edac.rst: move concepts dictionary from edac.h

Instead of storing the concepts dictionary inside header file,
move it to the subsystem documentation.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

Documentation/driver-api/edac.rst

@@ -1,6 +1,112 @@
 Error Detection And Correction (EDAC) Devices
 =============================================
 
+Main Concepts used at the EDAC subsystem
+----------------------------------------
+
+There are several things to be aware of that aren't at all obvious, like
+*sockets, *socket sets*, *banks*, *rows*, *chip-select rows*, *channels*,
+etc...
+
+These are some of the many terms that are thrown about that don't always
+mean what people think they mean (Inconceivable!).  In the interest of
+creating a common ground for discussion, terms and their definitions
+will be established.
+
+* Memory devices
+
+The individual DRAM chips on a memory stick.  These devices commonly
+output 4 and 8 bits each (x4, x8). Grouping several of these in parallel
+provides the number of bits that the memory controller expects:
+typically 72 bits, in order to provide 64 bits + 8 bits of ECC data.
+
+* Memory Stick
+
+A printed circuit board that aggregates multiple memory devices in
+parallel.  In general, this is the Field Replaceable Unit (FRU) which
+gets replaced, in the case of excessive errors. Most often it is also
+called DIMM (Dual Inline Memory Module).
+
+* Memory Socket
+
+A physical connector on the motherboard that accepts a single memory
+stick. Also called as "slot" on several datasheets.
+
+* Channel
+
+A memory controller channel, responsible to communicate with a group of
+DIMMs. Each channel has its own independent control (command) and data
+bus, and can be used independently or grouped with other channels.
+
+* Branch
+
+It is typically the highest hierarchy on a Fully-Buffered DIMM memory
+controller. Typically, it contains two channels. Two channels at the
+same branch can be used in single mode or in lockstep mode. When
+lockstep is enabled, the cacheline is doubled, but it generally brings
+some performance penalty. Also, it is generally not possible to point to
+just one memory stick when an error occurs, as the error correction code
+is calculated using two DIMMs instead of one. Due to that, it is capable
+of correcting more errors than on single mode.
+
+* Single-channel
+
+The data accessed by the memory controller is contained into one dimm
+only. E. g. if the data is 64 bits-wide, the data flows to the CPU using
+one 64 bits parallel access. Typically used with SDR, DDR, DDR2 and DDR3
+memories. FB-DIMM and RAMBUS use a different concept for channel, so
+this concept doesn't apply there.
+
+* Double-channel
+
+The data size accessed by the memory controller is interlaced into two
+dimms, accessed at the same time. E. g. if the DIMM is 64 bits-wide (72
+bits with ECC), the data flows to the CPU using a 128 bits parallel
+access.
+
+* Chip-select row
+
+This is the name of the DRAM signal used to select the DRAM ranks to be
+accessed. Common chip-select rows for single channel are 64 bits, for
+dual channel 128 bits. It may not be visible by the memory controller,
+as some DIMM types have a memory buffer that can hide direct access to
+it from the Memory Controller.
+
+* Single-Ranked stick
+
+A Single-ranked stick has 1 chip-select row of memory. Motherboards
+commonly drive two chip-select pins to a memory stick. A single-ranked
+stick, will occupy only one of those rows. The other will be unused.
+
+.. _doubleranked:
+
+* Double-Ranked stick
+
+A double-ranked stick has two chip-select rows which access different
+sets of memory devices.  The two rows cannot be accessed concurrently.
+
+* Double-sided stick
+
+**DEPRECATED TERM**, see :ref:`Double-Ranked stick <doubleranked>`.
+
+A double-sided stick has two chip-select rows which access different sets
+of memory devices. The two rows cannot be accessed concurrently.
+"Double-sided" is irrespective of the memory devices being mounted on
+both sides of the memory stick.
+
+* Socket set
+
+All of the memory sticks that are required for a single memory access or
+all of the memory sticks spanned by a chip-select row.  A single socket
+set has two chip-select rows and if double-sided sticks are used these
+will occupy those chip-select rows.
+
+* Bank
+
+This term is avoided because it is unclear when needing to distinguish
+between chip-select rows and socket sets.
+
+
 Memory Controllers
 ------------------
 

include/linux/edac.h

@@ -330,114 +330,6 @@ enum scrub_type {
 #define OP_RUNNING_POLL_INTR	0x203
 #define OP_OFFLINE		0x300
 
