* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
sparc: using HZ needs an include of linux/param.h
sparc32: convert to asm-generic/hardirq.h
sparc64: Cache per-cpu %pcr register value in perf code.
sparc64: Fix comment typo in perf_event.c
sparc64: Minor coding style fixups in perf code.
sparc64: Add a basic conflict engine in preparation for multi-counter support.
sparc64: Increase vmalloc size to fix percpu regressions.
sparc64: Add initial perf event conflict resolution and checks.
sparc: Niagara1 perf event support.
sparc: Add Niagara2 HW cache event support.
sparc: Support all ultra3 and ultra4 derivatives.
sparc: Support HW cache events.
The hardware counter ->event_base state records and encoding of
the "struct perf_event_map" entry used for the event.
We use this to make sure that when we have more than 1 event,
both can be scheduled into the hardware at the same time.
As usual, structure of code is largely cribbed from powerpc.
Signed-off-by: David S. Miller <davem@davemloft.net>
Implement page mapping percpu first chunk allocator as a fallback to
the embedding allocator. The next patch will make the embedding
allocator check distances between units to determine whether it fits
within the vmalloc area so that this fallback can be used on such
cases.
sparc64 currently has relatively small vmalloc area which makes it
impossible to create any dynamic chunks on certain configurations
leading to percpu allocation failures. This and the next patch should
allow those configurations to keep working until proper solution is
found.
While at it, mark pcpu_cpu_distance() with __init.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Since we now use the embedding percpu allocator we have to make the
vmalloc area at least as large as the stretch can be between nodes.
Besides some minor asm adjustments, this turned out to be pretty
trivial.
Signed-off-by: David S. Miller <davem@davemloft.net>
Cribbed from powerpc code, as usual. :-)
Currently it is only used to validate that all counters
have the same user/kernel/hv attributes.
Signed-off-by: David S. Miller <davem@davemloft.net>
* remove asm/atomic.h inclusion from linux/utsname.h --
not needed after kref conversion
* remove linux/utsname.h inclusion from files which do not need it
NOTE: it looks like fs/binfmt_elf.c do not need utsname.h, however
due to some personality stuff it _is_ needed -- cowardly leave ELF-related
headers and files alone.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-next: (30 commits)
Use macros for .data.page_aligned section.
Use macros for .bss.page_aligned section.
Use new __init_task_data macro in arch init_task.c files.
kbuild: Don't define ALIGN and ENTRY when preprocessing linker scripts.
arm, cris, mips, sparc, powerpc, um, xtensa: fix build with bash 4.0
kbuild: add static to prototypes
kbuild: fail build if recordmcount.pl fails
kbuild: set -fconserve-stack option for gcc 4.5
kbuild: echo the record_mcount command
gconfig: disable "typeahead find" search in treeviews
kbuild: fix cc1 options check to ensure we do not use -fPIC when compiling
checkincludes.pl: add option to remove duplicates in place
markup_oops: use modinfo to avoid confusion with underscored module names
checkincludes.pl: provide usage helper
checkincludes.pl: close file as soon as we're done with it
ctags: usability fix
kernel hacking: move STRIP_ASM_SYMS from General
gitignore usr/initramfs_data.cpio.bz2 and usr/initramfs_data.cpio.lzma
kbuild: Check if linker supports the -X option
kbuild: introduce ld-option
...
Fix trivial conflict in scripts/basic/fixdep.c
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (34 commits)
trivial: fix typo in aic7xxx comment
trivial: fix comment typo in drivers/ata/pata_hpt37x.c
trivial: typo in kernel-parameters.txt
trivial: fix typo in tracing documentation
trivial: add __init/__exit macros in drivers/gpio/bt8xxgpio.c
trivial: add __init macro/ fix of __exit macro location in ipmi_poweroff.c
trivial: remove unnecessary semicolons
trivial: Fix duplicated word "options" in comment
trivial: kbuild: remove extraneous blank line after declaration of usage()
trivial: improve help text for mm debug config options
trivial: doc: hpfall: accept disk device to unload as argument
trivial: doc: hpfall: reduce risk that hpfall can do harm
trivial: SubmittingPatches: Fix reference to renumbered step
trivial: fix typos "man[ae]g?ment" -> "management"
trivial: media/video/cx88: add __init/__exit macros to cx88 drivers
trivial: fix typo in CONFIG_DEBUG_FS in gcov doc
trivial: fix missing printk space in amd_k7_smp_check
trivial: fix typo s/ketymap/keymap/ in comment
trivial: fix typo "to to" in multiple files
trivial: fix typos in comments s/DGBU/DBGU/
...
