On Fri, May 03, 2019 at 06:24:05PM -0500, Jeremy Linton wrote:
> The ACPI specification implies that the IDENTICAL flag should be
> set on all non leaf nodes where the children are identical.
> This means that we need to be searching for the last node with
> the identical flag set rather than the first one.
>
> Since this flag is also dependent on the table revision, we
> need to add a bit of extra code to verify the table revision,
> and the next node's state in the traversal. Since we want to
> avoid function pointers here, lets just special case
> the IDENTICAL flag.
>
> Signed-off-by: Jeremy Linton <jeremy.linton@xxxxxxx>
> ---
> drivers/acpi/pptt.c | 28 +++++++++++++++++++++++++---
> 1 file changed, 25 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c
> index 1865515297ca..456e1c0a35ae 100644
> --- a/drivers/acpi/pptt.c
> +++ b/drivers/acpi/pptt.c
> @@ -432,17 +432,39 @@ static void cache_setup_acpi_cpu(struct acpi_table_header *table,
> }
> }
>
> +static bool flag_identical(struct acpi_table_header *table_hdr,
> + struct acpi_pptt_processor *cpu)
Not sure if it's email client problem, but I see quite a few mis-alignment
with parenthesis like above one.
> +{
> + struct acpi_pptt_processor *next;
> +
> + /* heterogeneous machines must use PPTT revision > 1 */
> + if (table_hdr->revision < 2)
> + return false;
> +
> + /* Locate the last node in the tree with IDENTICAL set */
> + if (cpu->flags & ACPI_PPTT_ACPI_IDENTICAL) {
> + next = fetch_pptt_node(table_hdr, cpu->parent);
> + if (!(next && next->flags & ACPI_PPTT_ACPI_IDENTICAL))
> + return true;
> + }
> +
> + return false;
> +}
> +
> /* Passing level values greater than this will result in search termination */
> #define PPTT_ABORT_PACKAGE 0xFF
>
> -static struct acpi_pptt_processor *acpi_find_processor_package_id(struct acpi_table_header *table_hdr,
> +static struct acpi_pptt_processor *acpi_find_processor_tag_id(struct acpi_table_header *table_hdr,
> struct acpi_pptt_processor *cpu,
> int level, int flag)
> {
> struct acpi_pptt_processor *prev_node;
>
> while (cpu && level) {
> - if (cpu->flags & flag)
> + if (flag == ACPI_PPTT_ACPI_IDENTICAL) {
flag_identical anyways check the flag, so I assume you can drop the above
check.
> + if (flag_identical(table_hdr, cpu))
> + break;
> + } else if (cpu->flags & flag)
> break;
> pr_debug("level %d\n", level);
> prev_node = fetch_pptt_node(table_hdr, cpu->parent);
> @@ -480,7 +502,7 @@ static int topology_get_acpi_cpu_tag(struct acpi_table_header *table,
>
> cpu_node = acpi_find_processor_node(table, acpi_cpu_id);
> if (cpu_node) {
> - cpu_node = acpi_find_processor_package_id(table, cpu_node,
> + cpu_node = acpi_find_processor_tag_id(table, cpu_node,
> level, flag);
Again misaligned, may be that's because of renaming.
--
Regards,
Sudeep
