[PATCH v2 7/7] platform/x86/amd/hsmp: Support SYSFS_HUGE_BIN_FILE for metric table reads

[Muralidhara M K <muralidhara.mk@amd.com>]

The metric table for Family 1Ah Model 50h-5Fh (hsmp_metric_table_zen6)
is approximately 13KB, exceeding the PAGE_SIZE (4KB) cap imposed by the
standard sysfs binary attribute read path.

Set the SYSFS_HUGE_BIN_FILE flag in the bin_attribute mode for the
metric table in both acpi.c and plat.c so that reads are routed through
seq_file, which dynamically grows its buffer to accommodate the full
table.  This lets userspace read the entire table in a single read()
call.

Drop the static .size initializer from the bin_attribute since the
bin_size callback (added in the previous patch) already provides the
runtime table size at sysfs group registration time.

Co-developed-by: Muthusamy Ramalingam <muthusamy.ramalingam@amd.com>
Signed-off-by: Muthusamy Ramalingam <muthusamy.ramalingam@amd.com>
Signed-off-by: Muralidhara M K <muralidhara.mk@amd.com>
---
Changes v1->v2: New patch

 drivers/platform/x86/amd/hsmp/acpi.c | 3 +--
 drivers/platform/x86/amd/hsmp/plat.c | 6 ++++--
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/platform/x86/amd/hsmp/acpi.c b/drivers/platform/x86/amd/hsmp/acpi.c
index f3cfc99ef73d..ea99625d0f36 100644
--- a/drivers/platform/x86/amd/hsmp/acpi.c
+++ b/drivers/platform/x86/amd/hsmp/acpi.c
@@ -513,9 +513,8 @@ static int init_acpi(struct device *dev)
 }
 
 static const struct bin_attribute  hsmp_metric_tbl_attr = {
-	.attr = { .name = HSMP_METRICS_TABLE_NAME, .mode = 0444},
+	.attr = { .name = HSMP_METRICS_TABLE_NAME, .mode = SYSFS_HUGE_BIN_FILE | 0444},
 	.read = hsmp_metric_tbl_acpi_read,
-	.size = sizeof(struct hsmp_metric_table),
 };
 
 static const struct bin_attribute *hsmp_attr_list[] = {
diff --git a/drivers/platform/x86/amd/hsmp/plat.c b/drivers/platform/x86/amd/hsmp/plat.c
index d8dd90dfeb4e..625602a0d44c 100644
--- a/drivers/platform/x86/amd/hsmp/plat.c
+++ b/drivers/platform/x86/amd/hsmp/plat.c
@@ -97,10 +97,12 @@ static_assert(MAX_AMD_NUM_NODES == 8);
 
 #define HSMP_BIN_ATTR(index, _list)					\
 static const struct bin_attribute attr##index = {			\
-	.attr = { .name = HSMP_METRICS_TABLE_NAME, .mode = 0444},	\
+	.attr = {							\
+		.name = HSMP_METRICS_TABLE_NAME,			\
+		.mode = SYSFS_HUGE_BIN_FILE | 0444,				\
+	},								\
 	.private = (void *)index,					\
 	.read = hsmp_metric_tbl_plat_read,				\
-	.size = sizeof(struct hsmp_metric_table),			\
 };									\
 static const struct bin_attribute _list[] = {				\
 	&attr##index,							\
-- 
2.34.1