Merge branch 'origin'

Conflicts:
	Documentation/video4linux/CARDLIST.cx88
	drivers/media/video/cx88/Kconfig
	drivers/media/video/em28xx/em28xx-video.c
	drivers/media/video/saa7134/saa7134-dvb.c

Resolved as in the original merge by Mauro Carvalho Chehab

1 files changed, 234 insertions, 0 deletions

diff --git a/Documentation/fujitsu/frv/kernel-ABI.txt b/Documentation/fujitsu/frv/kernel-ABI.txt
new file mode 100644
index 000000000000..0ed9b0a779bc
--- /dev/null
+++ b/Documentation/fujitsu/frv/kernel-ABI.txt
@@ -0,0 +1,234 @@
+				 =================================
+				 INTERNAL KERNEL ABI FOR FR-V ARCH
+				 =================================
+
+The internal FRV kernel ABI is not quite the same as the userspace ABI. A number of the registers
+are used for special purposed, and the ABI is not consistent between modules vs core, and MMU vs
+no-MMU.
+
+This partly stems from the fact that FRV CPUs do not have a separate supervisor stack pointer, and
+most of them do not have any scratch registers, thus requiring at least one general purpose
+register to be clobbered in such an event. Also, within the kernel core, it is possible to simply
+jump or call directly between functions using a relative offset. This cannot be extended to modules
+for the displacement is likely to be too far. Thus in modules the address of a function to call
+must be calculated in a register and then used, requiring two extra instructions.
+
+This document has the following sections:
+
+ (*) System call register ABI
+ (*) CPU operating modes
+ (*) Internal kernel-mode register ABI
+ (*) Internal debug-mode register ABI
+ (*) Virtual interrupt handling
+
+
+========================
+SYSTEM CALL REGISTER ABI
+========================
+
+When a system call is made, the following registers are effective:
+
+	REGISTERS	CALL			RETURN
+	===============	=======================	=======================
+	GR7		System call number	Preserved
+	GR8		Syscall arg #1		Return value
+	GR9-GR13	Syscall arg #2-6	Preserved
+
+
+===================
+CPU OPERATING MODES
+===================
+
+The FR-V CPU has three basic operating modes. In order of increasing capability:
+
+  (1) User mode.
+
+      Basic userspace running mode.
+
+  (2) Kernel mode.
+
+      Normal kernel mode. There are many additional control registers available that may be
+      accessed in this mode, in addition to all the stuff available to user mode. This has two
+      submodes:
+
+      (a) Exceptions enabled (PSR.T == 1).
+
+      	  Exceptions will invoke the appropriate normal kernel mode handler. On entry to the
+      	  handler, the PSR.T bit will be cleared.
+
+      (b) Exceptions disabled (PSR.T == 0).
+
+      	  No exceptions or interrupts may happen. Any mandatory exceptions will cause the CPU to
+      	  halt unless the CPU is told to jump into debug mode instead.
+
+  (3) Debug mode.
+
+      No exceptions may happen in this mode. Memory protection and management exceptions will be
+      flagged for later consideration, but the exception handler won't be invoked. Debugging traps
+      such as hardware breakpoints and watchpoints will be ignored. This mode is entered only by
+      debugging events obtained from the other two modes.
+
+      All kernel mode registers may be accessed, plus a few extra debugging specific registers.
+
+
+=================================
+INTERNAL KERNEL-MODE REGISTER ABI
+=================================
+
+There are a number of permanent register assignments that are set up by entry.S in the exception
+prologue. Note that there is a complete set of exception prologues for each of user->kernel
+transition and kernel->kernel transition. There are also user->debug and kernel->debug mode
+transition prologues.
+
+
+	REGISTER	FLAVOUR	USE
+	===============	=======	====================================================
+	GR1			Supervisor stack pointer
+	GR15			Current thread info pointer
+	GR16			GP-Rel base register for small data
+	GR28			Current exception frame pointer (__frame)
+	GR29			Current task pointer (current)
+	GR30			Destroyed by kernel mode entry
+	GR31		NOMMU	Destroyed by debug mode entry
+	GR31		MMU	Destroyed by TLB miss kernel mode entry
+	CCR.ICC2		Virtual interrupt disablement tracking
+	CCCR.CC3		Cleared by exception prologue (atomic op emulation)
+	SCR0		MMU	See mmu-layout.txt.
+	SCR1		MMU	See mmu-layout.txt.
+	SCR2		MMU	Save for EAR0 (destroyed by icache insns in debug mode)
+	SCR3		MMU	Save for GR31 during debug exceptions
+	DAMR/IAMR	NOMMU	Fixed memory protection layout.
+	DAMR/IAMR	MMU	See mmu-layout.txt.
+
+
+Certain registers are also used or modified across function calls:
+
+	REGISTER	CALL				RETURN
+	===============	===============================	===============================
+	GR0		Fixed Zero			-
+	GR2		Function call frame pointer
+	GR3		Special				Preserved
+	GR3-GR7		-				Clobbered
+	GR8		Function call arg #1		Return value (or clobbered)
+	GR9		Function call arg #2		Return value MSW (or clobbered)
+	GR10-GR13	Function call arg #3-#6		Clobbered
+	GR14		-				Clobbered
