Re: [PATCH v3 1/7] ACPI/PPTT: Add Processor Properties Topology Table parsing

[Jeremy Linton]

Hi,

On 10/13/2017 09:23 AM, tn wrote:
> Hi Jeremy,
>
> On 12.10.2017 21:48, Jeremy Linton wrote:
> > ACPI 6.2 adds a new table, which describes how processing units
> > are related to each other in tree like fashion. Caches are
> > also sprinkled throughout the tree and describe the properties
> > of the caches in relation to other caches and processing units.
> >
> > Add the code to parse the cache hierarchy and report the total
> > number of levels of cache for a given core using
> > acpi_find_last_cache_level() as well as fill out the individual
> > cores cache information with cache_setup_acpi() once the
> > cpu_cacheinfo structure has been populated by the arch specific
> > code.
> >
> > Further, report peers in the topology using setup_acpi_cpu_topology()
> > to report a unique ID for each processing unit at a given level
> > in the tree. These unique id's can then be used to match related
> > processing units which exist as threads, COD (clusters
> > on die), within a given package, etc.
> >
> > Signed-off-by: Jeremy Linton <jeremy.linton@xxxxxxx>
> > ---
> > Â drivers/acpi/pptt.c | 485 
> > ++++++++++++++++++++++++++++++++++++++++++++++++++++
> > Â 1 file changed, 485 insertions(+)
> > Â create mode 100644 drivers/acpi/pptt.c
> >
> > diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c
> > new file mode 100644
> > index 000000000000..c86715fed4a7
> > --- /dev/null
> > +++ b/drivers/acpi/pptt.c
> > @@ -0,1 +1,485 @@
> > +/*
> > + * Copyright (C) 2017, ARM
> > + *
> > + * This program is free software; you can redistribute it and/or 
> > modify it
> > + * under the terms and conditions of the GNU General Public License,
> > + * version 2, as published by the Free Software Foundation.
> > + *
> > + * This program is distributed in the hope it will be useful, but 
> > WITHOUT
> > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public 
> > License for
> > + * more details.
> > + *
> > + * This file implements parsing of Processor Properties Topology 
> > Table (PPTT)
> > + * which is optionally used to describe the processor and cache 
> > topology.
> > + * Due to the relative pointers used throughout the table, this doesn't
> > + * leverage the existing subtable parsing in the kernel.
> > + */
> > +#define pr_fmt(fmt) "ACPI PPTT: " fmt
> > +
> > +#include <linux/acpi.h>
> > +#include <linux/cacheinfo.h>
> > +#include <acpi/processor.h>
> > +
> > +/*
> > + * Given the PPTT table, find and verify that the subtable entry
> > + * is located within the table
> > + */
> > +static struct acpi_subtable_header *fetch_pptt_subtable(
> > +ÂÂÂ struct acpi_table_header *table_hdr, u32 pptt_ref)
> > +{
> > +ÂÂÂ struct acpi_subtable_header *entry;
> > +
> > +ÂÂÂ /* there isn't a subtable at reference 0 */
> > +ÂÂÂ if (!pptt_ref)
> > +ÂÂÂÂÂÂÂ return NULL;
> > +
> > +ÂÂÂ if (pptt_ref + sizeof(struct acpi_subtable_header) > 
> > table_hdr->length)
> > +ÂÂÂÂÂÂÂ return NULL;
> > +
> > +ÂÂÂ entry = (struct acpi_subtable_header *)((u8 *)table_hdr + pptt_ref);
>
> You can use ACPI_ADD_PTR() here.

Hmmm, that is a useful macro.


> > +
> > +ÂÂÂ if (pptt_ref + entry->length > table_hdr->length)
> > +ÂÂÂÂÂÂÂ return NULL;
> > +
> > +ÂÂÂ return entry;
> > +}
> > +
> > +static struct acpi_pptt_processor *fetch_pptt_node(
> > +ÂÂÂ struct acpi_table_header *table_hdr, u32 pptt_ref)
> > +{
> > +ÂÂÂ return (struct acpi_pptt_processor 
> > *)fetch_pptt_subtable(table_hdr, pptt_ref);
> > +}
> > +
> > +static struct acpi_pptt_cache *fetch_pptt_cache(
> > +ÂÂÂ struct acpi_table_header *table_hdr, u32 pptt_ref)
> > +{
> > +ÂÂÂ return (struct acpi_pptt_cache *)fetch_pptt_subtable(table_hdr, 
> > pptt_ref);
> > +}
> > +
> > +static struct acpi_subtable_header *acpi_get_pptt_resource(
> > +ÂÂÂ struct acpi_table_header *table_hdr,
> > +ÂÂÂ struct acpi_pptt_processor *node, int resource)
> > +{
> > +ÂÂÂ u32 ref;
> > +
> > +ÂÂÂ if (resource >= node->number_of_priv_resources)
> > +ÂÂÂÂÂÂÂ return NULL;
> > +
> > +ÂÂÂ ref = *(u32 *)((u8 *)node + sizeof(struct acpi_pptt_processor) +
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂ sizeof(u32) * resource);
>
> ACPI_ADD_PTR()
>
> > +
> > +ÂÂÂ return fetch_pptt_subtable(table_hdr, ref);
> > +}
> > +
> > +/*
> > + * given a pptt resource, verify that it is a cache node, then walk
> > + * down each level of caches, counting how many levels are found
> > + * as well as checking the cache type (icache, dcache, unified). If a
> > + * level & type match, then we set found, and continue the search.
> > + * Once the entire cache branch has been walked return its max
> > + * depth.
> > + */
> > +static int acpi_pptt_walk_cache(struct acpi_table_header *table_hdr,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ int local_level,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ struct acpi_subtable_header *res,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ struct acpi_pptt_cache **found,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ int level, int type)
> > +{
> > +ÂÂÂ struct acpi_pptt_cache *cache;
> > +
> > +ÂÂÂ if (res->type != ACPI_PPTT_TYPE_CACHE)
> > +ÂÂÂÂÂÂÂ return 0;
> > +
> > +ÂÂÂ cache = (struct acpi_pptt_cache *) res;
> > +ÂÂÂ while (cache) {
> > +ÂÂÂÂÂÂÂ local_level++;
> > +
> > +ÂÂÂÂÂÂÂ if ((local_level == level) &&
> > +ÂÂÂÂÂÂÂÂÂÂÂ (cache->flags & ACPI_PPTT_CACHE_TYPE_VALID) &&
> > +ÂÂÂÂÂÂÂÂÂÂÂ ((cache->attributes & ACPI_PPTT_MASK_CACHE_TYPE) == type)) {
> > +ÂÂÂÂÂÂÂÂÂÂÂ if (*found != NULL)
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ pr_err("Found duplicate cache level/type unable to 
> > determine uniqueness\n");
> > +
> > +ÂÂÂÂÂÂÂÂÂÂÂ pr_debug("Found cache @ level %d\n", level);
> > +ÂÂÂÂÂÂÂÂÂÂÂ *found = cache;
> > +ÂÂÂÂÂÂÂÂÂÂÂ /*
> > +ÂÂÂÂÂÂÂÂÂÂÂÂ * continue looking at this node's resource list
> > +ÂÂÂÂÂÂÂÂÂÂÂÂ * to verify that we don't find a duplicate
> > +ÂÂÂÂÂÂÂÂÂÂÂÂ * cache node.
> > +ÂÂÂÂÂÂÂÂÂÂÂÂ */
> > +ÂÂÂÂÂÂÂ }
> > +ÂÂÂÂÂÂÂ cache = fetch_pptt_cache(table_hdr, cache->next_level_of_cache);
> > +ÂÂÂ }
> > +ÂÂÂ return local_level;
> > +}
> > +
> > +/*
> > + * Given a CPU node look for cache levels that exist at this level, 
> > and then
> > + * for each cache node, count how many levels exist below (logically 
> > above) it.
> > + * If a level and type are specified, and we find that level/type, abort
> > + * processing and return the acpi_pptt_cache structure.
> > + */
> > +static struct acpi_pptt_cache *acpi_find_cache_level(
