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Subject: Re: [PATCH 2/8] lightnvm: show generic geometry in sysfs
To:     Javier Gonzalez <javier@cnexlabs.com>
Cc:     "linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>
References: <1518530768-20956-1-git-send-email-javier@cnexlabs.com>
 <1518530768-20956-3-git-send-email-javier@cnexlabs.com>
 <caa2634b-63bf-3a35-ed53-220aab2bd05a@lightnvm.io>
 <E53B65E9-3D1A-49BB-AA5D-F3D2C4032484@cnexlabs.com>
From:   =?UTF-8?Q?Matias_Bj=c3=b8rling?= <mb@lightnvm.io>
Message-ID: <dc558965-9c1f-26f1-9274-12a6f8057825@lightnvm.io>
Date:   Mon, 19 Feb 2018 08:27:03 +0100
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On 02/16/2018 07:35 AM, Javier Gonzalez wrote:
> 
>> On 15 Feb 2018, at 02.20, Matias Bjørling <mb@lightnvm.io> wrote:
>>
>> On 02/13/2018 03:06 PM, Javier González wrote:
>>> From: Javier González <javier@javigon.com>
>>> Apart from showing the geometry returned by the different identify
>>> commands, provide the generic geometry too, as this is the geometry that
>>> targets will use to describe the device.
>>> Signed-off-by: Javier González <javier@cnexlabs.com>
>>> ---
>>>   drivers/nvme/host/lightnvm.c | 146 ++++++++++++++++++++++++++++---------------
>>>   1 file changed, 97 insertions(+), 49 deletions(-)
>>> diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
>>> index 97739e668602..7bc75182c723 100644
>>> --- a/drivers/nvme/host/lightnvm.c
>>> +++ b/drivers/nvme/host/lightnvm.c
>>> @@ -944,8 +944,27 @@ static ssize_t nvm_dev_attr_show(struct device *dev,
>>>   		return scnprintf(page, PAGE_SIZE, "%u.%u\n",
>>>   						dev_geo->major_ver_id,
>>>   						dev_geo->minor_ver_id);
>>> -	} else if (strcmp(attr->name, "capabilities") == 0) {
>>> -		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.cap);
>>> +	} else if (strcmp(attr->name, "clba") == 0) {
>>> +		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.clba);
>>> +	} else if (strcmp(attr->name, "csecs") == 0) {
>>> +		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.csecs);
>>> +	} else if (strcmp(attr->name, "sos") == 0) {
>>> +		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.sos);
>>> +	} else if (strcmp(attr->name, "ws_min") == 0) {
>>> +		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.ws_min);
>>> +	} else if (strcmp(attr->name, "ws_opt") == 0) {
>>> +		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.ws_opt);
>>> +	} else if (strcmp(attr->name, "maxoc") == 0) {
>>> +		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.maxoc);
>>> +	} else if (strcmp(attr->name, "maxocpu") == 0) {
>>> +		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.maxocpu);
>>> +	} else if (strcmp(attr->name, "mw_cunits") == 0) {
>>> +		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.mw_cunits);
>>> +	} else if (strcmp(attr->name, "media_capabilities") == 0) {
>>> +		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.mccap);
>>> +	} else if (strcmp(attr->name, "max_phys_secs") == 0) {
>>> +		return scnprintf(page, PAGE_SIZE, "%u\n",
>>> +				ndev->ops->max_phys_sect);
>>>   	} else if (strcmp(attr->name, "read_typ") == 0) {
>>>   		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.trdt);
>>>   	} else if (strcmp(attr->name, "read_max") == 0) {
>>> @@ -984,19 +1003,8 @@ static ssize_t nvm_dev_attr_show_12(struct device *dev,
>>>     	attr = &dattr->attr;
>>>   -	if (strcmp(attr->name, "vendor_opcode") == 0) {
>>> -		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.vmnt);
>>> -	} else if (strcmp(attr->name, "device_mode") == 0) {
>>> -		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.dom);
>>> -	/* kept for compatibility */
>>> -	} else if (strcmp(attr->name, "media_manager") == 0) {
