Commit 2a95ea6c0d ("procfs: do not overflow get_{idle,iowait}_time
for nohz") did not take into account that one some architectures jiffies
and cputime use different units.
This causes get_idle_time() to return numbers in the wrong units, making
the idle time fields in /proc/stat wrong.
Instead of converting the usec value returned by
get_cpu_{idle,iowait}_time_us to units of jiffies, use the new function
usecs_to_cputime64 to convert it to the correct unit of cputime64_t.
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Artem S. Tashkinov" <t.artem@mailcity.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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>
SROMC static memory mapping is included in the common s5p initialization
code. Hence, remove the duplicated SROMC static memory mapping for EXYNOS.
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Cc: stable@kernel.org
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Following is happened when CONFIG_CPU_FREQ_S3C24XX_DEBUGFS
is selected without building of s3c2410-iotiming.c file:
arch/arm/mach-s3c2440/built-in.o:(.data+0x38c): undefined reference to `s3c2410_iotiming_debugfs
Basically, the CONFIG_S3C2410_IOTIMING is not selected for
MACH_MINI2440. Because the s3c2410-iotiming.c is not ever
compiled and enabling CONFIG_CPU_FREQ_S3C24XX_DEBUGFS option
caused undefined reference to s3c2410_iotiming_debugfs()
defined in that file. The s3c2410_iotiming_debugfs defined
as NULL for this case.
Signed-off-by: Denis Kuzmenko <linux@solonet.org.ua>
Cc: stable@kernel.org
[kgene.kim@samsung.com: removed useless changes]
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
This is required for THIS_MODULE. We recently stopped acquiring
it via some other header.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Currently kvmppc_start_thread() tries to wake other SMT threads via
xics_wake_cpu(). Unfortunately xics_wake_cpu only exists when
CONFIG_SMP=Y so when compiling with CONFIG_SMP=N we get:
arch/powerpc/kvm/built-in.o: In function `.kvmppc_start_thread':
book3s_hv.c:(.text+0xa1e0): undefined reference to `.xics_wake_cpu'
The following should be fine since kvmppc_start_thread() shouldn't
called to start non-zero threads when SMP=N since threads_per_core=1.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
kvmppc_h_pr is only available if CONFIG_KVM_BOOK3S_64_PR.
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
compute_tlbie_rb is only used on ppc64 and cannot be compiled on ppc32.
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Unlike all of the other cpuid bits, the TSC deadline timer bit is set
unconditionally, regardless of what userspace wants.
This is broken in several ways:
- if userspace doesn't use KVM_CREATE_IRQCHIP, and doesn't emulate the TSC
deadline timer feature, a guest that uses the feature will break
- live migration to older host kernels that don't support the TSC deadline
timer will cause the feature to be pulled from under the guest's feet;
breaking it
- guests that are broken wrt the feature will fail.
Fix by not enabling the feature automatically; instead report it to userspace.
Because the feature depends on KVM_CREATE_IRQCHIP, which we cannot guarantee
will be called, we expose it via a KVM_CAP_TSC_DEADLINE_TIMER and not
KVM_GET_SUPPORTED_CPUID.
Fixes the Illumos guest kernel, which uses the TSC deadline timer feature.
[avi: add the KVM_CAP + documentation]
Reported-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>
Tested-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
User space may create the PIT and forgets about setting up the irqchips.
In that case, firing PIT IRQs will crash the host:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000128
IP: [<ffffffffa10f6280>] kvm_set_irq+0x30/0x170 [kvm]
...
Call Trace:
[<ffffffffa11228c1>] pit_do_work+0x51/0xd0 [kvm]
[<ffffffff81071431>] process_one_work+0x111/0x4d0
[<ffffffff81071bb2>] worker_thread+0x152/0x340
[<ffffffff81075c8e>] kthread+0x7e/0x90
[<ffffffff815a4474>] kernel_thread_helper+0x4/0x10
Prevent this by checking the irqchip mode before starting a timer. We
can't deny creating the PIT if the irqchips aren't set up yet as
current user land expects this order to work.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Use raw_spin_unlock_irqrestore() as equivalent to
raw_spin_lock_irqsave().
Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1324646665-13334-1-git-send-email-robert.richter@amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This change fixes a linking problem, which happens if oprofile
is selected to be compiled as built-in:
`oprofile_arch_exit' referenced in section `.init.text' of
arch/arm/oprofile/built-in.o: defined in discarded section
`.exit.text' of arch/arm/oprofile/built-in.o
The problem is appeared after commit 87121ca504, which
introduced oprofile_arch_exit() calls from __init function. Note
that the aforementioned commit has been backported to stable
branches, and the problem is known to be reproduced at least
with 3.0.13 and 3.1.5 kernels.
Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@nokia.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: oprofile-list <oprofile-list@lists.sourceforge.net>
Cc: <stable@kernel.org>
Link: http://lkml.kernel.org/r/20111222151540.GB16765@erda.amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This silently was working for many years and stopped working on
Niagara-T3 machines.
We need to set the MSIQ to VALID before we can set it's state to IDLE.
On Niagara-T3, setting the state to IDLE first was causing HV_EINVAL
errors. The hypervisor documentation says, rather ambiguously, that
the MSIQ must be "initialized" before one can set the state.
I previously understood this to mean merely that a successful setconf()
operation has been performed on the MSIQ, which we have done at this
point. But it seems to also mean that it has been set VALID too.
Signed-off-by: David S. Miller <davem@davemloft.net>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
net: Add a flow_cache_flush_deferred function
ipv4: reintroduce route cache garbage collector
net: have ipconfig not wait if no dev is available
sctp: Do not account for sizeof(struct sk_buff) in estimated rwnd
asix: new device id
davinci-cpdma: fix locking issue in cpdma_chan_stop
sctp: fix incorrect overflow check on autoclose
r8169: fix Config2 MSIEnable bit setting.
llc: llc_cmsg_rcv was getting called after sk_eat_skb.
net: bpf_jit: fix an off-one bug in x86_64 cond jump target
iwlwifi: update SCD BC table for all SCD queues
Revert "Bluetooth: Revert: Fix L2CAP connection establishment"
Bluetooth: Clear RFCOMM session timer when disconnecting last channel
Bluetooth: Prevent uninitialized data access in L2CAP configuration
iwlwifi: allow to switch to HT40 if not associated
iwlwifi: tx_sync only on PAN context
mwifiex: avoid double list_del in command cancel path
ath9k: fix max phy rate at rate control init
nfc: signedness bug in __nci_request()
iwlwifi: do not set the sequence control bit is not needed
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
oprofile: Fix uninitialized memory access when writing to writing to oprofilefs
The former implementation adds a fix gpiochip label string
to the framework. This is confusing because orion_gpio_init
is called more than once and this ends up in different gpiochips
with the same label.
This patch adds the already present orion_gpio_chip_count to the
label string to make it unique in the system.
Signed-off-by: Holger Brunck <holger.brunck@keymile.com>
Cc: Lennert Buytenhek <kernel@wantstofly.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Olof Johansson <olof@lixom.net>
When printing the code bytes in show_registers(), the markers around the
byte at the fault address could make the printk() format string look
like a valid log level and facility code. This would prevent this byte
from being printed and result in a spurious newline:
[ 7555.765589] Code: 8b 32 e9 94 00 00 00 81 7d 00 ff 00 00 00 0f 87 96 00 00 00 48 8b 83 c0 00 00 00 44 89 e2 44 89 e6 48 89 df 48 8b 80 d8 02 00 00
[ 7555.765683] 8b 48 28 48 89 d0 81 e2 ff 0f 00 00 48 c1 e8 0c 48 c1 e0 04
Add KERN_CONT where needed, and elsewhere in show_registers() for
consistency.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Link: http://lkml.kernel.org/r/4EEFA7AE.9020407@ladisch.de
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
x86 jump instruction size is 2 or 5 bytes (near/long jump), not 2 or 6
bytes.
In case a conditional jump is followed by a long jump, conditional jump
target is one byte past the start of target instruction.
