FROMLIST: misc: fastrpc: Add missing unmapping user-requested remote heap

User request for remote heap allocation is supported using ioctl
interface but support for unmap is missing. This could result in
memory leak issues. Add unmap user request support for remote heap.

Link: https://lore.kernel.org/all/20250513042825.2147985-6-ekansh.gupta@oss.qualcomm.com/
Fixes: 532ad70 ("misc: fastrpc: Add mmap request assigning for static PD pool")
Cc: stable@kernel.org
Signed-off-by: Ekansh Gupta <ekansh.gupta@oss.qualcomm.com>

Author: ekanshibu

drivers/misc/fastrpc.c

@@ -197,6 +197,8 @@ struct fastrpc_buf {
 	struct dma_buf *dmabuf;
 	struct device *dev;
 	void *virt;
+	/* Type of buffer */
+	u32 flag;
 	u64 phys;
 	u64 size;
 	/* Lock for dma buf attachments */
@@ -1867,8 +1869,26 @@ static int fastrpc_req_munmap_impl(struct fastrpc_user *fl, struct fastrpc_buf *
 	err = fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE, sc,
 				      &args[0]);
 	if (!err) {
-		dev_dbg(dev, "unmmap\tpt 0x%09lx OK\n", buf->raddr);
+		if (buf->flag == ADSP_MMAP_REMOTE_HEAP_ADDR && fl->cctx->vmcount) {
+			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(buf->phys, (u64)buf->size,
+						  &src_perms, &dst_perms, 1);
+			if (err) {
+				dev_err(fl->sctx->dev, "Failed to assign memory phys 0x%llx size 0x%llx err %d\n",
+					buf->phys, buf->size, err);
+				return err;
+			}
+		}
 		fastrpc_buf_free(buf);
+		dev_dbg(dev, "unmmap\tpt 0x%09lx OK\n", buf->raddr);
 	} else {
 		dev_err(dev, "unmmap\tpt 0x%09lx ERROR\n", buf->raddr);
 	}
@@ -1882,6 +1902,7 @@ static int fastrpc_req_munmap(struct fastrpc_user *fl, char __user *argp)
 	struct fastrpc_req_munmap req;
 	struct device *dev = fl->sctx->dev;
 	int err;
+	unsigned long flags;
 
 	if (copy_from_user(&req, argp, sizeof(req)))
 		return -EFAULT;
@@ -1896,20 +1917,38 @@ static int fastrpc_req_munmap(struct fastrpc_user *fl, char __user *argp)
 	}
 	spin_unlock(&fl->lock);
 
-	if (!buf) {
-		dev_err(dev, "mmap\t\tpt 0x%09llx [len 0x%08llx] not in list\n",
-			req.vaddrout, req.size);
-		return -EINVAL;
+	if (buf) {
+		err = fastrpc_req_munmap_impl(fl, buf);
+		if (err) {
+			spin_lock(&fl->lock);
+			list_add_tail(&buf->node, &fl->mmaps);
+			spin_unlock(&fl->lock);
+		}
+		return err;
 	}
 
-	err = fastrpc_req_munmap_impl(fl, buf);
-	if (err) {
-		spin_lock(&fl->lock);
-		list_add_tail(&buf->node, &fl->mmaps);
-		spin_unlock(&fl->lock);
+	spin_lock_irqsave(&fl->cctx->lock, flags);
+	list_for_each_entry_safe(iter, b, &fl->cctx->rhmaps, node) {
+		if (iter->raddr == req.vaddrout && iter->size == req.size) {
+			list_del(&iter->node);
+			buf = iter;
+			break;
+		}
 	}
+	spin_unlock_irqrestore(&fl->cctx->lock, flags);
+	if (buf) {
+		err = fastrpc_req_munmap_impl(fl, buf);
+		if (err) {
+			spin_lock_irqsave(&fl->cctx->lock, flags);
+			list_add_tail(&buf->node, &fl->cctx->rhmaps);
+			spin_unlock_irqrestore(&fl->cctx->lock, flags);
+		}
+		return err;
+	}
+	dev_err(dev, "mmap\t\tpt 0x%09llx [len 0x%08llx] not in list\n",
+		req.vaddrout, req.size);
 
-	return err;
+	return -EINVAL;
 }
 
 static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp)
@@ -1977,6 +2016,7 @@ static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp)
 
 	/* update the buffer to be able to deallocate the memory on the DSP */
 	buf->raddr = (uintptr_t) rsp_msg.vaddr;
+	buf->flag = req.flags;
 
 	/* let the client know the address to use */
 	req.vaddrout = rsp_msg.vaddr;