>>> -		return scnprintf(page, PAGE_SIZE, "%s\n", "gennvm");
>>> -	} else if (strcmp(attr->name, "ppa_format") == 0) {
>>> +	if (strcmp(attr->name, "ppa_format") == 0) {
>>>   		return nvm_dev_attr_show_ppaf((void *)&dev_geo->c.addrf, page);
>>> -	} else if (strcmp(attr->name, "media_type") == 0) {	/* u8 */
>>> -		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.mtype);
>>> -	} else if (strcmp(attr->name, "flash_media_type") == 0) {
>>> -		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.fmtype);
>>>   	} else if (strcmp(attr->name, "num_channels") == 0) {
>>>   		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->num_ch);
>>>   	} else if (strcmp(attr->name, "num_luns") == 0) {
>>> @@ -1011,8 +1019,6 @@ static ssize_t nvm_dev_attr_show_12(struct device *dev,
>>>   		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.fpg_sz);
>>>   	} else if (strcmp(attr->name, "hw_sector_size") == 0) {
>>>   		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.csecs);
>>> -	} else if (strcmp(attr->name, "oob_sector_size") == 0) {/* u32 */
>>> -		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.sos);
>>>   	} else if (strcmp(attr->name, "prog_typ") == 0) {
>>>   		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.tprt);
>>>   	} else if (strcmp(attr->name, "prog_max") == 0) {
>>> @@ -1021,13 +1027,21 @@ static ssize_t nvm_dev_attr_show_12(struct device *dev,
>>>   		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.tbet);
>>>   	} else if (strcmp(attr->name, "erase_max") == 0) {
>>>   		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.tbem);
>>> +	} else if (strcmp(attr->name, "vendor_opcode") == 0) {
>>> +		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.vmnt);
>>> +	} else if (strcmp(attr->name, "device_mode") == 0) {
>>> +		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.dom);
>>> +	/* kept for compatibility */
>>> +	} else if (strcmp(attr->name, "media_manager") == 0) {
>>> +		return scnprintf(page, PAGE_SIZE, "%s\n", "gennvm");
>>> +	} else if (strcmp(attr->name, "capabilities") == 0) {
>>> +		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.cap);
>>> +	} else if (strcmp(attr->name, "media_type") == 0) {	/* u8 */
>>> +		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.mtype);
>>> +	} else if (strcmp(attr->name, "flash_media_type") == 0) {
>>> +		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.fmtype);
>>>   	} else if (strcmp(attr->name, "multiplane_modes") == 0) {
>>>   		return scnprintf(page, PAGE_SIZE, "0x%08x\n", dev_geo->c.mpos);
>>> -	} else if (strcmp(attr->name, "media_capabilities") == 0) {
>>> -		return scnprintf(page, PAGE_SIZE, "0x%08x\n", dev_geo->c.mccap);
>>> -	} else if (strcmp(attr->name, "max_phys_secs") == 0) {
>>> -		return scnprintf(page, PAGE_SIZE, "%u\n",
>>> -				ndev->ops->max_phys_sect);
>>>   	} else {
>>>   		return scnprintf(page, PAGE_SIZE,
>>>   			"Unhandled attr(%s) in `nvm_dev_attr_show_12`\n",
>>> @@ -1035,6 +1049,17 @@ static ssize_t nvm_dev_attr_show_12(struct device *dev,
>>>   	}
>>>   }
>>>   +static ssize_t nvm_dev_attr_show_lbaf(struct nvm_addr_format *lbaf,
>>> +					 char *page)
>>> +{
>>> +	return scnprintf(page, PAGE_SIZE,
>>> +		"0x%02x%02x%02x%02x%02x%02x%02x%02x\n",
>>> +				lbaf->ch_offset, lbaf->ch_len,
>>> +				lbaf->lun_offset, lbaf->lun_len,
>>> +				lbaf->chk_offset, lbaf->chk_len,
>>> +				lbaf->sec_offset, lbaf->sec_len);
>>> +}
>>> +
>>>   static ssize_t nvm_dev_attr_show_20(struct device *dev,
>>>   		struct device_attribute *dattr, char *page)
>>>   {
>>> @@ -1048,20 +1073,14 @@ static ssize_t nvm_dev_attr_show_20(struct device *dev,
>>>     	attr = &dattr->attr;
>>>   -	if (strcmp(attr->name, "groups") == 0) {