> > +ÂÂÂ struct acpi_table_header *table_hdr,
> > +ÂÂÂ struct acpi_pptt_processor *cpu_node,
> > +ÂÂÂ int *starting_level, int level, int type)
> > +{
> > +ÂÂÂ struct acpi_subtable_header *res;
> > +ÂÂÂ int number_of_levels = *starting_level;
> > +ÂÂÂ int resource = 0;
> > +ÂÂÂ struct acpi_pptt_cache *ret = NULL;
> > +ÂÂÂ int local_level;
> > +
> > +ÂÂÂ /* walk down from the processor node */
> > +ÂÂÂ while ((res = acpi_get_pptt_resource(table_hdr, cpu_node, 
> > resource))) {
> > +ÂÂÂÂÂÂÂ resource++;
> > +
> > +ÂÂÂÂÂÂÂ local_level = acpi_pptt_walk_cache(table_hdr, *starting_level,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ res, &ret, level, type);
> > +ÂÂÂÂÂÂÂ /*
> > +ÂÂÂÂÂÂÂÂ * we are looking for the max depth. Since its potentially
> > +ÂÂÂÂÂÂÂÂ * possible for a given node to have resources with differing
> > +ÂÂÂÂÂÂÂÂ * depths verify that the depth we have found is the largest.
> > +ÂÂÂÂÂÂÂÂ */
> > +ÂÂÂÂÂÂÂ if (number_of_levels < local_level)
> > +ÂÂÂÂÂÂÂÂÂÂÂ number_of_levels = local_level;
> > +ÂÂÂ }
> > +ÂÂÂ if (number_of_levels > *starting_level)
> > +ÂÂÂÂÂÂÂ *starting_level = number_of_levels;
> > +
> > +ÂÂÂ return ret;
> > +}
> > +
> > +/*
> > + * given a processor node containing a processing unit, walk into it 
> > and count
> > + * how many levels exist solely for it, and then walk up each level 
> > until we hit
> > + * the root node (ignore the package level because it may be possible 
> > to have
> > + * caches that exist across packages). Count the number of cache 
> > levels that
> > + * exist at each level on the way up.
> > + */
> > +static int acpi_process_node(struct acpi_table_header *table_hdr,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ struct acpi_pptt_processor *cpu_node)
> > +{
> > +ÂÂÂ int total_levels = 0;
> > +
> > +ÂÂÂ do {
> > +ÂÂÂÂÂÂÂ acpi_find_cache_level(table_hdr, cpu_node, &total_levels, 0, 0);
> > +ÂÂÂÂÂÂÂ cpu_node = fetch_pptt_node(table_hdr, cpu_node->parent);
> > +ÂÂÂ } while (cpu_node);
> > +
> > +ÂÂÂ return total_levels;
> > +}
> > +
> > +/* determine if the given node is a leaf node */
> > +static int acpi_pptt_leaf_node(struct acpi_table_header *table_hdr,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ struct acpi_pptt_processor *node)
> > +{
> > +ÂÂÂ struct acpi_subtable_header *entry;
> > +ÂÂÂ unsigned long table_end;
> > +ÂÂÂ u32 node_entry;
> > +ÂÂÂ struct acpi_pptt_processor *cpu_node;
> > +
> > +ÂÂÂ table_end = (unsigned long)table_hdr + table_hdr->length;
> > +ÂÂÂ node_entry = (u32)((u8 *)node - (u8 *)table_hdr);
> > +ÂÂÂ entry = (struct acpi_subtable_header *)((u8 *)table_hdr +
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ sizeof(struct acpi_table_pptt));
>
> ACPI_ADD_PTR()
>
> > +
> > +ÂÂÂ while (((unsigned long)entry) + sizeof(struct 
> > acpi_subtable_header) < table_end) {
> > +ÂÂÂÂÂÂÂ cpu_node = (struct acpi_pptt_processor *)entry;
> > +ÂÂÂÂÂÂÂ if ((entry->type == ACPI_PPTT_TYPE_PROCESSOR) &&
> > +ÂÂÂÂÂÂÂÂÂÂÂ (cpu_node->parent == node_entry))
> > +ÂÂÂÂÂÂÂÂÂÂÂ return 0;
> > +ÂÂÂÂÂÂÂ entry = (struct acpi_subtable_header *)((u8 *)entry + 
> > entry->length);
> > +ÂÂÂ }
> > +ÂÂÂ return 1;
> > +}
> > +
> > +/*
> > + * Find the subtable entry describing the provided processor
> > + */
> > +static struct acpi_pptt_processor *acpi_find_processor_node(
> > +ÂÂÂ struct acpi_table_header *table_hdr,
