From: Matthew Wilcox <willy@infradead.org>
Date: Fri, 15 Mar 2019 12:50:56 +0000 (-0400)
Subject: fastrpc: Convert ctxt_idr to XArray
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=48de4d9caf929e7d7ff66b47a46386ffa54e81dd;p=users%2Fwilly%2Fxarray.git

fastrpc: Convert ctxt_idr to XArray

Signed-off-by: Matthew Wilcox <willy@infradead.org>
---

diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index 98603e235cf0..9df14ee16e61 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -153,8 +153,8 @@ struct fastrpc_invoke_ctx {
 	int pid;
 	int tgid;
 	u32 sc;
+	unsigned int ctxid;
 	u32 *crc;
-	u64 ctxid;
 	u64 msg_sz;
 	struct kref refcount;
 	struct list_head node; /* list of ctxs */
@@ -183,7 +183,8 @@ struct fastrpc_channel_ctx {
 	struct rpmsg_device *rpdev;
 	struct fastrpc_session_ctx session[FASTRPC_MAX_SESSIONS];
 	spinlock_t lock;
-	struct idr ctx_idr;
+	unsigned int ctxt_nextid;
+	struct xarray ctxts;
 	struct list_head users;
 	struct miscdevice miscdev;
 };
@@ -306,9 +307,7 @@ static void fastrpc_context_free(struct kref *ref)
 	if (ctx->buf)
 		fastrpc_buf_free(ctx->buf);
 
-	spin_lock_irqsave(&cctx->lock, flags);
-	idr_remove(&cctx->ctx_idr, ctx->ctxid >> 4);
-	spin_unlock_irqrestore(&cctx->lock, flags);
+	xa_erase(&cctx->ctxts, ctx->ctxid);
 
 	kfree(ctx->maps);
 	kfree(ctx->olaps);
@@ -425,26 +424,21 @@ static struct fastrpc_invoke_ctx *fastrpc_context_alloc(
 	ctx->tgid = user->tgid;
 	ctx->cctx = cctx;
 	init_completion(&ctx->work);
+	kref_init(&ctx->refcount);
 	INIT_WORK(&ctx->put_work, fastrpc_context_put_wq);
 
 	spin_lock(&user->lock);
 	list_add_tail(&ctx->node, &user->pending);
 	spin_unlock(&user->lock);
 
-	spin_lock_irqsave(&cctx->lock, flags);
-	ret = idr_alloc_cyclic(&cctx->ctx_idr, ctx, 1,
-			       FASTRPC_CTX_MAX, GFP_ATOMIC);
-	if (ret < 0) {
-		spin_unlock_irqrestore(&cctx->lock, flags);
-		goto err_idr;
-	}
-	ctx->ctxid = ret << 4;
-	spin_unlock_irqrestore(&cctx->lock, flags);
-
-	kref_init(&ctx->refcount);
+	ret = xa_alloc_cyclic(&cctx->ctxts, &ctx->ctxid, ctx,
+			XA_LIMIT(0, FASTRPC_CTX_MAX - 1), &cctx->ctxt_nextid,
+			GFP_KERNEL);
+	if (ret < 0)
+		goto err_id;
 
 	return ctx;
-err_idr:
+err_id:
 	spin_lock(&user->lock);
 	list_del(&ctx->node);
 	spin_unlock(&user->lock);
@@ -864,7 +858,7 @@ static int fastrpc_invoke_send(struct fastrpc_session_ctx *sctx,
 	if (kernel)
 		msg->pid = 0;
 
-	msg->ctx = ctx->ctxid | fl->pd;
+	msg->ctx = (ctx->ctxid << 4) | fl->pd;
 	msg->handle = handle;
 	msg->sc = ctx->sc;
 	msg->addr = ctx->buf ? ctx->buf->phys : 0;
@@ -1429,7 +1423,7 @@ static int fastrpc_rpmsg_probe(struct rpmsg_device *rpdev)
 	dma_set_mask_and_coherent(rdev, DMA_BIT_MASK(32));
 	INIT_LIST_HEAD(&data->users);
 	spin_lock_init(&data->lock);
-	idr_init(&data->ctx_idr);
+	xa_init_flags(&data->ctxts, XA_FLAGS_ALLOC1);
 	data->domain_id = domain_id;
 	data->rpdev = rpdev;
 
@@ -1468,7 +1462,6 @@ static int fastrpc_rpmsg_callback(struct rpmsg_device *rpdev, void *data,
 	struct fastrpc_channel_ctx *cctx = dev_get_drvdata(&rpdev->dev);
 	struct fastrpc_invoke_rsp *rsp = data;
 	struct fastrpc_invoke_ctx *ctx;
-	unsigned long flags;
 	unsigned long ctxid;
 
 	if (len < sizeof(*rsp))
@@ -1476,10 +1469,7 @@ static int fastrpc_rpmsg_callback(struct rpmsg_device *rpdev, void *data,
 
 	ctxid = ((rsp->ctx & FASTRPC_CTXID_MASK) >> 4);
 
-	spin_lock_irqsave(&cctx->lock, flags);
-	ctx = idr_find(&cctx->ctx_idr, ctxid);
-	spin_unlock_irqrestore(&cctx->lock, flags);
-
+	ctx = xa_load(&cctx->ctxts, ctxid);
 	if (!ctx) {
 		dev_err(&rpdev->dev, "No context ID matches response\n");
 		return -ENOENT;