Bye-bye Performance Counters, welcome Performance Events!
In the past few months the perfcounters subsystem has grown out its
initial role of counting hardware events, and has become (and is
becoming) a much broader generic event enumeration, reporting, logging,
monitoring, analysis facility.
Naming its core object 'perf_counter' and naming the subsystem
'perfcounters' has become more and more of a misnomer. With pending
code like hw-breakpoints support the 'counter' name is less and
less appropriate.
All in one, we've decided to rename the subsystem to 'performance
events' and to propagate this rename through all fields, variables
and API names. (in an ABI compatible fashion)
The word 'event' is also a bit shorter than 'counter' - which makes
it slightly more convenient to write/handle as well.
Thanks goes to Stephane Eranian who first observed this misnomer and
suggested a rename.
User-space tooling and ABI compatibility is not affected - this patch
should be function-invariant. (Also, defconfigs were not touched to
keep the size down.)
This patch has been generated via the following script:
FILES=$(find * -type f | grep -vE 'oprofile|[^K]config')
sed -i \
-e 's/PERF_EVENT_/PERF_RECORD_/g' \
-e 's/PERF_COUNTER/PERF_EVENT/g' \
-e 's/perf_counter/perf_event/g' \
-e 's/nb_counters/nb_events/g' \
-e 's/swcounter/swevent/g' \
-e 's/tpcounter_event/tp_event/g' \
$FILES
for N in $(find . -name perf_counter.[ch]); do
M=$(echo $N | sed 's/perf_counter/perf_event/g')
mv $N $M
done
FILES=$(find . -name perf_event.*)
sed -i \
-e 's/COUNTER_MASK/REG_MASK/g' \
-e 's/COUNTER/EVENT/g' \
-e 's/\<event\>/event_id/g' \
-e 's/counter/event/g' \
-e 's/Counter/Event/g' \
$FILES
... to keep it as correct as possible. This script can also be
used by anyone who has pending perfcounters patches - it converts
a Linux kernel tree over to the new naming. We tried to time this
change to the point in time where the amount of pending patches
is the smallest: the end of the merge window.
Namespace clashes were fixed up in a preparatory patch - and some
stylistic fallout will be fixed up in a subsequent patch.
( NOTE: 'counters' are still the proper terminology when we deal
with hardware registers - and these sed scripts are a bit
over-eager in renaming them. I've undone some of that, but
in case there's something left where 'counter' would be
better than 'event' we can undo that on an individual basis
instead of touching an otherwise nicely automated patch. )
Suggested-by: Stephane Eranian <eranian@google.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mackerras <paulus@samba.org>
Reviewed-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <linux-arch@vger.kernel.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Commit 5622f295 ("x86, perf_counter, bts: Optimize BTS overflow
handling") removed the regs field from struct perf_sample_data and
added a regs parameter to perf_counter_overflow(). This breaks the
build on powerpc (and Sparc) as reported by Sachin Sant:
arch/powerpc/kernel/perf_counter.c: In function 'record_and_restart':
arch/powerpc/kernel/perf_counter.c:1165: error: unknown field 'regs' specified in initializer
This adjusts arch/powerpc/kernel/perf_counter.c to correspond with the
new struct perf_sample_data and perf_counter_overflow().
