* 'stable/irq.rework' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen/irq: Cleanup up the pirq_to_irq for DomU PV PCI passthrough guests as well.
xen: Use IRQF_FORCE_RESUME
xen/timer: Missing IRQF_NO_SUSPEND in timer code broke suspend.
xen: Fix compile error introduced by "switch to new irq_chip functions"
xen: Switch to new irq_chip functions
xen: Remove stale irq_chip.end
xen: events: do not free legacy IRQs
xen: events: allocate GSIs and dynamic IRQs from separate IRQ ranges.
xen: events: add xen_allocate_irq_{dynamic, gsi} and xen_free_irq
xen:events: move find_unbound_irq inside CONFIG_PCI_MSI
xen: handled remapped IRQs when enabling a pcifront PCI device.
genirq: Add IRQF_FORCE_RESUME
* 'stable/pcifront-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
pci/xen: When free-ing MSI-X/MSI irq->desc also use generic code.
pci/xen: Cleanup: convert int** to int[]
pci/xen: Use xen_allocate_pirq_msi instead of xen_allocate_pirq
xen-pcifront: Sanity check the MSI/MSI-X values
xen-pcifront: don't use flush_scheduled_work()
* 'stable/p2m-identity.v4.9.1' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen/m2p: Check whether the MFN has IDENTITY_FRAME bit set..
xen/m2p: No need to catch exceptions when we know that there is no RAM
xen/debug: WARN_ON when identity PFN has no _PAGE_IOMAP flag set.
xen/debugfs: Add 'p2m' file for printing out the P2M layout.
xen/setup: Set identity mapping for non-RAM E820 and E820 gaps.
xen/mmu: WARN_ON when racing to swap middle leaf.
xen/mmu: Set _PAGE_IOMAP if PFN is an identity PFN.
xen/mmu: Add the notion of identity (1-1) mapping.
xen: Mark all initial reserved pages for the balloon as INVALID_P2M_ENTRY.
* 'stable/e820' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen/e820: Don't mark balloon memory as E820_UNUSABLE when running as guest and fix overflow.
xen/setup: Inhibit resource API from using System RAM E820 gaps as PCI mem gaps.
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-mn10300:
MN10300: atomic_read() should ensure it emits a load
MN10300: The SMP_ICACHE_INV_FLUSH_RANGE IPI command does not exist
MN10300: Proper use of macros get_user() in the case of incremented pointers
* 'upstream' of git://git.linux-mips.org/pub/scm/upstream-linus: (26 commits)
MIPS: Alchemy: Fix reset for MTX-1 and XXS1500
MIPS: MTX-1: Make au1000_eth probe all PHY addresses
MIPS: Jz4740: Add HAVE_CLK
MIPS: Move idle task creation to work queue
MIPS, Perf-events: Use unsigned delta for right shift in event update
MIPS, Perf-events: Work with the new callchain interface
MIPS, Perf-events: Fix event check in validate_event()
MIPS, Perf-events: Work with the new PMU interface
MIPS, Perf-events: Work with irq_work
MIPS: Fix always CONFIG_LOONGSON_UART_BASE=y
MIPS: Loongson: Fix potentially wrong string handling
MIPS: Fix GCC-4.6 'set but not used' warning in arch/mips/mm/init.c
MIPS: Fix GCC-4.6 'set but not used' warning in ieee754int.h
MIPS: Remove unused code from arch/mips/kernel/syscall.c
MIPS: Fix GCC-4.6 'set but not used' warning in signal*.c
MIPS: MSP: Fix MSP71xx bpci interrupt handler return value
MIPS: Select R4K timer lib for all MSP platforms
MIPS: Loongson: Remove ad-hoc cmdline default
MIPS: Clear the correct flag in sysmips(MIPS_FIXADE, ...).
MIPS: Add an unreachable return statement to satisfy buggy GCCs.
...
