docs: Remove metag docs

Now that arch/metag/ has been removed, remove Meta architecture specific
documentation from the Documentation/ directory.
Signed-off-by: James Hogan <jhogan@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-metag@vger.kernel.org
Cc: linux-doc@vger.kernel.org

Documentation/00-INDEX

@@ -276,8 +276,6 @@ memory-hotplug.txt
 	- Hotpluggable memory support, how to use and current status.
 men-chameleon-bus.txt
 	- info on MEN chameleon bus.
-metag/
-	- directory with info about Linux on Meta architecture.
 mic/
 	- Intel Many Integrated Core (MIC) architecture device driver.
 mips/

Documentation/admin-guide/kernel-parameters.txt

@@ -1347,10 +1347,6 @@
 			       If specified, z/VM IUCV HVC accepts connections
 			       from listed z/VM user IDs only.
 
-	hwthread_map=	[METAG] Comma-separated list of Linux cpu id to
-			        hardware thread id mappings.
-				Format: <cpu>:<hwthread>
-
 	keep_bootcon	[KNL]
 			Do not unregister boot console at start. This is only
 			useful for debugging when something happens in the window

Documentation/devicetree/bindings/metag/meta.txt

-* Meta Processor Binding
-
-This binding specifies what properties must be available in the device tree
-representation of a Meta Processor Core, which is the root node in the tree.
-
-Required properties:
-
-    - compatible: Specifies the compatibility list for the Meta processor.
-      The type shall be <string> and the value shall include "img,meta".
-
-Optional properties:
-
-    - clocks: Clock consumer specifiers as described in
-      Documentation/devicetree/bindings/clock/clock-bindings.txt
-
-    - clock-names: Clock consumer names as described in
-      Documentation/devicetree/bindings/clock/clock-bindings.txt.
-
-Clocks are identified by name. Valid clocks are:
-
-    - "core": The Meta core clock from which the Meta timers are derived.
-
-* Examples
-
-/ {
-	compatible = "toumaz,tz1090", "img,meta";
-
-	clocks = <&meta_core_clk>;
-	clock-names = "core";
-};