[ v2: also fix Sparc, Markus Metzger <markus.t.metzger@intel.com> ]
Reported-by: Sachin Sant <sachinp@in.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Markus Metzger <markus.t.metzger@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: benh@kernel.crashing.org
Cc: linuxppc-dev@ozlabs.org
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <19127.8400.376239.586120@drongo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Tim Abbott <tabbott@ksplice.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Albin Tonnerre <albin.tonnerre@free-electrons.com> reported:
Bash 4 filters out variables which contain a dot in them.
This happends to be the case of CPPFLAGS_vmlinux.lds.
This is rather unfortunate, as it now causes
build failures when using SHELL=/bin/bash to compile,
or when bash happens to be used by make (eg when it's /bin/sh)
Remove the common definition of CPPFLAGS_vmlinux.lds by
pushing relevant stuff to either Makefile.build or the
arch specific kernel/Makefile where we build the linker script.
This is also nice cleanup as we move the information out where
it is used.
Notes for the different architectures touched:
arm - we use an already exported symbol
cris - we use a config symbol aleady available
[Not build tested]
mips - the jiffies complexity has moved to vmlinux.lds.S where we need it.
Added a few variables to CPPFLAGS - they are only used by
the linker script.
[Not build tested]
powerpc - removed assignment that is not needed
[not build tested]
sparc - simplified it using $(BITS)
um - introduced a few new exported variables to deal with this
xtensa - added options to CPP invocation
[not build tested]
Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Geoffrey Thomas <geofft@ksplice.com>
Signed-off-by: Tim Abbott <tabbott@ksplice.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Many years ago when this driver was written, it had a use, but these
days it's nothing but trouble and distributions should not enable it
in any situation.
Pretty much every console device a sparc machine could see has a
bonafide real driver, making the PROM console hack unnecessary.
If any new device shows up, we should write a driver instead of
depending upon this crutch to save us. We've been able to take care
of this even when no chip documentation exists (sunxvr500, sunxvr2500)
so there are no excuses.
Signed-off-by: David S. Miller <davem@davemloft.net>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (46 commits)
powerpc64: convert to dynamic percpu allocator
sparc64: use embedding percpu first chunk allocator
percpu: kill lpage first chunk allocator
x86,percpu: use embedding for 64bit NUMA and page for 32bit NUMA
percpu: update embedding first chunk allocator to handle sparse units
percpu: use group information to allocate vmap areas sparsely
vmalloc: implement pcpu_get_vm_areas()
vmalloc: separate out insert_vmalloc_vm()
percpu: add chunk->base_addr
percpu: add pcpu_unit_offsets[]
percpu: introduce pcpu_alloc_info and pcpu_group_info
percpu: move pcpu_lpage_build_unit_map() and pcpul_lpage_dump_cfg() upward
percpu: add @align to pcpu_fc_alloc_fn_t
percpu: make @dyn_size mandatory for pcpu_setup_first_chunk()
percpu: drop @static_size from first chunk allocators
percpu: generalize first chunk allocator selection
percpu: build first chunk allocators selectively
percpu: rename 4k first chunk allocator to page
percpu: improve boot messages
percpu: fix pcpu_reclaim() locking
...
Fix trivial conflict as by Tejun Heo in kernel/sched.c
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next-2.6: (21 commits)
sparc64: Initial niagara2 perf counter support.
sparc64: Perf counter 'nop' event is not constant.
sparc64: Provide a way to specify a perf counter overflow IRQ enable bit.
sparc64: Provide hypervisor tracing bit support for perf counters.
sparc64: Initial hw perf counter support.
sparc64: Implement a real set_perf_counter_pending().
sparc64: Use nmi_enter() and nmi_exit(), as needed.
sparc64: Provide extern decls for sparc_??u_type strings.
sparc64: Make touch_nmi_watchdog() actually work.
sparc64: Kill unnecessary cast in profile_timer_exceptions_notify().
sparc64: Manage NMI watchdog enabling like x86.
sparc: add basic support for 'perf'
sparc: convert /proc/io_map, /proc/dvma_map to seq_file
sparc, leon: sparc-leon specific SRMMU initialization and bootup fixes.
sparc,leon: Added support for AMBAPP bus.
sparc,leon: Introduce the sparc-leon CPU type.
sparc,leon: Redefine MMU register access asi if CONFIG_LEON
sparc,leon: CONFIG_SPARC_LEON option and leon specific files.
sparc64: cheaper asm/uaccess.h inclusion
SPARC: fix duplicate declaration
...
