> -----Original Message-----
> From: ltaylorsimp...@gmail.com <ltaylorsimp...@gmail.com>
> Sent: Wednesday, March 19, 2025 4:28 PM
> To: 'Brian Cain' <brian.c...@oss.qualcomm.com>; qemu-devel@nongnu.org
> Cc: richard.hender...@linaro.org; phi...@linaro.org; Matheus Bernardino
> (QUIC) <quic_mathb...@quicinc.com>; a...@rev.ng; a...@rev.ng; Marco
> Liebel (QUIC) <quic_mlie...@quicinc.com>; alex.ben...@linaro.org; Mark
> Burton (QUIC) <quic_mbur...@quicinc.com>; Sid Manning
> <sidn...@quicinc.com>; Brian Cain <bc...@quicinc.com>; 'Mike Lambert'
> <mlamb...@quicinc.com>
> Subject: RE: [PATCH 17/39] target/hexagon: Implement software interrupt
>
> WARNING: This email originated from outside of Qualcomm. Please be wary
> of any links or attachments, and do not enable macros.
>
> > -----Original Message-----
> > From: Brian Cain <brian.c...@oss.qualcomm.com>
> > Sent: Friday, February 28, 2025 11:28 PM
> > To: qemu-devel@nongnu.org
> > Cc: brian.c...@oss.qualcomm.com; richard.hender...@linaro.org;
> > phi...@linaro.org; quic_mathb...@quicinc.com; a...@rev.ng;
> a...@rev.ng;
> > quic_mlie...@quicinc.com; ltaylorsimp...@gmail.com;
> > alex.ben...@linaro.org; quic_mbur...@quicinc.com;
> sidn...@quicinc.com;
> > Brian Cain <bc...@quicinc.com>; Mike Lambert <mlamb...@quicinc.com>
> > Subject: [PATCH 17/39] target/hexagon: Implement software interrupt
> >
> > From: Brian Cain <bc...@quicinc.com>
> >
> > Co-authored-by: Mike Lambert <mlamb...@quicinc.com>
> > Signed-off-by: Brian Cain <brian.c...@oss.qualcomm.com>
> > ---
> > target/hexagon/cpu.h | 1 -
> > target/hexagon/hexswi.h | 17 +++
> > target/hexagon/cpu.c | 2 +
> > target/hexagon/hexswi.c | 258
> > +++++++++++++++++++++++++++++++++++++
> > target/hexagon/op_helper.c | 1 +
> > 5 files changed, 278 insertions(+), 1 deletion(-) create mode 100644
> > target/hexagon/hexswi.h create mode 100644 target/hexagon/hexswi.c
> >
> > diff --git a/target/hexagon/cpu.h b/target/hexagon/cpu.h index
> > dabee310c5..045581d7be 100644
> > --- a/target/hexagon/cpu.h
> > +++ b/target/hexagon/cpu.h
> > @@ -256,5 +256,4 @@ typedef HexagonCPU ArchCPU; void
> > hexagon_translate_init(void); void hexagon_translate_code(CPUState
> > *cs, TranslationBlock *tb,
> > int *max_insns, vaddr pc, void *host_pc);
> > -
>
> Gratuitous change
>
> > #endif /* HEXAGON_CPU_H */
> > diff --git a/target/hexagon/hexswi.h b/target/hexagon/hexswi.h new
> > file mode 100644 index 0000000000..5d232cb06c
> > --- /dev/null
> > +++ b/target/hexagon/hexswi.h
> > @@ -0,0 +1,17 @@
> > +/*
> > + * Copyright(c) 2025 Qualcomm Innovation Center, Inc. All Rights
> Reserved.
> > + *
> > + * SPDX-License-Identifier: GPL-2.0-or-later */
> > +
> > +#ifndef HEXSWI_H
> > +#define HEXSWI_H
> > +
> > +
> > +#include "cpu.h"
> > +
> > +void hexagon_cpu_do_interrupt(CPUState *cpu); void
> > +register_trap_exception(CPUHexagonState *env, int type, int imm,
> > + target_ulong PC);
> > +
> > +#endif /* HEXSWI_H */
> > diff --git a/target/hexagon/cpu.c b/target/hexagon/cpu.c index
> > 89a051b41d..843be8221f 100644
> > --- a/target/hexagon/cpu.c
> > +++ b/target/hexagon/cpu.c
> > @@ -33,6 +33,8 @@
> > #ifndef CONFIG_USER_ONLY
> > #include "sys_macros.h"
> > #include "qemu/main-loop.h"
> > +#include "hex_interrupts.h"
> > +#include "hexswi.h"
>
> Move these added include to a different patch where the contents are
> needed.
