RE: [PATCH 17/39] target/hexagon: Implement software interrupt

[<ltaylorsimpson@gmail.com>]

> -----Original Message-----
> From: Brian Cain <brian.cain@oss.qualcomm.com>
> Sent: Friday, February 28, 2025 11:28 PM
> To: qemu-devel@nongnu.org
> Cc: brian.cain@oss.qualcomm.com; richard.henderson@linaro.org;
> philmd@linaro.org; quic_mathbern@quicinc.com; ale@rev.ng; anjo@rev.ng;
> quic_mliebel@quicinc.com; ltaylorsimpson@gmail.com;
> alex.bennee@linaro.org; quic_mburton@quicinc.com;
> sidneym@quicinc.com; Brian Cain <bcain@quicinc.com>; Mike Lambert
> <mlambert@quicinc.com>
> Subject: [PATCH 17/39] target/hexagon: Implement software interrupt
> 
> From: Brian Cain <bcain@quicinc.com>
> 
> Co-authored-by: Mike Lambert <mlambert@quicinc.com>
> Signed-off-by: Brian Cain <brian.cain@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.

> +    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?

> +        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