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1623 commits)
netxen: update copyright
netxen: fix tx timeout recovery
netxen: fix file firmware leak
netxen: improve pci memory access
netxen: change firmware write size
tg3: Fix return ring size breakage
netxen: build fix for INET=n
cdc-phonet: autoconfigure Phonet address
Phonet: back-end for autoconfigured addresses
Phonet: fix netlink address dump error handling
ipv6: Add IFA_F_DADFAILED flag
net: Add DEVTYPE support for Ethernet based devices
mv643xx_eth.c: remove unused txq_set_wrr()
ucc_geth: Fix hangs after switching from full to half duplex
ucc_geth: Rearrange some code to avoid forward declarations
phy/marvell: Make non-aneg speed/duplex forcing work for 88E1111 PHYs
drivers/net/phy: introduce missing kfree
drivers/net/wan: introduce missing kfree
net: force bridge module(s) to be GPL
Subject: [PATCH] appletalk: Fix skb leak when ipddp interface is not loaded
...
Fixed up trivial conflicts:
- arch/x86/include/asm/socket.h
converted to <asm-generic/socket.h> in the x86 tree. The generic
header has the same new #define's, so that works out fine.
- drivers/net/tun.c
fix conflict between 89f56d1e9 ("tun: reuse struct sock fields") that
switched over to using 'tun->socket.sk' instead of the redundantly
available (and thus removed) 'tun->sk', and 2b980dbd ("lsm: Add hooks
to the TUN driver") which added a new 'tun->sk' use.
Noted in 'next' by Stephen Rothwell.
* 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (59 commits)
x86/gart: Do not select AGP for GART_IOMMU
x86/amd-iommu: Initialize passthrough mode when requested
x86/amd-iommu: Don't detach device from pt domain on driver unbind
x86/amd-iommu: Make sure a device is assigned in passthrough mode
x86/amd-iommu: Align locking between attach_device and detach_device
x86/amd-iommu: Fix device table write order
x86/amd-iommu: Add passthrough mode initialization functions
x86/amd-iommu: Add core functions for pd allocation/freeing
x86/dma: Mark iommu_pass_through as __read_mostly
x86/amd-iommu: Change iommu_map_page to support multiple page sizes
x86/amd-iommu: Support higher level PTEs in iommu_page_unmap
x86/amd-iommu: Remove old page table handling macros
x86/amd-iommu: Use 2-level page tables for dma_ops domains
x86/amd-iommu: Remove bus_addr check in iommu_map_page
x86/amd-iommu: Remove last usages of IOMMU_PTE_L0_INDEX
x86/amd-iommu: Change alloc_pte to support 64 bit address space
x86/amd-iommu: Introduce increase_address_space function
x86/amd-iommu: Flush domains if address space size was increased
x86/amd-iommu: Introduce set_dte_entry function
x86/amd-iommu: Add a gneric version of amd_iommu_flush_all_devices
...
On Niagara-2, for example, it's going to be different. So make
it something specified in sparc_pmu.
Signed-off-by: David S. Miller <davem@davemloft.net>
A PMU need only specify which bit in the PCR enabled hypervisor
tracing in order to enable this.
This will be used in Niagara-2 perf counter support.
Signed-off-by: David S. Miller <davem@davemloft.net>
When the perf counter subsystem needs to reschedule work out
from an NMI, it invokes set_perf_counter_pending().
This triggers a non-NMI irq which should invoke
perf_counter_do_pending().
Currently this won't trigger because sparc64 won't trigger
the perf counter subsystem from NMIs, but when the HW counter
support is added it will.