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: ce4100: Set pci ops via callback instead of module init
x86/mm: Fix pgd_lock deadlock
x86/mm: Handle mm_fault_error() in kernel space
x86: Don't check for BIOS corruption in first 64K when there's no need to
This reverts the parent commit. I hate doing that, but it's generating
some discussion ("half of it is right"), and since I am planning on
doing the 2.6.38 release later today we can punt it to stable if
required. Let's not rock the boat right now.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
oom_kill_process() starts with victim_points == 0. This means that
(most likely) any child has more points and can be killed erroneously.
Also, "children has a different mm" doesn't match the reality, we should
check child->mm != t->mm. This check is not exactly correct if t->mm ==
NULL but this doesn't really matter, oom_kill_task() will kill them
anyway.
Note: "Kill all processes sharing p->mm" in oom_kill_task() is wrong
too.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit 32fd6901 (MIPS: Alchemy: get rid of common/reset.c)
Alchemy-based boards use their own reset function. For MTX-1 and XXS1500,
the reset function pokes at the BCSR.SYSTEM_RESET register, but this does
not work. According to Bruno Randolf, this was not tested when written.
Previously, the generic au1000_restart() routine called the board specific
reset function, which for MTX-1 and XXS1500 did not work, but finally made
a jump to the reset vector, which really triggers a system restart. Fix
reboot for both targets by jumping to the reset vector.
Signed-off-by: Florian Fainelli <florian@openwrt.org>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2093/
Acked-by: Bruno Randolf <br1@einfach.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
When au1000_eth probes the MII bus for PHY address, if we do not set
au1000_eth platform data's phy_search_highest_address, the MII probing
logic will exit early and will assume a valid PHY is found at address 0.
For MTX-1, the PHY is at address 31, and without this patch, the link
detection/speed/duplex would not work correctly.
CC: stable@kernel.org
Signed-off-by: Florian Fainelli <florian@openwrt.org>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2111/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
To avoid forking usermode thread when creating an idle task, move fork_idle
to a work queue.
If kernel starts with maxcpus= option which does not bring all available
cpus online at boot time, idle tasks for offline cpus are not created. If
later offline cpus are hotplugged through sysfs, __cpu_up is called in
the context of the user task, and fork_idle copies its non-zero mm
pointer. This causes BUG() in per_cpu_trap_init.
This also avoids issues with resource limits of the CPU writing to sysfs,
containers, maybe others.
Signed-off-by: Maksim Rayskiy <mrayskiy@broadcom.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2070/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Leverage the commit for ARM by Will Deacon:
- 446a5a8b1e
ARM: 6205/1: perf: ensure counter delta is treated as unsigned
Hardware performance counters on ARM are 32-bits wide but atomic64_t
variables are used to represent counter data in the hw_perf_event structure.
The armpmu_event_update function right-shifts a signed 64-bit delta variable
and adds the result to the event count. This can lead to shifting in sign-bits
if the MSB of the 32-bit counter value is set. This results in perf output
such as:
Performance counter stats for 'sleep 20':
18446744073460670464 cycles <-- 0xFFFFFFFFF12A6000
7783773 instructions # 0.000 IPC
465 context-switches
161 page-faults
1172393 branches
20.154242147 seconds time elapsed
This patch ensures that the delta value is treated as unsigned so that the
right shift sets the upper bits to zero.
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
To: a.p.zijlstra@chello.nl
To: fweisbec@gmail.com
To: will.deacon@arm.com
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: wuzhangjin@gmail.com
Cc: paulus@samba.org
Cc: mingo@elte.hu
Cc: acme@redhat.com
Cc: matt@console-pimps.org
Cc: sshtylyov@mvista.com
Patchwork: http://patchwork.linux-mips.org/patch/2015/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This is the MIPS part of the following commits by Frederic Weisbecker:
- f72c1a931e
perf: Factorize callchain context handling
Store the kernel and user contexts from the generic layer instead
of archs, this gathers some repetitive code.
