This patch removes the dummy asm/kvm.h files on architectures not (yet)
supporting KVM and uses the same conditional headers installation as
already used for a.out.h .
Also removed are superfluous install rules in the s390 and x86 Kbuild
files (they are already in Kbuild.asm).
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
All users have now been converted to linux/semaphore.h and we don't need
to keep these files around any longer.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
With this commit all sparc64 header files are moved to asm-sparc.
The remaining files (71 files) were too different to be trivially
merged so divide them up in a _32.h and a _64.h file which
are both included from the file with no bit size.
The following script were used:
cd include
FILES=`wc -l asm-sparc64/*h | grep -v '^ 1' | cut -b 20-`
for FILE in ${FILES}; do
echo $FILE:
BASE=`echo $FILE | cut -d '.' -f 1`
FN32=${BASE}_32.h
FN64=${BASE}_64.h
GUARD=___ASM_SPARC_`echo $BASE | tr '-' '_' | tr [:lower:] [:upper:]`_H
git mv asm-sparc/$FILE asm-sparc/$FN32
git mv asm-sparc64/$FILE asm-sparc/$FN64
echo git mv done
printf "#ifndef %s\n" $GUARD > asm-sparc/$FILE
printf "#define %s\n" $GUARD >> asm-sparc/$FILE
printf "#if defined(__sparc__) && defined(__arch64__)\n" >> asm-sparc/$FILE
printf "#include <asm-sparc/%s>\n" $FN64 >> asm-sparc/$FILE
printf "#else\n" >> asm-sparc/$FILE
printf "#include <asm-sparc/%s>\n" $FN32 >> asm-sparc/$FILE
printf "#endif\n" >> asm-sparc/$FILE
printf "#endif\n" >> asm-sparc/$FILE
git add asm-sparc/$FILE
echo new file done
printf "#include <asm-sparc/%s>\n" $FILE > asm-sparc64/$FILE
git add asm-sparc64/$FILE
echo sparc64 file done
done
The guard contains three '_' to avoid conflict with existing guards.
In additing the two Kbuild files are emptied to avoid breaking
headers_* targets.
We will reintroduce the exported header files when the necessary
kbuild changes are merged.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
A manual inspection revealed that the following headerfiles
contained only trivial differences:
hw_irq.h idprom.h kmap_types.h kvm.h spinlock_types.h sunbpp.h unaligned.h
The only noteworthy change are that sparc64 had a volatile
qualifer that sparc missed in spinlock_types.h.
In addition a few comments were updated.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Used the following script to find equal header files:
SPARC64=`ls asm-sparc64`
for FILE in ${SPARC64}; do
cmp -s asm-sparc/$FILE asm-sparc64/$FILE;
if [ $? = 0 ]; then
printf "#include <asm-sparc/%s>\n" $FILE > asm-sparc64/$FILE
fi
done
A few of the equal files are a simple include from
asm-generic, but by including the file from asm-sparc
we know they are equal for sparc and sparc64.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Used the following script to copy the files:
cd include
set -e
SPARC64=`ls asm-sparc64`
for FILE in ${SPARC64}; do
if [ -f asm-sparc/$FILE ]; then
echo $FILE exist in asm-sparc
else
git mv asm-sparc64/$FILE asm-sparc/$FILE
printf "#include <asm-sparc/$FILE>\n" > asm-sparc64/$FILE
git add asm-sparc64/$FILE
fi
done
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Joined the two files as they contain distinct definitions.
Inspired by patch from: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Adrian Bunk <bunk@kernel.org>
Copy content of sparc64 file to sparc file.
There is only minimal possibilities for further unification.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Bring the commit e55c57e0b5
("[SPARC64]: Report any user access faults in termios accessors")
over to sparc when unifying the two files.
The diff was manually inspected to contain no
other relevant changes.
This unification therefore changes functionality of sparc.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
The type of tcflag_t differs from 32 and 64 bit.
For 32 bit it is long
For 64 bit it is int
Altough these have same size then I was not sure that
it was OK to change the 64 bit version to long as this
is part of the ABI so it was made conditional.
