Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752074AbaBRSah (ORCPT ); Tue, 18 Feb 2014 13:30:37 -0500 Received: from terminus.zytor.com ([198.137.202.10]:44745 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750951AbaBRSag (ORCPT ); Tue, 18 Feb 2014 13:30:36 -0500 User-Agent: K-9 Mail for Android In-Reply-To: <1392747763-3384-2-git-send-email-trenn@suse.de> References: <530265A3.3020302@zytor.com> <1392747763-3384-1-git-send-email-trenn@suse.de> <1392747763-3384-2-git-send-email-trenn@suse.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Subject: Re: [PATCH 1/4] ACPI: Provide support for ACPI table adding via OS From: "H. Peter Anvin" Date: Tue, 18 Feb 2014 10:27:23 -0800 To: Thomas Renninger CC: linux-kernel@vger.kernel.org, x86@kernel.org, devel@acpica.org, mingo@redhat.com, ck@conrad-kostecki.de, tglx@linutronix.de, rjw@rjwysocki.net Message-ID: <7af8855f-8055-467c-89c0-bcab453f3969@email.android.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Why can't you add SSDTs? It would be particularly useful. On February 18, 2014 10:22:40 AM PST, Thomas Renninger wrote: >This is done the same way as the previous ACPI physical table override >mechanism. >How to override or add tables via initrd, please look up: >Documentation/acpi/initrd_table_override.txt > >SSDTs can only be overridden, not added. > >Overriding only happens if the OEM id of the table header matches the >one >with the BIOS provided one. >All table types (SSDTs are an exception), must only show up once. >So either you: >- Add a fresh new table for adding of which type (signature) none >exists > in the BIOS -> OS ACPI table adding happens. >or >- Add a table which already exists in BIOS, but the OEM id must match >the >one of the table of the same type (signature) that exists in BIOS >already > -> OS ACPI table overriding happens > Typically one copies away the original ACPI table, disassembles, > modifies (for example adding debug strings), compiles it and provides > the table via initrd for overriding (will have the same OEM id). > But this is not necessary, one could also come up with a selfmade > table for overriding, by taking care that the signature and OEM id is > the same as the one provided by BIOS > >In ACPI table overriding case you see in dmesg: > ACPI: Override [DSDT- BXDSDT], this is unsafe: tainting kernel > Disabling lock debugging due to kernel taint > >In ACPI table adding case you see in dmesg (BGRT table got added): > ACPI: Add [BGRT-SLIC-WKS], this is unsafe: tainting kernel > ACPI: BGRT 000000007fffd1ba 000038 (v00 HPQOEM SLIC-WKS 01072009 > INTL 20130823) > >Signed-off-by: Thomas Renninger >CC: hpa@zytor.com >CC: tglx@linutronix.de >CC: ck@conrad-kostecki.de >CC: linux-kernel@vger.kernel.org >CC: x86@kernel.org >CC: mingo@redhat.com >CC: rjw@rjwysocki.net >CC: devel@acpica.org >--- >drivers/acpi/osl.c | 89 >+++++++++++++++++++++++++++++++++++++++++++++++++++- > 1 files changed, 88 insertions(+), 1 deletions(-) > >diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c >index fc1aa79..07439b4 100644 >--- a/drivers/acpi/osl.c >+++ b/drivers/acpi/osl.c >@@ -566,6 +566,8 @@ static const char * const table_sigs[] = { > > #define ACPI_OVERRIDE_TABLES 64 >static struct cpio_data __initdata >acpi_initrd_files[ACPI_OVERRIDE_TABLES]; >+/* Remember