- 56962b4449
perf: Generalize some arch callchain code
- Most archs use one callchain buffer per cpu, except x86 that needs
to deal with NMIs. Provide a default perf_callchain_buffer()
implementation that x86 overrides.
- Centralize all the kernel/user regs handling and invoke new arch
handlers from there: perf_callchain_user() / perf_callchain_kernel()
That avoid all the user_mode(), current->mm checks and so...
- Invert some parameters in perf_callchain_*() helpers: entry to the
left, regs to the right, following the traditional (dst, src).
- 70791ce9ba
perf: Generalize callchain_store()
callchain_store() is the same on every archs, inline it in
perf_event.h and rename it to perf_callchain_store() to avoid
any collision.
This removes repetitive code.
- c1a65932fd
perf: Drop unappropriate tests on arch callchains
Drop the TASK_RUNNING test on user tasks for callchains as
this check doesn't seem to make any sense.
Also remove the tests for !current that is not supposed to
happen and current->pid as this should be handled at the
generic level, with exclude_idle attribute.
Reported-by: Wu Zhangjin <wuzhangjin@gmail.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
To: a.p.zijlstra@chello.nl
To: will.deacon@arm.com
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: paulus@samba.org
Cc: mingo@elte.hu
Cc: acme@redhat.com
Cc: dengcheng.zhu@gmail.com
Cc: matt@console-pimps.org
Cc: sshtylyov@mvista.com
Patchwork: http://patchwork.linux-mips.org/patch/2014/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This is the MIPS part of the following commits by Peter Zijlstra:
- a4eaf7f146
perf: Rework the PMU methods
Replace pmu::{enable,disable,start,stop,unthrottle} with
pmu::{add,del,start,stop}, all of which take a flags argument.
The new interface extends the capability to stop a counter while
keeping it scheduled on the PMU. We replace the throttled state with
the generic stopped state.
This also allows us to efficiently stop/start counters over certain
code paths (like IRQ handlers).
It also allows scheduling a counter without it starting, allowing for
a generic frozen state (useful for rotating stopped counters).
The stopped state is implemented in two different ways, depending on
how the architecture implemented the throttled state:
1) We disable the counter:
a) the pmu has per-counter enable bits, we flip that
b) we program a NOP event, preserving the counter state
2) We store the counter state and ignore all read/overflow events
For MIPSXX, the stopped state is implemented in the way of 1.b as above.
- 33696fc0d1
perf: Per PMU disable
Changes perf_disable() into perf_pmu_disable().
- 24cd7f54a0
perf: Reduce perf_disable() usage
Since the current perf_disable() usage is only an optimization,
remove it for now. This eases the removal of the __weak
hw_perf_enable() interface.
- b0a873ebbf
perf: Register PMU implementations
Simple registration interface for struct pmu, this provides the
infrastructure for removing all the weak functions.
- 51b0fe3954
perf: Deconstify struct pmu
sed -ie 's/const struct pmu\>/struct pmu/g' `git grep -l "const struct pmu\>"`
Reported-by: Wu Zhangjin <wuzhangjin@gmail.com>
Acked-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
To: a.p.zijlstra@chello.nl
To: fweisbec@gmail.com
To: will.deacon@arm.com
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: wuzhangjin@gmail.com
Cc: paulus@samba.org
Cc: mingo@elte.hu
Cc: acme@redhat.com
Cc: dengcheng.zhu@gmail.com
Cc: matt@console-pimps.org
Cc: sshtylyov@mvista.com
Cc: ddaney@caviumnetworks.com
Patchwork: http://patchwork.linux-mips.org/patch/2012/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This is the MIPS part of the following commit by Peter Zijlstra:
- e360adbe29
irq_work: Add generic hardirq context callbacks
Provide a mechanism that allows running code in IRQ context. It is
most useful for NMI code that needs to interact with the rest of the
system -- like wakeup a task to drain buffers.
Perf currently has such a mechanism, so extract that and provide it as
a generic feature, independent of perf so that others may also
benefit.
