On 3/5/19 2:51 PM, Igor Konopko wrote:
Current lightnvm and pblk implementation does not care about NVMe max
data transfer size, which can be smaller than 64*K=256K. There are
existing NVMe controllers which NVMe max data transfer size is lower
that 256K (for example 128K, which happens for existing NVMe
controllers which are NVMe spec compliant). Such a controllers are not
able to handle command which contains 64 PPAs, since the the size of
DMAed buffer will be above the capabilities of such a controller.
Signed-off-by: Igor Konopko <igor.j.konopko@xxxxxxxxx>
Reviewed-by: Javier González <javier@xxxxxxxxxxx>
---
drivers/lightnvm/core.c | 9 +++++++--
drivers/nvme/host/lightnvm.c | 1 +
include/linux/lightnvm.h | 1 +
3 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index 5f82036..c01f83b 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -325,6 +325,7 @@ static int nvm_create_tgt(struct nvm_dev *dev, struct nvm_ioctl_create *create)
struct nvm_target *t;
struct nvm_tgt_dev *tgt_dev;
void *targetdata;
+ unsigned int mdts;
int ret;
switch (create->conf.type) {
@@ -412,8 +413,12 @@ static int nvm_create_tgt(struct nvm_dev *dev, struct nvm_ioctl_create *create)
tdisk->private_data = targetdata;
tqueue->queuedata = targetdata;
- blk_queue_max_hw_sectors(tqueue,
- (dev->geo.csecs >> 9) * NVM_MAX_VLBA);
+ mdts = (dev->geo.csecs >> 9) * NVM_MAX_VLBA;
+ if (dev->geo.mdts) {
+ mdts = min_t(u32, dev->geo.mdts,
+ (dev->geo.csecs >> 9) * NVM_MAX_VLBA);
+ }
+ blk_queue_max_hw_sectors(tqueue, mdts);
set_capacity(tdisk, tt->capacity(targetdata));
add_disk(tdisk);
diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
index 949e29e..4f20a10 100644
--- a/drivers/nvme/host/lightnvm.c
+++ b/drivers/nvme/host/lightnvm.c
@@ -977,6 +977,7 @@ int nvme_nvm_register(struct nvme_ns *ns, char *disk_name, int node)
geo->csecs = 1 << ns->lba_shift;
geo->sos = ns->ms;
geo->ext = ns->ext;
+ geo->mdts = ns->ctrl->max_hw_sectors;
dev->q = q;
memcpy(dev->name, disk_name, DISK_NAME_LEN);
diff --git a/include/linux/lightnvm.h b/include/linux/lightnvm.h
index 5d865a5..d3b0270 100644
--- a/include/linux/lightnvm.h
+++ b/include/linux/lightnvm.h
@@ -358,6 +358,7 @@ struct nvm_geo {
u16 csecs; /* sector size */
u16 sos; /* out-of-band area size */
bool ext; /* metadata in extended data buffer */
+ u32 mdts; /* Max data transfer size*/
/* device write constrains */
u32 ws_min; /* minimum write size */
I think I can pick this up. I'll let Javier/Hans rereview.
Given Javier's feedback on broken existing mdts implementations. When
they are brought to light, we may want to add in a quirk list to update
MDTS accordingly. Javier, will this address the issue you have regarding
using mdts?
-Matias
