Adds a cpu_mapping struct to describe, in a declarative fashion, the mapping between fields in a struct, and a corresponding TCG global. As such, tcg_global_mem_new() can be automatically called given an array of cpu_mappings.
This change is not limited to helper-to-tcg, but will be required in future commits to map between offsets into CPUArchState and TCGv globals in a target-agnostic way. Signed-off-by: Anton Johansson <[email protected]> --- include/tcg/tcg-global-mappings.h | 111 ++++++++++++++++++++++++++++++ tcg/meson.build | 1 + tcg/tcg-global-mappings.c | 61 ++++++++++++++++ 3 files changed, 173 insertions(+) create mode 100644 include/tcg/tcg-global-mappings.h create mode 100644 tcg/tcg-global-mappings.c diff --git a/include/tcg/tcg-global-mappings.h b/include/tcg/tcg-global-mappings.h new file mode 100644 index 0000000000..736380fb20 --- /dev/null +++ b/include/tcg/tcg-global-mappings.h @@ -0,0 +1,111 @@ +/* + * Copyright(c) 2024 rev.ng Labs Srl. All Rights Reserved. + * + * 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/>. + */ + +#ifndef TCG_GLOBAL_MAP_H +#define TCG_GLOBAL_MAP_H + +#include "qemu/osdep.h" + +/** + * cpu_tcg_mapping: Declarative mapping of offsets into a struct to global + * TCGvs. Parseable by LLVM-based tools. + * @tcg_var_name: String name of the TCGv to use as destination of the mapping. + * @tcg_var_base_address: Address of the above TCGv. + * @cpu_var_names: Array of printable names of TCGvs, used when calling + * tcg_global_mem_new from init_cpu_tcg_mappings. + * @cpu_var_base_offset: Base offset of field in the source struct. + * @cpu_var_size: Size of field in the source struct, if the field is an array, + * this holds the size of the element type. + * @cpu_var_stride: Stride between array elements in the source struct. This + * can be greater than the element size when mapping a field + * in an array of structs. + * @number_of_elements: Number of elements of array in the source struct. + */ +typedef struct cpu_tcg_mapping { + const char *tcg_var_name; + void *tcg_var_base_address; + + const char *const *cpu_var_names; + size_t cpu_var_base_offset; + size_t cpu_var_size; + size_t cpu_var_stride; + + size_t number_of_elements; +} cpu_tcg_mapping; + +#define STRUCT_SIZEOF_FIELD(S, member) sizeof(((S *)0)->member) + +#define STRUCT_ARRAY_SIZE(S, array) \ + (STRUCT_SIZEOF_FIELD(S, array) / STRUCT_SIZEOF_FIELD(S, array[0])) + +/* + * Following are a few macros that aid in constructing + * `cpu_tcg_mapping`s for a few common cases. + */ + +/* Map between single CPU register and to TCG global */ +#define CPU_TCG_MAP(struct_type, tcg_var, cpu_var, name_str) \ + (cpu_tcg_mapping) \ + { \ + .tcg_var_name = stringify(tcg_var), .tcg_var_base_address = &tcg_var, \ + .cpu_var_names = (const char *[]){name_str}, \ + .cpu_var_base_offset = offsetof(struct_type, cpu_var), \ + .cpu_var_size = STRUCT_SIZEOF_FIELD(struct_type, cpu_var), \ + .cpu_var_stride = 0, .number_of_elements = 1, \ + } + +/* Map between array of CPU registers and array of TCG globals. */ +#define