Hi Connie,
On 4/14/25 6:38 PM, Cornelia Huck wrote:
> From: Eric Auger <eric.au...@redhat.com>
>
> The known ID regs are described in a new initialization function
> dubbed initialize_cpu_sysreg_properties(). That code will be
> automatically generated from linux arch/arm64/tools/sysreg. For the
> time being let's just describe a single id reg, CTR_EL0. In this
> description we only care about non RES/RAZ fields, ie. named fields.
>
> The registers are populated in an array indexed by ARMIDRegisterIdx
> and their fields are added in a sorted list.
>
> [CH: adapted to reworked register storage]
> Signed-off-by: Eric Auger <eric.au...@redhat.com>
> Signed-off-by: Cornelia Huck <coh...@redhat.com>
> ---
> target/arm/cpu-custom.h | 60 ++++++++++++++++++++++++++++++
> target/arm/cpu-sysreg-properties.c | 41 ++++++++++++++++++++
> target/arm/cpu64.c | 2 +
> target/arm/meson.build | 1 +
> 4 files changed, 104 insertions(+)
> create mode 100644 target/arm/cpu-custom.h
do we still want reference to the "custom" terminology, following
initial comments?
> create mode 100644 target/arm/cpu-sysreg-properties.c
>
> diff --git a/target/arm/cpu-custom.h b/target/arm/cpu-custom.h
> new file mode 100644
> index 000000000000..615347376e56
> --- /dev/null
> +++ b/target/arm/cpu-custom.h
> @@ -0,0 +1,60 @@
> +/*
> + * handle ID registers and their fields
> + *
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + */
> +#ifndef ARM_CPU_CUSTOM_H
> +#define ARM_CPU_CUSTOM_H
> +
> +#include "qemu/osdep.h"
> +#include "qemu/error-report.h"
> +#include "cpu.h"
> +#include "cpu-sysregs.h"
> +
> +typedef struct ARM64SysRegField {
> + const char *name; /* name of the field, for instance CTR_EL0_IDC */
> + int index;
worth to add a comment saying this is the ARMIDRegisterIdx of the parent
sysreg.
> + int lower;
> + int upper;
> +} ARM64SysRegField;
> +
> +typedef struct ARM64SysReg {
> + const char *name; /* name of the sysreg, for instance CTR_EL0 */
> + ARMSysRegs sysreg;
> + int index;
now that we have different kinds of indexing, may be worth adding a
comment to explain which one is being used.
I guess here it is ARMIDRegisterIdx. So you could even change the data type.
> + GList *fields; /* list of named fields, excluding RES* */
> +} ARM64SysReg;
> +
> +void initialize_cpu_sysreg_properties(void);
> +
> +/*
> + * List of exposed ID regs (automatically populated from linux
> + * arch/arm64/tools/sysreg)
> + */
> +extern ARM64SysReg arm64_id_regs[NUM_ID_IDX];
> +
> +/* Allocate a new field and insert it at the head of the @reg list */
> +static inline GList *arm64_sysreg_add_field(ARM64SysReg *reg, const char
> *name,
> + uint8_t min, uint8_t max) {
> +
> + ARM64SysRegField *field = g_new0(ARM64SysRegField, 1);
> +
> + field->name = name;
> + field->lower = min;
> + field->upper = max;
> + field->index = reg->index;
> +
> + reg->fields = g_list_append(reg->fields, field);
> + return reg->fields;
> +}
> +
> +static inline ARM64SysReg *arm64_sysreg_get(ARMIDRegisterIdx index)
> +{
> + ARM64SysReg *reg = &arm64_id_regs[index];
> +
> + reg->index = index;
> + reg->sysreg = id_register_sysreg[index];
> + return reg;
> +}
> +
> +#endif
> diff --git a/target/arm/cpu-sysreg-properties.c
> b/target/arm/cpu-sysreg-properties.c
> new file mode 100644
> index 000000000000..8b7ef5badfb9
> --- /dev/null
> +++ b/target/arm/cpu-sysreg-properties.c
> @@ -0,0 +1,41 @@
> +/*
> + * QEMU ARM CPU SYSREG PROPERTIES
> + * to be generated from linux sysreg
> + *
> + * Copyright (c) Red Hat, Inc. 2024
maybe increment the year now ;-)
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version 2
> + * of the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, see
> + * <http://www.gnu.org/licenses/gpl-2.0.html>
> + */
> +
> +#include "cpu-custom.h"
> +
> +ARM64SysReg arm64_id_regs[NUM_ID_IDX];
> +
> +void initialize_cpu_sysreg_properties(void)
> +{
> + memset(arm64_id_regs, 0, sizeof(ARM64SysReg) * NUM_ID_IDX);
> + /* CTR_EL0 */
> + ARM64SysReg *CTR_EL0 = arm64_sysreg_get(CTR_EL0_IDX);
> + CTR_EL0->name = "CTR_EL0";
> + arm64_sysreg_add_field(CTR_EL0, "TminLine", 32, 37);
> + arm64_sysreg_add_field(CTR_EL0, "DIC", 29, 29);
> + arm64_sysreg_add_field(CTR_EL0, "IDC", 28, 28);
> + arm64_sysreg_add_field(CTR_EL0, "CWG", 24, 27);
> + arm64_sysreg_add_field(CTR_EL0, "ERG", 20, 23);
> + arm64_sysreg_add_field(CTR_EL0, "DminLine", 16, 19);
> + arm64_sysreg_add_field(CTR_EL0, "L1Ip", 14, 15);
> + arm64_sysreg_add_field(CTR_EL0, "IminLine", 0, 3);
> +}
> +
> diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
> index 9769401a8585..839442745ea4 100644
> --- a/target/arm/cpu64.c
> +++ b/target/arm/cpu64.c
> @@ -35,6 +35,7 @@
> #include "internals.h"
> #include "cpu-features.h"
> #include "cpregs.h"
> +#include "cpu-custom.h"
>
> /* convert between <register>_IDX and SYS_<register> */
> #define DEF(NAME, OP0, OP1, CRN, CRM, OP2) \
> @@ -891,6 +892,7 @@ static void aarch64_cpu_register_types(void)
> {
> size_t i;
>
> + initialize_cpu_sysreg_properties();
> type_register_static(&aarch64_cpu_type_info);
>
> for (i = 0; i < ARRAY_SIZE(aarch64_cpus); ++i) {
> diff --git a/target/arm/meson.build b/target/arm/meson.build
> index 3065081d241d..1c97c1ef7580 100644
> --- a/target/arm/meson.build
> +++ b/target/arm/meson.build
> @@ -14,6 +14,7 @@ arm_ss.add(when: 'CONFIG_HVF', if_true:
> files('hyp_gdbstub.c'))
> arm_ss.add(when: 'TARGET_AARCH64', if_true: files(
> 'cpu64.c',
> 'gdbstub64.c',
> + 'cpu-sysreg-properties.c',
> ))
>
> arm_system_ss = ss.source_set()