:$ diff -u include/asm-sparc/termbits.h include/asm-sparc64/termbits.h
:-- include/asm-sparc/termbits.h 2008-06-13 06:42:07.000000000 +0200
:++ include/asm-sparc64/termbits.h 2008-06-13 06:42:07.000000000 +0200
:@@ -1,11 +1,11 @@
:-#ifndef _SPARC_TERMBITS_H
:-#define _SPARC_TERMBITS_H
:+#ifndef _SPARC64_TERMBITS_H
:+#define _SPARC64_TERMBITS_H
:
: #include <linux/posix_types.h>
:
: typedef unsigned char cc_t;
: typedef unsigned int speed_t;
:-typedef unsigned long tcflag_t;
:+typedef unsigned int tcflag_t;
:
: #define NCC 8
: struct termio {
:@@ -102,7 +102,7 @@
: #define IXANY 0x00000800
: #define IXOFF 0x00001000
: #define IMAXBEL 0x00002000
:-#define IUTF8 0x00004000
:+#define IUTF8 0x00004000
:
: /* c_oflag bits */
: #define OPOST 0x00000001
:@@ -171,7 +171,6 @@
: #define HUPCL 0x00000400
: #define CLOCAL 0x00000800
: #define CBAUDEX 0x00001000
:-/* We'll never see these speeds with the Zilogs, but for completeness... */
: #define BOTHER 0x00001000
: #define B57600 0x00001001
: #define B115200 0x00001002
:@@ -199,7 +198,7 @@
: #define B3500000 0x00001012
: #define B4000000 0x00001013 */
: #define CIBAUD 0x100f0000 /* input baud rate (not used) */
:-#define CMSPAR 0x40000000 /* mark or space (stick) parity */
:+#define CMSPAR 0x40000000 /* mark or space (stick) parity */
: #define CRTSCTS 0x80000000 /* flow control */
:
: #define IBSHIFT 16 /* Shift from CBAUD to CIBAUD */
:@@ -258,4 +257,4 @@
: #define TCSADRAIN 1
: #define TCSAFLUSH 2
:
:-#endif /* !(_SPARC_TERMBITS_H) */
:+#endif /* !(_SPARC64_TERMBITS_H) */
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
RLIM_INFINITY differ from 32 and 64 bit.
The rest is equal.
:$ diff -u include/asm-sparc/resource.h include/asm-sparc64/resource.h
:-- include/asm-sparc/resource.h 2008-06-13 06:46:39.000000000 +0200
:++ include/asm-sparc64/resource.h 2008-06-13 06:46:39.000000000 +0200
:@@ -1,11 +1,11 @@
: /*
: * resource.h: Resource definitions.
: *
:- * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
:+ * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
: */
:
:-#ifndef _SPARC_RESOURCE_H
:-#define _SPARC_RESOURCE_H
:+#ifndef _SPARC64_RESOURCE_H
:+#define _SPARC64_RESOURCE_H
:
: /*
: * These two resource limit IDs have a Sparc/Linux-specific ordering,
:@@ -14,13 +14,6 @@
: #define RLIMIT_NOFILE 6 /* max number of open files */
: #define RLIMIT_NPROC 7 /* max number of processes */
:
:-/*
:- * SuS says limits have to be unsigned.
:- * We make this unsigned, but keep the
:- * old value for compatibility:
:- */
:-#define RLIM_INFINITY 0x7fffffff
:-
: #include <asm-generic/resource.h>
:
:-#endif /* !(_SPARC_RESOURCE_H) */
:+#endif /* !(_SPARC64_RESOURCE_H) */
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Padding in the sembuf structure made conditional
as only 32 bit sparc did so.
:$ diff -u include/asm-sparc/sembuf.h include/asm-sparc64/sembuf.h
:-- include/asm-sparc/sembuf.h 2008-06-13 06:42:07.000000000 +0200
:++ include/asm-sparc64/sembuf.h 2008-06-13 06:42:07.000000000 +0200
:@@ -1,21 +1,18 @@
:-#ifndef _SPARC_SEMBUF_H
:-#define _SPARC_SEMBUF_H
:+#ifndef _SPARC64_SEMBUF_H
:+#define _SPARC64_SEMBUF_H
:
: /*
:- * The semid64_ds structure for sparc architecture.
:+ * The semid64_ds structure for sparc64 architecture.
: * Note extra padding because this structure is passed back and forth
: * between kernel and user space.
: *
: * Pad space is left for:
:- * - 64-bit time_t to solve y2038 problem
:- * - 2 miscellaneous 32-bit values
:+ * - 2 miscellaneous 64-bit values
: */
:
: struct semid64_ds {
: struct ipc64_perm sem_perm; /* permissions .. see ipc.h */
:- unsigned int __pad1;
: __kernel_time_t sem_otime; /* last semop time */
:- unsigned int __pad2;
: __kernel_time_t sem_ctime; /* last change time */
: unsigned long sem_nsems; /* no. of semaphores in array */
: unsigned long __unused1;
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Padding from 32 bit sparc kept using preprocessor magic
:$ diff -u include/asm-sparc/msgbuf.h include/asm-sparc64/msgbuf.h
:-- include/asm-sparc/msgbuf.h 2008-06-13 06:42:07.000000000 +0200
:++ include/asm-sparc64/msgbuf.h 2008-06-13 06:42:07.000000000 +0200
:@@ -7,17 +7,13 @@
: * between kernel and user space.
