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Subject[PATCH] staging: Initial memrar ABI document
Date
Signed-off-by: Ossama Othman <ossama.othman@intel.com>
---
drivers/staging/memrar/memrar-abi | 89 +++++++++++++++++++++++++++++++++++++
1 files changed, 89 insertions(+), 0 deletions(-)
create mode 100644 drivers/staging/memrar/memrar-abi

diff --git a/drivers/staging/memrar/memrar-abi b/drivers/staging/memrar/memrar-abi
new file mode 100644
index 0000000..98a6bb1
--- /dev/null
+++ b/drivers/staging/memrar/memrar-abi
@@ -0,0 +1,89 @@
+What: /dev/memrar
+Date: March 2010
+KernelVersion: Kernel version this feature first showed up in.
+Contact: Ossama Othman <ossama.othman@intel.com>
+Description: The Intel Moorestown Restricted Access Region (RAR)
+ Handler driver exposes an ioctl() based interface that
+ allows a user to reserve and release blocks of RAR
+ memory.
+
+ Note: A sysfs based one was not appropriate for the
+ RAR handler's usage model.
+
+ =========================================================
+ ioctl() Requests
+ =========================================================
+ RAR_HANDLER_RESERVE
+ -------------------
+ Description: Reserve RAR block.
+ Type: struct RAR_block_info
+ Direction: in/out
+ Errors: EINVAL (invalid RAR type or size)
+ ENOMEM (not enough RAR memory)
+
+ RAR_HANDLER_STAT
+ ----------------
+ Description: Get RAR statistics.
+ Type: struct RAR_stat
+ Direction: in/out
+ Errors: EINVAL (invalid RAR type)
+
+ RAR_HANDLER_RELEASE
+ -------------------
+ Description: Release previously reserved RAR block.
+ Type: 32 bit unsigned integer
+ (e.g. uint32_t), i.e the RAR "handle".
+ Direction: in
+ Errors: EINVAL (invalid RAR handle)
+
+
+ =========================================================
+ ioctl() Request Parameter Types
+ =========================================================
+ The structures referred to above are defined as
+ follows:
+
+ /**
+ * struct RAR_block_info - user space struct that
+ * describes RAR buffer
+ * @type: Type of RAR memory (e.g.,
+ * RAR_TYPE_VIDEO or RAR_TYPE_AUDIO) [in]
+ * @size: Requested size of a block in bytes to
+ * be reserved in RAR. [in]
+ * @handle: Handle that can be used to refer to
+ * reserved block. [out]
+ *
+ * This is the basic structure exposed to the user
+ * space that describes a given RAR buffer. It used
+ * as the parameter for the RAR_HANDLER_RESERVE ioctl.
+ * The buffer's underlying bus address is not exposed
+ * to the user. User space code refers to the buffer
+ * entirely by "handle".
+ */
+ struct RAR_block_info {
+ __u32 type;
+ __u32 size;
+ __u32 handle;
+ };
+
+ /**
+ * struct RAR_stat - RAR statistics structure
+ * @type: Type of RAR memory (e.g.,
+ * RAR_TYPE_VIDEO or
+ * RAR_TYPE_AUDIO) [in]
+ * @capacity: Total size of RAR memory
+ * region. [out]
+ * @largest_block_size: Size of the largest reservable
+ * block. [out]
+ *
+ * This structure is used for RAR_HANDLER_STAT ioctl.
+ */
+ struct RAR_stat {
+ __u32 type;
+ __u32 capacity;
+ __u32 largest_block_size;
+ };
+
+ Lastly, the RAR_HANDLER_RELEASE ioctl expects a
+ "handle" to the RAR block of memory. It is a 32 bit
+ unsigned integer.
--
1.6.3.3


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