| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <1323250088-1729-1-git-send-email-sjur.brandeland@stericsson.com>
Date: Wed, 7 Dec 2011 10:27:59 +0100
From: Sjur Brændeland <sjur.brandeland@...ricsson.com>
To: linux-kernel@...r.kernel.org
Cc: Linus Walleij <linus.walleij@...aro.org>,
Paul Bolle <pebolle@...cali.nl>,
Sjur Brændeland <sjur.brandeland@...ricsson.com>
Subject: [PATCH 0/9] XSHM: Shared Memory Driver for ST-E Thor M7400 LTE modem
Introduction:
~~~~~~~~~~~~~
This patch-set introduces the Shared Memory Driver for ST-Ericsson's
Thor M7400 LTE modem.
The shared memory model is implemented for Chip-to-chip and
uses a reserved memory area and a number of bi-directional
channels. Each channel has it's own designated data area where payload
data is copied into.
Two different channel types are defined, one stream channel which is
implemented as a traditional ring-buffer, and a packet channel which
is a ring-buffer of fix sized buffers where each buffer contains
an array of CAIF frames.
The notification of read and write index updates are handled in a
separate driver called c2c_genio. This driver will be contributed separately,
but the API is included in this patch-set.
The channel configuration is stored in shared memory, each channel
has a designated area in shared memory for configuration data,
read and write indexes and a data area.
Configuration
~~~~~~~~~~~~~~~
IPC-TOC
+--------------------+ Index Area
| Channel Descr 0 | -----> +------------+
| | -+ | Read Index |
|--------------------| | |------------|
| Channel Descr 1 | | | Write Index|
| | | +------------+
|--------------------| | Data Area
| ... | | +------------+
| | +---> | |
+--------------------+ | |
| |
+------------+
A IPC-TOC (table of content) is used for holding configuration data
for the channels (struct xshm_ipctoc). It contains an array of
channel descriptors (struct xshm_ipctoc_channel). The channel
descriptors points out the data area and the location of
read and write indexes.
The configuration is provided from user-space using gen-netlink.
The gen-netlink format is defined in xshm_netlink.h and and handled
in xshm_boot.c
Packet data
~~~~~~~~~~~
The packet channel is set up to minimize interrupts needed to
transfer a packet and to allow efficient DMA operations on the modem.
Ring Buffer Indexes:
+------------+
+-| Read Index |
| |------------|
| | Write Index|------------------------+
| +------------+ |
| |
V |
Buffer-0: V Buffer-1:
+----------------------------------------+---------------+---
|ofs,len|ofs,len| ....| frm-0|frm-1| ... | ofs,len | ....|...
+----------------------------------------+---------------+--
| | ^ ^
+---------------------+ |
+---------------------+
Packet data is organized in a channel containing a number of fixed-
size buffers. The channel has a read and write pointer to a buffer in a normal
ring-buffer fashion.
Each buffer holds an array of CAIF-frames, and starts with an descriptor array
containing pointers to the data frames in the buffer. The descriptor array
contains offset and length of each frame.
The packet device (caif_xshm.c) is implemented as a network interface of
type ARPHRD_CAIF.
Stream data
~~~~~~~~~~~
The driver for the stream channel is implemented as a character device
interface to user space. The character device implements non-blocking open
and non-blocking IO in general. The character device is implementing
a traditional circular buffer directly in the shared memory region for
the channel.
Driver model
~~~~~~~~~~~~~~
Current implementation is using the platform bus for XSHM devices.
The packet channels are named "xshmp", and stream channel "xshms".
/sys/bus:
|-- platform
| |-- devices
| | |-- xshmp.1 -> ../../../devices/platform/xshm/xshmp.1
| | `-- xshms.0 -> ../../../devices/platform/xshm/xshms.0
| |-- drivers
| | |-- xshmp
| | | |-- module -> ../../../../module/caif_xshm
| | | `-- xshmp.1 -> ../../../../devices/platform/xshm/xshmp.1
| | `-- xshms
| | |-- module -> ../../../../module/xshm_chr
| | `-- xshms.0 -> ../../../../devices/platform/xshm/xshms.0
/sys/devices:
|-- platform
| |-- uevent
| `-- xshm
| |-- bootimg
| |-- caif_ready
| |-- ipc_ready
| |-- subsystem -> ../../../bus/platform
| |-- xshmp.1
| | |-- driver -> ../../../../bus/platform/drivers/xshmp
| | |-- subsystem -> ../../../../bus/platform
| `-- xshms.0
| |-- driver -> ../../../../bus/platform/drivers/xshms
| |-- misc
| | `-- xshm0
| | |-- device -> ../../../xshms.0
| | |-- subsystem -> ../../../../../../class/misc
`-- virtual
|-- net
| |-- cfshm0
Review comments and feedback is welcome.
Patchset is based on todays linux-next.
Regards,
Sjur Brændeland
Sjur Brændeland (9):
xshm: Shared Memory layout for ST-E M7400 driver.
xshm: Channel config definitions for ST-E M7400 driver.
xshm: Config data use for platform devices.
xshm: geni/geno driver interface.
xshm: genio dummy driver
xshm: Platform device for XSHM
xshm: Character device for XSHM channel access.
xshm: Makefile and Kconfig for M7400 Shared Memory Drivers
caif-xshm: Add CAIF driver for Shared memory for M7400
drivers/Kconfig | 2 +
drivers/Makefile | 1 +
drivers/net/caif/Kconfig | 10 +
drivers/net/caif/Makefile | 1 +
drivers/net/caif/caif_xshm.c | 935 +++++++++++++++++++++++++++
drivers/xshm/Kconfig | 17 +
drivers/xshm/Makefile | 3 +
drivers/xshm/genio_dummy.c | 61 ++
drivers/xshm/xshm_boot.c | 1187 ++++++++++++++++++++++++++++++++++
drivers/xshm/xshm_chr.c | 1269 +++++++++++++++++++++++++++++++++++++
drivers/xshm/xshm_dev.c | 468 ++++++++++++++
include/linux/Kbuild | 1 +
include/linux/c2c_genio.h | 195 ++++++
include/linux/xshm/Kbuild | 1 +
include/linux/xshm/xshm_ipctoc.h | 160 +++++
include/linux/xshm/xshm_netlink.h | 95 +++
include/linux/xshm/xshm_pdev.h | 188 ++++++
17 files changed, 4594 insertions(+), 0 deletions(-)
create mode 100644 drivers/net/caif/caif_xshm.c
create mode 100644 drivers/xshm/Kconfig
create mode 100644 drivers/xshm/Makefile
create mode 100644 drivers/xshm/genio_dummy.c
create mode 100644 drivers/xshm/xshm_boot.c
create mode 100644 drivers/xshm/xshm_chr.c
create mode 100644 drivers/xshm/xshm_dev.c
create mode 100644 include/linux/c2c_genio.h
create mode 100644 include/linux/xshm/Kbuild
create mode 100644 include/linux/xshm/xshm_ipctoc.h
create mode 100644 include/linux/xshm/xshm_netlink.h
create mode 100644 include/linux/xshm/xshm_pdev.h
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists