In actbl2.h, acpi_pptt_cache describes the fields in the original
Cache Type Structure. In PPTT table version 3 a new field was added at the
end, cache_id. This is described in acpi_pptt_cache_v1 but rather than
including all v1 fields it just includes this one.

In lieu of this being fixed in acpica, introduce acpi_pptt_cache_v1_full to
contain all the fields of the Cache Type Structure . Update the existing
code to use this new struct. This simplifies the code and removes a
non-standard use of ACPI_ADD_PTR.

Signed-off-by: Ben Horgan <ben.horgan@arm.com>
---
I have opened a pull request to acpica to update acpi_pptt_cache_v1 to
include all fields. https://github.com/acpica/acpica/pull/1059

Change since v4:
Use fields directly in acpi_pptt_cache_v1_full
Delay the casting

Changes since v3:
New patch
---
  drivers/acpi/pptt.c | 47 +++++++++++++++++++++++++++++++++++----------
  1 file changed, 37 insertions(+), 10 deletions(-)

diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c
index 2856254e29d7..53fde9bd8140 100644
--- a/drivers/acpi/pptt.c
+++ b/drivers/acpi/pptt.c

@@ -21,6 +21,25 @@
  #include <linux/cacheinfo.h>
  #include <acpi/processor.h>
  
+/*
+ * The acpi_pptt_cache_v1 in actbl2.h, which is imported from acpica,
+ * only contains the cache_id field rather than all the fields of the
+ * Cache Type Structure. Use this alternative structure until it is
+ * resolved in acpica.
+ */
+struct acpi_pptt_cache_v1_full {
+	struct acpi_subtable_header header;
+	u16 reserved;
+	u32 flags;
+	u32 next_level_of_cache;
+	u32 size;
+	u32 number_of_sets;
+	u8 associativity;
+	u8 attributes;
+	u16 line_size;
+	u32 cache_id;
+};