From: Matthew Wilcox <willy@infradead.org>
Date: Tue, 12 Feb 2019 21:17:48 +0000 (-0500)
Subject: cxl: Convert adapter_idr to XArray
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=021b93e462fc8aa03b8bbaa1badcfd2b1215807c;p=users%2Fwilly%2Fxarray.git

cxl: Convert adapter_idr to XArray

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

diff --git a/drivers/misc/cxl/main.c b/drivers/misc/cxl/main.c
index 5fddec36b945..802ad5e2ac26 100644
--- a/drivers/misc/cxl/main.c
+++ b/drivers/misc/cxl/main.c
@@ -13,9 +13,9 @@
 #include <linux/mm.h>
 #include <linux/of.h>
 #include <linux/slab.h>
-#include <linux/idr.h>
 #include <linux/pci.h>
 #include <linux/sched/task.h>
+#include <linux/xarray.h>
 
 #include <asm/cputable.h>
 #include <misc/cxl-base.h>
@@ -23,8 +23,7 @@
 #include "cxl.h"
 #include "trace.h"
 
-static DEFINE_SPINLOCK(adapter_idr_lock);
-static DEFINE_IDR(cxl_adapter_idr);
+static DEFINE_XARRAY_ALLOC(cxl_adapters);
 
 uint cxl_verbose;
 module_param_named(verbose, cxl_verbose, uint, 0600);
@@ -76,13 +75,13 @@ static inline void cxl_slbia_core(struct mm_struct *mm)
 	struct cxl *adapter;
 	struct cxl_afu *afu;
 	struct cxl_context *ctx;
-	unsigned long index;
-	int card, slice;
+	unsigned long card, index;
+	int slice;
 
 	pr_devel("%s called\n", __func__);
 
-	spin_lock(&adapter_idr_lock);
-	idr_for_each_entry(&cxl_adapter_idr, adapter, card) {
+	xa_lock(&cxl_adapters);
+	xa_for_each(&cxl_adapters, card, adapter) {
 		/* XXX: Make this lookup faster with link from mm to ctx */
 		spin_lock(&adapter->afu_list_lock);
 		for (slice = 0; slice < adapter->slices; slice++) {
@@ -94,7 +93,7 @@ static inline void cxl_slbia_core(struct mm_struct *mm)
 		}
 		spin_unlock(&adapter->afu_list_lock);
 	}
-	spin_unlock(&adapter_idr_lock);
+	xa_unlock(&cxl_adapters);
 }
 
 static struct cxl_calls cxl_calls = {
@@ -182,34 +181,24 @@ struct cxl *get_cxl_adapter(int num)
 {
 	struct cxl *adapter;
 
-	spin_lock(&adapter_idr_lock);
-	if ((adapter = idr_find(&cxl_adapter_idr, num)))
+	xa_lock(&cxl_adapters);
+	adapter = xa_load(&cxl_adapters, num);
+	if (adapter)
 		get_device(&adapter->dev);
-	spin_unlock(&adapter_idr_lock);
+	xa_unlock(&cxl_adapters);
 
 	return adapter;
 }
 
 static int cxl_alloc_adapter_nr(struct cxl *adapter)
 {
-	int i;
-
-	idr_preload(GFP_KERNEL);
-	spin_lock(&adapter_idr_lock);
-	i = idr_alloc(&cxl_adapter_idr, adapter, 0, 0, GFP_NOWAIT);
-	spin_unlock(&adapter_idr_lock);
-	idr_preload_end();
-	if (i < 0)
-		return i;
-
-	adapter->adapter_num = i;
-
-	return 0;
+	return xa_alloc(&cxl_adapters, &adapter->adapter_num, adapter,
+			xa_limit_32b, GFP_KERNEL);
 }
 
 void cxl_remove_adapter_nr(struct cxl *adapter)
 {
-	idr_remove(&cxl_adapter_idr, adapter->adapter_num);
+	xa_erase(&cxl_adapters, adapter->adapter_num);
 }
 
 struct cxl *cxl_alloc_adapter(void)
@@ -366,7 +355,6 @@ static void exit_cxl(void)
 	cxl_file_exit();
 	if (cxl_is_power8())
 		unregister_cxl_calls(&cxl_calls);
-	idr_destroy(&cxl_adapter_idr);
 }
 
 module_init(init_cxl);
diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index 74597685db8a..582522ab7bc8 100644
--- a/drivers/misc/cxl/pci.c
+++ b/drivers/misc/cxl/pci.c
@@ -912,9 +912,7 @@ static int cxl_afu_descriptor_looks_ok(struct cxl_afu *afu)
 		 * in that case we ignore the value and I'd rather not risk
 		 * breaking any existing dedicated process AFUs that left it as
 		 * 0 (not that I'm aware of any). It is clearly an error for an
-		 * AFU directed AFU to set this to 0, and would have previously
-		 * triggered a bug resulting in the maximum not being enforced
-		 * at all since idr_alloc treats 0 as no maximum.
+		 * AFU directed AFU to set this to 0.
 		 */
 		dev_err(&afu->dev, "AFU does not support any processes\n");
 		return -EINVAL;