Documentation/metag/00-INDEX

-00-INDEX
-	- this file
-kernel-ABI.txt
-	- Documents metag ABI details

Documentation/metag/kernel-ABI.txt

-			==========================
-			KERNEL ABIS FOR METAG ARCH
-			==========================
-
-This document describes the Linux ABIs for the metag architecture, and has the
-following sections:
-
- (*) Outline of registers
- (*) Userland registers
- (*) Kernel registers
- (*) System call ABI
- (*) Calling conventions
-
-
-====================
-OUTLINE OF REGISTERS
-====================
-
-The main Meta core registers are arranged in units:
-
-	UNIT	Type	DESCRIPTION	GP	EXT	PRIV	GLOBAL
-	=======	=======	===============	=======	=======	=======	=======
-	CT	Special	Control unit
-	D0	General	Data unit 0	0-7	8-15	16-31	16-31
-	D1	General	Data unit 1	0-7	8-15	16-31	16-31
-	A0	General	Address unit 0	0-3	4-7	 8-15	 8-15
-	A1	General	Address unit 1	0-3	4-7	 8-15	 8-15
-	PC	Special	PC unit		0		 1
-	PORT	Special	Ports
-	TR	Special	Trigger unit			 0-7
-	TT	Special	Trace unit			 0-5
-	FX	General	FP unit			0-15
-
-GP registers form part of the main context.
-
-Extended context registers (EXT) may not be present on all hardware threads and
-can be context switched if support is enabled and the appropriate bits are set
-in e.g. the D0.8 register to indicate what extended state to preserve.
-
-Global registers are shared between threads and are privilege protected.
-
-See arch/metag/include/asm/metag_regs.h for definitions relating to core
-registers and the fields and bits they contain. See the TRMs for further details
-about special registers.
-
-Several special registers are preserved in the main context, these are the
-interesting ones:
-
-	REG	(ALIAS)		PURPOSE
-	=======================	===============================================
-	CT.1	(TXMODE)	Processor mode bits (particularly for DSP)
-	CT.2	(TXSTATUS)	Condition flags and LSM_STEP (MGET/MSET step)
-	CT.3	(TXRPT)		Branch repeat counter
-	PC.0	(PC)		Program counter
-
-Some of the general registers have special purposes in the ABI and therefore
-have aliases:
-
-	D0 REG	(ALIAS)	PURPOSE		D1 REG	(ALIAS)	PURPOSE
-	===============	===============	===============	=======================
-	D0.0	(D0Re0)	32bit result	D1.0	(D1Re0)	Top half of 64bit result
-	D0.1	(D0Ar6)	Argument 6	D1.1	(D1Ar5)	Argument 5
-	D0.2	(D0Ar4)	Argument 4	D1.2	(D1Ar3)	Argument 3
-	D0.3	(D0Ar2)	Argument 2	D1.3	(D1Ar1)	Argument 1
-	D0.4	(D0FrT)	Frame temp	D1.4	(D1RtP)	Return pointer
-	D0.5		Call preserved	D1.5		Call preserved
-	D0.6		Call preserved	D1.6		Call preserved
-	D0.7		Call preserved	D1.7		Call preserved
-
-	A0 REG	(ALIAS)	PURPOSE		A1 REG	(ALIAS)	PURPOSE
-	===============	===============	===============	=======================
-	A0.0	(A0StP)	Stack pointer	A1.0	(A1GbP)	Global base pointer
-	A0.1	(A0FrP)	Frame pointer	A1.1	(A1LbP)	Local base pointer
-	A0.2				A1.2
-	A0.3				A1.3
-
-
-==================
-USERLAND REGISTERS
-==================
-
-All the general purpose D0, D1, A0, A1 registers are preserved when entering the
-kernel (including asynchronous events such as interrupts and timer ticks) except
-the following which have special purposes in the ABI:
-
-	REGISTERS	WHEN	STATUS		PURPOSE
-	===============	=======	===============	===============================
-	D0.8		DSP	Preserved	ECH, determines what extended
-						DSP state to preserve.
-	A0.0	(A0StP)	ALWAYS	Preserved	Stack >= A0StP may be clobbered
-						at any time by the creation of a
-						signal frame.
-	A1.0	(A1GbP)	SMP	Clobbered	Used as temporary for loading
-						kernel stack pointer and saving
-						core context.
-	A0.15		!SMP	Protected	Stores kernel stack pointer.
-	A1.15		ALWAYS	Protected	Stores kernel base pointer.
-
-On UP A0.15 is used to store the kernel stack pointer for storing the userland
-context. A0.15 is global between hardware threads though which means it cannot
-be used on SMP for this purpose. Since no protected local registers are
-available A1GbP is reserved for use as a temporary to allow a percpu stack
-pointer to be loaded for storing the rest of the context.
-
-
-================
-KERNEL REGISTERS
-================
-
-When in the kernel the following registers have special purposes in the ABI:
-
-	REGISTERS	WHEN	STATUS		PURPOSE
-	===============	=======	===============	===============================
-	A0.0	(A0StP)	ALWAYS	Preserved	Stack >= A0StP may be clobbered
-						at any time by the creation of
-						an irq signal frame.
-	A1.0	(A1GbP)	ALWAYS	Preserved	Reserved (kernel base pointer).
-
-
-===============
-SYSTEM CALL ABI
-===============
-
-When a system call is made, the following registers are effective:
-
-	REGISTERS	CALL			RETURN
-	===============	=======================	===============================
-	D0.0	(D0Re0)				Return value (or -errno)
-	D1.0	(D1Re0)	System call number	Clobbered
