Commit Graph

19 Commits

Author SHA1 Message Date
Maciej W. Rozycki
619b6e18fc [MIPS] R4000/R4400 daddiu erratum workaround
This complements the generic R4000/R4400 errata workaround code and adds 
bits for the daddiu problem.  In most places it just modifies handwritten 
assembly code so that the assembler is allowed to use a temporary register 
as daddiu may now be treated as a macro that expands to a sequence of li 
and daddu.  It is the AT register or, where AT is unavailable or used 
explicitly for another purpose, an explicitly-named register is selected, 
using the .set at=<reg> feature added recently to gas.  This feature is 
only used if CONFIG_CPU_DADDI_WORKAROUNDS has been set, so if the 
workaround remains disabled, the required version of binutils stays 
unchanged.

 Similarly, daddiu instructions put in branch delay slots in noreorder 
fragments are now taken out of them and the assembler is allowed to 
reorder them itself as possible (which it does making the whole idea of 
scheduling them into delay slots manually questionable).

 Also in the very few places where such a simple conversion was not 
possible, a handcoded longer sequence is implemented.

 Other than that there are changes to code responsible for building the 
TLB fault and page clear/copy handlers to avoid daddiu as appropriate.  
These are only effective if the erratum is verified to be present at the 
run time.

 Finally there is a trivial update to __delay(), because it uses daddiu in 
a branch delay slot.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-01-29 10:14:55 +00:00
Ralf Baechle
21a151d8ca [MIPS] checkfiles: Fix "need space after that ','" errors.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-11 23:46:15 +01:00
Ralf Baechle
49a89efbbb [MIPS] Fix "no space between function name and open parenthesis" warnings.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-11 23:46:15 +01:00
Ralf Baechle
d0c91ae2bb [MIPS] Export __copy_user_inatomic.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-03-07 00:07:17 +00:00
Ralf Baechle
e03b526932 [MIPS] Fixup copy_from_user_inatomic
From the 01408c4939 log message:

The problem is that when we write to a file, the copy from userspace to
pagecache is first done with preemption disabled, so if the source
address is not immediately available the copy fails *and* *zeros* *the*
*destination*.

This is a problem because a concurrent read (which admittedly is an odd
thing to do) might see zeros rather that was there before the write, or
what was there after, or some mixture of the two (any of these being a
reasonable thing to see).

If the copy did fail, it will immediately be retried with preemption
re-enabled so any transient problem with accessing the source won't
cause an error.

The first copying does not need to zero any uncopied bytes, and doing
so causes the problem.  It uses copy_from_user_atomic rather than
copy_from_user so the simple expedient is to change copy_from_user_atomic
to *not* zero out bytes on failure.

< --- end cite --- >

This patch finally implements at least a not so pretty solution by
duplicating the relevant part of __copy_user.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-02-20 01:26:42 +00:00
Ralf Baechle
6f3aa38e19 [MIPS] Remove stray instruction from __get_user_asm_ll32.
This did result in double clearing of the error return value on success
only but should make a meassurable overhead for sigreturn.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-02-13 22:40:51 +00:00
Ralf Baechle
cb66fb3f15 [MIPS] 32-bit: Fix warning about cast for fetching pointer from userspace.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-02-13 22:40:51 +00:00
Ralf Baechle
cd1fb9eabe Revert "[MIPS] Fix warning in get_user when fetching pointer object from userspace."
This reverts commit 4ed3a77f38.
2007-02-13 22:40:50 +00:00
Ralf Baechle
4ed3a77f38 [MIPS] Fix warning in get_user when fetching pointer object from userspace.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-02-10 22:38:44 +00:00
Chris Dearman
131c1a2b6e [MIPS] Comment fix
Signed-off-by: Chris Dearman <chris@mips.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-02-06 16:53:24 +00:00
David Woodhouse
62c4f0a2d5 Don't include linux/config.h from anywhere else in include/
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-04-26 12:56:16 +01:00
Atsushi Nemoto
8ecbbcaf08 [MIPS] Fixes for uaccess.h with gcc >= 4.0.1
It seems current get_user() incorrectly sign-extend an unsigned int
value on 64bit kernel.  I think this is because '(__typeof__(val))'
cast in final assignment.  I suppose the cast should be
'(__typeof__(*(addr))'.
    
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-02-21 16:58:22 +00:00
Ralf Baechle
3218357c94 [MIPS] More uaccess.h fixes with gcc >= 4.0.1.
From Richard Sandiford <richard@codesourcery.com>:
    
This patch caused a miscompilation of the restore_gp_regs() block
in restore_sigcontext().  This was in a 32-bit kernel compiled with
GCC CVS head.
    
restore_gp_regs() copies 64-bit user fields into 32-bit variables,
and in this combination, the new __get_user_asm_ll32() clobbers too
many registers.  It says:
    
/*
 * Get a long long 64 using 32 bit registers.
 */
{									\
	__asm__ __volatile__(						\
	"1:	lw	%1, (%3)				\n"	\
	"2:	lw	%D1, 4(%3)				\n"	\
	"	move	%0, $0					\n"	\
	"3:	.section	.fixup,\"ax\"			\n"	\
	"4:	li	%0, %4					\n"	\
	"	move	%1, $0					\n"	\
	"	move	%D1, $0					\n"	\
	"	j	3b					\n"	\
	"	.previous					\n"	\
	"	.section	__ex_table,\"a\"		\n"	\
	"	" __UA_ADDR "	1b, 4b				\n"	\
	"	" __UA_ADDR "	2b, 4b				\n"	\
	"	.previous					\n"	\
	: "=r" (__gu_err), "=&r" (val)					\
	: "0" (0), "r" (addr), "i" (-EFAULT));				\
}

and this requires val (%1) to be a 64-bit value.  In the case I saw,
gcc was using $3 for the 32-bit val, and wasn't expecting $4 to be
clobbered.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-02-14 19:13:24 +00:00
Ralf Baechle
4feb8f8f45 [MIPS] Bullet proof uaccess.h against 4.0.1 miss-compilation.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-02-07 13:30:23 +00:00
Ralf Baechle
27c7c1657d Drop might_sleep() calls from get_user() & co. This should fix the issue
in http://www.linux-mips.org/cgi-bin/mesg.cgi?a=linux-mips&i=200508171321.20094.Joshua.Wise%40sicortex.com and it's the right thing to do anyway because
it was inflating those functions way too much.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2005-10-29 19:32:10 +01:00
Ralf Baechle
fe00f943e0 Sparseify MIPS.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2005-10-29 19:30:50 +01:00
Jesper Juhl
97de50c0ad [PATCH] remove verify_area(): remove verify_area() from various uaccess.h headers
Remove the deprecated (and unused) verify_area() from various uaccess.h
headers.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-07 16:57:35 -07:00
Ralf Baechle
875d43e72b [PATCH] mips: clean up 32/64-bit configuration
Start cleaning 32-bit vs. 64-bit configuration.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:06 -07:00
Linus Torvalds
1da177e4c3 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 15:20:36 -07:00