linux/Documentation/driver-api
Ben Widawsky 8adaf747c9 cxl/mem: Find device capabilities
Provide enough functionality to utilize the mailbox of a memory device.
The mailbox is used to interact with the firmware running on the memory
device. The flow is proven with one implemented command, "identify".
Because the class code has already told the driver this is a memory
device and the identify command is mandatory.

CXL devices contain an array of capabilities that describe the
interactions software can have with the device or firmware running on
the device. A CXL compliant device must implement the device status and
the mailbox capability. Additionally, a CXL compliant memory device must
implement the memory device capability. Each of the capabilities can
[will] provide an offset within the MMIO region for interacting with the
CXL device.

The capabilities tell the driver how to find and map the register space
for CXL Memory Devices. The registers are required to utilize the CXL
spec defined mailbox interface. The spec outlines two mailboxes, primary
and secondary. The secondary mailbox is earmarked for system firmware,
and not handled in this driver.

Primary mailboxes are capable of generating an interrupt when submitting
a background command. That implementation is saved for a later time.

Reported-by: Colin Ian King <colin.king@canonical.com> (coverity)
Reported-by: Dan Carpenter <dan.carpenter@oracle.com> (smatch)
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com> (v2)
Link: https://www.computeexpresslink.org/download-the-specification
Link: https://lore.kernel.org/r/20210217040958.1354670-3-ben.widawsky@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-02-16 20:36:38 -08:00
..
80211 docs: net: 80211: reduce docs build time 2020-10-08 10:41:49 +02:00
acpi Replace HTTP links with HTTPS ones: documentation 2020-06-08 09:30:19 -06:00
backlight
cxl cxl/mem: Find device capabilities 2021-02-16 20:36:38 -08:00
dmaengine dmaengine: doc: client: Update for dmaengine_get_dma_device() usage 2020-12-11 21:20:08 +05:30
driver-model rtc: rework rtc_register_device() resource management 2020-11-19 12:50:12 +01:00
early-userspace Replace HTTP links with HTTPS ones: Documentation/driver-api 2020-06-26 11:09:04 -06:00
firmware docs: driver-api: firmware: fallback-mechanisms: Fix rendering of bullet point 2020-09-08 13:32:06 +02:00
fpga docs: fpga: replace :c:member: macros 2020-10-15 07:49:43 +02:00
gpio Documentation: gpio: fix typo and unclear legacy API section 2020-12-05 20:23:34 +01:00
i3c docs: driver-api: i3c: Replace HTTP links with HTTPS ones 2020-07-13 09:32:36 -06:00
iio docs: get rid of :c:type explicit declarations for structs 2020-10-15 07:49:40 +02:00
md
media media: Documentation: ccs: Reorder SPDX and copyright notice lines 2020-12-03 10:39:24 +01:00
mei docs updates for v5.10-rc1 2020-10-16 15:02:21 -07:00
memory-devices Replace HTTP links with HTTPS ones: Documentation/driver-api 2020-06-26 11:09:04 -06:00
mmc Replace HTTP links with HTTPS ones: Documentation/driver-api 2020-06-26 11:09:04 -06:00
mtd MTD core: 2020-12-16 14:58:35 -08:00
nfc
nvdimm docs: add some new files to their respective index.rst files 2020-09-10 10:48:20 -06:00
pci
phy docs: phy: Drop duplicate 'be made' 2019-07-26 08:15:26 -06:00
pldmfw Add pldmfw library for PLDM firmware update 2020-07-28 17:07:06 -07:00
pm docs: devices.rst: fix a C reference markup 2020-10-15 07:49:44 +02:00
rapidio Replace HTTP links with HTTPS ones: Documentation/driver-api 2020-06-26 11:09:04 -06:00
serial tty: vt: Replace HTTP links with HTTPS ones 2020-07-21 20:04:54 +02:00
