[PATCH v2 07/13] firmware: arm_scmi: Make clock rates allocation dynamic
From: Cristian Marussi <cristian.marussi@arm.com>
Date: 2026-03-10 18:41:09
Also in:
arm-scmi, linux-clk, linux-renesas-soc, lkml
Subsystem:
system control & power/management interface (scpi/scmi) message protocol drivers, the rest · Maintainers:
Sudeep Holla, Linus Torvalds
Leveraging SCMI Clock protocol dynamic discovery capabilities, move away from the static per-clock rates allocation model in favour of a dynamic runtime allocation based on effectively discovered resources. No functional change. Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> --- drivers/firmware/arm_scmi/clock.c | 19 ++++++++++++++++--- include/linux/scmi_protocol.h | 1 - 2 files changed, 16 insertions(+), 4 deletions(-)
diff --git a/drivers/firmware/arm_scmi/clock.c b/drivers/firmware/arm_scmi/clock.c
index 467b13a3a18f..c9b62edce4fd 100644
--- a/drivers/firmware/arm_scmi/clock.c
+++ b/drivers/firmware/arm_scmi/clock.c@@ -161,7 +161,7 @@ struct scmi_clock_desc { u32 id; bool rate_discrete; unsigned int num_rates; - u64 rates[SCMI_MAX_NUM_RATES]; + u64 *rates; #define RATE_MIN 0 #define RATE_MAX 1 #define RATE_STEP 2
@@ -480,6 +480,18 @@ iter_clk_describe_update_state(struct scmi_iterator_state *st, QUIRK_OUT_OF_SPEC_TRIPLET); } + if (!st->max_resources) { + int num_rates = st->num_returned + st->num_remaining; + + p->clkd->rates = devm_kcalloc(p->dev, num_rates, + sizeof(*p->clkd->rates), GFP_KERNEL); + if (!p->clkd->rates) + return -ENOMEM; + + /* max_resources is used by the iterators to control bounds */ + st->max_resources = st->num_returned + st->num_remaining; + } + return 0; }
@@ -493,6 +505,8 @@ iter_clk_describe_process_response(const struct scmi_protocol_handle *ph, p->clkd->rates[st->desc_index + st->loop_idx] = RATE_TO_U64(r->rate[st->loop_idx]); + + /* Count only effectively discovered rates */ p->clkd->num_rates++; return 0;
@@ -515,8 +529,7 @@ scmi_clock_describe_rates_get(const struct scmi_protocol_handle *ph, u32 clk_id, .dev = ph->dev, }; - iter = ph->hops->iter_response_init(ph, &ops, SCMI_MAX_NUM_RATES, - CLOCK_DESCRIBE_RATES, + iter = ph->hops->iter_response_init(ph, &ops, 0, CLOCK_DESCRIBE_RATES, sizeof(struct scmi_msg_clock_describe_rates), &cpriv); if (IS_ERR(iter))
diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index d97b4e734744..5552ac04c820 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h@@ -15,7 +15,6 @@ #define SCMI_MAX_STR_SIZE 64 #define SCMI_SHORT_NAME_MAX_SIZE 16 -#define SCMI_MAX_NUM_RATES 16 /** * struct scmi_revision_info - version information structure
--
2.53.0