>
> > #endif
> >
> > static void hexagon_v66_cpu_init(Object *obj) { } diff --git
> > a/target/hexagon/hexswi.c b/target/hexagon/hexswi.c new file mode
> > 100644 index 0000000000..5fcf9b2be9
> > --- /dev/null
> > +++ b/target/hexagon/hexswi.c
> > @@ -0,0 +1,258 @@
> > +/*
> > + * Copyright(c) 2019-2025 Qualcomm Innovation Center, Inc. All Rights
> > Reserved.
> > + *
> > + * SPDX-License-Identifier: GPL-2.0-or-later */
> > +
> > +#include "qemu/osdep.h"
> > +#include "cpu.h"
> > +#ifdef CONFIG_USER_ONLY
>
> This file is only included in the system-mode build, so we don't need these
> guards. Several in this file.
>
> > +#include "exec/helper-proto.h"
> > +#include "qemu.h"
> > +#endif
> > +#include "exec/cpu_ldst.h"
> > +#include "exec/exec-all.h"
> > +#include "qemu/log.h"
> > +#include "qemu/main-loop.h"
> > +#include "arch.h"
> > +#include "internal.h"
> > +#include "macros.h"
> > +#include "sys_macros.h"
> > +#include "tcg/tcg-op.h"
> > +#ifndef CONFIG_USER_ONLY
> > +#include "hex_mmu.h"
> > +#include "hexswi.h"
> > +#endif
> > +
> > +#ifndef CONFIG_USER_ONLY
> > +
> > +
> > +static void set_addresses(CPUHexagonState *env, target_ulong
> pc_offset,
> > + target_ulong exception_index)
> > +
> > +{
> > + arch_set_system_reg(env, HEX_SREG_ELR,
> > + arch_get_thread_reg(env, HEX_REG_PC) + pc_offset);
> > + arch_set_thread_reg(env, HEX_REG_PC,
> > + arch_get_system_reg(env, HEX_SREG_EVB) |
> > + (exception_index << 2)); }
> > +
> > +static const char *event_name[] = {
> > + [HEX_EVENT_RESET] = "HEX_EVENT_RESET",
> > + [HEX_EVENT_IMPRECISE] = "HEX_EVENT_IMPRECISE",
> > + [HEX_EVENT_TLB_MISS_X] = "HEX_EVENT_TLB_MISS_X",
> > + [HEX_EVENT_TLB_MISS_RW] = "HEX_EVENT_TLB_MISS_RW",
> > + [HEX_EVENT_TRAP0] = "HEX_EVENT_TRAP0",
> > + [HEX_EVENT_TRAP1] = "HEX_EVENT_TRAP1",
> > + [HEX_EVENT_FPTRAP] = "HEX_EVENT_FPTRAP",
> > + [HEX_EVENT_DEBUG] = "HEX_EVENT_DEBUG",
> > + [HEX_EVENT_INT0] = "HEX_EVENT_INT0",
> > + [HEX_EVENT_INT1] = "HEX_EVENT_INT1",
> > + [HEX_EVENT_INT2] = "HEX_EVENT_INT2",
> > + [HEX_EVENT_INT3] = "HEX_EVENT_INT3",
> > + [HEX_EVENT_INT4] = "HEX_EVENT_INT4",
> > + [HEX_EVENT_INT5] = "HEX_EVENT_INT5",
> > + [HEX_EVENT_INT6] = "HEX_EVENT_INT6",
> > + [HEX_EVENT_INT7] = "HEX_EVENT_INT7",
> > + [HEX_EVENT_INT8] = "HEX_EVENT_INT8",
> > + [HEX_EVENT_INT9] = "HEX_EVENT_INT9",
> > + [HEX_EVENT_INTA] = "HEX_EVENT_INTA",
> > + [HEX_EVENT_INTB] = "HEX_EVENT_INTB",
> > + [HEX_EVENT_INTC] = "HEX_EVENT_INTC",
> > + [HEX_EVENT_INTD] = "HEX_EVENT_INTD",
> > + [HEX_EVENT_INTE] = "HEX_EVENT_INTE",
> > + [HEX_EVENT_INTF] = "HEX_EVENT_INTF"
> > +};
> > +
> > +void hexagon_cpu_do_interrupt(CPUState *cs)
> > +
> > +{
> > + CPUHexagonState *env = cpu_env(cs);
> > + BQL_LOCK_GUARD();
> > +
> > + qemu_log_mask(CPU_LOG_INT, "\t%s: event 0x%x:%s, cause
> > 0x%x(%d)\n",
> > + __func__, cs->exception_index,
> > + event_name[cs->exception_index], env->cause_code,
> > + env->cause_code);
> > +
> > + env->llsc_addr = ~0;
> > +
> > + uint32_t ssr = arch_get_system_reg(env, HEX_SREG_SSR);
>
> Declarations at the beginning of the function.