Signed-off-by: Markus Kötter <nepenthesdev@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If oprofilefs_ulong_from_user() is called with count equals
zero, *val remains unchanged. Depending on the implementation it
might be uninitialized.
Change oprofilefs_ulong_from_user()'s interface to return count
on success. Thus, we are able to return early if count equals
zero which avoids using *val uninitialized. Fixing all users of
oprofilefs_ulong_ from_user().
This follows write syscall implementation when count is zero:
"If count is zero ... [and if] no errors are detected, 0 will be
returned without causing any other effect." (man 2 write)
Reported-By: Mike Waychison <mikew@google.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@vger.kernel.org>
Cc: oprofile-list <oprofile-list@lists.sourceforge.net>
Link: http://lkml.kernel.org/r/20111219153830.GH16765@erda.amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
in 0d6cfa3a75 I fixed the mach-types
records. We also need to make the name consistent in Kconfig else
the machine_is_eukrea_cpuimx35sd macro fails, and thus audio codec
is not properly initalized.
Signed-off-by: Eric Bénard <eric@eukrea.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
commit 8d75a26 "ARM: mx35: use generic function for displaying silicon revision"
disabled IIM clock after reading silicon revision which will prevent
reboot in internal boot mode.
Signed-off-by: Eric Bénard <eric@eukrea.com>
Cc: Jason Liu <jason.hui@linaro.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
in 0d6cfa3a75 I fixed the mach-types
records. We also need to make the name consistent in Kconfig else
the machine_is_eukrea_cpuimx25sd macro fails, and thus audio codec
is not properly initalized.
Signed-off-by: Eric Bénard <eric@eukrea.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
WARNING: arch/arm/plat-mxc/built-in.o(.data+0x488): Section mismatch in reference from the variable mxc_driver to the function .init.text:mxc_cpufreq_init()
The variable mxc_driver references
the function __init mxc_cpufreq_init()
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console
Signed-off-by: Richard Zhao <richard.zhao@linaro.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
According to imx pwm RM, the real period value should be
PERIOD value in PWMPR plus 2.
PWMO (Hz) = PCLK(Hz) / (period +2)
Signed-off-by: Jason Chen <jason.chen@linaro.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: stable@kernel.org
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
sparc32: Be less strict in matching %lo part of relocation.
sbus: convert drivers/sbus/char/* to use module_platform_driver()
bbc_i2c: Remove unneeded err variable
sparc: Use kmemdup rather than duplicating its implementation
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
ARM: OMAP: rx51: fix USB
ARM: OMAP: mcbsp: Fix possible memory corruption
arm/imx: fix power button on imx51 babbage board
ARM: imx: fix cpufreq build errors
ARM: mx5: add __initconst for fec pdata
MXC PWM: should active during DOZE/WAIT/DBG mode
ARM: EXYNOS: Fix build error without CONFIG_LOCAL_TIMERS
ARM: EXYNOS: Fix for stall in case of cpu hotplug or sleep
ARM: S5PV210: Set 1000ns as PWM backlight period on SMDKV210
ARM: SAMSUNG: remove duplicated header include
Seems the commit 7e89098 was overly aggressive in adding iva and mailbox
hwmods so now they are registered twice.