>>> +	if (strcmp(attr->name, "lba_format") == 0) {
>>> +		return nvm_dev_attr_show_lbaf((void *)&dev_geo->c.addrf, page);
>>> +	} else if (strcmp(attr->name, "groups") == 0) {
>>>   		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->num_ch);
>>>   	} else if (strcmp(attr->name, "punits") == 0) {
>>>   		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->num_lun);
>>>   	} else if (strcmp(attr->name, "chunks") == 0) {
>>>   		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.num_chk);
>>> -	} else if (strcmp(attr->name, "clba") == 0) {
>>> -		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.clba);
>>> -	} else if (strcmp(attr->name, "ws_min") == 0) {
>>> -		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.ws_min);
>>> -	} else if (strcmp(attr->name, "ws_opt") == 0) {
>>> -		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.ws_opt);
>>> -	} else if (strcmp(attr->name, "mw_cunits") == 0) {
>>> -		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.mw_cunits);
>>>   	} else if (strcmp(attr->name, "write_typ") == 0) {
>>>   		return scnprintf(page, PAGE_SIZE, "%u\n", dev_geo->c.tprt);
>>>   	} else if (strcmp(attr->name, "write_max") == 0) {
>>> @@ -1086,7 +1105,19 @@ static ssize_t nvm_dev_attr_show_20(struct device *dev,
>>>     /* general attributes */
>>>   static NVM_DEV_ATTR_RO(version);
>>> -static NVM_DEV_ATTR_RO(capabilities);
>>> +
>>> +static NVM_DEV_ATTR_RO(ws_min);
>>> +static NVM_DEV_ATTR_RO(ws_opt);
>>> +static NVM_DEV_ATTR_RO(mw_cunits);
>>> +static NVM_DEV_ATTR_RO(maxoc);
>>> +static NVM_DEV_ATTR_RO(maxocpu);
>>> +
>>> +static NVM_DEV_ATTR_RO(media_capabilities);
>>> +static NVM_DEV_ATTR_RO(max_phys_secs);
>>> +
>>> +static NVM_DEV_ATTR_RO(clba);
>>> +static NVM_DEV_ATTR_RO(csecs);
>>> +static NVM_DEV_ATTR_RO(sos);
>>>     static NVM_DEV_ATTR_RO(read_typ);
>>>   static NVM_DEV_ATTR_RO(read_max);
>>> @@ -1105,42 +1136,53 @@ static NVM_DEV_ATTR_12_RO(num_blocks);
>>>   static NVM_DEV_ATTR_12_RO(num_pages);
>>>   static NVM_DEV_ATTR_12_RO(page_size);
>>>   static NVM_DEV_ATTR_12_RO(hw_sector_size);
>>> -static NVM_DEV_ATTR_12_RO(oob_sector_size);
>>>   static NVM_DEV_ATTR_12_RO(prog_typ);
>>>   static NVM_DEV_ATTR_12_RO(prog_max);
>>>   static NVM_DEV_ATTR_12_RO(erase_typ);
>>>   static NVM_DEV_ATTR_12_RO(erase_max);
>>>   static NVM_DEV_ATTR_12_RO(multiplane_modes);
>>> -static NVM_DEV_ATTR_12_RO(media_capabilities);
>>> -static NVM_DEV_ATTR_12_RO(max_phys_secs);
>>> +static NVM_DEV_ATTR_12_RO(capabilities);
>>>     static struct attribute *nvm_dev_attrs_12[] = {
>>>   	&dev_attr_version.attr,
>>> -	&dev_attr_capabilities.attr,
>>> -
>>> -	&dev_attr_vendor_opcode.attr,
>>> -	&dev_attr_device_mode.attr,
>>> -	&dev_attr_media_manager.attr,
>>>   	&dev_attr_ppa_format.attr,
>>> -	&dev_attr_media_type.attr,
>>> -	&dev_attr_flash_media_type.attr,
>>> +
>>>   	&dev_attr_num_channels.attr,
>>>   	&dev_attr_num_luns.attr,
>>>   	&dev_attr_num_planes.attr,
>>>   	&dev_attr_num_blocks.attr,
>>>   	&dev_attr_num_pages.attr,
>>>   	&dev_attr_page_size.attr,
>>> +
>>>   	&dev_attr_hw_sector_size.attr,
>>> -	&dev_attr_oob_sector_size.attr,
>>> +
>>> +	&dev_attr_clba.attr,
>>> +	&dev_attr_csecs.attr,
>>> +	&dev_attr_sos.attr,
>>> +
>>> +	&dev_attr_ws_min.attr,
>>> +	&dev_attr_ws_opt.attr,
>>> +	&dev_attr_maxoc.attr,
>>> +	&dev_attr_maxocpu.attr,
>>> +	&dev_attr_mw_cunits.attr,
>>> +
>>> +	&dev_attr_media_capabilities.attr,
>>> +	&dev_attr_max_phys_secs.attr,
>>> +
>>
>> This breaks user-space. The intention is for user-space to decide
>> based on version id. Then it can either retrieve the 1.2 or 2.0
>> attributes. The 2.0 attributes should not be available when a device
>> is 1.2.
