On Mon, Dec 10, 2018 at 10:03:40PM -0800, Dan Williams wrote:
> I have a use case to detect the presence of a memory-side-cache early
> at init time [1]. To me this means that hmat_init() needs to happen as
> a part of acpi_numa_init(). Subsequently I think that also means that
> the sysfs portion needs to be broken out to its own init path that can
> probably run at module_init() priority.
>
> Perhaps we should split this patch set into two? The table parsing
> with an in-kernel user is a bit easier to reason about and can go in
> first. Towards that end can I steal / refllow patches 1 & 2 into the
> memory randomization series? Other ideas how to handle this?
>
> [1]: https://lkml.org/lkml/2018/10/12/309
To that end, will something like the following work for you? This just
needs to happen after patch 1.
---
diff --git a/drivers/acpi/numa.c b/drivers/acpi/numa.c
index f5e09c39ff22..03ef3c8ba4ea 100644
--- a/drivers/acpi/numa.c
+++ b/drivers/acpi/numa.c
@@ -40,6 +40,8 @@ static int pxm_to_node_map[MAX_PXM_DOMAINS]
static int node_to_pxm_map[MAX_NUMNODES]
= { [0 ... MAX_NUMNODES - 1] = PXM_INVAL };
+static unsigned long node_side_cached[BITS_TO_LONGS(MAX_PXM_DOMAINS)];
+
unsigned char acpi_srat_revision __initdata;
int acpi_numa __initdata;
@@ -262,6 +264,7 @@ acpi_numa_memory_affinity_init(struct
acpi_srat_mem_affinity *ma)
u64 start, end;
u32 hotpluggable;
int node, pxm;
+ bool side_cached;
if (srat_disabled())
goto out_err;
@@ -308,6 +311,11 @@ acpi_numa_memory_affinity_init(struct
acpi_srat_mem_affinity *ma)
pr_warn("SRAT: Failed to mark hotplug range [mem
%#010Lx-%#010Lx] in memblock\n",
(unsigned long long)start, (unsigned long long)end - 1);
+ side_cached = test_bit(pxm, node_side_cached);
+ if (side_cached && memblock_mark_sidecached(start, ma->length))
+ pr_warn("SRAT: Failed to mark side cached range [mem
%#010Lx-%#010Lx] in memblock\n",
+ (unsigned long long)start, (unsigned long long)end - 1);
+
max_possible_pfn = max(max_possible_pfn, PFN_UP(end - 1));
return 0;
@@ -411,6 +419,19 @@ acpi_parse_memory_affinity(union acpi_subtable_headers *
header,
return 0;
}
+static int __init
+acpi_parse_cache(union acpi_subtable_headers *header, const unsigned long end)
+{
+ struct acpi_hmat_cache *cache = (void *)header;
+ u32 attrs;
+
+ attrs = cache->cache_attributes;
+ if (((attrs & ACPI_HMAT_CACHE_ASSOCIATIVITY) >> 8) ==
+ ACPI_HMAT_CA_DIRECT_MAPPED)
+ set_bit(cache->memory_PD, node_side_cached);
+ return 0;
+}
+
static int __init acpi_parse_srat(struct acpi_table_header *table)
{
struct acpi_table_srat *srat = (struct acpi_table_srat *)table;
@@ -422,6 +443,11 @@ static int __init acpi_parse_srat(struct acpi_table_header
*table)
return 0;
}
+static __init int acpi_parse_hmat(struct acpi_table_header *table)
+{
+ return 0;
+}
+
static int __init
acpi_table_parse_srat(enum acpi_srat_type id,
acpi_tbl_entry_handler handler, unsigned int max_entries)
@@ -460,6 +486,16 @@ int __init acpi_numa_init(void)
sizeof(struct acpi_table_srat),
srat_proc, ARRAY_SIZE(srat_proc), 0);
+ if (!acpi_table_parse(ACPI_SIG_HMAT, acpi_parse_hmat)) {
+ struct acpi_subtable_proc hmat_proc;
+
+ memset(&hmat_proc, 0, sizeof(hmat_proc));
+ hmat_proc.handler = acpi_parse_cache;
+ hmat_proc.id = ACPI_HMAT_TYPE_CACHE;
+ acpi_table_parse_entries_array(ACPI_SIG_HMAT,
+ sizeof(struct acpi_table_hmat),
+ &hmat_proc, 1, 0);
+ }
cnt = acpi_table_parse_srat(ACPI_SRAT_TYPE_MEMORY_AFFINITY,
acpi_parse_memory_affinity, 0);
}
diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index aee299a6aa76..a24c918a4496 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -44,6 +44,7 @@ enum memblock_flags {
MEMBLOCK_HOTPLUG = 0x1, /* hotpluggable region */
MEMBLOCK_MIRROR = 0x2, /* mirrored region */
MEMBLOCK_NOMAP = 0x4, /* don't add to kernel direct mapping */
+ MEMBLOCK_SIDECACHED = 0x8, /* System side caches memory access */
};
/**
@@ -130,6 +131,7 @@ int memblock_clear_hotplug(phys_addr_t base, phys_addr_t
size);
int memblock_mark_mirror(phys_addr_t base, phys_addr_t size);
int memblock_mark_nomap(phys_addr_t base, phys_addr_t size);
int memblock_clear_nomap(phys_addr_t base, phys_addr_t size);
+int memblock_mark_sidecached(phys_addr_t base, phys_addr_t size);
enum memblock_flags choose_memblock_flags(void);
unsigned long memblock_free_all(void);
@@ -227,6 +229,11 @@ static inline bool memblock_is_nomap(struct
memblock_region *m)
return m->flags & MEMBLOCK_NOMAP;
}
+static inline bool memblock_is_sidecached(struct memblock_region *m)
+{
+ return m->flags & MEMBLOCK_SIDECACHED;
+}
+
#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
int memblock_search_pfn_nid(unsigned long pfn, unsigned long *start_pfn,
unsigned long *end_pfn);
diff --git a/mm/memblock.c b/mm/memblock.c
index 9a2d5ae81ae1..827b709afdcd 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -865,6 +865,11 @@ int __init_memblock memblock_mark_hotplug(phys_addr_t
base, phys_addr_t size)
return memblock_setclr_flag(base, size, 1, MEMBLOCK_HOTPLUG);
}
+int __init_memblock memblock_mark_sidecached(phys_addr_t base, phys_addr_t
size)
+{
+ return memblock_setclr_flag(base, size, 1, MEMBLOCK_SIDECACHED);
+}
+
/**
* memblock_clear_hotplug - Clear flag MEMBLOCK_HOTPLUG for a specified region.
* @base: the base phys addr of the region
--