> > +ÂÂÂ u32 acpi_cpu_id)
> > +{
> > +ÂÂÂ struct acpi_subtable_header *entry;
> > +ÂÂÂ unsigned long table_end;
> > +ÂÂÂ struct acpi_pptt_processor *cpu_node;
> > +
> > +ÂÂÂ table_end = (unsigned long)table_hdr + table_hdr->length;
> > +ÂÂÂ entry = (struct acpi_subtable_header *)((u8 *)table_hdr +
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ sizeof(struct acpi_table_pptt));
>
> ACPI_ADD_PTR()
>
> > +
> > +ÂÂÂ /* find the processor structure associated with this cpuid */
> > +ÂÂÂ while (((unsigned long)entry) + sizeof(struct 
> > acpi_subtable_header) < table_end) {
> > +ÂÂÂÂÂÂÂ cpu_node = (struct acpi_pptt_processor *)entry;
> > +
> > +ÂÂÂÂÂÂÂ if ((entry->type == ACPI_PPTT_TYPE_PROCESSOR) &&
> > +ÂÂÂÂÂÂÂÂÂÂÂ acpi_pptt_leaf_node(table_hdr, cpu_node)) {
> > +ÂÂÂÂÂÂÂÂÂÂÂ pr_debug("checking phy_cpu_id %d against acpi id %d\n",
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ acpi_cpu_id, cpu_node->acpi_processor_id);
> > +ÂÂÂÂÂÂÂÂÂÂÂ if (acpi_cpu_id == cpu_node->acpi_processor_id) {
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ /* found the correct entry */
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ pr_debug("match found!\n");
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ return (struct acpi_pptt_processor *)entry;
> > +ÂÂÂÂÂÂÂÂÂÂÂ }
> > +ÂÂÂÂÂÂÂ }
> > +
> > +ÂÂÂÂÂÂÂ if (entry->length == 0) {
> > +ÂÂÂÂÂÂÂÂÂÂÂ pr_err("Invalid zero length subtable\n");
> > +ÂÂÂÂÂÂÂÂÂÂÂ break;
> > +ÂÂÂÂÂÂÂ }
>
> For a better table content validation, this could be done at the 
> beginning of the loop, like that:
>
> if (WARN_TAINT(entry->length == 0, TAINT_FIRMWARE_WORKAROUND,
>  ÂÂÂÂÂÂ "Invalid zero length subtable, bad PPTT table!\n"))
>  ÂÂÂÂÂÂÂÂÂÂÂ break;
>
>
> > +ÂÂÂÂÂÂÂ entry = (struct acpi_subtable_header *)
> > +ÂÂÂÂÂÂÂÂÂÂÂ ((u8 *)entry + entry->length);
>
> ACPI_ADD_PTR()
>
> > +ÂÂÂ }
> > +
> > +ÂÂÂ return NULL;
> > +}
> > +
> > +/*
> > + * Given a acpi_pptt_processor node, walk up until we identify the
> > + * package that the node is associated with or we run out of levels
> > + * to request.
> > + */
> > +static struct acpi_pptt_processor *acpi_find_processor_package_id(
> > +ÂÂÂ struct acpi_table_header *table_hdr,
> > +ÂÂÂ struct acpi_pptt_processor *cpu,
> > +ÂÂÂ int level)
> > +{
> > +ÂÂÂ struct acpi_pptt_processor *prev_node;
> > +
> > +ÂÂÂ while (cpu && level && !(cpu->flags & ACPI_PPTT_PHYSICAL_PACKAGE)) {
> > +ÂÂÂÂÂÂÂ pr_debug("level %d\n", level);
> > +ÂÂÂÂÂÂÂ prev_node = fetch_pptt_node(table_hdr, cpu->parent);
> > +ÂÂÂÂÂÂÂ if (prev_node == NULL)
> > +ÂÂÂÂÂÂÂÂÂÂÂ break;
> > +ÂÂÂÂÂÂÂ cpu = prev_node;
> > +ÂÂÂÂÂÂÂ level--;
> > +ÂÂÂ }
> > +ÂÂÂ return cpu;
> > +}
> > +
> > +static int acpi_parse_pptt(struct acpi_table_header *table_hdr, u32 
> > acpi_cpu_id)
> > +{
> > +ÂÂÂ int number_of_levels = 0;
> > +ÂÂÂ struct acpi_pptt_processor *cpu;
> > +
> > +ÂÂÂ cpu = acpi_find_processor_node(table_hdr, acpi_cpu_id);
> > +ÂÂÂ if (cpu)
> > +ÂÂÂÂÂÂÂ number_of_levels = acpi_process_node(table_hdr, cpu);
> > +
> > +ÂÂÂ return number_of_levels;
> > +}
> > +
>
> Based on ACPI spec 6.2:
>
> > +#define ACPI_6_2_CACHE_TYPE_DATAÂÂÂÂÂÂÂÂÂÂÂÂÂ (0x0)
> > +#define ACPI_6_2_CACHE_TYPE_INSTRÂÂÂÂÂÂÂÂÂÂÂÂÂ (1<<2)
> > +#define ACPI_6_2_CACHE_TYPE_UNIFIEDÂÂÂÂÂÂÂÂÂÂÂÂÂ (1<<3)
>
> Bits:3:2: Cache type:
> 0x0 Data
> 0x1 Instruction
> 0x2 or 0x3 Indicate a unified cache