-/*
- * Concepts used at the EDAC subsystem
- *
- * There are several things to be aware of that aren't at all obvious:
- *
- * SOCKETS, SOCKET SETS, BANKS, ROWS, CHIP-SELECT ROWS, CHANNELS, etc..
- *
- * These are some of the many terms that are thrown about that don't always
- * mean what people think they mean (Inconceivable!).  In the interest of
- * creating a common ground for discussion, terms and their definitions
- * will be established.
- *
- * Memory devices:	The individual DRAM chips on a memory stick.  These
- *			devices commonly output 4 and 8 bits each (x4, x8).
- *			Grouping several of these in parallel provides the
- *			number of bits that the memory controller expects:
- *			typically 72 bits, in order to provide 64 bits +
- *			8 bits of ECC data.
- *
- * Memory Stick:	A printed circuit board that aggregates multiple
- *			memory devices in parallel.  In general, this is the
- *			Field Replaceable Unit (FRU) which gets replaced, in
- *			the case of excessive errors. Most often it is also
- *			called DIMM (Dual Inline Memory Module).
- *
- * Memory Socket:	A physical connector on the motherboard that accepts
- *			a single memory stick. Also called as "slot" on several
- *			datasheets.
- *
- * Channel:		A memory controller channel, responsible to communicate
- *			with a group of DIMMs. Each channel has its own
- *			independent control (command) and data bus, and can
- *			be used independently or grouped with other channels.
- *
- * Branch:		It is typically the highest hierarchy on a
- *			Fully-Buffered DIMM memory controller.
- *			Typically, it contains two channels.
- *			Two channels at the same branch can be used in single
- *			mode or in lockstep mode.
- *			When lockstep is enabled, the cacheline is doubled,
- *			but it generally brings some performance penalty.
- *			Also, it is generally not possible to point to just one
- *			memory stick when an error occurs, as the error
- *			correction code is calculated using two DIMMs instead
- *			of one. Due to that, it is capable of correcting more
- *			errors than on single mode.
- *
- * Single-channel:	The data accessed by the memory controller is contained
- *			into one dimm only. E. g. if the data is 64 bits-wide,
- *			the data flows to the CPU using one 64 bits parallel
- *			access.
- *			Typically used with SDR, DDR, DDR2 and DDR3 memories.
- *			FB-DIMM and RAMBUS use a different concept for channel,
- *			so this concept doesn't apply there.
- *
- * Double-channel:	The data size accessed by the memory controller is
- *			interlaced into two dimms, accessed at the same time.
- *			E. g. if the DIMM is 64 bits-wide (72 bits with ECC),
- *			the data flows to the CPU using a 128 bits parallel
- *			access.
- *
- * Chip-select row:	This is the name of the DRAM signal used to select the
- *			DRAM ranks to be accessed. Common chip-select rows for
- *			single channel are 64 bits, for dual channel 128 bits.
- *			It may not be visible by the memory controller, as some
- *			DIMM types have a memory buffer that can hide direct
- *			access to it from the Memory Controller.
- *
- * Single-Ranked stick:	A Single-ranked stick has 1 chip-select row of memory.
- *			Motherboards commonly drive two chip-select pins to
- *			a memory stick. A single-ranked stick, will occupy
- *			only one of those rows. The other will be unused.
- *
- * Double-Ranked stick:	A double-ranked stick has two chip-select rows which
- *			access different sets of memory devices.  The two
- *			rows cannot be accessed concurrently.
- *
- * Double-sided stick:	DEPRECATED TERM, see Double-Ranked stick.
- *			A double-sided stick has two chip-select rows which
- *			access different sets of memory devices. The two
- *			rows cannot be accessed concurrently. "Double-sided"
- *			is irrespective of the memory devices being mounted
- *			on both sides of the memory stick.
- *
- * Socket set:		All of the memory sticks that are required for
- *			a single memory access or all of the memory sticks
- *			spanned by a chip-select row.  A single socket set
- *			has two chip-select rows and if double-sided sticks
- *			are used these will occupy those chip-select rows.
- *
- * Bank:		This term is avoided because it is unclear when
- *			needing to distinguish between chip-select rows and
- *			socket sets.
- *
- * Controller pages:
- *
- * Physical pages:
- *
- * Virtual pages:
- *
- *
- * STRUCTURE ORGANIZATION AND CHOICES
- *
- *
- *
- * PS - I enjoyed writing all that about as much as you enjoyed reading it.
- */
-
 /**
  * enum edac_mc_layer - memory controller hierarchy layer
  *