------------[ cut here ]------------
WARNING: at arch/arm/mach-omap2/omap_hwmod.c:1959 omap_hwmod_register+0x104/0x12c()
omap_hwmod: iva: _register returned -22
Modules linked in:
[<c0012aa4>] (unwind_backtrace+0x0/0xec) from [<c002f970>] (warn_slowpath_common+0x4c/0x64)
[<c002f970>] (warn_slowpath_common+0x4c/0x64) from [<c002fa08>] (warn_slowpath_fmt+0x2c/0x3c)
[<c002fa08>] (warn_slowpath_fmt+0x2c/0x3c) from [<c02fdb4c>] (omap_hwmod_register+0x104/0x12c)
[<c02fdb4c>] (omap_hwmod_register+0x104/0x12c) from [<c02fbb44>] (omap3_init_early+0x1c/0x28)
[<c02fbb44>] (omap3_init_early+0x1c/0x28) from [<c02f9580>] (setup_arch+0x6b8/0x7a4)
[<c02f9580>] (setup_arch+0x6b8/0x7a4) from [<c02f754c>] (start_kernel+0x6c/0x264)
[<c02f754c>] (start_kernel+0x6c/0x264) from [<80008040>] (0x80008040)
---[ end trace 1b75b31a2719ed1c ]---
------------[ cut here ]------------
WARNING: at arch/arm/mach-omap2/omap_hwmod.c:1959 omap_hwmod_register+0x104/0x12c()
omap_hwmod: mailbox: _register returned -22
Modules linked in:
[<c0012aa4>] (unwind_backtrace+0x0/0xec) from [<c002f970>] (warn_slowpath_common+0x4c/0x64)
[<c002f970>] (warn_slowpath_common+0x4c/0x64) from [<c002fa08>] (warn_slowpath_fmt+0x2c/0x3c)
[<c002fa08>] (warn_slowpath_fmt+0x2c/0x3c) from [<c02fdb4c>] (omap_hwmod_register+0x104/0x12c)
[<c02fdb4c>] (omap_hwmod_register+0x104/0x12c) from [<c02fbb44>] (omap3_init_early+0x1c/0x28)
[<c02fbb44>] (omap3_init_early+0x1c/0x28) from [<c02f9580>] (setup_arch+0x6b8/0x7a4)
[<c02f9580>] (setup_arch+0x6b8/0x7a4) from [<c02f754c>] (start_kernel+0x6c/0x264)
[<c02f754c>] (start_kernel+0x6c/0x264) from [<80008040>] (0x80008040)
---[ end trace 1b75b31a2719ed1d ]---
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
The bisection implemented in unwind_find_origin() stopped to early. If
there is only a single entry left to check the original code just took
the end point as origin which might be wrong.
This was introduced in commit de66a97901 ("ARM: 7187/1: fix unwinding
for XIP kernels").
Reported-and-tested-by: Nick Bowler <nbowler@elliptictech.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'stable/for-linus-fixes-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen/swiotlb: Use page alignment for early buffer allocation.
xen: only limit memory map to maximum reservation for domain 0.
d312ae878b "xen: use maximum reservation to limit amount of usable RAM"
clamped the total amount of RAM to the current maximum reservation. This is
correct for dom0 but is not correct for guest domains. In order to boot a guest
"pre-ballooned" (e.g. with memory=1G but maxmem=2G) in order to allow for
future memory expansion the guest must derive max_pfn from the e820 provided by
the toolstack and not the current maximum reservation (which can reflect only
the current maximum, not the guest lifetime max). The existing algorithm
already behaves this correctly if we do not artificially limit the maximum
number of pages for the guest case.
For a guest booted with maxmem=512, memory=128 this results in:
[ 0.000000] BIOS-provided physical RAM map:
[ 0.000000] Xen: 0000000000000000 - 00000000000a0000 (usable)
[ 0.000000] Xen: 00000000000a0000 - 0000000000100000 (reserved)
-[ 0.000000] Xen: 0000000000100000 - 0000000008100000 (usable)
-[ 0.000000] Xen: 0000000008100000 - 0000000020800000 (unusable)
+[ 0.000000] Xen: 0000000000100000 - 0000000020800000 (usable)
...
[ 0.000000] NX (Execute Disable) protection: active
[ 0.000000] DMI not present or invalid.
[ 0.000000] e820 update range: 0000000000000000 - 0000000000010000 (usable) ==> (reserved)
[ 0.000000] e820 remove range: 00000000000a0000 - 0000000000100000 (usable)
-[ 0.000000] last_pfn = 0x8100 max_arch_pfn = 0x1000000
+[ 0.000000] last_pfn = 0x20800 max_arch_pfn = 0x1000000
[ 0.000000] initial memory mapped : 0 - 027ff000
[ 0.000000] Base memory trampoline at [c009f000] 9f000 size 4096
-[ 0.000000] init_memory_mapping: 0000000000000000-0000000008100000
-[ 0.000000] 0000000000 - 0008100000 page 4k
-[ 0.000000] kernel direct mapping tables up to 8100000 @ 27bb000-27ff000
+[ 0.000000] init_memory_mapping: 0000000000000000-0000000020800000
+[ 0.000000] 0000000000 - 0020800000 page 4k
+[ 0.000000] kernel direct mapping tables up to 20800000 @ 26f8000-27ff000
[ 0.000000] xen: setting RW the range 27e8000 - 27ff000
[ 0.000000] 0MB HIGHMEM available.