Originally I was trying to do something more clever than the switch 
(given the less than optimal bit definitions), but the result wasn't as 
clear as the switch, so I just plugged that in but forgot about the 3rd 
case.

> > +#define ACPI_6_2_CACHE_POLICY_WBÂÂÂÂÂÂÂÂÂÂÂÂÂ (0x0)
> > +#define ACPI_6_2_CACHE_POLICY_WTÂÂÂÂÂÂÂÂÂÂÂÂÂ (1<<4)
> > +#define ACPI_6_2_CACHE_READ_ALLOCATEÂÂÂÂÂÂÂÂÂÂÂÂÂ (0x0)
> > +#define ACPI_6_2_CACHE_WRITE_ALLOCATEÂÂÂÂÂÂÂÂÂÂÂÂÂ (0x01)
> > +#define ACPI_6_2_CACHE_RW_ALLOCATEÂÂÂÂÂÂÂÂÂÂÂÂÂ (0x02)
>
> Bits 1:0: Allocation type
> 0x0 - Read allocate
> 0x1 - Write allocate
> 0x2 or 0x03 indicate Read and Write allocate
>
> BTW, why these are not part of ACPICA code (actbl1.h header) and have 
> ACPI_PPTT prefixes?

Well I guess they probably should be the only question is how one goes 
about defining the duplicates..

AKA:

#define ACPI_PPTT_CACHE_RW_ALLOCATE              (0x02)
#define ACPI_PPTT_CACHE_RW_ALLOCATE_ALT          (0x03)

