Re: [PATCH 09/15] lightnvm: implement get log report chunk helpers

[Matias BjÃrling]

On 02/28/2018 04:49 PM, Javier GonzÃlez wrote:
> 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 GonzÃlez <javier@xxxxxxxxxxxx>
> ---
>   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?