-[ 0.000000] 129MB LOWMEM available.
-[ 0.000000] mapped low ram: 0 - 08100000
-[ 0.000000] low ram: 0 - 08100000
+[ 0.000000] 520MB LOWMEM available.
+[ 0.000000] mapped low ram: 0 - 20800000
+[ 0.000000] low ram: 0 - 20800000
With this change "xl mem-set <domain> 512M" will successfully increase the
guest RAM (by reducing the balloon).
There is no change for dom0.
Reported-and-Tested-by: George Shuklin <george.shuklin@gmail.com>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: stable@kernel.org
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The "(insn & 0x01800000) != 0x01800000" test matches 'restore'
but that is a legitimate place to see the %lo() part of a 32-bit
symbol relocation, particularly in tail calls.
Signed-off-by: David S. Miller <davem@davemloft.net>
Tested-by: Sergei Trofimovich <slyfox@gentoo.org>
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
Revert "x86, efi: Calling __pa() with an ioremap()ed address is invalid"
x86, efi: Make efi_call_phys_{prelog,epilog} CONFIG_RELOCATABLE-aware
Commit 10299e2e4e (ARM: RX-51:
Enable isp1704 power on/off) added power management for isp1704.
However, the transceiver should be powered on by default,
otherwise USB doesn't work at all for networking during
boot.
All kernels after v3.0 are affected.
Cc: stable@kernel.org
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Reviewed-by: Sebastian Reichel <sre@debian.org>
[tony@atomide.com: updated comments]
Signed-off-by: Tony Lindgren <tony@atomide.com>
Commits 09d28d ("ARM: OMAP: mcbsp: Start generalize omap2_mcbsp_set_clks_src")
and 7bc0c4 ("ARM: OMAP: mcbsp: Start generalize signal muxing functions")
incorrectly set two struct omap_mcbsp_platform_data fields after
omap_device_build_ss and kfree calls.
Fix this by moving these pdata assignments before those calls.
Signed-off-by: Jarkko Nikula <jarkko.nikula@bitmer.com>
Reported-by: NeilBrown <neilb@suse.de>
Signed-off-by: Tony Lindgren <tony@atomide.com>
This hangs my MacBook Air at boot time; I get no console
messages at all. I reverted this on top of -rc5 and my machine
boots again.
This reverts commit e8c7106280.
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Keith Packard <keithp@keithp.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Huang Ying <huang.ying.caritas@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1321621751-3650-1-git-send-email-matt@console
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arm_dma_zone_size is used by arm_bootmem_free() which is called by
paging_init(). Thus it needs to be set before calling it.
Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Cc: stable@kernel.org
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
efi_call_phys_prelog() sets up a 1:1 mapping of the physical address
range in swapper_pg_dir. Instead of replacing then restoring entries
in swapper_pg_dir we should be using initial_page_table which already
contains the 1:1 mapping.
It's safe to blindly switch back to swapper_pg_dir in the epilog
because the physical EFI routines are only called before
efi_enter_virtual_mode(), e.g. before any user processes have been
forked. Therefore, we don't need to track which pgd was in %cr3 when
we entered the prelog.
The previous code actually contained a bug because it assumed that the
kernel was loaded at a physical address within the first 8MB of ram,
usually at 0x100000. However, this isn't the case with a
CONFIG_RELOCATABLE=y kernel which could have been loaded anywhere in
the physical address space.
Also delete the ancient (and bogus) comments about the page table
being restored after the lock is released. There is no locking.
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Darrent Hart <dvhart@linux.intel.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/1323346250.3894.74.camel@mfleming-mobl1.ger.corp.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>