> > +
> > +static u8 acpi_cache_type(enum cache_type type)
> > +{
> > +ÂÂÂ switch (type) {
> > +ÂÂÂ case CACHE_TYPE_DATA:
> > +ÂÂÂÂÂÂÂ pr_debug("Looking for data cache\n");
> > +ÂÂÂÂÂÂÂ return ACPI_6_2_CACHE_TYPE_DATA;
> > +ÂÂÂ case CACHE_TYPE_INST:
> > +ÂÂÂÂÂÂÂ pr_debug("Looking for instruction cache\n");
> > +ÂÂÂÂÂÂÂ return ACPI_6_2_CACHE_TYPE_INSTR;
> > +ÂÂÂ default:
> > +ÂÂÂÂÂÂÂ pr_debug("Unknown cache type, assume unified\n");
> > +ÂÂÂ case CACHE_TYPE_UNIFIED:
> > +ÂÂÂÂÂÂÂ pr_debug("Looking for unified cache\n");
> > +ÂÂÂÂÂÂÂ return ACPI_6_2_CACHE_TYPE_UNIFIED;
> > +ÂÂÂ }
> > +}
> > +
> > +/* find the ACPI node describing the cache type/level for the given 
> > CPU */
> > +static struct acpi_pptt_cache *acpi_find_cache_node(
> > +ÂÂÂ struct acpi_table_header *table_hdr, u32 acpi_cpu_id,
> > +ÂÂÂ enum cache_type type, unsigned int level,
> > +ÂÂÂ struct acpi_pptt_processor **node)
> > +{
> > +ÂÂÂ int total_levels = 0;
> > +ÂÂÂ struct acpi_pptt_cache *found = NULL;
> > +ÂÂÂ struct acpi_pptt_processor *cpu_node;
> > +ÂÂÂ u8 acpi_type = acpi_cache_type(type);
> > +
> > +ÂÂÂ pr_debug("Looking for CPU %d's level %d cache type %d\n",
> > +ÂÂÂÂÂÂÂÂ acpi_cpu_id, level, acpi_type);
> > +
> > +ÂÂÂ cpu_node = acpi_find_processor_node(table_hdr, acpi_cpu_id);
> > +ÂÂÂ if (!cpu_node)
> > +ÂÂÂÂÂÂÂ return NULL;
> > +
> > +ÂÂÂ do {
> > +ÂÂÂÂÂÂÂ found = acpi_find_cache_level(table_hdr, cpu_node, 
> > &total_levels, level, acpi_type);
>
> Please align line to 80 characters at maximum.

ok,

> > +ÂÂÂÂÂÂÂ *node = cpu_node;
> > +ÂÂÂÂÂÂÂ cpu_node = fetch_pptt_node(table_hdr, cpu_node->parent);
> > +ÂÂÂ } while ((cpu_node) && (!found));
> > +
> > +ÂÂÂ return found;
> > +}
> > +
> > +int acpi_find_last_cache_level(unsigned int cpu)
> > +{
> > +ÂÂÂ u32 acpi_cpu_id;
> > +ÂÂÂ struct acpi_table_header *table;
> > +ÂÂÂ int number_of_levels = 0;
> > +ÂÂÂ acpi_status status;
> > +
> > +ÂÂÂ pr_debug("Cache Setup find last level cpu=%d\n", cpu);
> > +
> > +ÂÂÂ acpi_cpu_id = acpi_cpu_get_madt_gicc(cpu)->uid;
> > +ÂÂÂ status = acpi_get_table(ACPI_SIG_PPTT, 0, &table);
> > +ÂÂÂ if (ACPI_FAILURE(status)) {
> > +ÂÂÂÂÂÂÂ pr_err_once("No PPTT table found, cache topology may be 
> > inaccurate\n");
> > +ÂÂÂ } else {
> > +ÂÂÂÂÂÂÂ number_of_levels = acpi_parse_pptt(table, acpi_cpu_id);
> > +ÂÂÂÂÂÂÂ acpi_put_table(table);
> > +ÂÂÂ }
> > +ÂÂÂ pr_debug("Cache Setup find last level level=%d\n", 
> > number_of_levels);
> > +
> > +ÂÂÂ return number_of_levels;
> > +}
> > +
> > +/*
> > + * The ACPI spec implies that the fields in the cache structures are 
> > used to
> > + * extend and correct the information probed from the hardware. In 
> > the case
> > + * of arm64 the CCSIDR probing has been removed because it might be 
> > incorrect.
> > + */
> > +static void update_cache_properties(struct cacheinfo *this_leaf,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ struct acpi_pptt_cache *found_cache,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ struct acpi_pptt_processor *cpu_node)
> > +{
> > +ÂÂÂ if (found_cache->flags & ACPI_PPTT_SIZE_PROPERTY_VALID)
> > +ÂÂÂÂÂÂÂ this_leaf->size = found_cache->size;
> > +ÂÂÂ if (found_cache->flags & ACPI_PPTT_LINE_SIZE_VALID)
> > +ÂÂÂÂÂÂÂ this_leaf->coherency_line_size = found_cache->line_size;
> > +ÂÂÂ if (found_cache->flags & ACPI_PPTT_NUMBER_OF_SETS_VALID)
> > +ÂÂÂÂÂÂÂ this_leaf->number_of_sets = found_cache->number_of_sets;
> > +ÂÂÂ if (found_cache->flags & ACPI_PPTT_ASSOCIATIVITY_VALID)
> > +ÂÂÂÂÂÂÂ this_leaf->ways_of_associativity = found_cache->associativity;
> > +ÂÂÂ if (found_cache->flags & ACPI_PPTT_WRITE_POLICY_VALID)
> > +ÂÂÂÂÂÂÂ switch (found_cache->attributes & ACPI_PPTT_MASK_WRITE_POLICY) {
> > +ÂÂÂÂÂÂÂ case ACPI_6_2_CACHE_POLICY_WT:
> > +ÂÂÂÂÂÂÂÂÂÂÂ this_leaf->attributes = CACHE_WRITE_THROUGH;
> > +ÂÂÂÂÂÂÂÂÂÂÂ break;
> > +ÂÂÂÂÂÂÂ case ACPI_6_2_CACHE_POLICY_WB:
> > +ÂÂÂÂÂÂÂÂÂÂÂ this_leaf->attributes = CACHE_WRITE_BACK;
> > +ÂÂÂÂÂÂÂÂÂÂÂ break;
> > +ÂÂÂÂÂÂÂ default:
> > +ÂÂÂÂÂÂÂÂÂÂÂ pr_err("Unknown ACPI cache policy %d\n",
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ found_cache->attributes & 
> > ACPI_PPTT_MASK_WRITE_POLICY);
> > +ÂÂÂÂÂÂÂ }
>
> The 'default' case can never happen, please remove dead code.