physical address of overriden or added tables */ >+static acpi_physical_address >acpi_table_overridden[ACPI_OVERRIDE_TABLES]; > > #define MAP_CHUNK_SIZE (NR_FIX_BTMAPS << PAGE_SHIFT) > >@@ -715,7 +717,7 @@ acpi_os_physical_table_override(struct >acpi_table_header *existing_table, > *address = 0; > return AE_OK; > #else >- int table_offset = 0; >+ int no, table_offset = 0; > struct acpi_table_header *table; > > *table_length = 0; >@@ -759,6 +761,12 @@ acpi_os_physical_table_override(struct >acpi_table_header *existing_table, > *table_length = table->length; > acpi_os_unmap_memory(table, ACPI_HEADER_SIZE); > *address = acpi_tables_addr + table_offset; >+ for (no = 0; no < ACPI_OVERRIDE_TABLES; no++) { >+ if (acpi_table_overridden[no] == 0) { >+ acpi_table_overridden[no] = *address; >+ break; >+ } >+ } > break; > } while (table_offset + ACPI_HEADER_SIZE < all_tables_size); > >@@ -768,6 +776,85 @@ acpi_os_physical_table_override(struct >acpi_table_header *existing_table, > #endif > } > >+acpi_status >+acpi_os_physical_table_add(acpi_physical_address *address, >+ u32 *table_length) >+{ >+#ifndef CONFIG_ACPI_INITRD_TABLE_OVERRIDE >+ *table_length = 0; >+ *address = 0; >+ return AE_OK; >+#else >+ int no, table_offset = 0; >+ struct acpi_table_header *table; >+ >+ *table_length = 0; >+ *address = 0; >+ >+ if (!acpi_tables_addr) >+ return AE_OK; >+ >+ do { >+ if (table_offset + ACPI_HEADER_SIZE > all_tables_size) { >+ WARN_ON(1); >+ return AE_OK; >+ } >+ >+ table = acpi_os_map_memory(acpi_tables_addr + table_offset, >+ ACPI_HEADER_SIZE); >+ >+ if (table_offset + table->length > all_tables_size) { >+ acpi_os_unmap_memory(table, ACPI_HEADER_SIZE); >+ WARN_ON(1); >+ return AE_OK; >+ } >+ >+ table_offset += table->length; >+ >+ /* Do not add SSDTs for now, they might be intended to get >+ overridden when an SSDT gets loaded dynamically in ACPI >+ context at any time later */ >+ if (!memcmp("SSDT", table->signature, 4)) { >+ acpi_os_unmap_memory(table, >+ ACPI_HEADER_SIZE); >+ continue; >+ } >+ >+ /* Only add tables that have not been overridden already */ >+ for (no = 0; no < ACPI_OVERRIDE_TABLES; no++) { >+ if (acpi_table_overridden[no] == 0) >+ break; >+ if (acpi_table_overridden[no] == >+ acpi_tables_addr + table_offset - table->length) >+ break; >+ } >+ /* All tables have been added or overridden */ >+ if (acpi_table_overridden[no] != 0) { >+ acpi_os_unmap_memory(table, ACPI_HEADER_SIZE); >+ continue; >+ } >+ /* Max table override/add limit reached */ >+ if (no == ACPI_OVERRIDE_TABLES) { >+ acpi_os_unmap_memory(table, ACPI_HEADER_SIZE); >+ return AE_ERROR; >+ } >+ >+ table_offset -= table->length; >+ *table_length = table->length; >+ *address = acpi_tables_addr + table_offset; >+ /* do not add this table again */ >+ acpi_table_overridden[no] = *address; >+ pr_warn(PREFIX >+ "Add [%4.4s-%8.8s], this is unsafe: tainting kernel\n", >+ table->signature, table->oem_table_id); >+ add_taint(TAINT_OVERRIDDEN_ACPI_TABLE, LOCKDEP_NOW_UNRELIABLE); >+ acpi_os_unmap_memory(table, ACPI_HEADER_SIZE); >+ return AE_OK; >+ } while (table_offset + ACPI_HEADER_SIZE < all_tables_size); >+ return AE_OK; >+#endif >+} >+ > static irqreturn_t acpi_irq(int irq, void *dev_id) > { > u32 handled; -- Sent from my mobile phone. 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