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linux/arch/sparc/kernel/winfixup.S

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[SPARC64]: Refine register window trap handling. When saving and restoing trap state, do the window spill/fill handling inline so that we never trap deeper than 2 trap levels. This is important for chips like Niagara. The window fixup code is massively simplified, and many more improvements are now possible. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-04 08:10:01 +00:00
/* winfixup.S: Handle cases where user stack pointer is found to be bogus.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*
[SPARC64]: Refine register window trap handling. When saving and restoing trap state, do the window spill/fill handling inline so that we never trap deeper than 2 trap levels. This is important for chips like Niagara. The window fixup code is massively simplified, and many more improvements are now possible. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-04 08:10:01 +00:00
* Copyright (C) 1997, 2006 David S. Miller (davem@davemloft.net)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
#include <asm/asi.h>
#include <asm/head.h>
#include <asm/page.h>
#include <asm/ptrace.h>
#include <asm/processor.h>
#include <asm/spitfire.h>
#include <asm/thread_info.h>
.text
[SPARC64]: Refine register window trap handling. When saving and restoing trap state, do the window spill/fill handling inline so that we never trap deeper than 2 trap levels. This is important for chips like Niagara. The window fixup code is massively simplified, and many more improvements are now possible. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-04 08:10:01 +00:00
/* It used to be the case that these register window fault
* handlers could run via the save and restore instructions
* done by the trap entry and exit code. They now do the
* window spill/fill by hand, so that case no longer can occur.
*/
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
.align 32
fill_fixup:
[SPARC64]: Add explicit register args to trap state loading macros. This, as well as making the code cleaner, allows a simplification in the TSB miss handling path. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-03 05:55:10 +00:00
TRAP_LOAD_THREAD_REG(%g6, %g1)
[SPARC64]: Refine register window trap handling. When saving and restoing trap state, do the window spill/fill handling inline so that we never trap deeper than 2 trap levels. This is important for chips like Niagara. The window fixup code is massively simplified, and many more improvements are now possible. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-04 08:10:01 +00:00
rdpr %tstate, %g1
and %g1, TSTATE_CWP, %g1
or %g4, FAULT_CODE_WINFIXUP, %g4
stb %g4, [%g6 + TI_FAULT_CODE]
stx %g5, [%g6 + TI_FAULT_ADDR]
wrpr %g1, %cwp
ba,pt %xcc, etrap
rd %pc, %g7
call do_sparc64_fault
add %sp, PTREGS_OFF, %o0
sparc64: Fix bootup regressions on some Kconfig combinations. The system call tracing bug fix mentioned in the Fixes tag below increased the amount of assembler code in the sequence of assembler files included by head_64.S This caused to total set of code to exceed 0x4000 bytes in size, which overflows the expression in head_64.S that works to place swapper_tsb at address 0x408000. When this is violated, the TSB is not properly aligned, and also the trap table is not aligned properly either. All of this together results in failed boots. So, do two things: 1) Simplify some code by using ba,a instead of ba/nop to get those bytes back. 2) Add a linker script assertion to make sure that if this happens again the build will fail. Fixes: 1a40b95374f6 ("sparc: Fix system call tracing register handling.") Reported-by: Meelis Roos <mroos@linux.ee> Reported-by: Joerg Abraham <joerg.abraham@nokia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-27 21:27:37 +00:00
ba,a,pt %xcc, rtrap
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
[SPARC64]: Refine register window trap handling. When saving and restoing trap state, do the window spill/fill handling inline so that we never trap deeper than 2 trap levels. This is important for chips like Niagara. The window fixup code is massively simplified, and many more improvements are now possible. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-04 08:10:01 +00:00
/* Be very careful about usage of the trap globals here.