>>
> 
> Why does it break it? I'm only adding new entries.
> 
> The objective is to expose the genneric geometry, since this is the
> structure that is passed on to the targets. Since some of the values are
> calculated, there is value on exposing this information, I believe.
> 
> Another way of doing it, is adding the generic geometry at the target
> level, showing what base values it is getting, including the real number
> of channels/groups and luns/pus.
> 
> Would this be better in your opinion?
> 

No. It should be one set of attributes for 1.2 (keep the way it is 
today), and then separate 2.0 attributes. User-space should then 
identify either by either 1 or 2 in the version attribute.

> 
>>>   	&dev_attr_read_typ.attr,
>>>   	&dev_attr_read_max.attr,
>>>   	&dev_attr_prog_typ.attr,
>>>   	&dev_attr_prog_max.attr,
>>>   	&dev_attr_erase_typ.attr,
>>>   	&dev_attr_erase_max.attr,
>>> +
>>> +	&dev_attr_vendor_opcode.attr,
>>> +	&dev_attr_device_mode.attr,
>>> +	&dev_attr_media_manager.attr,
>>> +	&dev_attr_capabilities.attr,
>>> +	&dev_attr_media_type.attr,
>>> +	&dev_attr_flash_media_type.attr,
>>>   	&dev_attr_multiplane_modes.attr,
>>> -	&dev_attr_media_capabilities.attr,
>>> -	&dev_attr_max_phys_secs.attr,
>>>     	NULL,
>>>   };
>>> @@ -1152,12 +1194,9 @@ static const struct attribute_group nvm_dev_attr_group_12 = {
>>>     /* 2.0 values */
>>>   static NVM_DEV_ATTR_20_RO(groups);
>>> +static NVM_DEV_ATTR_20_RO(lba_format);
>>>   static NVM_DEV_ATTR_20_RO(punits);
>>>   static NVM_DEV_ATTR_20_RO(chunks);
>>> -static NVM_DEV_ATTR_20_RO(clba);
>>> -static NVM_DEV_ATTR_20_RO(ws_min);
>>> -static NVM_DEV_ATTR_20_RO(ws_opt);
>>> -static NVM_DEV_ATTR_20_RO(mw_cunits);
>>>   static NVM_DEV_ATTR_20_RO(write_typ);
>>>   static NVM_DEV_ATTR_20_RO(write_max);
>>>   static NVM_DEV_ATTR_20_RO(reset_typ);
>>> @@ -1165,16 +1204,25 @@ static NVM_DEV_ATTR_20_RO(reset_max);
>>>     static struct attribute *nvm_dev_attrs_20[] = {
>>>   	&dev_attr_version.attr,
>>> -	&dev_attr_capabilities.attr,
>>> +	&dev_attr_lba_format.attr,
>>>     	&dev_attr_groups.attr,
>>>   	&dev_attr_punits.attr,
>>>   	&dev_attr_chunks.attr,
>>> +
>>>   	&dev_attr_clba.attr,
>>> +	&dev_attr_csecs.attr,
>>> +	&dev_attr_sos.attr,
>>
>> csecs and sos are derived from the the generic block device data structures.
> 
> As mentioned above, it is to represent the generic geometry.

They are not part of the 2.0 spec. The fields can be derived from elsewhere.

> 
>>
>>> +
>>>   	&dev_attr_ws_min.attr,
>>>   	&dev_attr_ws_opt.attr,
>>> +	&dev_attr_maxoc.attr,
>>> +	&dev_attr_maxocpu.attr,
>>
>> When the maxoc/maxocpu are in another patch, these changes can be included.
> 
> ok.
> 
>>
>>>   	&dev_attr_mw_cunits.attr,
>>>   +	&dev_attr_media_capabilities.attr,
>>
>> What is the meaning of media in this context? The 2.0 spec defines
>> vector copy and double resets in its capabilities, it does not have
>> media in mind.
>>
> 
> It refers to the mcap (vector copy and double resets for now, as you
> mention). I kept the name, name, but I can rename it if it is better...
> 
>>> +	&dev_attr_max_phys_secs.attr,
>>> +
>>
>> I kill max_phys_secs in another patch. It has been made redundant
>> after null_blk has been removed.
> 
> I'll answer this on the patch - I have a questions here.
> 
>>>   	&dev_attr_read_typ.attr,
>>>   	&dev_attr_read_max.attr,
>>>   	&dev_attr_write_typ.attr,
> 
> Javier
>