Merge tag 'libnvdimm-for-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm updates from Ira Weiny:
 "A kmap conversion and a bug fix this go around:

   - drivers/nvdimm: Use local kmaps

   - nvdimm: virtio_pmem: serialize flush requests"

* tag 'libnvdimm-for-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  nvdimm: virtio_pmem: serialize flush requests
  drivers/nvdimm: Use local kmaps

Author: torvalds

drivers/nvdimm/btt.c

@@ -1104,10 +1104,10 @@ static int btt_data_read(struct arena_info *arena, struct page *page,
 {
 	int ret;
 	u64 nsoff = to_namespace_offset(arena, lba);
-	void *mem = kmap_atomic(page);
+	void *mem = kmap_local_page(page);
 
 	ret = arena_read_bytes(arena, nsoff, mem + off, len, NVDIMM_IO_ATOMIC);
-	kunmap_atomic(mem);
+	kunmap_local(mem);
 
 	return ret;
 }
@@ -1117,20 +1117,20 @@ static int btt_data_write(struct arena_info *arena, u32 lba,
 {
 	int ret;
 	u64 nsoff = to_namespace_offset(arena, lba);
-	void *mem = kmap_atomic(page);
+	void *mem = kmap_local_page(page);
 
 	ret = arena_write_bytes(arena, nsoff, mem + off, len, NVDIMM_IO_ATOMIC);
-	kunmap_atomic(mem);
+	kunmap_local(mem);
 
 	return ret;
 }
 
 static void zero_fill_data(struct page *page, unsigned int off, u32 len)
 {
-	void *mem = kmap_atomic(page);
+	void *mem = kmap_local_page(page);
 
 	memset(mem + off, 0, len);
-	kunmap_atomic(mem);
+	kunmap_local(mem);
 }
 
 #ifdef CONFIG_BLK_DEV_INTEGRITY

drivers/nvdimm/nd_virtio.c

@@ -44,6 +44,8 @@ static int virtio_pmem_flush(struct nd_region *nd_region)
 	unsigned long flags;
 	int err, err1;
 
+	guard(mutex)(&vpmem->flush_lock);
+
 	/*
 	 * Don't bother to submit the request to the device if the device is
 	 * not activated.
@@ -53,7 +55,6 @@ static int virtio_pmem_flush(struct nd_region *nd_region)
 		return -EIO;
 	}
 
-	might_sleep();
 	req_data = kmalloc(sizeof(*req_data), GFP_KERNEL);
 	if (!req_data)
 		return -ENOMEM;

drivers/nvdimm/pmem.c

@@ -128,10 +128,10 @@ static void write_pmem(void *pmem_addr, struct page *page,
 	void *mem;
 
 	while (len) {
-		mem = kmap_atomic(page);
+		mem = kmap_local_page(page);
 		chunk = min_t(unsigned int, len, PAGE_SIZE - off);
 		memcpy_flushcache(pmem_addr, mem + off, chunk);
-		kunmap_atomic(mem);
+		kunmap_local(mem);
 		len -= chunk;
 		off = 0;
 		page++;
@@ -147,10 +147,10 @@ static blk_status_t read_pmem(struct page *page, unsigned int off,
 	void *mem;
 
 	while (len) {
-		mem = kmap_atomic(page);
+		mem = kmap_local_page(page);
 		chunk = min_t(unsigned int, len, PAGE_SIZE - off);
 		rem = copy_mc_to_kernel(mem + off, pmem_addr, chunk);
-		kunmap_atomic(mem);
+		kunmap_local(mem);
 		if (rem)
 			return BLK_STS_IOERR;
 		len -= chunk;

drivers/nvdimm/virtio_pmem.c

@@ -64,6 +64,7 @@ static int virtio_pmem_probe(struct virtio_device *vdev)
 		goto out_err;
 	}
 
+	mutex_init(&vpmem->flush_lock);
 	vpmem->vdev = vdev;
 	vdev->priv = vpmem;
 	err = init_vq(vpmem);

drivers/nvdimm/virtio_pmem.h

@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <uapi/linux/virtio_pmem.h>
 #include <linux/libnvdimm.h>
+#include <linux/mutex.h>
 #include <linux/spinlock.h>
 
 struct virtio_pmem_request {
@@ -35,6 +36,9 @@ struct virtio_pmem {
 	/* Virtio pmem request queue */
 	struct virtqueue *req_vq;
 
+	/* Serialize flush requests to the device. */
+	struct mutex flush_lock;
+
 	/* nvdimm bus registers virtio pmem device */
 	struct nvdimm_bus *nvdimm_bus;
 	struct nvdimm_bus_descriptor nd_desc;