* You cannot touch %g5 as that has the fault information.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*/
spill_fixup:
[SPARC64]: Refine register window trap handling. When saving and restoing trap state, do the window spill/fill handling inline so that we never trap deeper than 2 trap levels. This is important for chips like Niagara. The window fixup code is massively simplified, and many more improvements are now possible. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-04 08:10:01 +00:00
spill_fixup_mna:
spill_fixup_dax:
[SPARC64]: Add explicit register args to trap state loading macros. This, as well as making the code cleaner, allows a simplification in the TSB miss handling path. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-03 05:55:10 +00:00
TRAP_LOAD_THREAD_REG(%g6, %g1)
[SPARC64]: Refine register window trap handling. When saving and restoing trap state, do the window spill/fill handling inline so that we never trap deeper than 2 trap levels. This is important for chips like Niagara. The window fixup code is massively simplified, and many more improvements are now possible. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-04 08:10:01 +00:00
ldx [%g6 + TI_FLAGS], %g1
sparc64: Make montmul/montsqr/mpmul usable in 32-bit threads. The Montgomery Multiply, Montgomery Square, and Multiple-Precision Multiply instructions work by loading a combination of the floating point and multiple register windows worth of integer registers with the inputs. These values are 64-bit. But for 32-bit userland processes we only save the low 32-bits of each integer register during a register spill. This is because the register window save area is in the user stack and has a fixed layout. Therefore, the only way to use these instruction in 32-bit mode is to perform the following sequence: 1) Load the top-32bits of a choosen integer register with a sentinel, say "-1". This will be in the outer-most register window. The idea is that we're trying to see if the outer-most register window gets spilled, and thus the 64-bit values were truncated. 2) Load all the inputs for the montmul/montsqr/mpmul instruction, down to the inner-most register window. 3) Execute the opcode. 4) Traverse back up to the outer-most register window. 5) Check the sentinel, if it's still "-1" store the results. Otherwise retry the entire sequence. This retry is extremely troublesome. If you're just unlucky and an interrupt or other trap happens, it'll push that outer-most window to the stack and clear the sentinel when we restore it. We could retry forever and never make forward progress if interrupts arrive at a fast enough rate (consider perf events as one example). So we have do limited retries and fallback to software which is extremely non-deterministic. Luckily it's very straightforward to provide a mechanism to let 32-bit applications use a 64-bit stack. Stacks in 64-bit mode are biased by 2047 bytes, which means that the lowest bit is set in the actual %sp register value. So if we see bit zero set in a 32-bit application's stack we treat it like a 64-bit stack. Runtime detection of such a facility is tricky, and cumbersome at best. For example, just trying to use a biased stack and seeing if it works is hard to recover from (the signal handler will need to use an alt stack, plus something along the lines of longjmp). Therefore, we add a system call to report a bitmask of arch specific features like this in a cheap and less hairy way. With help from Andy Polyakov. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-26 22:18:37 +00:00
andcc %sp, 0x1, %g0
movne %icc, 0, %g1
[SPARC64]: Refine register window trap handling. When saving and restoing trap state, do the window spill/fill handling inline so that we never trap deeper than 2 trap levels. This is important for chips like Niagara. The window fixup code is massively simplified, and many more improvements are now possible. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-04 08:10:01 +00:00
andcc %g1, _TIF_32BIT, %g0
ldub [%g6 + TI_WSAVED], %g1
sll %g1, 3, %g3
add %g6, %g3, %g3
stx %sp, [%g3 + TI_RWIN_SPTRS]
sll %g1, 7, %g3
bne,pt %xcc, 1f
add %g6, %g3, %g3
stx %l0, [%g3 + TI_REG_WINDOW + 0x00]
stx %l1, [%g3 + TI_REG_WINDOW + 0x08]
stx %l2, [%g3 + TI_REG_WINDOW + 0x10]
stx %l3, [%g3 + TI_REG_WINDOW + 0x18]
stx %l4, [%g3 + TI_REG_WINDOW + 0x20]
stx %l5, [%g3 + TI_REG_WINDOW + 0x28]
stx %l6, [%g3 + TI_REG_WINDOW + 0x30]
stx %l7, [%g3 + TI_REG_WINDOW + 0x38]
stx %i0, [%g3 + TI_REG_WINDOW + 0x40]