The IRQ context callback is generated through self-IPIs where
possible, or on architectures like powerpc the decrementer (the
built-in timer facility) is set to generate an interrupt immediately.
Architectures that don't have anything like this get to do with a
callback from the timer tick. These architectures can call
irq_work_run() at the tail of any IRQ handlers that might enqueue such
work (like the perf IRQ handler) to avoid undue latencies in
processing the work.
For MIPSXX, we need to call irq_work_run() at the tail of the perf IRQ
handler as described above.
Reported-by: Wu Zhangjin <wuzhangjin@gmail.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
To: fweisbec@gmail.com
To: will.deacon@arm.com
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: paulus@samba.org
Cc: mingo@elte.hu
Cc: acme@redhat.com
Cc: matt@console-pimps.org
Cc: sshtylyov@mvista.com,
Patchwork: http://patchwork.linux-mips.org/patch/2011/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This error was reported by cppcheck:
arch/mips/loongson/common/machtype.c:56: error: Dangerous usage of 'str' (strncpy doesn't always 0-terminate it)
If strncpy copied MACHTYPE_LEN bytes, the destination string str
was not terminated.
The patch adds one more byte to str and makes sure that this byte is
always 0.
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Cc: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: Arnaud Patard <apatard@mandriva.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/2053/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Under some combinations of CONFIG_*, lastpfn in page_is_ram is 'set
but not used'. Mark it as __maybe_unused to quiet the warning/error.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2033/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
GCC-4.6 can find more unused code than previous versions could.
In the case of arch/mips/math-emu/ieee754int.h, the COMPXSP and
COMPXDP macros are used in several places, but a couple of them leave
xs unused. The easiest thing to do is mark it as __maybe_unused to
quiet the warning.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2032/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
GCC-4.6 can find more unused code than previous versions could.
In the case of protected_restore_fp_context{,32}, the variable tmp is
really used. Its use is tricky in that we really care about the side
effects of the __put_user() calls. So we must mark tmp with
__maybe_unused to quiet the warning.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2035/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Loongson builds have an ad-hoc cmdline default of "console=ttyS0,115200
root=/dev/hda1". These settings come from a vendor; I remember builds
from Lemote branch requiring a "console=tty" override in order to get a
working console.
At least on Yeeloong, they're particularly useless: there's no external
serial port, and the IDE drive is now recognised as /dev/sda.
Signed-off-by: Robert Millan <rmh@gnu.org>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1759/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The sysmips(MIPS_FIXADE, ...) case contains an obvious copy-and-paste
error in the handling of the TIF_LOGADE flag. Fix that
Patchwork: https://patchwork.linux-mips.org/patch/1997/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
It was reported that GCC-4.3.3 (with CodeSourcery extensions) fails
without this.
Reported-by: Jonas Gorski <jonas.gorski@gmail.com>
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2010/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
trace.func should be set to the recorded ip of the mcount calling site
in the __mcount_loc section to filter the function entries configured
through the tracing/set_graph_function interface, but before, this is
set to the self_ra(the return address of mcount), which has made
set_graph_function not work as expected.
This fixes it via calculating the right recorded ip in the __mcount_loc
section and assign it to trace.func.
Reported-by: Zhiping Zhong <xzhong86@163.com>
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Sergei Shtylyov <sshtylyov@mvista.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2017/
Signed-off-by: Ralf Baechle <ralf@duck.linux-mips.net>
This moves the comments out of ftrace_make_nop() and cleans it. At the
same time, a macro MCOUNT_OFFSET_INSNS is defined for sharing with the
next patch.
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2008/
Signed-off-by: Ralf Baechle <ralf@duck.linux-mips.net>
The old prepare_ftrace_return() for MIPS is confused and have introduced
some problem. This patch cleans up the names of the arguments, variables
and related functions.