CPU_TCG_MAP_ARRAY(struct_type, tcg_var, cpu_var, names) \ + (cpu_tcg_mapping) \ + { \ + .tcg_var_name = #tcg_var, .tcg_var_base_address = tcg_var, \ + .cpu_var_names = names, \ + .cpu_var_base_offset = offsetof(struct_type, cpu_var), \ + .cpu_var_size = STRUCT_SIZEOF_FIELD(struct_type, cpu_var[0]), \ + .cpu_var_stride = STRUCT_SIZEOF_FIELD(struct_type, cpu_var[0]), \ + .number_of_elements = STRUCT_ARRAY_SIZE(struct_type, cpu_var), \ + } + +/* + * Map between single member in an array of structs to an array + * of TCG globals, e.g. maps + * + * cpu_state.array_of_structs[i].member + * + * to + * + * tcg_global_member[i] + */ +#define CPU_TCG_MAP_ARRAY_OF_STRUCTS(struct_type, tcg_var, cpu_struct, \ + cpu_var, names) \ + (cpu_tcg_mapping) \ + { \ + .tcg_var_name = #tcg_var, .tcg_var_base_address = tcg_var, \ + .cpu_var_names = names, \ + .cpu_var_base_offset = offsetof(struct_type, cpu_struct[0].cpu_var), \ + .cpu_var_size = \ + STRUCT_SIZEOF_FIELD(struct_type, cpu_struct[0].cpu_var), \ + .cpu_var_stride = STRUCT_SIZEOF_FIELD(struct_type, cpu_struct[0]), \ + .number_of_elements = STRUCT_ARRAY_SIZE(struct_type, cpu_struct), \ + } + +extern cpu_tcg_mapping tcg_global_mappings[]; +extern size_t tcg_global_mapping_count; + +void init_cpu_tcg_mappings(cpu_tcg_mapping *mappings, size_t size); + +#endif /* TCG_GLOBAL_MAP_H */ diff --git a/tcg/meson.build b/tcg/meson.build index 69ebb4908a..a0d6b09d85 100644 --- a/tcg/meson.build +++ b/tcg/meson.build @@ -13,6 +13,7 @@ tcg_ss.add(files( 'tcg-op-ldst.c', 'tcg-op-gvec.c', 'tcg-op-vec.c', + 'tcg-global-mappings.c', )) if get_option('tcg_interpreter') diff --git a/tcg/tcg-global-mappings.c b/tcg/tcg-global-mappings.c new file mode 100644 index 0000000000..cc1f07fae4 --- /dev/null +++ b/tcg/tcg-global-mappings.c @@ -0,0 +1,61 @@ +/* + * Copyright(c) 2024 rev.ng Labs Srl. All Rights Reserved. + * + * 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/>. + */ + +#include "tcg/tcg-global-mappings.h" +#include "tcg/tcg-op-common.h" +#include "tcg/tcg.h" + +void init_cpu_tcg_mappings(cpu_tcg_mapping *mappings, size_t size) +{ + uintptr_t tcg_addr; + size_t cpu_offset; + const char *name; + cpu_tcg_mapping m; + + /* + * Paranoid assertion, this should always hold since + * they're typedef'd to pointers. But you never know! + */ + g_assert(sizeof(TCGv_i32) == sizeof(TCGv_i64)); + + /* + * Loop over entries in tcg_global_mappings and + * create the `mapped to` TCGv's. + */ + for (int i = 0; i < size; ++i) { + m = mappings[i]; + + for (int j = 0; j < m.number_of_elements; ++j) { + /* + * Here we are using the fact that + * sizeof(TCGv_i32) == sizeof(TCGv_i64) == sizeof(TCGv) + */ + assert(sizeof(TCGv_i32) == sizeof(TCGv_i64)); + tcg_addr = (uintptr_t)m.tcg_var_base_address + j * sizeof(TCGv_i32); + cpu_offset = m.cpu_var_base_offset + j * m.cpu_var_stride; + name = m.cpu_var_names[j]; + + if (m.cpu_var_size < 8) { + *(TCGv_i32 *)tcg_addr = + tcg_global_mem_new_i32(tcg_env, cpu_offset, name); + } else { + *(TCGv_i64 *)tcg_addr = + tcg_global_mem_new_i64(tcg_env, cpu_offset, name); + } + } + } +} -- 2.45.2