+	GR15-GR16	Special				Preserved
+	GR17-GR27	-				Preserved
+	GR28-GR31	Special				Only accessed explicitly
+	LR		Return address after CALL	Clobbered
+	CCR/CCCR	-				Mostly Clobbered
+
+
+================================
+INTERNAL DEBUG-MODE REGISTER ABI
+================================
+
+This is the same as the kernel-mode register ABI for functions calls. The difference is that in
+debug-mode there's a different stack and a different exception frame. Almost all the global
+registers from kernel-mode (including the stack pointer) may be changed.
+
+	REGISTER	FLAVOUR	USE
+	===============	=======	====================================================
+	GR1			Debug stack pointer
+	GR16			GP-Rel base register for small data
+	GR31			Current debug exception frame pointer (__debug_frame)
+	SCR3		MMU	Saved value of GR31
+
+
+Note that debug mode is able to interfere with the kernel's emulated atomic ops, so it must be
+exceedingly careful not to do any that would interact with the main kernel in this regard. Hence
+the debug mode code (gdbstub) is almost completely self-contained. The only external code used is
+the sprintf family of functions.
+
+Futhermore, break.S is so complicated because single-step mode does not switch off on entry to an
+exception. That means unless manually disabled, single-stepping will blithely go on stepping into
+things like interrupts. See gdbstub.txt for more information.
+
+
+==========================
+VIRTUAL INTERRUPT HANDLING
+==========================
+
+Because accesses to the PSR is so slow, and to disable interrupts we have to access it twice (once
+to read and once to write), we don't actually disable interrupts at all if we don't have to. What
+we do instead is use the ICC2 condition code flags to note virtual disablement, such that if we
+then do take an interrupt, we note the flag, really disable interrupts, set another flag and resume
+execution at the point the interrupt happened. Setting condition flags as a side effect of an
+arithmetic or logical instruction is really fast. This use of the ICC2 only occurs within the
+kernel - it does not affect userspace.
+
+The flags we use are:
+
+ (*) CCR.ICC2.Z [Zero flag]
+
+     Set to virtually disable interrupts, clear when interrupts are virtually enabled. Can be
+     modified by logical instructions without affecting the Carry flag.
+
+ (*) CCR.ICC2.C [Carry flag]
+
+     Clear to indicate hardware interrupts are really disabled, set otherwise.
+
+
+What happens is this:
+
+ (1) Normal kernel-mode operation.
+
+	ICC2.Z is 0, ICC2.C is 1.
+
+ (2) An interrupt occurs. The exception prologue examines ICC2.Z and determines that nothing needs
+     doing. This is done simply with an unlikely BEQ instruction.
+
+ (3) The interrupts are disabled (local_irq_disable)
+
+	ICC2.Z is set to 1.
+
+ (4) If interrupts were then re-enabled (local_irq_enable):
+
+	ICC2.Z would be set to 0.
+
+     A TIHI #2 instruction (trap #2 if condition HI - Z==0 && C==0) would be used to trap if
+     interrupts were now virtually enabled, but physically disabled - which they're not, so the
+     trap isn't taken. The kernel would then be back to state (1).
+
+ (5) An interrupt occurs. The exception prologue examines ICC2.Z and determines that the interrupt
+     shouldn't actually have happened. It jumps aside, and there disabled interrupts by setting
+     PSR.PIL to 14 and then it clears ICC2.C.
+
+ (6) If interrupts were then saved and disabled again (local_irq_save):
+
+	ICC2.Z would be shifted into the save variable and masked off (giving a 1).
+
+	ICC2.Z would then be set to 1 (thus unchanged), and ICC2.C would be unaffected (ie: 0).
+
+ (7) If interrupts were then restored from state (6) (local_irq_restore):
+
+	ICC2.Z would be set to indicate the result of XOR'ing the saved value (ie: 1) with 1, which
+	gives a result of 0 - thus leaving ICC2.Z set.
+
+	ICC2.C would remain unaffected (ie: 0).
+
+     A TIHI #2 instruction would be used to again assay the current state, but this would do
+     nothing as Z==1.
+
+ (8) If interrupts were then enabled (local_irq_enable):
+
+	ICC2.Z would be cleared. ICC2.C would be left unaffected. Both flags would now be 0.
+
+     A TIHI #2 instruction again issued to assay the current state would then trap as both Z==0
+     [interrupts virtually enabled] and C==0 [interrupts really disabled] would then be true.
+
+ (9) The trap #2 handler would simply enable hardware interrupts (set PSR.PIL to 0), set ICC2.C to
+     1 and return.
+
+(10) Immediately upon returning, the pending interrupt would be taken.
+
+(11) The interrupt handler would take the path of actually processing the interrupt (ICC2.Z is
+     clear, BEQ fails as per step (2)).
+
+(12) The interrupt handler would then set ICC2.C to 1 since hardware interrupts are definitely
+     enabled - or else the kernel wouldn't be here.
+
+(13) On return from the interrupt handler, things would be back to state (1).
+
+This trap (#2) is only available in kernel mode. In user mode it will result in SIGILL.