Signed-off-by: David S. Miller <davem@davemloft.net>
It guards it's actions on nmi_watchdog_active, but nothing ever
sets that and it's initial value is zero.
Signed-off-by: David S. Miller <davem@davemloft.net>
Use a per-cpu 'wd_enabled' boolean and a global atomic_t count
of watchdog NMI enabled cpus which is set to '-1' if something
is wrong with the watchdog and it can't be used.
Signed-off-by: David S. Miller <davem@davemloft.net>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
sparc64: Fix bootup with mcount in some configs.
sparc64: Kill spurious NMI watchdog triggers by increasing limit to 30 seconds.
Functions invoked early when booting up a cpu can't use
tracing because mcount requires a valid 'current_thread_info()'
and TLB mappings to be setup.
The code path of sun4v_register_mondo_queues --> register_one_mondo
is one such case. sun4v_register_mondo_queues already has the
necessary 'notrace' annotation, but register_one_mondo does not.
Normally register_one_mondo is inlined so the bug doesn't trigger,
but with some config/compiler combinations, it won't be so we
must properly mark it notrace.
While we're here, add 'notrace' annoations to prom_printf and
prom_halt so that early error handling won't have the same problem.
Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Reported-by: Leif Sawyer <lsawyer@gci.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This wires up the perf_counter_open() syscall so that basic
software support for perf is working.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is a compromise and a temporary workaround for bootup NMI
watchdog triggers some people see with qla2xxx devices present.
This happens when, for example:
CPU 0 is in the driver init and looping submitting mailbox commands to
load the firmware, then waiting for completion.
CPU 1 is receiving the device interrupts. CPU 1 is where the NMI
watchdog triggers.
CPU 0 is submitting mailbox commands fast enough that by the time CPU
1 returns from the device interrupt handler, a new one is pending.
This sequence runs for more than 5 seconds.
The problematic case is CPU 1's timer interrupt running when the
barrage of device interrupts begin. Then we have:
timer interrupt
return for softirq checking
pending, thus enable interrupts
qla2xxx interrupt
return
qla2xxx interrupt
return
... 5+ seconds pass
final qla2xxx interrupt for fw load
return
run timer softirq
return
At some point in the multi-second qla2xxx interrupt storm we trigger
the NMI watchdog on CPU 1 from the NMI interrupt handler.
The timer softirq, once we get back to running it, is smart enough to
run the timer work enough times to make up for the missed timer
interrupts.
However, the NMI watchdogs (both x86 and sparc) use the timer
interrupt count to notice the cpu is wedged. But in the above
scenerio we'll receive only one such timer interrupt even if we last
all the way back to running the timer softirq.
The default watchdog trigger point is only 5 seconds, which is pretty
low (the softwatchdog triggers at 60 seconds). So increase it to 30
seconds for now.
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a keyctl to install a process's session keyring onto its parent. This
replaces the parent's session keyring. Because the COW credential code does
not permit one process to change another process's credentials directly, the
change is deferred until userspace next starts executing again. Normally this
will be after a wait*() syscall.
To support this, three new security hooks have been provided:
cred_alloc_blank() to allocate unset security creds, cred_transfer() to fill in
the blank security creds and key_session_to_parent() - which asks the LSM if
the process may replace its parent's session keyring.
The replacement may only happen if the process has the same ownership details
as its parent, and the process has LINK permission on the session keyring, and
the session keyring is owned by the process, and the LSM permits it.
Note that this requires alteration to each architecture's notify_resume path.
This has been done for all arches barring blackfin, m68k* and xtensa, all of
which need assembly alteration to support TIF_NOTIFY_RESUME. This allows the
replacement to be performed at the point the parent process resumes userspace
execution.
This allows the userspace AFS pioctl emulation to fully emulate newpag() and
the VIOCSETTOK and VIOCSETTOK2 pioctls, all of which require the ability to
alter the parent process's PAG membership. However, since kAFS doesn't use
PAGs per se, but rather dumps the keys into the session keyring, the session
keyring of the parent must be replaced if, for example, VIOCSETTOK is passed
the newpag flag.