For MIPS, the 2nd argument of prepare_ftrace_return() is not really the
'selfpc' described in ftrace-design.txt but instead it is the self
return address. This did break the compatibility of the generic
interface but really reduced one unneeded calculation for to get the
current function name, the parent return address and the self return
address are enough, no need to tranform the self return address to the
self address.
But set_graph_function of function graph tracer is an exception, it does
need the 2nd argument of prepare_ftrace_return() as 'selfpc', for it
will use 'selfpc' to match user's configuration of function graph
entries, but in reality, it doesn't need the 'selfpc' but the recorded
ip address of the mcount calling site in the __mcount_loc section. So,
the 2nd argument of prepare_ftrace_return() is not important, the real
requirement is the right recorded ip address should be calculated and
assign to trace.func, this will be fixed in the next patches.
Reported-by: Zhiping Zhong <xzhong86@163.com>
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2007/
Signed-off-by: Ralf Baechle <ralf@duck.linux-mips.net>
The old in_module() may not work in some situations(e.g. when module &
kernel are in the same address space when CONFIG_MAPPED_KERNEL=y), The
in_kernel_space() is more generic and it is also easy to be implemented
via cloning the existing core_kernel_text(), so, replace the in_module()
with in_kernel_space().
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2005/
Signed-off-by: Ralf Baechle <ralf@duck.linux-mips.net>
This simply moves the "ip-=4" statement down to the end of the do { ...
} while (...); loop, which reduces one unneeded subtration and the
subsequent memory loading and comparison.
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2006/
Signed-off-by: Ralf Baechle <ralf@duck.linux-mips.net>
* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
NFS: NFSROOT should default to "proto=udp"
nfs4: remove duplicated #include
NFSv4: nfs4_state_mark_reclaim_nograce() should be static
NFSv4: Fix the setlk error handler
NFSv4.1: Fix the handling of the SEQUENCE status bits
NFSv4/4.1: Fix nfs4_schedule_state_recovery abuses
NFSv4.1 reclaim complete must wait for completion
NFSv4: remove duplicate clientid in struct nfs_client
NFSv4.1: Retry CREATE_SESSION on NFS4ERR_DELAY
sunrpc: Propagate errors from xs_bind() through xs_create_sock()
(try3-resend) Fix nfs_compat_user_ino64 so it doesn't cause problems if bit 31 or 63 are set in fileid
nfs: fix compilation warning
nfs: add kmalloc return value check in decode_and_add_ds
SUNRPC: Remove resource leak in svc_rdma_send_error()
nfs: close NFSv4 COMMIT vs. CLOSE race
SUNRPC: Close a race in __rpc_wait_for_completion_task()
The kernel automatically evaluates partition tables of storage devices.
The code for evaluating OSF partitions contains a bug that leaks data
from kernel heap memory to userspace for certain corrupted OSF
partitions.
In more detail:
for (i = 0 ; i < le16_to_cpu(label->d_npartitions); i++, partition++) {
iterates from 0 to d_npartitions - 1, where d_npartitions is read from
the partition table without validation and partition is a pointer to an
array of at most 8 d_partitions.
Add the proper and obvious validation.
Signed-off-by: Timo Warns <warns@pre-sense.de>
Cc: stable@kernel.org
[ Changed the patch trivially to not repeat the whole le16_to_cpu()
thing, and to use an explicit constant for the magic value '8' ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
THP's collapse_huge_page() has an understandable but ugly difference
in when its huge page is allocated: inside if NUMA but outside if not.
It's hardly surprising that the memcg failure path forgot that, freeing
the page in the non-NUMA case, then hitting a VM_BUG_ON in get_page()
(or even worse, using the freed page).
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If there is no proper PFN value in the M2P for the MFN
(so we get 0xFFFFF.. or 0x55555, or 0x0), we should
consult the M2P override to see if there is an entry for this.
[Note: we also consult the M2P override if the MFN
is past our machine_to_phys size].
