From: Richard Henderson Date: Mon, 22 Mar 2021 11:24:24 +0000 (+0100) Subject: exec: Rename exec-vary.c as page-vary.c X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=6670d4d0e38249323df755a92ffdf04f2c6b7894;p=qemu.git exec: Rename exec-vary.c as page-vary.c exec-vary.c is about variable page size handling, rename it page-vary.c. Currently this file is target specific (built once for each target), comment this. Signed-off-by: Philippe Mathieu-Daudé Message-Id: <20210322112427.4045204-2-f4bug@amsat.org> [rth: Update MAINTAINERS] Signed-off-by: Richard Henderson --- diff --git a/MAINTAINERS b/MAINTAINERS index 9147e9a429..ed68de3cec 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -117,6 +117,7 @@ R: Paolo Bonzini S: Maintained F: softmmu/cpus.c F: cpus-common.c +F: page-vary.c F: accel/tcg/ F: accel/stubs/tcg-stub.c F: util/cacheinfo.c diff --git a/exec-vary.c b/exec-vary.c deleted file mode 100644 index a603b1b433..0000000000 --- a/exec-vary.c +++ /dev/null @@ -1,108 +0,0 @@ -/* - * Variable page size handling - * - * Copyright (c) 2003 Fabrice Bellard - * - * This library is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public - * License as published by the Free Software Foundation; either - * version 2.1 of the License, or (at your option) any later version. - * - * This library 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 - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with this library; if not, see . - */ - -#include "qemu/osdep.h" -#include "qemu-common.h" - -#define IN_EXEC_VARY 1 - -#include "exec/exec-all.h" - -#ifdef TARGET_PAGE_BITS_VARY -# ifdef CONFIG_ATTRIBUTE_ALIAS -/* - * We want to declare the "target_page" variable as const, which tells - * the compiler that it can cache any value that it reads across calls. - * This avoids multiple assertions and multiple reads within any one user. - * - * This works because we finish initializing the data before we ever read - * from the "target_page" symbol. - * - * This also requires that we have a non-constant symbol by which we can - * perform the actual initialization, and which forces the data to be - * allocated within writable memory. Thus "init_target_page", and we use - * that symbol exclusively in the two functions that initialize this value. - * - * The "target_page" symbol is created as an alias of "init_target_page". - */ -static TargetPageBits init_target_page; - -/* - * Note that this is *not* a redundant decl, this is the definition of - * the "target_page" symbol. The syntax for this definition requires - * the use of the extern keyword. This seems to be a GCC bug in - * either the syntax for the alias attribute or in -Wredundant-decls. - * - * See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91765 - */ -# pragma GCC diagnostic push -# pragma GCC diagnostic ignored "-Wredundant-decls" - -extern const TargetPageBits target_page - __attribute__((alias("init_target_page"))); - -# pragma GCC diagnostic pop -# else -/* - * When aliases are not supported then we force two different declarations, - * by way of suppressing the header declaration with IN_EXEC_VARY. - * We assume that on such an old compiler, LTO cannot be used, and so the - * compiler cannot not detect the mismatched declarations, and all is well. - */ -TargetPageBits target_page; -# define init_target_page target_page -# endif -#endif - -bool set_preferred_target_page_bits(int bits) -{ - /* - * The target page size is the lowest common denominator for all - * the CPUs in the system, so we can only make it smaller, never - * larger. And we can't make it smaller once we've committed to - * a particular size. - */ -#ifdef TARGET_PAGE_BITS_VARY - assert(bits >= TARGET_PAGE_BITS_MIN); - if (init_target_page.bits == 0 || init_target_page.bits > bits) { - if (init_target_page.decided) { - return false; - } - init_target_page.bits = bits; - } -#endif - return true; -} - -void finalize_target_page_bits(void) -{ -#ifdef TARGET_PAGE_BITS_VARY - if (init_target_page.bits == 0) { - init_target_page.bits = TARGET_PAGE_BITS_MIN; - } - init_target_page.mask = (target_long)-1 << init_target_page.bits; - init_target_page.decided = true; - - /* - * For the benefit of an -flto build, prevent the compiler from - * hoisting a read from target_page before we finish initializing. - */ - barrier(); -#endif -} diff --git a/meson.build b/meson.build index 5c85a15364..f0dd8aa089 100644 --- a/meson.build +++ b/meson.build @@ -1933,7 +1933,6 @@ subdir('softmmu') common_ss.add(capstone) specific_ss.add(files('cpu.c', 'disas.c', 'gdbstub.c'), capstone) -specific_ss.add(files('exec-vary.c')) specific_ss.add(when: 'CONFIG_TCG', if_true: files( 'fpu/softfloat.c', 'tcg/optimize.c', @@ -1945,6 +1944,8 @@ specific_ss.add(when: 'CONFIG_TCG', if_true: files( )) specific_ss.add(when: 'CONFIG_TCG_INTERPRETER', if_true: files('tcg/tci.c')) +specific_ss.add(files('page-vary.c')) + subdir('backends') subdir('disas') subdir('migration') diff --git a/page-vary.c b/page-vary.c new file mode 100644 index 0000000000..344f9fcf76 --- /dev/null +++ b/page-vary.c @@ -0,0 +1,108 @@ +/* + * Variable page size handling -- target specific part. + * + * Copyright (c) 2003 Fabrice Bellard + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, see . + */ + +#include "qemu/osdep.h" +#include "qemu-common.h" + +#define IN_EXEC_VARY 1 + +#include "exec/exec-all.h" + +#ifdef TARGET_PAGE_BITS_VARY +# ifdef CONFIG_ATTRIBUTE_ALIAS +/* + * We want to declare the "target_page" variable as const, which tells + * the compiler that it can cache any value that it reads across calls. + * This avoids multiple assertions and multiple reads within any one user. + * + * This works because we finish initializing the data before we ever read + * from the "target_page" symbol. + * + * This also requires that we have a non-constant symbol by which we can + * perform the actual initialization, and which forces the data to be + * allocated within writable memory. Thus "init_target_page", and we use + * that symbol exclusively in the two functions that initialize this value. + * + * The "target_page" symbol is created as an alias of "init_target_page". + */ +static TargetPageBits init_target_page; + +/* + * Note that this is *not* a redundant decl, this is the definition of + * the "target_page" symbol. The syntax for this definition requires + * the use of the extern keyword. This seems to be a GCC bug in + * either the syntax for the alias attribute or in -Wredundant-decls. + * + * See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91765 + */ +# pragma GCC diagnostic push +# pragma GCC diagnostic ignored "-Wredundant-decls" + +extern const TargetPageBits target_page + __attribute__((alias("init_target_page"))); + +# pragma GCC diagnostic pop +# else +/* + * When aliases are not supported then we force two different declarations, + * by way of suppressing the header declaration with IN_EXEC_VARY. + * We assume that on such an old compiler, LTO cannot be used, and so the + * compiler cannot not detect the mismatched declarations, and all is well. + */ +TargetPageBits target_page; +# define init_target_page target_page +# endif +#endif + +bool set_preferred_target_page_bits(int bits) +{ + /* + * The target page size is the lowest common denominator for all + * the CPUs in the system, so we can only make it smaller, never + * larger. And we can't make it smaller once we've committed to + * a particular size. + */ +#ifdef TARGET_PAGE_BITS_VARY + assert(bits >= TARGET_PAGE_BITS_MIN); + if (init_target_page.bits == 0 || init_target_page.bits > bits) { + if (init_target_page.decided) { + return false; + } + init_target_page.bits = bits; + } +#endif + return true; +} + +void finalize_target_page_bits(void) +{ +#ifdef TARGET_PAGE_BITS_VARY + if (init_target_page.bits == 0) { + init_target_page.bits = TARGET_PAGE_BITS_MIN; + } + init_target_page.mask = (target_long)-1 << init_target_page.bits; + init_target_page.decided = true; + + /* + * For the benefit of an -flto build, prevent the compiler from + * hoisting a read from target_page before we finish initializing. + */ + barrier(); +#endif +}