.c b/target/arm/translate.c
index 4f29d09..99b38dd 100644
--- a/target/arm/translate.c
+++ b/target/arm/translate.c
@@ -11818,7 +11818,20 @@
if (!s->v8m_secure || (insn & 0x0040f0ff)) {
goto illegal_op;
}
- /* Just NOP since FP support is not implemented */
+
+ if (arm_dc_feature(s, ARM_FEATURE_VFP)) {
+ TCGv_i32 fptr = load_reg(s, rn);
+
+ if (extract32(insn, 20, 1)) {
+ /* VLLDM */
+ } else {
+ gen_helper_v7m_vlstm(cpu_env, fptr);
+ }
+ tcg_temp_free_i32(fptr);
+
+ /* End the TB, because we have updated FP control bits */
+ s->base.is_jmp = DISAS_UPDATE;
+ }
break;
}
if (arm_dc_feature(s, ARM_FEATURE_VFP) &&