: *
: * Pad space is left for:
:- * - 64-bit time_t to solve y2038 problem
:- * - 2 miscellaneous 32-bit values
:+ * - 2 miscellaneous 64-bit values
: */
:
: struct msqid64_ds {
: struct ipc64_perm msg_perm;
:- unsigned int __pad1;
: __kernel_time_t msg_stime; /* last msgsnd time */
:- unsigned int __pad2;
: __kernel_time_t msg_rtime; /* last msgrcv time */
:- unsigned int __pad3;
: __kernel_time_t msg_ctime; /* last change time */
: unsigned long msg_cbytes; /* current number of bytes on queue */
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Trivial differenses in comments - used the version from sparc64
:$ diff -u include/asm-sparc/ioctls.h include/asm-sparc64/ioctls.h
:-- include/asm-sparc/ioctls.h 2008-06-13 08:46:29.000000000 +0200
:++ include/asm-sparc64/ioctls.h 2008-06-13 08:46:29.000000000 +0200
:@@ -1,5 +1,5 @@
:-#ifndef _ASM_SPARC_IOCTLS_H
:-#define _ASM_SPARC_IOCTLS_H
:+#ifndef _ASM_SPARC64_IOCTLS_H
:+#define _ASM_SPARC64_IOCTLS_H
:
: #include <asm/ioctl.h>
:
:@@ -22,7 +22,7 @@
:
: /* Note that all the ioctls that are not available in Linux have a
: * double underscore on the front to: a) avoid some programs to
:- * thing we support some ioctls under Linux (autoconfiguration stuff)
:+ * think we support some ioctls under Linux (autoconfiguration stuff)
: */
: /* Little t */
: #define TIOCGETD _IOR('t', 0, int)
:@@ -110,7 +110,7 @@
: #define TIOCSERGETLSR 0x5459 /* Get line status register */
: #define TIOCSERGETMULTI 0x545A /* Get multiport config */
: #define TIOCSERSETMULTI 0x545B /* Set multiport config */
:-#define TIOCMIWAIT 0x545C /* Wait input */
:+#define TIOCMIWAIT 0x545C /* Wait for change on serial input line(s) */
: #define TIOCGICOUNT 0x545D /* Read serial port inline interrupt counts */
:
: /* Kernel definitions */
:@@ -133,4 +133,4 @@
: #define TIOCPKT_NOSTOP 16
: #define TIOCPKT_DOSTOP 32
:
:-#endif /* !(_ASM_SPARC_IOCTLS_H) */
:+#endif /* !(_ASM_SPARC64_IOCTLS_H) */
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Copy was done using the following simple script:
set -e
SPARC64="h display7seg.h envctrl.h psrcompat.h pstate.h uctx.h utrap.h watchdog.h"
for FILE in ${SPARC64}; do
if [ -f asm-sparc/$FILE ]; then
echo $FILE exist in asm-sparc
fi
cat asm-sparc64/$FILE > asm-sparc/$FILE
printf "#include <asm-sparc/$FILE>\n" > asm-sparc64/$FILE
done
The name of the copied files are added to asm-sparc/Kbuild
to keep "make headers_check" functional.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Alexander Beregalov reported this build failure:
$ make CROSS_COMPILE=sparc64-unknown-linux-gnu- image modules && sudo
make modules_install
CHK include/linux/version.h
CHK include/linux/utsrelease.h
CALL scripts/checksyscalls.sh
CHK include/linux/compile.h
dnsdomainname: Unknown host
CC arch/sparc64/kernel/sparc64_ksyms.o
arch/sparc64/kernel/sparc64_ksyms.c:116: error: '_mcount' undeclared
here (not in a function)
cc1: warnings being treated as errors
arch/sparc64/kernel/sparc64_ksyms.c:116: error: type defaults to 'int'
in declaration of '_mcount'
And bisected it back to:
| commit 395a59d0f8
| Author: Abhishek Sagar <sagar.abhishek@gmail.com>
| Date: Sat Jun 21 23:47:27 2008 +0530
|
| ftrace: store mcount address in rec->ip
the mcount prototype is only available under CONFIG_FTRACE,
extend it to CONFIG_MCOUNT as well.
