Merge tag 'scmi-fixes-5.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into arm/fixes

Arm SCMI firmware driver fixes for v5.19

Few more fixes to address:
1. Issue reported on Juno with HDLCD clock which turned out to be yet
   another firmware issue. The firmware is not conformant to the spec and
   we now have to workaround as this may be copied to other platforms as
   well. The spec expects to return size of 3 for a range clock rate
   description while the firmware returns 1. We have other ways to validate
   all the 3 entries the driver reads are polpulated and we use the same
   to workaround this firmware bug.

2. Optee transport not setting the correct reponse length which is similar
   to the one reported earlier on Rockchip platform.

3. Drop the usage of the deprecated ida_simple_{get,remove} and migrate to the
   ida_{alloc,free}

* tag 'scmi-fixes-5.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
  firmware: arm_scmi: Remove usage of the deprecated ida_simple_xxx API
  firmware: arm_scmi: Fix response size warning for OPTEE transport
  firmware: arm_scmi: Relax CLOCK_DESCRIBE_RATES out-of-spec checks

Link: https://lore.kernel.org/r/20220628133315.699803-1-sudeep.holla@arm.com
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

5 files changed, 38 insertions, 5 deletions

diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index f6fe723ab869..d4e23101448a 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -181,7 +181,7 @@ scmi_device_create(struct device_node *np, struct device *parent, int protocol,
 		return NULL;
 	}
 
-	id = ida_simple_get(&scmi_bus_id, 1, 0, GFP_KERNEL);
+	id = ida_alloc_min(&scmi_bus_id, 1, GFP_KERNEL);
 	if (id < 0) {
 		kfree_const(scmi_dev->name);
 		kfree(scmi_dev);
@@ -204,7 +204,7 @@ scmi_device_create(struct device_node *np, struct device *parent, int protocol,
 put_dev:
 	kfree_const(scmi_dev->name);
 	put_device(&scmi_dev->dev);
-	ida_simple_remove(&scmi_bus_id, id);
+	ida_free(&scmi_bus_id, id);
 	return NULL;
 }
 
@@ -212,7 +212,7 @@ void scmi_device_destroy(struct scmi_device *scmi_dev)
 {
 	kfree_const(scmi_dev->name);
 	scmi_handle_put(scmi_dev->handle);
-	ida_simple_remove(&scmi_bus_id, scmi_dev->id);
+	ida_free(&scmi_bus_id, scmi_dev->id);
 	device_unregister(&scmi_dev->dev);
 }
 
diff --git a/drivers/firmware/arm_scmi/clock.c b/drivers/firmware/arm_scmi/clock.c
index c7a83f6e38e5..3ed7ae0d6781 100644
--- a/drivers/firmware/arm_scmi/clock.c
+++ b/drivers/firmware/arm_scmi/clock.c
@@ -194,6 +194,7 @@ static int rate_cmp_func(const void *_r1, const void *_r2)
 }
 
 struct scmi_clk_ipriv {
+	struct device *dev;
 	u32 clk_id;
 	struct scmi_clock_info *clk;
 };
@@ -223,6 +224,29 @@ iter_clk_describe_update_state(struct scmi_iterator_state *st,
 	st->num_returned = NUM_RETURNED(flags);
 	p->clk->rate_discrete = RATE_DISCRETE(flags);
 
+	/* Warn about out of spec replies ... */
+	if (!p->clk->rate_discrete &&
+	    (st->num_returned != 3 || st->num_remaining != 0)) {
+		dev_warn(p->dev,
+			 "Out-of-spec CLOCK_DESCRIBE_RATES reply for %s - returned:%d remaining:%d rx_len:%zd\n",
+			 p->clk->name, st->num_returned, st->num_remaining,
+			 st->rx_len);
+
+		/*
+		 * A known quirk: a triplet is returned but num_returned != 3
+		 * Check for a safe payload size and fix.
+		 */
+		if (st->num_returned != 3 && st->num_remaining == 0 &&
+		    st->rx_len == sizeof(*r) + sizeof(__le32) * 2 * 3) {
+			st->num_returned = 3;
+			st->num_remaining = 0;
+		} else {
+			dev_err(p->dev,
+				"Cannot fix out-of-spec reply !\n");
+			return -EPROTO;
+		}
+	}
+
 	return 0;
 }
 