Ok,

> > +ÂÂÂ if (found_cache->flags & ACPI_PPTT_ALLOCATION_TYPE_VALID)
> > +ÂÂÂÂÂÂÂ switch (found_cache->attributes & 
> > ACPI_PPTT_MASK_ALLOCATION_TYPE) {
> > +ÂÂÂÂÂÂÂ case ACPI_6_2_CACHE_READ_ALLOCATE:
> > +ÂÂÂÂÂÂÂÂÂÂÂ this_leaf->attributes |= CACHE_READ_ALLOCATE;
> > +ÂÂÂÂÂÂÂÂÂÂÂ break;
> > +ÂÂÂÂÂÂÂ case ACPI_6_2_CACHE_WRITE_ALLOCATE:
> > +ÂÂÂÂÂÂÂÂÂÂÂ this_leaf->attributes |= CACHE_WRITE_ALLOCATE;
> > +ÂÂÂÂÂÂÂÂÂÂÂ break;
> > +ÂÂÂÂÂÂÂ case ACPI_6_2_CACHE_RW_ALLOCATE:
> > +ÂÂÂÂÂÂÂÂÂÂÂ this_leaf->attributes |=
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ CACHE_READ_ALLOCATE|CACHE_WRITE_ALLOCATE;
> > +ÂÂÂÂÂÂÂÂÂÂÂ break;
> > +ÂÂÂÂÂÂÂ default:
> > +ÂÂÂÂÂÂÂÂÂÂÂ pr_err("Unknown ACPI cache allocation policy %d\n",
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂ found_cache->attributes & 
> > ACPI_PPTT_MASK_ALLOCATION_TYPE);
> > +ÂÂÂÂÂÂÂ }
>
> Same here if you fix bits definitions.