-	D0.1	(D0Ar6)	Syscall arg #6		Preserved
-	D1.1	(D1Ar5)	Syscall arg #5		Preserved
-	D0.2	(D0Ar4)	Syscall arg #4		Preserved
-	D1.2	(D1Ar3)	Syscall arg #3		Preserved
-	D0.3	(D0Ar2)	Syscall arg #2		Preserved
-	D1.3	(D1Ar1)	Syscall arg #1		Preserved
-
-Due to the limited number of argument registers and some system calls with badly
-aligned 64-bit arguments, 64-bit values are always packed in consecutive
-arguments, even if this is contrary to the normal calling conventions (where the
-two halves would go in a matching pair of data registers).
-
-For example fadvise64_64 usually has the signature:
-
-	long sys_fadvise64_64(i32 fd, i64 offs, i64 len, i32 advice);
-
-But for metag fadvise64_64 is wrapped so that the 64-bit arguments are packed:
-
-	long sys_fadvise64_64_metag(i32 fd,      i32 offs_lo,
-				    i32 offs_hi, i32 len_lo,
-				    i32 len_hi,  i32 advice)
-
-So the arguments are packed in the registers like this:
-
-	D0 REG	(ALIAS)	VALUE		D1 REG	(ALIAS)	VALUE
-	===============	===============	===============	=======================
-	D0.1	(D0Ar6)	advice		D1.1	(D1Ar5)	hi(len)
-	D0.2	(D0Ar4)	lo(len)		D1.2	(D1Ar3)	hi(offs)
-	D0.3	(D0Ar2)	lo(offs)	D1.3	(D1Ar1)	fd
-
-
-===================
-CALLING CONVENTIONS
-===================
-
-These calling conventions apply to both user and kernel code. The stack grows
-from low addresses to high addresses in the metag ABI. The stack pointer (A0StP)
-should always point to the next free address on the stack and should at all
-times be 64-bit aligned. The following registers are effective at the point of a
-call:
-
-	REGISTERS	CALL			RETURN
-	===============	=======================	===============================
-	D0.0	(D0Re0)				32bit return value
-	D1.0	(D1Re0)				Upper half of 64bit return value
-	D0.1	(D0Ar6)	32bit argument #6	Clobbered
-	D1.1	(D1Ar5)	32bit argument #5	Clobbered
-	D0.2	(D0Ar4)	32bit argument #4	Clobbered
-	D1.2	(D1Ar3)	32bit argument #3	Clobbered
-	D0.3	(D0Ar2)	32bit argument #2	Clobbered
-	D1.3	(D1Ar1)	32bit argument #1	Clobbered
-	D0.4	(D0FrT)				Clobbered
-	D1.4	(D1RtP)	Return pointer		Clobbered
-	D{0-1}.{5-7}				Preserved
-	A0.0	(A0StP)	Stack pointer		Preserved
-	A1.0	(A0GbP)				Preserved
-	A0.1	(A0FrP)	Frame pointer		Preserved
-	A1.1	(A0LbP)				Preserved
-	A{0-1},{2-3}				Clobbered
-
-64-bit arguments are placed in matching pairs of registers (i.e. the same
-register number in both D0 and D1 units), with the least significant half in D0
-and the most significant half in D1, leaving a gap where necessary. Further
-arguments are stored on the stack in reverse order (earlier arguments at higher
-addresses):
-
-	ADDRESS		0     1     2     3	4     5     6     7
-	===============	===== ===== ===== =====	===== ===== ===== =====
-	A0StP       -->
-	A0StP-0x08	32bit argument #8	32bit argument #7
-	A0StP-0x10	32bit argument #10	32bit argument #9
-
-Function prologues tend to look a bit like this:
-
-	/* If frame pointer in use, move it to frame temp register so it can be
-	   easily pushed onto stack */
-	MOV	D0FrT,A0FrP
-
-	/* If frame pointer in use, set it to stack pointer */
-	ADD	A0FrP,A0StP,#0
-
-	/* Preserve D0FrT, D1RtP, D{0-1}.{5-7} on stack, incrementing A0StP */
-	MSETL	[A0StP++],D0FrT,D0.5,D0.6,D0.7
-
-	/* Allocate some stack space for local variables */
-	ADD	A0StP,A0StP,#0x10
-
-At this point the stack would look like this:
-
-	ADDRESS		0     1     2     3	4     5     6     7
-	===============	===== ===== ===== =====	===== ===== ===== =====
-	A0StP       -->
-	A0StP-0x08
-	A0StP-0x10
-	A0StP-0x18	Old D0.7		Old D1.7
-	A0StP-0x20	Old D0.6		Old D1.6
-	A0StP-0x28	Old D0.5		Old D1.5
-	A0FrP       -->	Old A0FrP (frame ptr)	Old D1RtP (return ptr)
-	A0FrP-0x08	32bit argument #8	32bit argument #7
-	A0FrP-0x10	32bit argument #10	32bit argument #9
-
-Function epilogues tend to differ depending on the use of a frame pointer. An
-example of a frame pointer epilogue:
-
-	/* Restore D0FrT, D1RtP, D{0-1}.{5-7} from stack, incrementing A0FrP */
-	MGETL	D0FrT,D0.5,D0.6,D0.7,[A0FrP++]
-	/* Restore stack pointer to where frame pointer was before increment */
-	SUB	A0StP,A0FrP,#0x20
-	/* Restore frame pointer from frame temp */
-	MOV	A0FrP,D0FrT
-	/* Return to caller via restored return pointer */
-	MOV	PC,D1RtP
-
-If the function hasn't touched the frame pointer, MGETL cannot be safely used
-with A0StP as it always increments and that would expose the stack to clobbering
-by interrupts (kernel) or signals (user). Therefore it's common to see the MGETL
-split into separate GETL instructions:
-
-	/* Restore D0FrT, D1RtP, D{0-1}.{5-7} from stack */
-	GETL	D0FrT,D1RtP,[A0StP+#-0x30]
-	GETL	D0.5,D1.5,[A0StP+#-0x28]
-	GETL	D0.6,D1.6,[A0StP+#-0x20]
-	GETL	D0.7,D1.7,[A0StP+#-0x18]
-	/* Restore stack pointer */
-	SUB	A0StP,A0StP,#0x30
-	/* Return to caller via restored return pointer */
-	MOV	PC,D1RtP