stx %i1, [%g3 + TI_REG_WINDOW + 0x48]
stx %i2, [%g3 + TI_REG_WINDOW + 0x50]
stx %i3, [%g3 + TI_REG_WINDOW + 0x58]
stx %i4, [%g3 + TI_REG_WINDOW + 0x60]
stx %i5, [%g3 + TI_REG_WINDOW + 0x68]
stx %i6, [%g3 + TI_REG_WINDOW + 0x70]
ba,pt %xcc, 2f
stx %i7, [%g3 + TI_REG_WINDOW + 0x78]
1: stw %l0, [%g3 + TI_REG_WINDOW + 0x00]
stw %l1, [%g3 + TI_REG_WINDOW + 0x04]
stw %l2, [%g3 + TI_REG_WINDOW + 0x08]
stw %l3, [%g3 + TI_REG_WINDOW + 0x0c]
stw %l4, [%g3 + TI_REG_WINDOW + 0x10]
stw %l5, [%g3 + TI_REG_WINDOW + 0x14]
stw %l6, [%g3 + TI_REG_WINDOW + 0x18]
stw %l7, [%g3 + TI_REG_WINDOW + 0x1c]
stw %i0, [%g3 + TI_REG_WINDOW + 0x20]
stw %i1, [%g3 + TI_REG_WINDOW + 0x24]
stw %i2, [%g3 + TI_REG_WINDOW + 0x28]
stw %i3, [%g3 + TI_REG_WINDOW + 0x2c]
stw %i4, [%g3 + TI_REG_WINDOW + 0x30]
stw %i5, [%g3 + TI_REG_WINDOW + 0x34]
stw %i6, [%g3 + TI_REG_WINDOW + 0x38]
stw %i7, [%g3 + TI_REG_WINDOW + 0x3c]
2: add %g1, 1, %g1
stb %g1, [%g6 + TI_WSAVED]
rdpr %tstate, %g1
andcc %g1, TSTATE_PRIV, %g0
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
saved
[SPARC64]: Refine register window trap handling. When saving and restoing trap state, do the window spill/fill handling inline so that we never trap deeper than 2 trap levels. This is important for chips like Niagara. The window fixup code is massively simplified, and many more improvements are now possible. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-04 08:10:01 +00:00
be,pn %xcc, 1f
and %g1, TSTATE_CWP, %g1
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
retry
[SPARC64]: Refine register window trap handling. When saving and restoing trap state, do the window spill/fill handling inline so that we never trap deeper than 2 trap levels. This is important for chips like Niagara. The window fixup code is massively simplified, and many more improvements are now possible. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-04 08:10:01 +00:00
1: mov FAULT_CODE_WRITE | FAULT_CODE_DTLB | FAULT_CODE_WINFIXUP, %g4
stb %g4, [%g6 + TI_FAULT_CODE]
stx %g5, [%g6 + TI_FAULT_ADDR]
wrpr %g1, %cwp
ba,pt %xcc, etrap
rd %pc, %g7
call do_sparc64_fault
add %sp, PTREGS_OFF, %o0
[SPARC64]: %l6 trap return handling no longer necessary. Now that we indicate the "restart system call" in the trap type field of pt_regs->magic, we don't need to set the %l6 boolean in all of the trap return paths. And we therefore don't need to pass it to do_notify_resume(). Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-24 10:15:22 +00:00
ba,a,pt %xcc, rtrap
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
winfix_mna:
[SPARC64]: Refine register window trap handling. When saving and restoing trap state, do the window spill/fill handling inline so that we never trap deeper than 2 trap levels. This is important for chips like Niagara. The window fixup code is massively simplified, and many more improvements are now possible. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-04 08:10:01 +00:00
andn %g3, 0x7f, %g3
add %g3, 0x78, %g3
wrpr %g3, %tnpc
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
done
[SPARC64]: Refine register window trap handling. When saving and restoing trap state, do the window spill/fill handling inline so that we never trap deeper than 2 trap levels. This is important for chips like Niagara. The window fixup code is massively simplified, and many more improvements are now possible. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-04 08:10:01 +00:00
fill_fixup_mna:
rdpr %tstate, %g1
and %g1, TSTATE_CWP, %g1
wrpr %g1, %cwp
ba,pt %xcc, etrap
rd %pc, %g7
[SPARC64]: SUN4V memory exception trap handlers. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-10 04:20:34 +00:00
sethi %hi(tlb_type), %g1
lduw [%g1 + %lo(tlb_type)], %g1
cmp %g1, 3
bne,pt %icc, 1f
[SPARC64]: Refine register window trap handling. When saving and restoing trap state, do the window spill/fill handling inline so that we never trap deeper than 2 trap levels. This is important for chips like Niagara. The window fixup code is massively simplified, and many more improvements are now possible. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-04 08:10:01 +00:00
add %sp, PTREGS_OFF, %o0
[SPARC64]: Fix unaligned access winfxup handling on SUN4V. Another case where we have to force ourselves into global register level one. Also make sure the arguments passed to sun4v_do_mna() are correct. This area actually needs some more work, for example spill fixup is not necessarily going to do the right thing for this case. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-19 00:39:39 +00:00