Sure,

> > +}
> > +
> > +static void cache_setup_acpi_cpu(struct acpi_table_header *table,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ unsigned int cpu)
> > +{
> > +ÂÂÂ struct acpi_pptt_cache *found_cache;
> > +ÂÂÂ struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
> > +ÂÂÂ u32 acpi_cpu_id = acpi_cpu_get_madt_gicc(cpu)->uid;
> > +ÂÂÂ struct cacheinfo *this_leaf;
> > +ÂÂÂ unsigned int index = 0;
> > +ÂÂÂ struct acpi_pptt_processor *cpu_node = NULL;
> > +
> > +ÂÂÂ while (index < get_cpu_cacheinfo(cpu)->num_leaves) {
> > +ÂÂÂÂÂÂÂ this_leaf = this_cpu_ci->info_list + index;
> > +ÂÂÂÂÂÂÂ found_cache = acpi_find_cache_node(table, acpi_cpu_id,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ this_leaf->type,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ this_leaf->level,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ &cpu_node);
> > +ÂÂÂÂÂÂÂ pr_debug("found = %p %p\n", found_cache, cpu_node);
> > +ÂÂÂÂÂÂÂ if (found_cache)
> > +ÂÂÂÂÂÂÂÂÂÂÂ update_cache_properties(this_leaf,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ found_cache,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ cpu_node);
> > +
> > +ÂÂÂÂÂÂÂ index++;
> > +ÂÂÂ }
> > +}
> > +
> > +static int topology_setup_acpi_cpu(struct acpi_table_header *table,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ unsigned int cpu, int level)
> > +{
> > +ÂÂÂ struct acpi_pptt_processor *cpu_node;
> > +ÂÂÂ u32 acpi_cpu_id = acpi_cpu_get_madt_gicc(cpu)->uid;
> > +
> > +ÂÂÂ cpu_node = acpi_find_processor_node(table, acpi_cpu_id);
> > +ÂÂÂ if (cpu_node) {
> > +ÂÂÂÂÂÂÂ cpu_node = acpi_find_processor_package_id(table, cpu_node, 
> > level);
> > +ÂÂÂÂÂÂÂ /* Only the first level has a guaranteed id */
> > +ÂÂÂÂÂÂÂ if (level == 0)
> > +ÂÂÂÂÂÂÂÂÂÂÂ return cpu_node->acpi_processor_id;
> > +ÂÂÂÂÂÂÂ return (int)((u8 *)cpu_node - (u8 *)table);
> > +ÂÂÂ }
> > +ÂÂÂ pr_err_once("PPTT table found, but unable to locate core for %d\n",
> > +ÂÂÂÂÂÂÂÂÂÂÂ cpu);
> > +ÂÂÂ return -ENOENT;
> > +}
> > +
> > +/*
> > + * simply assign a ACPI cache entry to each known CPU cache entry
> > + * determining which entries are shared is done later.
> > + */
> > +int cache_setup_acpi(unsigned int cpu)
> > +{
> > +ÂÂÂ struct acpi_table_header *table;
> > +ÂÂÂ acpi_status status;
> > +
> > +ÂÂÂ pr_debug("Cache Setup ACPI cpu %d\n", cpu);
> > +
> > +ÂÂÂ status = acpi_get_table(ACPI_SIG_PPTT, 0, &table);
> > +ÂÂÂ if (ACPI_FAILURE(status)) {
> > +ÂÂÂÂÂÂÂ pr_err_once("No PPTT table found, cache topology may be 
> > inaccurate\n");
> > +ÂÂÂÂÂÂÂ return -ENOENT;
> > +ÂÂÂ }
> > +
> > +ÂÂÂ cache_setup_acpi_cpu(table, cpu);
> > +ÂÂÂ acpi_put_table(table);
> > +
> > +ÂÂÂ return status;
> > +}
> > +
> > +/*
> > + * Determine a topology unique ID for each 
> > thread/core/cluster/socket/etc.
> > + * This ID can then be used to group peers.
> > + */
> > +int setup_acpi_cpu_topology(unsigned int cpu, int level)
> > +{
> > +ÂÂÂ struct acpi_table_header *table;
> > +ÂÂÂ acpi_status status;
> > +ÂÂÂ int retval;
> > +
> > +ÂÂÂ status = acpi_get_table(ACPI_SIG_PPTT, 0, &table);
> > +ÂÂÂ if (ACPI_FAILURE(status)) {
> > +ÂÂÂÂÂÂÂ pr_err_once("No PPTT table found, cpu topology may be 
> > inaccurate\n");
> > +ÂÂÂÂÂÂÂ return -ENOENT;
> > +ÂÂÂ }
> > +ÂÂÂ retval = topology_setup_acpi_cpu(table, cpu, level);
> > +ÂÂÂ pr_debug("Topology Setup ACPI cpu %d, level %d ret = %d\n",
> > +ÂÂÂÂÂÂÂÂ cpu, level, retval);
> > +ÂÂÂ acpi_put_table(table);
> > +
> > +ÂÂÂ return retval;
> > +}
>
> Thanks,
> Tomasz

Thanks for taking the time to look at this.