We consult the P2M with the PFN. In case the returned
MFN is one of the special values: 0xFFF.., 0x5555
(which signify that the MFN can be either "missing" or it
belongs to DOMID_IO) or the p2m(m2p(mfn)) != mfn, we check
the M2P override. If we fail the M2P override check, we reset
the PFN value to INVALID_P2M_ENTRY.
Next we try to find the MFN in the P2M using the MFN
value (not the PFN value) and if found, we know
that this MFN is an identity value and return it as so.
Otherwise we have exhausted all the posibilities and we
return the PFN, which at this stage can either be a real
PFN value found in the machine_to_phys.. array, or
INVALID_P2M_ENTRY value.
[v1: Added Review-by tag]
Reviewed-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
.. beyound what we think is the end of memory. However there might
be more System RAM - but assigned to a guest. Hence jump to the
M2P override check and consult.
[v1: Added Review-by tag]
Reviewed-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Only enabled if XEN_DEBUG is enabled. We print a warning
when:
pfn_to_mfn(pfn) == pfn, but no VM_IO (_PAGE_IOMAP) flag set
(and pfn is an identity mapped pfn)
pfn_to_mfn(pfn) != pfn, and VM_IO flag is set.
(ditto, pfn is an identity mapped pfn)
[v2: Make it dependent on CONFIG_XEN_DEBUG instead of ..DEBUG_FS]
[v3: Fix compiler warning]
Reviewed-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
We walk over the whole P2M tree and construct a simplified view of
which PFN regions belong to what level and what type they are.
Only enabled if CONFIG_XEN_DEBUG_FS is set.
[v2: UNKN->UNKNOWN, use uninitialized_var]
[v3: Rebased on top of mmu->p2m code split]
[v4: Fixed the else if]
Reviewed-by: Ian Campbell <Ian.Campbell@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
We walk the E820 region and start at 0 (for PV guests we start
at ISA_END_ADDRESS) and skip any E820 RAM regions. For all other
regions and as well the gaps we set them to be identity mappings.
The reasons we do not want to set the identity mapping from 0->
ISA_END_ADDRESS when running as PV is b/c that the kernel would
try to read DMI information and fail (no permissions to read that).
There is a lot of gnarly code to deal with that weird region so
we won't try to do a cleanup in this patch.
This code ends up calling 'set_phys_to_identity' with the start
and end PFN of the the E820 that are non-RAM or have gaps.
On 99% of machines that means one big region right underneath the
4GB mark. Usually starts at 0xc0000 (or 0x80000) and goes to
0x100000.
[v2: Fix for E820 crossing 1MB region and clamp the start]
[v3: Squshed in code that does this over ranges]
[v4: Moved the comment to the correct spot]
[v5: Use the "raw" E820 from the hypervisor]
[v6: Added Review-by tag]
Reviewed-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The initial bootup code uses set_phys_to_machine quite a lot, and after
bootup it would be used by the balloon driver. The balloon driver does have
mutex lock so this should not be necessary - but just in case, add
a WARN_ON if we do hit this scenario. If we do fail this, it is OK
to continue as there is a backup mechanism (VM_IO) that can bypass
the P2M and still set the _PAGE_IOMAP flags.
[v2: Change from WARN to BUG_ON]
[v3: Rebased on top of xen->p2m code split]
[v4: Change from BUG_ON to WARN]
Reviewed-by: Ian Campbell <Ian.Campbell@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
If we find that the PFN is within the P2M as an identity
PFN make sure to tack on the _PAGE_IOMAP flag.
Reviewed-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Our P2M tree structure is a three-level. On the leaf nodes
we set the Machine Frame Number (MFN) of the PFN. What this means
is that when one does: pfn_to_mfn(pfn), which is used when creating
PTE entries, you get the real MFN of the hardware. When Xen sets
up a guest it initially populates a array which has descending
(or ascending) MFN values, as so:
idx: 0, 1, 2
[0x290F, 0x290E, 0x290D, ..]
so pfn_to_mfn(2)==0x290D. If you start, restart many guests that list
starts looking quite random.