Reported-and-bisected-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Record the address of the mcount call-site. Currently all archs except sparc64
record the address of the instruction following the mcount call-site. Some
general cleanups are entailed. Storing mcount addresses in rec->ip enables
looking them up in the kprobe hash table later on to check if they're kprobe'd.
Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com>
Cc: davem@davemloft.net
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
I added a full memory clobber on all asm accessors except the _raw
ones.
Signed-off-by: David S. Miller <davem@davemloft.net>
global_reg_snapshot shouldn't be visible in our userspace headers.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a cpu really is stuck in the kernel, it can be often
impossible to figure out which cpu is stuck where. The
worst case is when the stuck cpu has interrupts disabled.
Therefore, implement a global cpu state capture that uses
SMP message interrupts which are not disabled by the
normal IRQ enable/disable APIs of the kernel.
As long as we can get a sysrq 'y' to the kernel, we can
get a dump. Even if the console interrupt cpu is wedged,
we can trigger it from userspace using /proc/sysrq-trigger
The output is made compact so that this facility is more
useful on high cpu count systems, which is where this
facility will likely find itself the most useful :)
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch removes the CVS keywords that weren't updated for a long time
from comments.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Just like mmap, we need to validate address ranges regardless
of MAP_FIXED.
sparc{,64}_mmap_check()'s flag argument is unused, remove.
Based upon a report and preliminary patch by
Jan Lieskovsky <jlieskov@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
So, forever, we've had this ptrace_signal_deliver implementation
which tries to handle all of the nasties that can occur when the
debugger looks at a process about to take a signal. It's meant
to address all of these issues inside of the kernel so that the
debugger need not be mindful of such things.
Problem is, this doesn't work.
The idea was that we should do the syscall restart business first, so
that the debugger captures that state. Otherwise, if the debugger for
example saves the child's state, makes the child execute something
else, then restores the saved state, we won't handle the syscall
restart properly because we lose the "we're in a syscall" state.
The code here worked for most cases, but if the debugger actually
passes the signal through to the child unaltered, it's possible that
we would do a syscall restart when we shouldn't have.
In particular this breaks the case of debugging a process under a gdb
which is being debugged by yet another gdb. gdb uses sigsuspend
to wait for SIGCHLD of the inferior, but if gdb itself is being
debugged by a top-level gdb we get a ptrace_stop(). The top-level gdb
does a PTRACE_CONT with SIGCHLD to let the inferior gdb see the
signal. But ptrace_signal_deliver() assumed the debugger would cancel
out the signal and therefore did a syscall restart, because the return
error was ERESTARTNOHAND.
Fix this by simply making ptrace_signal_deliver() a nop, and providing
a way for the debugger to control system call restarting properly:
1) Report a "in syscall" software bit in regs->{tstate,psr}.
It is set early on in trap entry to a system call and is fully
visible to the debugger via ptrace() and regsets.
2) Test this bit right before doing a syscall restart. We have
to do a final recheck right after get_signal_to_deliver() in
case the debugger cleared the bit during ptrace_stop().
3) Clear the bit in trap return so we don't accidently try to set
that bit in the real register.
As a result we also get a ptrace_{is,clear}_syscall() for sparc32 just
like sparc64 has.
M68K has this same exact bug, and is now the only other user of the
ptrace_signal_deliver hook. It needs to be fixed in the same exact
way as sparc.
Signed-off-by: David S. Miller <davem@davemloft.net>
Forever we had a PTRACE_SUNOS_DETACH which was unconditionally
recognized, regardless of the personality of the process.
Unfortunately, this value is what ended up in the GLIBC sys/ptrace.h
header file on sparc as PTRACE_DETACH and PT_DETACH.
So continue to recognize this old value. Luckily, it doesn't conflict
with anything we actually care about.
Signed-off-by: David S. Miller <davem@davemloft.net>
This modifies <asm-sparc64/types.h> to use the <asm-generic/int-*.h>
generic include files.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: David S. Miller <davem@davemloft.net>
Lots of asm-*/futex.h call pagefault_enable and pagefault_disable, which
are declared in linux/uaccess.h, without including linux/uaccess.h.
They all include asm/uaccess.h, so this patch replaces asm/uaccess.h
with linux/uaccess.h.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Unaligned access is ok for the following arches:
cris, m68k, mn10300, powerpc, s390, x86
Arches that use the memmove implementation for native endian, and
the byteshifting for the opposite endianness.
h8300, m32r, xtensa
Packed struct for native endian, byteshifting for other endian:
alpha, blackfin, ia64, parisc, sparc, sparc64, mips, sh
m86knommu is generic_be for Coldfire, otherwise unaligned access is ok.
frv, arm chooses endianness based on compiler settings, uses the byteshifting
versions. Remove the unaligned trap handler from frv as it is now unused.
v850 is le, uses the byteshifting versions for both be and le.
