[PATCH RFC 4/5] lightnvm: introduce nvm_submit_ppa

["Matias Bjørling" <m@bjorling.me>]

Internal logic for both core and media managers, does not have a
backing bio for issuing I/Os. Introduce nvm_submit_ppa to allow raw
I/Os to be submitted to the underlying device driver.

The function request the device, ppa, data buffer and its length and
will submit the I/O synchronously to the device. The return value may
therefore be used to detect any errors regarding the issued I/O.

Signed-off-by: Matias Bjørling <m@bjorling.me>
---
 drivers/lightnvm/core.c  | 31 +++++++++++++++++++++++++++++++
 include/linux/lightnvm.h |  1 +
 2 files changed, 32 insertions(+)

diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index 081b0f5..77a9907 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -288,6 +288,37 @@ int nvm_erase_ppa(struct nvm_dev *dev, struct ppa_addr ppa)
 }
 EXPORT_SYMBOL(nvm_erase_ppa);
 
+int nvm_submit_ppa(struct nvm_dev *dev, struct ppa_addr ppa, int opcode,
+							void *buf, int len)
+{
+	struct nvm_rq rqd;
+	struct bio *bio;
+	int ret;
+
+	bio = bio_map_kern(dev->q, buf, len, GFP_KERNEL);
+	if (IS_ERR_OR_NULL(bio))
+		return -ENOMEM;
+
+	memset(&rqd, 0, sizeof(struct nvm_rq));
+	ret = nvm_set_rqd_ppalist(dev, &rqd, &ppa, 1);
+	if (ret) {
+		bio_put(bio);
+		return ret;
+	}
+
+	rqd.opcode = opcode;
+	rqd.flags = NVM_IO_F_SYNC;
+	rqd.bio = bio;
+	nvm_generic_to_addr_mode(dev, &rqd);
+
+	ret = dev->ops->submit_io(dev, &rqd);
+
+	nvm_free_rqd_ppalist(dev, &rqd);
+
+	return ret;
+}
+EXPORT_SYMBOL(nvm_submit_ppa);
+
 static int nvm_core_init(struct nvm_dev *dev)
 {
 	struct nvm_id *id = &dev->identity;
diff --git a/include/linux/lightnvm.h b/include/linux/lightnvm.h
index 770278a..0017d55 100644
--- a/include/linux/lightnvm.h
+++ b/include/linux/lightnvm.h
@@ -437,6 +437,7 @@ extern int nvm_set_rqd_ppalist(struct nvm_dev *, struct nvm_rq *,
 extern void nvm_free_rqd_ppalist(struct nvm_dev *, struct nvm_rq *);
 extern int nvm_erase_ppa(struct nvm_dev *, struct ppa_addr);
 extern int nvm_erase_blk(struct nvm_dev *, struct nvm_block *);
+extern int nvm_submit_ppa(struct nvm_dev *, struct ppa_addr, int, void *, int);
 #else /* CONFIG_NVM */
 struct nvm_dev_ops;
 
-- 
2.1.4