[Sid Manning]
Will fix
>
> > + if (GET_SSR_FIELD(SSR_EX, ssr) == 1) {
> > + arch_set_system_reg(env, HEX_SREG_DIAG, env->cause_code);
> > + env->cause_code = HEX_CAUSE_DOUBLE_EXCEPT;
> > + cs->exception_index = HEX_EVENT_PRECISE;
> > + }
> > +
> > + switch (cs->exception_index) {
> > + case HEX_EVENT_TRAP0:
> > + if (env->cause_code == 0) {
> > + qemu_log_mask(LOG_UNIMP,
> > + "trap0 is unhandled, no semihosting
> > available\n");
> > + }
> > +
> > + hexagon_ssr_set_cause(env, env->cause_code);
> > + set_addresses(env, 4, cs->exception_index);
> > + break;
> > +
> > + case HEX_EVENT_TRAP1:
> > + hexagon_ssr_set_cause(env, env->cause_code);
> > + set_addresses(env, 4, cs->exception_index);
> > + break;
> > +
> > + case HEX_EVENT_TLB_MISS_X:
> > + switch (env->cause_code) {
> > + case HEX_CAUSE_TLBMISSX_CAUSE_NORMAL:
> > + case HEX_CAUSE_TLBMISSX_CAUSE_NEXTPAGE:
> > + qemu_log_mask(CPU_LOG_MMU,
> > + "TLB miss EX exception (0x%x) caught: "
> > + "Cause code (0x%x) "
> > + "TID = 0x%" PRIx32 ", PC = 0x%" PRIx32
> > + ", BADVA = 0x%" PRIx32 "\n",
> > + cs->exception_index, env->cause_code,
> > env->threadId,
> > + arch_get_thread_reg(env, HEX_REG_PC),
> > + arch_get_system_reg(env, HEX_SREG_BADVA));
> > +
> > + hexagon_ssr_set_cause(env, env->cause_code);
> > + set_addresses(env, 0, cs->exception_index);
> > + break;
> > +
> > + default:
> > + cpu_abort(cs,
> > + "1:Hexagon exception %d/0x%x: "
> > + "Unknown cause code %d/0x%x\n",
> > + cs->exception_index, cs->exception_index,
> > env->cause_code,
> > + env->cause_code);
> > + break;
> > + }
> > + break;
> > +
> > + case HEX_EVENT_TLB_MISS_RW:
> > + switch (env->cause_code) {
> > + case HEX_CAUSE_TLBMISSRW_CAUSE_READ:
> > + case HEX_CAUSE_TLBMISSRW_CAUSE_WRITE:
> > + qemu_log_mask(CPU_LOG_MMU,
> > + "TLB miss RW exception (0x%x) caught: "
> > + "Cause code (0x%x) "
> > + "TID = 0x%" PRIx32 ", PC = 0x%" PRIx32
> > + ", BADVA = 0x%" PRIx32 "\n",
> > + cs->exception_index, env->cause_code,
> > env->threadId,
> > + env->gpr[HEX_REG_PC],
> > + arch_get_system_reg(env, HEX_SREG_BADVA));
> > +
> > + hexagon_ssr_set_cause(env, env->cause_code);
> > + set_addresses(env, 0, cs->exception_index);
> > + /* env->sreg[HEX_SREG_BADVA] is set when the exception is
> > + raised
> > */
> > + break;
> > +
> > + default:
> > + cpu_abort(cs,
> > + "2:Hexagon exception %d/0x%x: "
> > + "Unknown cause code %d/0x%x\n",
> > + cs->exception_index, cs->exception_index,
> > env->cause_code,
> > + env->cause_code);
> > + break;
> > + }
> > + break;
> > +
> > + case HEX_EVENT_FPTRAP:
> > + hexagon_ssr_set_cause(env, env->cause_code);
> > + arch_set_thread_reg(env, HEX_REG_PC,
> > + arch_get_system_reg(env, HEX_SREG_EVB) |
> > + (cs->exception_index << 2));
>
> Why not use set_addresses here? How is ELR set?
[Sid Manning]
I think at this level the FP traps are not complete. ELR is supposed to point
to the next instruction, next_PC, that is why set_addresses isn't used. We
will have to add some checks of usr:fp's to know if instructions with FPOPS
attribute need next_PC or not.