soundwire docs: soundwire: fix some identation at stream.rst 2020-09-10 10:49:29 -06:00
thermal Power management updates for 5.11-rc1 2020-12-15 16:30:31 -08:00
usb usb: docs: document altmode register/unregister functions 2020-10-15 07:49:48 +02:00
xilinx
auxiliary_bus.rst driver core: auxiliary bus: make remove function return void 2020-12-04 13:30:48 +01:00
basics.rst docs: basics.rst: avoid duplicated C function declaration 2020-10-15 07:49:45 +02:00
clk.rst
component.rst
connector.rst net/connector: Add const qualifier to cb_id 2020-12-16 11:06:49 -08:00
console.rst
dcdbas.rst
devfreq.rst docs: Add initial documentation for devfreq 2019-11-19 13:16:53 -07:00
device_link.rst docs: device_link.rst: remove duplicated kernel-doc include 2020-10-15 07:49:42 +02:00
device-io.rst Driver-API: Documentation: Replace deprecated :c:func: Usage 2020-07-13 09:56:03 -06:00
dma-buf.rst dma-buf: Fix kerneldoc formatting 2020-12-15 10:57:29 +01:00
edac.rst
eisa.rst
firewire.rst
frame-buffer.rst
generic-counter.rst Documentation/driver-api: generic-counter: drop doubled word 2020-07-07 20:24:07 +01:00
hsi.rst
i2c.rst
index.rst cxl/mem: Introduce a driver for CXL-2.0-Type-3 endpoints 2021-02-16 20:36:38 -08:00
infiniband.rst RDMA/core: Remove FMR pool API 2020-06-02 20:32:53 -03:00
infrastructure.rst docs: infrastructure.rst: exclude device_link_state from device.h 2020-10-15 07:49:46 +02:00
input.rst Input: remove input_polled_dev implementation 2020-12-02 12:35:14 -08:00
interconnect.rst interconnect: Add interconnect_graph file to debugfs 2019-12-16 09:49:54 +02:00
io_ordering.rst Documentation: Add io_ordering.rst to driver-api manual 2020-03-10 11:33:19 -06:00
io-mapping.rst io-mapping: Provide iomap_local variant 2020-11-24 14:42:09 +01:00
ioctl.rst docs: move core-api/ioctl.rst to driver-api/ 2020-03-10 11:21:08 -06:00
ipmb.rst drivers: ipmi: Support raw i2c packet in IPMB 2019-12-11 13:21:36 -06:00
ipmi.rst Minor cleanups to the IPMI driver for 5.9 2020-08-08 09:32:18 -07:00
isa.rst
isapnp.rst
libata.rst docs: libata.rst: fix a wrong usage of :c:type: tag 2020-10-15 07:49:44 +02:00
lightnvm-pblk.rst
mailbox.rst docs: move mailbox.txt to driver-api and rename it 2020-06-26 11:33:38 -06:00
men-chameleon-bus.rst
message-based.rst
misc_devices.rst
miscellaneous.rst
mtdnand.rst docs: mtd: Avoid htmldocs warnings 2020-12-10 22:37:32 +01:00
ntb.rst Documentation/driver-api: ntb: drop doubled word 2020-07-13 11:18:17 -06:00
nvmem.rst nvmem: core: add nvmem_device_find 2019-10-07 09:47:37 -07:00
parport-lowlevel.rst
pinctl.rst docs/pinctrl: fix compile errors in example code 2019-07-29 00:20:09 +02:00
pps.rst
pti_intel_mid.rst docs: driver-api: pti_intel_mid: Enable syntax highlighting for C code block 2019-10-18 09:40:13 -06:00
ptp.rst docs: ptp.rst: add support for Renesas (IDT) ClockMatrix 2020-07-17 10:25:21 -07:00
pwm.rst
regulator.rst docs: get rid of :c:type explicit declarations for structs 2020-10-15 07:49:40 +02:00
reset.rst docs: add a reset controller chapter to the driver API docs 2020-12-08 10:48:04 -07:00
rfkill.rst
s390-drivers.rst
scsi.rst
slimbus.rst
sm501.rst
spi.rst
switchtec.rst
sync_file.rst
target.rst docs: scsi: target.rst: remove iSCSI transport class kernel-doc markup 2020-10-15 07:49:42 +02:00
uio-howto.rst Documentation/driver-api: uio-howto: drop doubled word 2020-07-10 14:58:01 +02:00
vfio-mediated-device.rst
vfio.rst
vme.rst
w1.rst docs: driver-api: address duplicate label warning 2020-04-07 13:41:34 -06:00
xillybus.rst Documentation/driver-api: xillybus: drop doubled word 2020-07-10 14:58:01 +02:00
zorro.rst