Hi, > From: linux-acpi-owner at vger.kernel.org [mailto:linux-acpi- > owner at vger.kernel.org] On Behalf Of Matt Fleming [Lv Zheng] First, is it possible for you to submit an ACPICA patch instead of a Linux patch. The reasoning for doing this can be found at: https://acpica.org/Licensing > Subject: [PATCH 1/2] ACPICA: Tables: Add function to remove ACPI tables > > There are existing internal functions that allow the removal of ACPI > tables, but they're not exposed to the OS in any useful way. > > Introduce acpi_remove_table() which allows tables to be invalidated in > the global table list, resulting in failure of subsequent calls to > acpi_get_table() for those tables. > > The rationale for this change is the ability to remove the BGRT table > during kexec boot. The BGRT table refers to memory regions that are no > longer reserved by the firmware once the kexec kernel boots, having > been released for general allocation by the previous kernel. > > Cc: Dave Young <dyoung at redhat.com> > Cc: Rafael J. Wysocki <rafael.j.wysocki at intel.com> > Cc: Josh Triplett <josh at joshtriplett.org> > Cc: Borislav Petkov <bp at alien8.de> > Cc: Matthew Garrett <mjg59 at srcf.ucam.org> > Cc: Vivek Goyal <vgoyal at redhat.com> > Cc: <kexec at lists.infradead.org> > Signed-off-by: Matt Fleming <matt at codeblueprint.co.uk> > --- > drivers/acpi/acpica/tbxface.c | 54 > +++++++++++++++++++++++++++++++++++++++++++ > include/acpi/acpixf.h | 3 +++ > 2 files changed, 57 insertions(+) > > diff --git a/drivers/acpi/acpica/tbxface.c b/drivers/acpi/acpica/tbxface.c > index 326df65decef..999eecd89601 100644 > --- a/drivers/acpi/acpica/tbxface.c > +++ b/drivers/acpi/acpica/tbxface.c > @@ -480,3 +480,57 @@ cleanup: > } > > ACPI_EXPORT_SYMBOL(acpi_remove_table_handler) > + > +/************************************************************** > ***************** > + * > + * FUNCTION: acpi_remove_table [Lv Zheng] I'd prefer acpi_uninstall_table() in order to keep the consistencies of the function naming. There is in fact a state machine defined by the table manager design: UNINSTALLED - install -> INSTALLED/INVALIDATED - validate -> VALIDATED/UNLOADED - load -> LOADED LOADED -> unload -> UNLOADED/VALIDATED -> invalidate - INVALIDATED/INSTALLED -> uninstall -> UNINSTALLED > + * > + * PARAMETERS: signature - ACPI signature of needed table > + * instance - Which instance (for SSDTs) > + * > + * RETURN: Status > + * > + * DESCRIPTION: Finds and removes an ACPI table. > + * > + > **************************************************************** > **************/ > +acpi_status [Lv Zheng] You need to put __init here. Otherwise another API (for example, acpi_unload_table()) should be provided instead of this. > acpi_remove_table(char *signature, u32 instance) [Lv Zheng] I'm not sure if using instance is a good idea here. We have extensions not upstreamed that have something to do with the table indexing. But well, it doesn't look bad for now. > +{ > + struct acpi_table_desc *table_desc; > + acpi_status status; > + u32 i; > + u32 j; > + > + /* Parameter validation */ > + if (!signature) { > + return (AE_BAD_PARAMETER); > + } > + > + /* Walk the root table list */ > + > + for (i = 0, j = 0; i < acpi_gbl_root_table_list.current_table_count; > + i++) { > + if (!ACPI_COMPARE_NAME > + (&(acpi_gbl_root_table_list.tables[i].signature), > + signature)) { > + continue; > + } [Lv Zheng] After removing a table, the instance no remains 2 for the next table of the same signature. Is it intentional? > + > + if (++j < instance) { > + continue; > + } > + > + table_desc = &acpi_gbl_root_table_list.tables[i]; > + > + status = acpi_tb_validate_table(table_desc); > + if (ACPI_FAILURE(status)) { > + return (status); > + } [Lv Zheng] You needn't invoke acpi_tb_validate_table() here. > + > + acpi_tb_uninstall_table(table_desc); > + return (AE_OK); > + } > + > + return (AE_NOT_FOUND); > +} > + > +ACPI_EXPORT_SYMBOL(acpi_remove_table); > diff --git a/include/acpi/acpixf.h b/include/acpi/acpixf.h > index c96621e87c19..47e51612293e 100644 > --- a/include/acpi/acpixf.h > +++ b/include/acpi/acpixf.h > @@ -505,6 +505,9 @@ ACPI_EXTERNAL_RETURN_STATUS(acpi_status > ACPI_EXTERNAL_RETURN_STATUS(acpi_status > acpi_remove_table_handler(acpi_table_handler > handler)) > +ACPI_EXTERNAL_RETURN_STATUS(acpi_status > + acpi_remove_table(acpi_string signature, > + u32 instance)) > [Lv Zheng] It is better to move this declaration close to acpi_install_table(). Thanks and best regards -Lv > /* > * Namespace and name interfaces > -- > 2.6.2 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo at vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
