FROMLIST: misc: fastrpc: Allocate entire reserved memory for Audio PD in probe

The entire reserved-memory region is now assigned to DSP VMIDs during
channel setup and stored in cctx->remote_heap. Memory is reclaimed in
rpmsg_remove by revoking DSP permissions and freeing the buffer, tying
heap lifecycle to the rpmsg channel.

Link: https://lore.kernel.org/all/20260115082851.570-5-jianping.li@oss.qualcomm.com/
Signed-off-by: Jianping Li <jianping.li@oss.qualcomm.com>

Author: Jianping-Li

drivers/misc/fastrpc.c

@@ -295,6 +295,8 @@ struct fastrpc_channel_ctx {
 	struct kref refcount;
 	/* Flag if dsp attributes are cached */
 	bool valid_attributes;
+	/* Flag if audio PD init mem was allocated */
+	bool audio_init_mem;
 	u32 dsp_attributes[FASTRPC_MAX_DSP_ATTRIBUTES];
 	struct fastrpc_device *secure_fdevice;
 	struct fastrpc_device *fdevice;
@@ -1396,7 +1398,6 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl,
 	struct fastrpc_phy_page pages[1];
 	char *name;
 	int err;
-	bool scm_done = false;
 	struct {
 		int client_id;
 		u32 namelen;
@@ -1426,31 +1427,6 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl,
 	inbuf.client_id = fl->client_id;
 	inbuf.namelen = init.namelen;
 	inbuf.pageslen = 0;
-	if (!fl->cctx->remote_heap) {
-		err = fastrpc_remote_heap_alloc(fl, fl->sctx->dev, init.memlen,
-						&fl->cctx->remote_heap);
-		if (err)
-			goto err_name;
-
-		/* Map if we have any heap VMIDs associated with this ADSP Static Process. */
-		if (fl->cctx->vmcount) {
-			u64 src_perms = BIT(QCOM_SCM_VMID_HLOS);
-
-			err = qcom_scm_assign_mem(fl->cctx->remote_heap->dma_addr,
-						  (u64)fl->cctx->remote_heap->size,
-						  &src_perms, fl->cctx->vmperms,
-						  fl->cctx->vmcount);
-			if (err) {
-				dev_err(fl->sctx->dev,
-					"Failed to assign memory with dma_addr %pad size 0x%llx err %d\n",
-					&fl->cctx->remote_heap->dma_addr,
-					fl->cctx->remote_heap->size, err);
-				goto err_map;
-			}
-			scm_done = true;
-			inbuf.pageslen = 1;
-		}
-	}
 
 	fl->pd = USER_PD;
 
@@ -1462,8 +1438,15 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl,
 	args[1].length = inbuf.namelen;
 	args[1].fd = -1;
 
-	pages[0].addr = fl->cctx->remote_heap->dma_addr;
-	pages[0].size = fl->cctx->remote_heap->size;
+	if (!fl->cctx->audio_init_mem) {
+		pages[0].addr = fl->cctx->remote_heap->dma_addr;
+		pages[0].size = fl->cctx->remote_heap->size;
+		fl->cctx->audio_init_mem = true;
+		inbuf.pageslen = 1;
+	} else {
+		pages[0].addr = 0;
+		pages[0].size = 0;
+	}
 
 	args[2].ptr = (u64)(uintptr_t) pages;
 	args[2].length = sizeof(*pages);
@@ -1481,26 +1464,7 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl,
 
 	return 0;
 err_invoke:
-	if (fl->cctx->vmcount && scm_done) {
-		u64 src_perms = 0;
-		struct qcom_scm_vmperm dst_perms;
-		u32 i;
-
-		for (i = 0; i < fl->cctx->vmcount; i++)
-			src_perms |= BIT(fl->cctx->vmperms[i].vmid);
-
-		dst_perms.vmid = QCOM_SCM_VMID_HLOS;
-		dst_perms.perm = QCOM_SCM_PERM_RWX;
-		err = qcom_scm_assign_mem(fl->cctx->remote_heap->dma_addr,
-					  (u64)fl->cctx->remote_heap->size,
-					  &src_perms, &dst_perms, 1);
-		if (err)
-			dev_err(fl->sctx->dev, "Failed to assign memory dma_addr %pad size 0x%llx err %d\n",
-				&fl->cctx->remote_heap->dma_addr, fl->cctx->remote_heap->size, err);
-	}
-err_map:
-	fastrpc_buf_free(fl->cctx->remote_heap);
-err_name:
+	fl->cctx->audio_init_mem = false;
 	kfree(name);
 err:
 	kfree(args);
@@ -2516,7 +2480,7 @@ static int fastrpc_rpmsg_probe(struct rpmsg_device *rpdev)
 		}
 	}
 
-	if (domain_id == SDSP_DOMAIN_ID) {
+	if (domain_id == SDSP_DOMAIN_ID || domain_id == ADSP_DOMAIN_ID) {
 		struct resource res;
 		u64 src_perms;
 
@@ -2527,6 +2491,15 @@ static int fastrpc_rpmsg_probe(struct rpmsg_device *rpdev)
 			qcom_scm_assign_mem(res.start, resource_size(&res), &src_perms,
 					    data->vmperms, data->vmcount);
 		}
+		if (domain_id == ADSP_DOMAIN_ID) {
+			data->remote_heap =
+				kzalloc(sizeof(*data->remote_heap), GFP_KERNEL);
+			if (!data->remote_heap)
+				return -ENOMEM;
+
+			data->remote_heap->dma_addr = res.start;
+			data->remote_heap->size = resource_size(&res);
+		}
 
 	}
 
@@ -2608,10 +2581,13 @@ static void fastrpc_rpmsg_remove(struct rpmsg_device *rpdev)
 	struct fastrpc_buf *buf, *b;
 	struct fastrpc_user *user;
 	unsigned long flags;
+	bool skip_free = false;
+	int err;
 
 	/* No invocations past this point */
 	spin_lock_irqsave(&cctx->lock, flags);
 	cctx->rpdev = NULL;
+	cctx->audio_init_mem = false;
 	list_for_each_entry(user, &cctx->users, user)
 		fastrpc_notify_users(user);
 	spin_unlock_irqrestore(&cctx->lock, flags);
@@ -2625,7 +2601,26 @@ static void fastrpc_rpmsg_remove(struct rpmsg_device *rpdev)
 	list_for_each_entry_safe(buf, b, &cctx->invoke_interrupted_mmaps, node)
 		list_del(&buf->node);
 
-	fastrpc_buf_free(cctx->remote_heap);
+	if (cctx->remote_heap) {
+		if (cctx->vmcount) {
+			u64 src_perms = 0;
+			struct qcom_scm_vmperm dst_perms;
+
+			for (u32 i = 0; i < cctx->vmcount; i++)
+				src_perms |= BIT(cctx->vmperms[i].vmid);
+
+			dst_perms.vmid = QCOM_SCM_VMID_HLOS;
+			dst_perms.perm = QCOM_SCM_PERM_RWX;
+
+			err = qcom_scm_assign_mem(cctx->remote_heap->dma_addr,
+						  cctx->remote_heap->size,
+						  &src_perms, &dst_perms, 1);
+			if (err)
+				skip_free = true;
+		}
+		if (!skip_free)
+			fastrpc_buf_free(cctx->remote_heap);
+	}
 
 	of_platform_depopulate(&rpdev->dev);