Re: [PATCH v4 02/18] ACPI / table: Add new function to get table entries

Grant Likely
2014-09-15T16:48:27Z

On Fri, 12 Sep 2014 22:00:00 +0800, Hanjun Guo <hanjun.guo@linaro.org> wrote:
> From: Ashwin Chaugule <ashwin.chaugule@linaro.org>
>
> 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 <ashwin.chaugule@linaro.org>
> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>

Makes sense.

Acked-by: Grant Likely <grant.likely@linaro.org>

g.

> ---
> drivers/acpi/tables.c | 67 ++++++++++++++++++++++++++++++++++---------------
> include/linux/acpi.h | 4 +++
> 2 files changed, 51 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
> index 6d5a6cd..21ae521 100644
> --- a/drivers/acpi/tables.c
> +++ b/drivers/acpi/tables.c
> @@ -192,17 +192,14 @@ 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;
> + int count = 0;
> unsigned long table_end;
> - acpi_size tbl_size;
>
> if (acpi_disabled)
> return -ENODEV;
> @@ -210,13 +207,11 @@ 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_size)
> + return -EINVAL;
>
> if (!table_header) {
> - pr_warn("%4.4s not present\n", id);
> + pr_warn("Table header not present\n");
> return -ENODEV;
> }
>
> @@ -232,30 +227,62 @@ acpi_table_parse_entries(char *id,
> if (entry->type == entry_id
> && (!max_entries || count++ < max_entries))
> if (handler(entry, table_end))
> - goto err;
> + return -EINVAL;
>
> /*
> * If entry->length is 0, break from this loop to avoid
> * infinite loop.
> */
> if (entry->length == 0) {
> - pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, entry_id);
> - goto err;
> + pr_err("[0x%02x] Invalid zero length\n", entry_id);
> + return -EINVAL;
> }
>
> entry = (struct acpi_subtable_header *)
> ((unsigned long)entry + entry->length);
> }
> +
> if (max_entries && count > max_entries) {
> pr_warn("[%4.4s:0x%02x] ignored %i entries of %i found\n",
> - id, entry_id, count - max_entries, count);
> + table_header->signature, entry_id, count - max_entries,
> + count);
> }
>
> - early_acpi_os_unmap_memory((char *)table_header, tbl_size);
> return count;
> -err:
> +}
> +
> +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;
> + int count;
> +
> + 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;
> + }
> +
> + count = acpi_parse_entries(table_size, handler, table_header,
> + entry_id, max_entries);
> +
> early_acpi_os_unmap_memory((char *)table_header, tbl_size);
> - return -EINVAL;
> + return count;
> }
>
> int __init
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index 807cbc4..36d5012 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -123,6 +123,10 @@ 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,
> --
> 1.7.9.5
>