Simon, Heinrich, On Mon, Oct 11, 2021 at 10:14:02AM -0600, Simon Glass wrote: > Hi Heinrich, > > On Mon, 11 Oct 2021 at 09:09, Heinrich Schuchardt <xypron.g...@gmx.de> wrote: > > > > > > > > On 10/11/21 16:32, Simon Glass wrote: > > > Hi Heinrich, > > > > > > On Mon, 11 Oct 2021 at 04:07, Heinrich Schuchardt <xypron.g...@gmx.de> > > > wrote: > > >> > > >> > > >> > > >> On 10/1/21 13:48, Peter Robinson wrote: > > >>> On Fri, Oct 1, 2021 at 6:03 AM AKASHI Takahiro > > >>> <takahiro.aka...@linaro.org> wrote: > > >>>> > > >>>> In blk_get_device_by_str(), the comment says: "Updates the partition > > >>>> table > > >>>> for the specified hw partition." > > >>>> Since hw partition is supported only on MMC, it makes no sense to do so > > >>>> for other devices. > > >>> > > >>> Is it not also supported on UFS, and I believe it may also be an > > >>> option in the NVME spec too. > > >> > > >> An NVMe device may expose multiple namespaces. blk_create_devicef() is > > >> called for each namespace. > > >> > > >> A SCSI device may have multiple LUNs. blk_create_devicef() is called for > > >> each LUN. > > >> > > >> This is what the tree shown by 'dm tree' with on NVMe namespace and one > > >> LUN. > > >> > > >> Class Index Driver Name > > >> --------------------------------------------------------------------- > > >> root 0 root_driver root_driver > > >> simple_bus 0 simple_bus |- soc > > >> spi 1 sifive_spi | |- spi@10050000 > > >> mmc 0 mmc_spi | | `- mmc@0 > > >> blk 0 mmc_blk | | `- m...@0.blk > > >> pci 0 pcie_sifive | |- pcie@e00000000 > > >> pci 1 pci_bridge_drv | | `- pci_0:0.0 > > >> pci 2 pci_bridge_drv | | `- pci_1:0.0 > > >> pci 5 pci_bridge_drv | | |- pci_2:3.0 > > >> ahci 0 ahci_pci | | | `- ahci_pci > > >> scsi 0 ahci_scsi | | | `- ahci_scsi > > >> blk 2 scsi_blk | | | `- ahci_scsi.id0lun0 > > >> pci 6 pci_bridge_drv | | |- pci_2:4.0 > > >> nvme 0 nvme | | | `- nvme#0 > > >> blk 1 nvme-blk | | | `- nvme#0.blk#1 > > >> > > >> Namespaces and LUNs are modeled as block devices (class = 'blk'). > > > > > > So multiple block devices per NVMe device? I did not know that was > > > supported. > > > > > > We need a sandbox driver for NVMe as it has no tests at present. Since > > > it has no tests, I don't think we can expect people to know how to > > > maintain whatever functionality is there. > > > > NVMe drives with multiple namespaces exist for servers but not for > > consumer NVMe drives. > > > > In QEMU you can define an NVMe device with multiple namespaces. Cf. > > https://qemu.readthedocs.io/en/latest/system/devices/nvme.html?highlight=namespace#additional-namespaces > > > > So for a first glimpse at the handling I suggest to use QEMU. > > Well that's fine, but every uclass must have a test and a sandbox > emulator as well.
Wait, it seems that you're discussing a different thing from my patch. While I don't know whether NVMe namespaces are a kind of "HW partitions", we don't care much here as long as any namespace can be handled simply as a normal block device, like scsi LUN's, in terms of U-Boot driver model. # On the other hand, we have to explicitly switch "hw partitions" # with blk_select_hwpart_devnum() on MMC devices even though we use # the *same* udevice(blk_desc). # See do_mmcrpmb() in cmd/mmc.c So I hope that *your* discussion doesn't make any difference to my patch. Right? -Takahiro Akashi > Regards, > Simon
