[PATCH v3 6/7] platform/x86/amd/hsmp: Drop ACPI sysfs metrics_bin in favour of the IOCTL

[Muralidhara M K]

The HSMP_IOCTL_GET_TELEMETRY_DATA character-device ioctl introduced in
the previous patch is now the canonical interface for reading the
metric table on the ACPI driver path.  Unlike the metrics_bin sysfs
binary attribute, the ioctl is not constrained by PAGE_SIZE, so it
works for the ~13 KB hsmp_metric_table_zen6 layout used on Family 1Ah
Model 50h-5Fh as well as for the existing hsmp_metric_table layout
used on protocol version 6.

Drop the metrics_bin bin_attribute from the ACPI hsmp_attr_grp.
Widen the remaining proto_ver gate in init_acpi() from
'== HSMP_PROTO_VER6' to '>= HSMP_PROTO_VER6' so
hsmp_get_tbl_dram_base() is invoked on protocol version 7
(Family 1Ah Model 50h-5Fh) and any future protocol version that
retains a compatible per-socket metric table.  This populates
sock->metric_tbl_addr and hsmp_pdev.hsmp_table_size, which the ioctl
handler requires.

This is an ABI change for users of the ACPI driver:
/sys/bus/platform/devices/AMDI0097:*/metrics_bin no longer exists.
Userspace must read telemetry through the HSMP_IOCTL_GET_TELEMETRY_DATA
ioctl on /dev/hsmp instead, sizing its buffer using the matching UAPI
metric table struct. The non-ACPI plat.c path is intentionally left
unchanged: it covers Family 1Ah Model 0h-Fh hardware that is fixed at
protocol version 6, and its per-socket metrics_bin remains available
for existing userspace tooling on those systems.

Co-developed-by: Muthusamy Ramalingam <muthusamy.ramalingam@xxxxxxx>
Signed-off-by: Muthusamy Ramalingam <muthusamy.ramalingam@xxxxxxx>
Signed-off-by: Muralidhara M K <muralidhara.mk@xxxxxxx>
---
Changes:
v1->v3: Remove bin attributes

 drivers/platform/x86/amd/hsmp/acpi.c | 34 +---------------------------
 1 file changed, 1 insertion(+), 33 deletions(-)

diff --git a/drivers/platform/x86/amd/hsmp/acpi.c b/drivers/platform/x86/amd/hsmp/acpi.c
index 97ed71593bdf..49765fefe1fb 100644
--- a/drivers/platform/x86/amd/hsmp/acpi.c
+++ b/drivers/platform/x86/amd/hsmp/acpi.c
@@ -231,25 +231,6 @@ static int hsmp_parse_acpi_table(struct device *dev, u16 sock_ind)
 	return hsmp_read_acpi_dsd(sock);
 }
 
-static ssize_t hsmp_metric_tbl_acpi_read(struct file *filp, struct kobject *kobj,
-					 const struct bin_attribute *bin_attr, char *buf,
-					 loff_t off, size_t count)
-{
-	struct device *dev = container_of(kobj, struct device, kobj);
-	struct hsmp_socket *sock = dev_get_drvdata(dev);
-
-	return hsmp_metric_tbl_read(sock, buf, count);
-}
-
-static umode_t hsmp_is_sock_attr_visible(struct kobject *kobj,
-					 const struct bin_attribute *battr, int id)
-{
-	if (hsmp_pdev->proto_ver == HSMP_PROTO_VER6)
-		return battr->attr.mode;
-
-	return 0;
-}
-
 static umode_t hsmp_is_sock_dev_attr_visible(struct kobject *kobj,
 					     struct attribute *attr, int id)
 {
@@ -491,7 +472,7 @@ static int init_acpi(struct device *dev)
 		return ret;
 	}
 
-	if (hsmp_pdev->proto_ver == HSMP_PROTO_VER6) {
+	if (hsmp_pdev->proto_ver >= HSMP_PROTO_VER6) {
 		ret = hsmp_get_tbl_dram_base(sock_ind);
 		if (ret)
 			dev_info(dev, "Failed to init metric table\n");
@@ -506,17 +487,6 @@ static int init_acpi(struct device *dev)
 	return 0;
 }
 
-static const struct bin_attribute  hsmp_metric_tbl_attr = {
-	.attr = { .name = HSMP_METRICS_TABLE_NAME, .mode = 0444},
-	.read = hsmp_metric_tbl_acpi_read,
-	.size = sizeof(struct hsmp_metric_table),
-};
-
-static const struct bin_attribute *hsmp_attr_list[] = {
-	&hsmp_metric_tbl_attr,
-	NULL
-};
-
 #define HSMP_DEV_ATTR(_name, _msg_id, _show, _mode)	\
 static struct hsmp_sys_attr hattr_##_name = {		\
 	.dattr = __ATTR(_name, _mode, _show, NULL),	\
@@ -559,9 +529,7 @@ static struct attribute *hsmp_dev_attr_list[] = {
 };
 
 static const struct attribute_group hsmp_attr_grp = {
-	.bin_attrs = hsmp_attr_list,
 	.attrs = hsmp_dev_attr_list,
-	.is_bin_visible = hsmp_is_sock_attr_visible,
 	.is_visible = hsmp_is_sock_dev_attr_visible,
 };
 
-- 
2.34.1