On 1 Mar 2018, at 11.40, Matias Bjørling [off-list ref] wrote:

On 02/28/2018 04:49 PM, Javier González wrote:

quoted

The 2.0 spec provides a report chunk log page that can be retrieved
using the stangard nvme get log page. This replaces the dedicated
get/put bad block table in 1.2.
This patch implements the helper functions to allow targets retrieve the
chunk metadata using get log page. It makes nvme_get_log_ext available
outside of nvme core so that we can use it form lightnvm.
Signed-off-by: Javier González <redacted>
---
 drivers/lightnvm/core.c      | 11 +++++++
 drivers/nvme/host/core.c     |  6 ++--
 drivers/nvme/host/lightnvm.c | 74 ++++++++++++++++++++++++++++++++++++++++++++
 drivers/nvme/host/nvme.h     |  3 ++
 include/linux/lightnvm.h     | 24 ++++++++++++++
 5 files changed, 115 insertions(+), 3 deletions(-)

diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index ed33e0b11788..4141871f460d 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c

@@ -712,6 +712,17 @@ static void nvm_free_rqd_ppalist(struct nvm_tgt_dev *tgt_dev,
 	nvm_dev_dma_free(tgt_dev->parent, rqd->ppa_list, rqd->dma_ppa_list);
 }
 +int nvm_get_chunk_meta(struct nvm_tgt_dev *tgt_dev, struct nvm_chk_meta *meta,
+		struct ppa_addr ppa, int nchks)
+{
+	struct nvm_dev *dev = tgt_dev->parent;
+
+	nvm_ppa_tgt_to_dev(tgt_dev, &ppa, 1);
+
+	return dev->ops->get_chk_meta(tgt_dev->parent, meta,
+						(sector_t)ppa.ppa, nchks);
+}
+EXPORT_SYMBOL(nvm_get_chunk_meta);
   int nvm_set_tgt_bb_tbl(struct nvm_tgt_dev *tgt_dev, struct ppa_addr *ppas,
 		       int nr_ppas, int type)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 2e9e9f973a75..af642ce6ba69 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c

@@ -2127,9 +2127,9 @@ static int nvme_init_subsystem(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
 	return ret;
 }
 -static int nvme_get_log_ext(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
-			    u8 log_page, void *log,
-			    size_t size, size_t offset)
+int nvme_get_log_ext(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
+		     u8 log_page, void *log,
+		     size_t size, size_t offset)
 {
 	struct nvme_command c = { };
 	unsigned long dwlen = size / 4 - 1;

diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
index f7135659f918..a1796241040f 100644
--- a/drivers/nvme/host/lightnvm.c
+++ b/drivers/nvme/host/lightnvm.c

@@ -35,6 +35,10 @@ enum nvme_nvm_admin_opcode {
 	nvme_nvm_admin_set_bb_tbl	= 0xf1,
 };
 +enum nvme_nvm_log_page {
+	NVME_NVM_LOG_REPORT_CHUNK	= 0xca,
+};
+
 struct nvme_nvm_ph_rw {
 	__u8			opcode;
 	__u8			flags;

@@ -236,6 +240,16 @@ struct nvme_nvm_id20 {
 	__u8			vs[1024];
 };
 +struct nvme_nvm_chk_meta {
+	__u8	state;
+	__u8	type;
+	__u8	wi;
+	__u8	rsvd[5];
+	__le64	slba;
+	__le64	cnlb;
+	__le64	wp;
+};
+
 /*
  * Check we didn't inadvertently grow the command struct
  */

@@ -252,6 +266,9 @@ static inline void _nvme_nvm_check_size(void)
 	BUILD_BUG_ON(sizeof(struct nvme_nvm_bb_tbl) != 64);
 	BUILD_BUG_ON(sizeof(struct nvme_nvm_id20_addrf) != 8);
 	BUILD_BUG_ON(sizeof(struct nvme_nvm_id20) != NVME_IDENTIFY_DATA_SIZE);
+	BUILD_BUG_ON(sizeof(struct nvme_nvm_chk_meta) != 32);
+	BUILD_BUG_ON(sizeof(struct nvme_nvm_chk_meta) !=
+						sizeof(struct nvm_chk_meta));
 }
   static void nvme_nvm_set_addr_12(struct nvm_addr_format_12 *dst,

@@ -555,6 +572,61 @@ static int nvme_nvm_set_bb_tbl(struct nvm_dev *nvmdev, struct ppa_addr *ppas,
 	return ret;
 }
 +/*
+ * Expect the lba in device format
+ */
+static int nvme_nvm_get_chk_meta(struct nvm_dev *ndev,
+				 struct nvm_chk_meta *meta,
+				 sector_t slba, int nchks)
+{
+	struct nvm_geo *geo = &ndev->geo;
+	struct nvme_ns *ns = ndev->q->queuedata;
+	struct nvme_ctrl *ctrl = ns->ctrl;
+	struct nvme_nvm_chk_meta *dev_meta = (struct nvme_nvm_chk_meta *)meta;
+	struct ppa_addr ppa;
+	size_t left = nchks * sizeof(struct nvme_nvm_chk_meta);
+	size_t log_pos, offset, len;
+	int ret, i;
+
+	/* Normalize lba address space to obtain log offset */
+	ppa.ppa = slba;
+	ppa = dev_to_generic_addr(ndev, ppa);
+
+	log_pos = ppa.m.chk;
+	log_pos += ppa.m.pu * geo->num_chk;
+	log_pos += ppa.m.grp * geo->num_lun * geo->num_chk;

Why is this done?

The log page does not map to the lba space. You need to convert it to
get one chunk at a time in the format.

   GRP:PU:CHK

I can see why taking a lba as argument is better than a ppa, since users
might use the lbas directly, but the conversion needs to be done
somewhere.

Javier