Ira Weiny wrote: > BIOS can configure memory devices as firmware first. This will send CXL > events to the firmware instead of the OS. The firmware can then inform > the OS of these events via UEFI. > > UEFI v2.10 section N.2.14 defines a Common Platform Error Record (CPER) > format for CXL Component Events. The format is mostly the same as the > CXL Common Event Record Format. The difference lies in the use of a > GUID as the CPER Section Type which matches the UUID defined in CXL 3.1 > Table 8-43. > > Currently a configuration such as this will trace a non standard event > in the log omitting useful details of the event. In addition the CXL > sub-system contains additional region and HPA information useful to the > user.[0] > > The CXL code is required to be called from process context as it needs > to take a device lock. The GHES code may be in interrupt context. This > complicated the use of a callback. Dan Williams suggested the use of > work items as an atomic way of switching between the callback execution > and a default handler.[1] > > The use of a kfifo simplifies queue processing by providing lock free > fifo operations. cxl_cper_kfifo_get() allows easier management of the > kfifo between the ghes and cxl modules. > > CXL 3.1 Table 8-127 requires a device to have a queue depth of 1 for > each of the four event logs. A combined queue depth of 32 is chosen to > provide room for 8 entries of each log type. > > Add GHES support to detect CXL CPER records. Add the ability for the > CXL sub-system to register a work queue to process the events. > > This patch adds back the functionality which was removed to fix the > report by Dan Carpenter[2]. > > [0] > Link: https://lore.kernel.org/all/cover.1711598777.git.alison.schofield@xxxxxxxxx/ > [1] > Link: https://lore.kernel.org/all/65d111eb87115_6c745294ac@xxxxxxxxxxxxxxxxxxxxxxxxx.notmuch/ > [2] > Link: https://lore.kernel.org/all/b963c490-2c13-4b79-bbe7-34c6568423c7@moroto.mountain/ Like I mentioned last time, perhaps Dave can reformat these lines on applying to: Link: http://lore.kernel.org/r/cover.1711598777.git.alison.schofield@xxxxxxxxx [0] Link: http://lore.kernel.org/r/65d111eb87115_6c745294ac@xxxxxxxxxxxxxxxxxxxxxxxxx.notmuch [1] Link: http://lore.kernel.org/r/b963c490-2c13-4b79-bbe7-34c6568423c7@moroto.mountain [2] Other than that, this looks good to me: Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx>
