From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Nowicki Subject: Re: [Linaro-acpi] [RFC] ACPI: Add new function to get table entries Date: Thu, 20 Mar 2014 11:16:18 +0100 Message-ID: <532ABFF2.6080103@linaro.org> References: <1395270568-30021-1-git-send-email-ashwin.chaugule@linaro.org> <532ABD83.9020003@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-wg0-f45.google.com ([74.125.82.45]:62389 "EHLO mail-wg0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750863AbaCTKPh (ORCPT ); Thu, 20 Mar 2014 06:15:37 -0400 Received: by mail-wg0-f45.google.com with SMTP id l18so417275wgh.4 for ; Thu, 20 Mar 2014 03:15:36 -0700 (PDT) In-Reply-To: <532ABD83.9020003@linaro.org> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Ashwin Chaugule , linaro-acpi@lists.linaro.org Cc: linux-acpi@vger.kernel.org, rjw@rjwysocki.net, lenb@kernel.org On 20.03.2014 11:05, Tomasz Nowicki wrote: > > > On 20.03.2014 00:09, Ashwin Chaugule wrote: >> The acpi_table_parse() function has a callback that >> passes a pointer to a table_header. Add a new function >> which takes this pointer and parses its entries. This >> eliminates the need to re-traverse all the tables for >> each call. e.g. as in acpi_table_parse_madt() which is >> normally called after acpi_table_parse(). >> >> Signed-off-by: Ashwin Chaugule >> --- >> drivers/acpi/tables.c | 69 >> +++++++++++++++++++++++++++++++++++---------------- >> include/linux/acpi.h | 4 +++ >> 2 files changed, 51 insertions(+), 22 deletions(-) >> >> diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c >> index 5837f85..b7bd6a3 100644 >> --- a/drivers/acpi/tables.c >> +++ b/drivers/acpi/tables.c >> @@ -199,19 +199,15 @@ void acpi_table_print_madt_entry(struct >> acpi_subtable_header *header) >> } >> } >> >> - >> int __init >> -acpi_table_parse_entries(char *id, >> - unsigned long table_size, >> - int entry_id, >> - acpi_tbl_entry_handler handler, >> - unsigned int max_entries) >> +acpi_parse_entries(unsigned long table_size, >> + acpi_tbl_entry_handler handler, >> + struct acpi_table_header *table_header, >> + int entry_id, unsigned int max_entries) >> { >> - struct acpi_table_header *table_header = NULL; >> struct acpi_subtable_header *entry; >> unsigned int count = 0; >> unsigned long table_end; >> - acpi_size tbl_size; >> >> if (acpi_disabled) >> return -ENODEV; >> @@ -219,16 +215,14 @@ acpi_table_parse_entries(char *id, >> if (!handler) >> return -EINVAL; >> >> - if (strncmp(id, ACPI_SIG_MADT, 4) == 0) >> - acpi_get_table_with_size(id, acpi_apic_instance, >> &table_header, &tbl_size); >> - else >> - acpi_get_table_with_size(id, 0, &table_header, &tbl_size); >> - >> if (!table_header) { >> - printk(KERN_WARNING PREFIX "%4.4s not present\n", id); >> + pr_warn(PREFIX "Table header not present\n"); >> return -ENODEV; >> } >> >> + if (!table_size) >> + table_size = table_header->length; >> + > > If table_size == 0, that would causes 'entry' and 'table_end' are equal > and no entries at all. For that case I would suggest to print error and > return. > > Tomasz > >> table_end = (unsigned long)table_header + table_header->length; >> >> /* Parse all entries looking for a match. */ >> @@ -240,15 +234,18 @@ acpi_table_parse_entries(char *id, >> table_end) { >> if (entry->type == entry_id >> && (!max_entries || count++ < max_entries)) >> - if (handler(entry, table_end)) >> + if (handler(entry, table_end)) { >> + count = -EINVAL; >> goto err; >> + } >> >> /* >> * If entry->length is 0, break from this loop to avoid >> * infinite loop. >> */ >> if (entry->length == 0) { >> - pr_err(PREFIX "[%4.4s:0x%02x] Invalid zero length\n", id, >> entry_id); >> + pr_err(PREFIX "[0x%02x] Invalid zero length\n", entry_id); >> + count = -EINVAL; >> goto err; >> } >> >> @@ -256,15 +253,43 @@ acpi_table_parse_entries(char *id, >> ((unsigned long)entry + entry->length); >> } >> if (max_entries && count > max_entries) { >> - printk(KERN_WARNING PREFIX "[%4.4s:0x%02x] ignored %i entries >> of " >> - "%i found\n", id, entry_id, count - max_entries, count); >> + printk(KERN_WARNING PREFIX "[0x%02x] ignored %i entries of " >> + "%i found\n", entry_id, count - max_entries, count); >> } >> >> - early_acpi_os_unmap_memory((char *)table_header, tbl_size); >> - return count; >> err: >> - early_acpi_os_unmap_memory((char *)table_header, tbl_size); >> - return -EINVAL; >> + early_acpi_os_unmap_memory((char *)table_header, >> (acpi_size)table_size); >> + return count; > > Changelog is saying that acpi_parse_entries() takes already mapped table > and parses entries. IMO, caller should takes care about unmapping table. > It can be still parsed using different ID later on. > > Tomasz > >> +} >> + >> +int __init >> +acpi_table_parse_entries(char *id, >> + unsigned long table_size, >> + int entry_id, >> + acpi_tbl_entry_handler handler, >> + unsigned int max_entries) >> +{ >> + struct acpi_table_header *table_header = NULL; >> + acpi_size tbl_size; >> + >> + if (acpi_disabled) >> + return -ENODEV; >> + >> + if (!handler) >> + return -EINVAL; >> + >> + if (strncmp(id, ACPI_SIG_MADT, 4) == 0) >> + acpi_get_table_with_size(id, acpi_apic_instance, >> &table_header, &tbl_size); >> + else >> + acpi_get_table_with_size(id, 0, &table_header, &tbl_size); >> + >> + if (!table_header) { >> + pr_warn("%4.4s not present\n", id); >> + return -ENODEV; >> + } >> + >> + return acpi_parse_entries(table_header->length, handler, >> table_header, >> + entry_id, max_entries); Also, first argument of acpi_parse_entries() expect subtable start point offset, but now it points to the end of table. Tomasz >> } >> >> int __init >> diff --git a/include/linux/acpi.h b/include/linux/acpi.h >> index 1151a1d..da959fd 100644 >> --- a/include/linux/acpi.h >> +++ b/include/linux/acpi.h >> @@ -118,6 +118,10 @@ int acpi_numa_init (void); >> >> int acpi_table_init (void); >> int acpi_table_parse(char *id, acpi_tbl_table_handler handler); >> +int __init acpi_parse_entries(unsigned long table_size, >> + acpi_tbl_entry_handler handler, >> + struct acpi_table_header *table_header, >> + int entry_id, unsigned int max_entries); >> int __init acpi_table_parse_entries(char *id, unsigned long table_size, >> int entry_id, >> acpi_tbl_entry_handler handler, >>