This can be tested with the following program:
#include <stdio.h>
#include <stdlib.h>
#include <keyutils.h>
#define KEYCTL_SESSION_TO_PARENT 18
#define OSERROR(X, S) do { if ((long)(X) == -1) { perror(S); exit(1); } } while(0)
int main(int argc, char **argv)
{
key_serial_t keyring, key;
long ret;
keyring = keyctl_join_session_keyring(argv[1]);
OSERROR(keyring, "keyctl_join_session_keyring");
key = add_key("user", "a", "b", 1, keyring);
OSERROR(key, "add_key");
ret = keyctl(KEYCTL_SESSION_TO_PARENT);
OSERROR(ret, "KEYCTL_SESSION_TO_PARENT");
return 0;
}
Compiled and linked with -lkeyutils, you should see something like:
[dhowells@andromeda ~]$ keyctl show
Session Keyring
-3 --alswrv 4043 4043 keyring: _ses
355907932 --alswrv 4043 -1 \_ keyring: _uid.4043
[dhowells@andromeda ~]$ /tmp/newpag
[dhowells@andromeda ~]$ keyctl show
Session Keyring
-3 --alswrv 4043 4043 keyring: _ses
1055658746 --alswrv 4043 4043 \_ user: a
[dhowells@andromeda ~]$ /tmp/newpag hello
[dhowells@andromeda ~]$ keyctl show
Session Keyring
-3 --alswrv 4043 4043 keyring: hello
340417692 --alswrv 4043 4043 \_ user: a
Where the test program creates a new session keyring, sticks a user key named
'a' into it and then installs it on its parent.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
When page alloc debugging is not enabled, we essentially accept any
virtual address for linear kernel TLB misses. But with kgdb, kernel
address probing, and other facilities we can try to access arbitrary
crap.
So, make sure the address we miss on will translate to physical memory
that actually exists.
In order to make this work we have to embed the valid address bitmap
into the kernel image. And in order to make that less expensive we
make an adjustment, in that the max physical memory address is
decreased to "1 << 41", even on the chips that support a 42-bit
physical address space. We can do this because bit 41 indicates
"I/O space" and thus covers non-memory ranges.
The result of this is that:
1) kpte_linear_bitmap shrinks from 2K to 1K in size
2) we need 64K more for the valid address bitmap
We can't let the valid address bitmap be dynamically allocated
once we start using it to validate TLB misses, otherwise we have
crazy issues to deal with wrt. recursive TLB misses and such.
If we're in a TLB miss it could be the deepest trap level that's legal
inside of the cpu. So if we TLB miss referencing the bitmap, the cpu
will be out of trap levels and enter RED state.
To guard against out-of-range accesses to the bitmap, we have to check
to make sure no bits in the physical address above bit 40 are set. We
could export and use last_valid_pfn for this check, but that's just an
unnecessary extra memory reference.
On the plus side of all this, since we load all of these translations
into the special 4MB mapping TSB, and we check the TSB first for TLB
misses, there should be absolutely no real cost for these new checks
in the TLB miss path.
Reported-by: heyongli@gmail.com
Signed-off-by: David S. Miller <davem@davemloft.net>
Normally, srmmu uses different trap table register values to allow
determination of the cpu we're on. All of the trap tables have
identical content, they just sit at different offsets from the first
trap table, and the offset shifted down and masked out determines
the cpu we are on.
The code tries to free them up when they aren't actually used
(don't have all 4 cpus, we're on sun4d, etc.) but that causes
problems.
For one thing it triggers false positives in the DMA debugging
code. And fixing that up while preserving this relative offset
thing isn't trivial.
So just kill the freeing code, it costs us at most 3 pages, big
deal...
Signed-off-by: David S. Miller <davem@davemloft.net>
Linus Torvalds
David S. Miller
Tejun Heo
Alexey Dobriyan
Joe Perches
Ingo Molnar
Paul Mackerras
Sam Ravnborg
Geoffrey Thomas
James Morris
Jens Axboe
David Howells