>
> > + break;
> > +
> > + case HEX_EVENT_DEBUG:
> > + hexagon_ssr_set_cause(env, env->cause_code);
> > + set_addresses(env, 0, cs->exception_index);
> > + qemu_log_mask(LOG_UNIMP, "single-step exception is not
> > handled\n");
> > + break;
> > +
> > + case HEX_EVENT_PRECISE:
> > + switch (env->cause_code) {
> > + case HEX_CAUSE_FETCH_NO_XPAGE:
> > + case HEX_CAUSE_FETCH_NO_UPAGE:
> > + case HEX_CAUSE_PRIV_NO_READ:
> > + case HEX_CAUSE_PRIV_NO_UREAD:
> > + case HEX_CAUSE_PRIV_NO_WRITE:
> > + case HEX_CAUSE_PRIV_NO_UWRITE:
> > + case HEX_CAUSE_MISALIGNED_LOAD:
> > + case HEX_CAUSE_MISALIGNED_STORE:
> > + case HEX_CAUSE_PC_NOT_ALIGNED:
> > + qemu_log_mask(CPU_LOG_MMU,
> > + "MMU permission exception (0x%x) caught: "
> > + "Cause code (0x%x) "
> > + "TID = 0x%" PRIx32 ", PC = 0x%" PRIx32
> > + ", BADVA = 0x%" PRIx32 "\n",
> > + cs->exception_index, env->cause_code,
> > env->threadId,
> > + env->gpr[HEX_REG_PC],
> > + arch_get_system_reg(env, HEX_SREG_BADVA));
> > +
> > +
> > + hexagon_ssr_set_cause(env, env->cause_code);
> > + set_addresses(env, 0, cs->exception_index);
> > + /* env->sreg[HEX_SREG_BADVA] is set when the exception is
> > + raised
> > */
> > + break;
> > +
> > + case HEX_CAUSE_DOUBLE_EXCEPT:
> > + case HEX_CAUSE_PRIV_USER_NO_SINSN:
> > + case HEX_CAUSE_PRIV_USER_NO_GINSN:
> > + case HEX_CAUSE_INVALID_OPCODE:
> > + case HEX_CAUSE_NO_COPROC_ENABLE:
> > + case HEX_CAUSE_NO_COPROC2_ENABLE:
> > + case HEX_CAUSE_UNSUPORTED_HVX_64B:
> > + case HEX_CAUSE_REG_WRITE_CONFLICT:
> > + case HEX_CAUSE_VWCTRL_WINDOW_MISS:
> > + hexagon_ssr_set_cause(env, env->cause_code);
> > + set_addresses(env, 0, cs->exception_index);
> > + break;
> > +
> > + case HEX_CAUSE_COPROC_LDST:
> > + hexagon_ssr_set_cause(env, env->cause_code);
> > + set_addresses(env, 0, cs->exception_index);
> > + break;
> > +
> > + case HEX_CAUSE_STACK_LIMIT:
> > + hexagon_ssr_set_cause(env, env->cause_code);
> > + set_addresses(env, 0, cs->exception_index);
> > + break;
> > +
> > + default:
> > + cpu_abort(cs,
> > + "3:Hexagon exception %d/0x%x: "
> > + "Unknown cause code %d/0x%x\n",
> > + cs->exception_index, cs->exception_index,
> > env->cause_code,
> > + env->cause_code);
> > + break;
> > + }
> > + break;
> > +
> > + case HEX_EVENT_IMPRECISE:
> > + qemu_log_mask(LOG_UNIMP,
> > + "Imprecise exception: this case is not yet handled");
> > + break;
> > +
> > + default:
> > + qemu_log_mask(LOG_UNIMP,
> > + "Hexagon Unsupported exception 0x%x/0x%x\n",
> > + cs->exception_index, env->cause_code);
> > + break;
> > + }
> > +
> > + cs->exception_index = HEX_EVENT_NONE; }
> > +
> > +void register_trap_exception(CPUHexagonState *env, int traptype, int
> > imm,
> > + target_ulong PC) {
> > + CPUState *cs = env_cpu(env);
> > +
> > + cs->exception_index = (traptype == 0) ? HEX_EVENT_TRAP0 :
> > HEX_EVENT_TRAP1;
> > + ASSERT_DIRECT_TO_GUEST_UNSET(env, cs->exception_index);
> > +
> > + env->cause_code = imm;
> > + env->gpr[HEX_REG_PC] = PC;
> > + cpu_loop_exit(cs);
> > +}
> > +#endif
> > diff --git a/target/hexagon/op_helper.c b/target/hexagon/op_helper.c
> > index 42805d0f1d..687e7f45c2 100644
> > --- a/target/hexagon/op_helper.c
> > +++ b/target/hexagon/op_helper.c
> > @@ -38,6 +38,7 @@
> > #include "hex_mmu.h"
> > #include "hw/intc/l2vic.h"
> > #include "hex_interrupts.h"
> > +#include "hexswi.h"
>
> Move this do a different patch where the contents are needed
>
> > #endif
> >
> > #define SF_BIAS 127
> > --
> > 2.34.1
>