@@ -255,7 +279,6 @@ iter_clk_describe_process_response(const struct scmi_protocol_handle *ph,
 
 		*rate = RATE_TO_U64(r->rate[st->loop_idx]);
 		p->clk->list.num_rates++;
-		//XXX dev_dbg(ph->dev, "Rate %llu Hz\n", *rate);
 	}
 
 	return ret;
@@ -275,6 +298,7 @@ scmi_clock_describe_rates_get(const struct scmi_protocol_handle *ph, u32 clk_id,
 	struct scmi_clk_ipriv cpriv = {
 		.clk_id = clk_id,
 		.clk = clk,
+		.dev = ph->dev,
 	};
 
 	iter = ph->hops->iter_response_init(ph, &ops, SCMI_MAX_NUM_RATES,
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index c1922bd650ae..8b7ac6663d57 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -1223,6 +1223,7 @@ static int scmi_iterator_run(void *iter)
 		if (ret)
 			break;
 
+		st->rx_len = i->t->rx.len;
 		ret = iops->update_state(st, i->resp, i->priv);
 		if (ret)
 			break;
diff --git a/drivers/firmware/arm_scmi/optee.c b/drivers/firmware/arm_scmi/optee.c
index b503c22cfd32..8abace56b958 100644
--- a/drivers/firmware/arm_scmi/optee.c
+++ b/drivers/firmware/arm_scmi/optee.c
@@ -117,6 +117,7 @@ struct scmi_optee_channel {
 	u32 channel_id;
 	u32 tee_session;
 	u32 caps;
+	u32 rx_len;
 	struct mutex mu;
 	struct scmi_chan_info *cinfo;
 	union {
@@ -302,6 +303,9 @@ static int invoke_process_msg_channel(struct scmi_optee_channel *channel, size_t
 		return -EIO;
 	}
 
+	/* Save response size */
+	channel->rx_len = param[2].u.memref.size;
+
 	return 0;
 }
 
@@ -353,6 +357,7 @@ static int setup_dynamic_shmem(struct device *dev, struct scmi_optee_channel *ch
 	shbuf = tee_shm_get_va(channel->tee_shm, 0);
 	memset(shbuf, 0, msg_size);
 	channel->req.msg = shbuf;
+	channel->rx_len = msg_size;
 
 	return 0;
 }
@@ -508,7 +513,7 @@ static void scmi_optee_fetch_response(struct scmi_chan_info *cinfo,
 	struct scmi_optee_channel *channel = cinfo->transport_info;
 
 	if (channel->tee_shm)
-		msg_fetch_response(channel->req.msg, SCMI_OPTEE_MAX_MSG_SIZE, xfer);
+		msg_fetch_response(channel->req.msg, channel->rx_len, xfer);
 	else
 		shmem_fetch_response(channel->req.shmem, xfer);
 }
diff --git a/drivers/firmware/arm_scmi/protocols.h b/drivers/firmware/arm_scmi/protocols.h
index c679f3fb8718..51c31379f9b3 100644
--- a/drivers/firmware/arm_scmi/protocols.h
+++ b/drivers/firmware/arm_scmi/protocols.h
@@ -179,6 +179,8 @@ struct scmi_protocol_handle {
  * @max_resources: Maximum acceptable number of items, configured by the caller
  *		   depending on the underlying resources that it is querying.
  * @loop_idx: The iterator loop index in the current multi-part reply.
+ * @rx_len: Size in bytes of the currenly processed message; it can be used by
+ *	    the user of the iterator to verify a reply size.
  * @priv: Optional pointer to some additional state-related private data setup
  *	  by the caller during the iterations.
  */
@@ -188,6 +190,7 @@ struct scmi_iterator_state {
 	unsigned int num_remaining;
 	unsigned int max_resources;
 	unsigned int loop_idx;
+	size_t rx_len;
 	void *priv;
 };