On Thu, 20 Aug 2020 17:21:29 -0500
Bjorn Helgaas [off-list ref] wrote:

On Wed, Aug 19, 2020 at 10:51:09PM +0800, Jonathan Cameron wrote:

quoted

In ACPI 6.3, the Memory Proximity Domain Attributes Structure
changed substantially.  One of those changes was that the flag
for "Memory Proximity Domain field is valid" was deprecated.

This was because the field "Proximity Domain for the Memory"
became a required field and hence having a validity flag makes
no sense.

So the correct logic is to always assume the field is there.
Current code assumes it never is.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 drivers/acpi/numa/hmat.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/acpi/numa/hmat.c b/drivers/acpi/numa/hmat.c
index 2c32cfb72370..07cfe50136e0 100644
--- a/drivers/acpi/numa/hmat.c
+++ b/drivers/acpi/numa/hmat.c

@@ -424,7 +424,7 @@ static int __init hmat_parse_proximity_domain(union acpi_subtable_headers *heade
 		pr_info("HMAT: Memory Flags:%04x Processor Domain:%u Memory Domain:%u\n",
 			p->flags, p->processor_PD, p->memory_PD);
 
-	if (p->flags & ACPI_HMAT_MEMORY_PD_VALID && hmat_revision == 1) {
+	if ((p->flags & ACPI_HMAT_MEMORY_PD_VALID && hmat_revision == 1) || hmat_revision == 2) {  

Hi Bjorn,

I hope/assume the spec is written in such a way that p->memory_PD is
required for any revision > 1?  So maybe this should be:

  if ((p->flags & ACPI_HMAT_MEMORY_PD_VALID && hmat_revision == 1) ||
      hmat_revision > 1) {

Good point.  We have existing protections elsewhere against hmat_revision
being anything other than 1 or 2, so we should aim to keep that in only one place.

I'll tidy this up for v10.

thanks,

Jonathan

quoted

 		target = find_mem_target(p->memory_PD);
 		if (!target) {
 			pr_debug("HMAT: Memory Domain missing from SRAT\n");
-- 
2.19.1
  

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