mov %l4, %o2
[SPARC64]: Fix bogus call to sun4v_mna in winfixup code. The C function is named sun4v_do_mna not sun4v_mna. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-16 09:45:49 +00:00
call sun4v_do_mna
[SPARC64]: Fix unaligned access winfxup handling on SUN4V. Another case where we have to force ourselves into global register level one. Also make sure the arguments passed to sun4v_do_mna() are correct. This area actually needs some more work, for example spill fixup is not necessarily going to do the right thing for this case. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-19 00:39:39 +00:00
mov %l5, %o1
[SPARC64]: %l6 trap return handling no longer necessary. Now that we indicate the "restart system call" in the trap type field of pt_regs->magic, we don't need to set the %l6 boolean in all of the trap return paths. And we therefore don't need to pass it to do_notify_resume(). Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-24 10:15:22 +00:00
ba,a,pt %xcc, rtrap
[SPARC64]: Fix unaligned access winfxup handling on SUN4V. Another case where we have to force ourselves into global register level one. Also make sure the arguments passed to sun4v_do_mna() are correct. This area actually needs some more work, for example spill fixup is not necessarily going to do the right thing for this case. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-19 00:39:39 +00:00
1: mov %l4, %o1
mov %l5, %o2
call mem_address_unaligned
[SPARC64]: SUN4V memory exception trap handlers. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-10 04:20:34 +00:00
nop
[SPARC64]: %l6 trap return handling no longer necessary. Now that we indicate the "restart system call" in the trap type field of pt_regs->magic, we don't need to set the %l6 boolean in all of the trap return paths. And we therefore don't need to pass it to do_notify_resume(). Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-24 10:15:22 +00:00
ba,a,pt %xcc, rtrap
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
winfix_dax:
[SPARC64]: Refine register window trap handling. When saving and restoing trap state, do the window spill/fill handling inline so that we never trap deeper than 2 trap levels. This is important for chips like Niagara. The window fixup code is massively simplified, and many more improvements are now possible. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-04 08:10:01 +00:00
andn %g3, 0x7f, %g3
add %g3, 0x74, %g3
wrpr %g3, %tnpc
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
done
[SPARC64]: Refine register window trap handling. When saving and restoing trap state, do the window spill/fill handling inline so that we never trap deeper than 2 trap levels. This is important for chips like Niagara. The window fixup code is massively simplified, and many more improvements are now possible. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-04 08:10:01 +00:00
fill_fixup_dax:
rdpr %tstate, %g1
and %g1, TSTATE_CWP, %g1
wrpr %g1, %cwp
ba,pt %xcc, etrap
rd %pc, %g7
[SPARC64]: SUN4V memory exception trap handlers. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-10 04:20:34 +00:00
sethi %hi(tlb_type), %g1
[SPARC64]: Refine register window trap handling. When saving and restoing trap state, do the window spill/fill handling inline so that we never trap deeper than 2 trap levels. This is important for chips like Niagara. The window fixup code is massively simplified, and many more improvements are now possible. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-04 08:10:01 +00:00
mov %l4, %o1
[SPARC64]: SUN4V memory exception trap handlers. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-10 04:20:34 +00:00
lduw [%g1 + %lo(tlb_type)], %g1
[SPARC64]: Refine register window trap handling. When saving and restoing trap state, do the window spill/fill handling inline so that we never trap deeper than 2 trap levels. This is important for chips like Niagara. The window fixup code is massively simplified, and many more improvements are now possible. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-04 08:10:01 +00:00
mov %l5, %o2
[SPARC64]: SUN4V memory exception trap handlers. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-10 04:20:34 +00:00
cmp %g1, 3
bne,pt %icc, 1f
