diff mbox series

[05/22] firmware: arm_scmi: Dynamically allocate protocols array

Message ID 20220330150551.2573938-6-cristian.marussi@arm.com (mailing list archive)
State New, archived
Headers show
Series SCMIv3.1 Miscellaneous changes | expand

Commit Message

Cristian Marussi March 30, 2022, 3:05 p.m. UTC
Move away from a statically allocated array for holding the current set of
protocols implemented by the platform in favour of allocating it
dynamically based on the number of protocols effectively advertised by the
platform via BASE protocol exchanges.

While at that, rectify the BASE_DISCOVER_LIST_PROTOCOLS loop iterations to
terminate only when a number of protocols equal to the advertised ones has
been received, instead of looping till the platform returns no more
protocols descriptors: this new behaviour is better compliant with the
specification and it has been tested to work equally well against an SCMI
stack running on top of an official SCP firmware on a JUNO board.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 drivers/firmware/arm_scmi/base.c   | 17 ++++++++++-------
 drivers/firmware/arm_scmi/common.h |  1 -
 drivers/firmware/arm_scmi/driver.c |  6 ++++--
 3 files changed, 14 insertions(+), 10 deletions(-)

Comments

Sudeep Holla April 28, 2022, 10:27 a.m. UTC | #1
On Wed, Mar 30, 2022 at 04:05:34PM +0100, Cristian Marussi wrote:
> Move away from a statically allocated array for holding the current set of
> protocols implemented by the platform in favour of allocating it
> dynamically based on the number of protocols effectively advertised by the
> platform via BASE protocol exchanges.
> 
> While at that, rectify the BASE_DISCOVER_LIST_PROTOCOLS loop iterations to
> terminate only when a number of protocols equal to the advertised ones has
> been received, instead of looping till the platform returns no more
> protocols descriptors: this new behaviour is better compliant with the
> specification and it has been tested to work equally well against an SCMI
> stack running on top of an official SCP firmware on a JUNO board.
>

Nice, no idea why I forgot that we have num_protocols from the another
command when I originally wrote this. I may be carried away with the way
OPP or even the clock rate list works I guess.
diff mbox series

Patch

diff --git a/drivers/firmware/arm_scmi/base.c b/drivers/firmware/arm_scmi/base.c
index c1165d1282ef..d6322624da9f 100644
--- a/drivers/firmware/arm_scmi/base.c
+++ b/drivers/firmware/arm_scmi/base.c
@@ -178,6 +178,7 @@  scmi_base_implementation_list_get(const struct scmi_protocol_handle *ph,
 	__le32 *num_skip, *num_ret;
 	u32 tot_num_ret = 0, loop_num_ret;
 	struct device *dev = ph->dev;
+	struct scmi_revision_info *rev = ph->get_priv(ph);
 
 	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_LIST_PROTOCOLS,
 				      sizeof(*num_skip), 0, &t);
@@ -200,8 +201,9 @@  scmi_base_implementation_list_get(const struct scmi_protocol_handle *ph,
 			break;
 
 		loop_num_ret = le32_to_cpu(*num_ret);
-		if (loop_num_ret > MAX_PROTOCOLS_IMP - tot_num_ret) {
-			dev_err(dev, "No. of Protocol > MAX_PROTOCOLS_IMP");
+		if (loop_num_ret > rev->num_protocols - tot_num_ret) {
+			dev_err(dev,
+				"No. Returned protocols > Total protocols.\n");
 			break;
 		}
 
@@ -229,7 +231,7 @@  scmi_base_implementation_list_get(const struct scmi_protocol_handle *ph,
 		tot_num_ret += loop_num_ret;
 
 		ph->xops->reset_rx_to_maxsz(ph, t);
-	} while (loop_num_ret);
+	} while (tot_num_ret < rev->num_protocols);
 
 	ph->xops->xfer_put(ph, t);
 
@@ -372,10 +374,6 @@  static int scmi_base_protocol_init(const struct scmi_protocol_handle *ph)
 	if (ret)
 		return ret;
 
-	prot_imp = devm_kcalloc(dev, MAX_PROTOCOLS_IMP, sizeof(u8), GFP_KERNEL);
-	if (!prot_imp)
-		return -ENOMEM;
-
 	rev->major_ver = PROTOCOL_REV_MAJOR(version),
 	rev->minor_ver = PROTOCOL_REV_MINOR(version);
 	ph->set_priv(ph, rev);
@@ -384,6 +382,11 @@  static int scmi_base_protocol_init(const struct scmi_protocol_handle *ph)
 	if (ret)
 		return ret;
 
+	prot_imp = devm_kcalloc(dev, rev->num_protocols, sizeof(u8),
+				GFP_KERNEL);
+	if (!prot_imp)
+		return -ENOMEM;
+
 	scmi_base_vendor_id_get(ph, false);
 	scmi_base_vendor_id_get(ph, true);
 	scmi_base_implementation_version_get(ph);
diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index 4fda84bfab42..6885348a505d 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -30,7 +30,6 @@ 
 #define PROTOCOL_REV_MAJOR_MASK	GENMASK(31, 16)
 #define PROTOCOL_REV_MAJOR(x)	(u16)(FIELD_GET(PROTOCOL_REV_MAJOR_MASK, (x)))
 #define PROTOCOL_REV_MINOR(x)	(u16)(FIELD_GET(PROTOCOL_REV_MINOR_MASK, (x)))
-#define MAX_PROTOCOLS_IMP	16
 #define MAX_OPPS		16
 
 enum scmi_common_cmd {
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 7436c475e708..8e07bee16c8e 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -128,7 +128,8 @@  struct scmi_protocol_instance {
  *	       usage.
  * @protocols_mtx: A mutex to protect protocols instances initialization.
  * @protocols_imp: List of protocols implemented, currently maximum of
- *	MAX_PROTOCOLS_IMP elements allocated by the base protocol
+ *		   scmi_revision_info.num_protocols elements allocated by the
+ *		   base protocol
  * @active_protocols: IDR storing device_nodes for protocols actually defined
  *		      in the DT and confirmed as implemented by fw.
  * @atomic_threshold: Optional system wide DT-configured threshold, expressed
@@ -1309,11 +1310,12 @@  scmi_is_protocol_implemented(const struct scmi_handle *handle, u8 prot_id)
 {
 	int i;
 	struct scmi_info *info = handle_to_scmi_info(handle);
+	struct scmi_revision_info *rev = handle->version;
 
 	if (!info->protocols_imp)
 		return false;
 
-	for (i = 0; i < MAX_PROTOCOLS_IMP; i++)
+	for (i = 0; i < rev->num_protocols; i++)
 		if (info->protocols_imp[i] == prot_id)
 			return true;
 	return false;