Remove the now unused asm-generic implementation.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Current limitations:
1) On SMP single stepping has some fundamental issues,
shared with other sw single-step architectures such
as mips and arm.
2) On 32-bit sparc we don't support SMP kgdb yet. That
requires some reworking of the IPI mechanisms and
infrastructure on that platform.
Signed-off-by: David S. Miller <davem@davemloft.net>
Huge ptes have a special type on s390 and cannot be handled with the standard
pte functions in certain cases, e.g. because of a different location of the
invalid bit. This patch adds some new architecture- specific functions to
hugetlb common code, as a prerequisite for the s390 large page support.
This won't affect other architectures in functionality, but I need to add some
new dummy inline functions to the headers.
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A cow break on a hugetlbfs page with page_count > 1 will set a new pte with
set_huge_pte_at(), w/o any tlb flush operation. The old pte will remain in
the tlb and subsequent write access to the page will result in a page fault
loop, for as long as it may take until the tlb is flushed from somewhere else.
This patch introduces an architecture-specific huge_ptep_clear_flush()
function, which is called before the the set_huge_pte_at() in hugetlb_cow().
ATTENTION: This is just a nop on all architectures for now, the s390
implementation will come with our large page patch later. Other architectures
should define their own huge_ptep_clear_flush() if needed.
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch moves all architecture functions for hugetlb to architecture header
files (include/asm-foo/hugetlb.h) and converts all macros to inline functions.
It also removes (!) ARCH_HAS_HUGEPAGE_ONLY_RANGE,
ARCH_HAS_HUGETLB_FREE_PGD_RANGE, ARCH_HAS_PREPARE_HUGEPAGE_RANGE,
ARCH_HAS_SETCLEAR_HUGE_PTE and ARCH_HAS_HUGETLB_PREFAULT_HOOK.
Getting rid of the ARCH_HAS_xxx #ifdef and macro fugliness should increase
readability and maintainability, at the price of some code duplication. An
asm-generic common part would have reduced the loc, but we would end up with
new ARCH_HAS_xxx defines eventually.
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
s390 for one, cannot implement VM_MIXEDMAP with pfn_valid, due to their memory
model (which is more dynamic than most). Instead, they had proposed to
implement it with an additional path through vm_normal_page(), using a bit in
the pte to determine whether or not the page should be refcounted:
vm_normal_page()
{
...
if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
if (vma->vm_flags & VM_MIXEDMAP) {
#ifdef s390
if (!mixedmap_refcount_pte(pte))
return NULL;
#else
if (!pfn_valid(pfn))
return NULL;
#endif
goto out;
}
...
}
This is fine, however if we are allowed to use a bit in the pte to determine
refcountedness, we can use that to _completely_ replace all the vma based
schemes. So instead of adding more cases to the already complex vma-based
scheme, we can have a clearly seperate and simple pte-based scheme (and get
slightly better code generation in the process):
vm_normal_page()
{
#ifdef s390
if (!mixedmap_refcount_pte(pte))
return NULL;
return pte_page(pte);
#else
...
#endif
}
And finally, we may rather make this concept usable by any architecture rather
than making it s390 only, so implement a new type of pte state for this.
Unfortunately the old vma based code must stay, because some architectures may
not be able to spare pte bits. This makes vm_normal_page a little bit more
ugly than we would like, but the 2 cases are clearly seperate.
So introduce a pte_special pte state, and use it in mm/memory.c. It is
currently a noop for all architectures, so this doesn't actually result in any
compiled code changes to mm/memory.o.
BTW:
I haven't put vm_normal_page() into arch code as-per an earlier suggestion.
The reason is that, regardless of where vm_normal_page is actually
implemented, the *abstraction* is still exactly the same. Also, while it
depends on whether the architecture has pte_special or not, that is the
only two possible cases, and it really isn't an arch specific function --
the role of the arch code should be to provide primitive functions and
accessors with which to build the core code; pte_special does that. We do
not want architectures to know or care about vm_normal_page itself, and
we definitely don't want them being able to invent something new there
out of sight of mm/ code. If we made vm_normal_page an arch function, then
we have to make vm_insert_mixed (next patch) an arch function too. So I
don't think moving it to arch code fundamentally improves any abstractions,
while it does practically make the code more difficult to follow, for both
mm and arch developers, and easier to misuse.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Carsten Otte <cotte@de.ibm.com>
Cc: Jared Hulbert <jaredeh@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