[SPARC64]: Refine register window trap handling. When saving and restoing trap state, do the window spill/fill handling inline so that we never trap deeper than 2 trap levels. This is important for chips like Niagara. The window fixup code is massively simplified, and many more improvements are now possible. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-04 08:10:01 +00:00
add %sp, PTREGS_OFF, %o0
[SPARC64]: SUN4V memory exception trap handlers. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-10 04:20:34 +00:00
call sun4v_data_access_exception
nop
[SPARC64]: %l6 trap return handling no longer necessary. Now that we indicate the "restart system call" in the trap type field of pt_regs->magic, we don't need to set the %l6 boolean in all of the trap return paths. And we therefore don't need to pass it to do_notify_resume(). Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-24 10:15:22 +00:00
ba,a,pt %xcc, rtrap
arch/sparc: Avoid DCTI Couples Avoid un-intended DCTI Couples. Use of DCTI couples is deprecated. Also address the "Programming Note" for optimal performance. Here is the complete text from Oracle SPARC Architecture Specs. 6.3.4.7 DCTI Couples "A delayed control transfer instruction (DCTI) in the delay slot of another DCTI is referred to as a “DCTI couple”. The use of DCTI couples is deprecated in the Oracle SPARC Architecture; no new software should place a DCTI in the delay slot of another DCTI, because on future Oracle SPARC Architecture implementations DCTI couples may execute either slowly or differently than the programmer assumes it will. SPARC V8 and SPARC V9 Compatibility Note The SPARC V8 architecture left behavior undefined for a DCTI couple. The SPARC V9 architecture defined behavior in that case, but as of UltraSPARC Architecture 2005, use of DCTI couples was deprecated. Software should not expect high performance from DCTI couples, and performance of DCTI couples should be expected to decline further in future processors. Programming Note As noted in TABLE 6-5 on page 115, an annulled branch-always (branch-always with a = 1) instruction is not architecturally a DCTI. However, since not all implementations make that distinction, for optimal performance, a DCTI should not be placed in the instruction word immediately following an annulled branch-always instruction (BA,A or BPA,A)." Signed-off-by: Babu Moger <babu.moger@oracle.com> Reviewed-by: Rob Gardner <rob.gardner@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-17 20:52:21 +00:00
nop
[SPARC64]: SUN4V memory exception trap handlers. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-10 04:20:34 +00:00
1: call spitfire_data_access_exception
nop
[SPARC64]: %l6 trap return handling no longer necessary. Now that we indicate the "restart system call" in the trap type field of pt_regs->magic, we don't need to set the %l6 boolean in all of the trap return paths. And we therefore don't need to pass it to do_notify_resume(). Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-24 10:15:22 +00:00
ba,a,pt %xcc, rtrap
arch/sparc: Avoid DCTI Couples Avoid un-intended DCTI Couples. Use of DCTI couples is deprecated. Also address the "Programming Note" for optimal performance. Here is the complete text from Oracle SPARC Architecture Specs. 6.3.4.7 DCTI Couples "A delayed control transfer instruction (DCTI) in the delay slot of another DCTI is referred to as a “DCTI couple”. The use of DCTI couples is deprecated in the Oracle SPARC Architecture; no new software should place a DCTI in the delay slot of another DCTI, because on future Oracle SPARC Architecture implementations DCTI couples may execute either slowly or differently than the programmer assumes it will. SPARC V8 and SPARC V9 Compatibility Note The SPARC V8 architecture left behavior undefined for a DCTI couple. The SPARC V9 architecture defined behavior in that case, but as of UltraSPARC Architecture 2005, use of DCTI couples was deprecated. Software should not expect high performance from DCTI couples, and performance of DCTI couples should be expected to decline further in future processors. Programming Note As noted in TABLE 6-5 on page 115, an annulled branch-always (branch-always with a = 1) instruction is not architecturally a DCTI. However, since not all implementations make that distinction, for optimal performance, a DCTI should not be placed in the instruction word immediately following an annulled branch-always instruction (BA,A or BPA,A)." Signed-off-by: Babu Moger <babu.moger@oracle.com> Reviewed-by: Rob Gardner <rob.gardner@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-17 20:52:21 +00:00
nop
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