We graft this structure on our P2M tree structure and stick in
those MFN in the leafs. But for all other leaf entries, or for the top
root, or middle one, for which there is a void entry, we assume it is
"missing". So
pfn_to_mfn(0xc0000)=INVALID_P2M_ENTRY.
We add the possibility of setting 1-1 mappings on certain regions, so
that:
pfn_to_mfn(0xc0000)=0xc0000
The benefit of this is, that we can assume for non-RAM regions (think
PCI BARs, or ACPI spaces), we can create mappings easily b/c we
get the PFN value to match the MFN.
For this to work efficiently we introduce one new page p2m_identity and
allocate (via reserved_brk) any other pages we need to cover the sides
(1GB or 4MB boundary violations). All entries in p2m_identity are set to
INVALID_P2M_ENTRY type (Xen toolstack only recognizes that and MFNs,
no other fancy value).
On lookup we spot that the entry points to p2m_identity and return the identity
value instead of dereferencing and returning INVALID_P2M_ENTRY. If the entry
points to an allocated page, we just proceed as before and return the PFN.
If the PFN has IDENTITY_FRAME_BIT set we unmask that in appropriate functions
(pfn_to_mfn).
The reason for having the IDENTITY_FRAME_BIT instead of just returning the
PFN is that we could find ourselves where pfn_to_mfn(pfn)==pfn for a
non-identity pfn. To protect ourselves against we elect to set (and get) the
IDENTITY_FRAME_BIT on all identity mapped PFNs.
This simplistic diagram is used to explain the more subtle piece of code.
There is also a digram of the P2M at the end that can help.
Imagine your E820 looking as so:
1GB 2GB
/-------------------+---------\/----\ /----------\ /---+-----\
| System RAM | Sys RAM ||ACPI| | reserved | | Sys RAM |
\-------------------+---------/\----/ \----------/ \---+-----/
^- 1029MB ^- 2001MB
[1029MB = 263424 (0x40500), 2001MB = 512256 (0x7D100), 2048MB = 524288 (0x80000)]
And dom0_mem=max:3GB,1GB is passed in to the guest, meaning memory past 1GB
is actually not present (would have to kick the balloon driver to put it in).
When we are told to set the PFNs for identity mapping (see patch: "xen/setup:
Set identity mapping for non-RAM E820 and E820 gaps.") we pass in the start
of the PFN and the end PFN (263424 and 512256 respectively). The first step is
to reserve_brk a top leaf page if the p2m[1] is missing. The top leaf page
covers 512^2 of page estate (1GB) and in case the start or end PFN is not
aligned on 512^2*PAGE_SIZE (1GB) we loop on aligned 1GB PFNs from start pfn to
end pfn. We reserve_brk top leaf pages if they are missing (means they point
to p2m_mid_missing).
With the E820 example above, 263424 is not 1GB aligned so we allocate a
reserve_brk page which will cover the PFNs estate from 0x40000 to 0x80000.
Each entry in the allocate page is "missing" (points to p2m_missing).
Next stage is to determine if we need to do a more granular boundary check
on the 4MB (or 2MB depending on architecture) off the start and end pfn's.
We check if the start pfn and end pfn violate that boundary check, and if
so reserve_brk a middle (p2m[x][y]) leaf page. This way we have a much finer
granularity of setting which PFNs are missing and which ones are identity.
In our example 263424 and 512256 both fail the check so we reserve_brk two
pages. Populate them with INVALID_P2M_ENTRY (so they both have "missing" values)
and assign them to p2m[1][2] and p2m[1][488] respectively.
At this point we would at minimum reserve_brk one page, but could be up to
three. Each call to set_phys_range_identity has at maximum a three page
cost. If we were to query the P2M at this stage, all those entries from
start PFN through end PFN (so 1029MB -> 2001MB) would return INVALID_P2M_ENTRY
("missing").
