On Wed, Feb 13, 2019 at 7:51 AM liaoweixiong <liaoweixiong@xxxxxxxxxxxxxxxxx> wrote: > > > On 2019-01-31 00:07, Rob Herring wrote:> On Wed, Jan 23, 2019 at > 08:05:13PM +0800, liaoweixiong wrote: > >> Create DT binding document for blkoops. > >> > >> Signed-off-by: liaoweixiong <liaoweixiong@xxxxxxxxxxxxxxxxx> > >> --- > >> .../devicetree/bindings/pstore-block/blkoops.txt | 32 ++++++++++++++++++++++ > > > > /bindings/pstore/... > > > > I wouldn't call it blkoops either. I believe ramoops is called that to > > maintain compatibility keeping the same kernel module name that > > preceeded pstore. > > > > Fixed. > > In addition, I don't known whether should we move > ramreserved-memory/ooos.txt to /bindings/pstore. This is for maintainer > to decide, and do it on other patch. > > >> MAINTAINERS | 1 + > >> 2 files changed, 33 insertions(+) > >> create mode 100644 Documentation/devicetree/bindings/pstore-block/blkoops.txt > >> > >> diff --git a/Documentation/devicetree/bindings/pstore-block/blkoops.txt b/Documentation/devicetree/bindings/pstore-block/blkoops.txt > >> new file mode 100644 > >> index 0000000..a25835b > >> --- /dev/null > >> +++ b/Documentation/devicetree/bindings/pstore-block/blkoops.txt > >> @@ -0,0 +1,32 @@ > >> +Blkoops oops logger > >> +=================== > >> + > >> +Blkoops provides a block partition for oops, excluding panics now, so they can > >> +be recovered after a reboot. > >> + > >> +Any space of block partition will be used for a circular buffer of oops records. > >> +These records have a configurable size, with a size of 0 indicating that they > >> +should be disabled. > >> + > >> +"partition-size" and at least one of "dmesg-size" or "pmsg-size" must be set > >> +non-zero, but are otherwise optional as listed below. > >> + > >> +Blkoops will take value from Kconfig if device tree do not set, but settings > >> +from module parameters can also overwrite them. > > > > That's all kernel details not relevant to the binidng. > > > > Deleted. > > >> + > >> +Required properties: > >> + > >> +- compatible: must be "blkoops". > >> + > >> +- partition-size: size in kbytes, must be a multiple of 4. > > > > This seems unnecessary given a partition has a known size. > > > > partition-size is necessary for psotre/blk. User should tell pstore/blk > how large space can it use. The partition table says how big a partition is. If you only want to use part of it, then make the partition smaller or use a file system. This is a solved problem, so we don't need a new way in DT to handle this. > >> +Optional properties: > >> + > >> +- partition-path: strings must begin with "/dev", tell blkoops which partition > >> + it can used. If it is not set, blkoops will drop all data when reboot. > > > > No. '/dev/...' is a Linux thing and doesn't belong in DT. > > > > You should define a partition UUID and/or label and the kernel can find > > the right partition to use. > > > > pstore/blk do general read/write by filp_open/kernel_read/kernel_write, > which need device path. > In addition, i have no idea how to use UUID and/or label to do general > read/write on kernel layer, can you give me a tip? The kernel can mount a filesystem by label or UUID though I think those are filesystem UUID and label, not partition UUID and label. But certainly bootloaders find the EFI system partition by UUID. Rob