The next step is to walk from the start pfn to the end pfn setting
the IDENTITY_FRAME_BIT on each PFN. This is done in 'set_phys_range_identity'.
If we find that the middle leaf is pointing to p2m_missing we can swap it over
to p2m_identity - this way covering 4MB (or 2MB) PFN space. At this point we
do not need to worry about boundary aligment (so no need to reserve_brk a middle
page, figure out which PFNs are "missing" and which ones are identity), as that
has been done earlier. If we find that the middle leaf is not occupied by
p2m_identity or p2m_missing, we dereference that page (which covers
512 PFNs) and set the appropriate PFN with IDENTITY_FRAME_BIT. In our example
263424 and 512256 end up there, and we set from p2m[1][2][256->511] and
p2m[1][488][0->256] with IDENTITY_FRAME_BIT set.
All other regions that are void (or not filled) either point to p2m_missing
(considered missing) or have the default value of INVALID_P2M_ENTRY (also
considered missing). In our case, p2m[1][2][0->255] and p2m[1][488][257->511]
contain the INVALID_P2M_ENTRY value and are considered "missing."
This is what the p2m ends up looking (for the E820 above) with this
fabulous drawing:
p2m /--------------\
/-----\ | &mfn_list[0],| /-----------------\
| 0 |------>| &mfn_list[1],| /---------------\ | ~0, ~0, .. |
|-----| | ..., ~0, ~0 | | ~0, ~0, [x]---+----->| IDENTITY [@256] |
| 1 |---\ \--------------/ | [p2m_identity]+\ | IDENTITY [@257] |
|-----| \ | [p2m_identity]+\\ | .... |
| 2 |--\ \-------------------->| ... | \\ \----------------/
|-----| \ \---------------/ \\
| 3 |\ \ \\ p2m_identity
|-----| \ \-------------------->/---------------\ /-----------------\
| .. +->+ | [p2m_identity]+-->| ~0, ~0, ~0, ... |
\-----/ / | [p2m_identity]+-->| ..., ~0 |
/ /---------------\ | .... | \-----------------/
/ | IDENTITY[@0] | /-+-[x], ~0, ~0.. |
/ | IDENTITY[@256]|<----/ \---------------/
/ | ~0, ~0, .... |
| \---------------/
|
p2m_missing p2m_missing
/------------------\ /------------\
| [p2m_mid_missing]+---->| ~0, ~0, ~0 |
| [p2m_mid_missing]+---->| ..., ~0 |
\------------------/ \------------/
where ~0 is INVALID_P2M_ENTRY. IDENTITY is (PFN | IDENTITY_BIT)
Reviewed-by: Ian Campbell <ian.campbell@citrix.com>
[v5: Changed code to use ranges, added ASCII art]
[v6: Rebased on top of xen->p2m code split]
[v4: Squished patches in just this one]
[v7: Added RESERVE_BRK for potentially allocated pages]
[v8: Fixed alignment problem]
[v9: Changed 1<<3X to 1<<BITS_PER_LONG-X]
[v10: Copied git commit description in the p2m code + Add Review tag]
[v11: Title had '2-1' - should be '1-1' mapping]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
atomic_read() needs to ensure that it emits a load (which it can do by using
ACCESS_ONCE()).
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: David Howells <dhowells@redhat.com>
The invalidate-only versions of flush_icache_*range() are trying sending the
SMP_ICACHE_INV_FLUSH_RANGE IPI command in SMP kernels when they should be
sending SMP_ICACHE_INV_RANGE as the former does not exist.
Signed-off-by: David Howells <dhowells@redhat.com>
Using __get_user_check(x, ptr++, size) leads to double increment of pointer.
This macro uses the macro get_user directly, which itself is used in this way
(get_user(x, ptr++)) in some functions of the kernel. The patch fixes the
error.
Reported-by: Tkhai Kirill <tkhai@yandex.ru>
Signed-off-by: David Howells <dhowells@redhat.com>
