linux/arch
David Vrabel 162e371712 x86/xen: safely map and unmap grant frames when in atomic context
arch_gnttab_map_frames() and arch_gnttab_unmap_frames() are called in
atomic context but were calling alloc_vm_area() which might sleep.

Also, if a driver attempts to allocate a grant ref from an interrupt
and the table needs expanding, then the CPU may already by in lazy MMU
mode and apply_to_page_range() will BUG when it tries to re-enable
lazy MMU mode.

These two functions are only used in PV guests.

Introduce arch_gnttab_init() to allocates the virtual address space in
advance.

Avoid the use of apply_to_page_range() by using saving and using the
array of PTE addresses from the alloc_vm_area() call.

N.B. 'alloc_vm_area' pre-allocates the pagetable so there is no need
to worry about having to do a PGD/PUD/PMD walk (like apply_to_page_range
does) and we can instead do set_pte.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
----
[v2: Add comment about alloc_vm_area]
[v3: Fix compile error found by 0-day bot]
2014-07-14 15:28:02 -04:00
..
alpha Merge commit '3cf2f34' into sched/core, to fix build error 2014-06-12 13:46:37 +02:00
arc ARC: [SMP] Enable icache coherency 2014-06-26 11:59:01 +05:30
arm x86/xen: safely map and unmap grant frames when in atomic context 2014-07-14 15:28:02 -04:00
arm64 arm64: implement TASK_SIZE_OF 2014-07-08 17:30:59 +01:00
avr32 Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next 2014-06-03 12:57:53 -07:00
blackfin blackfin updates for Linux 3.16 2014-06-12 20:08:47 -07:00
c6x DeviceTree for 3.16: 2014-06-04 10:02:38 -07:00
cris cris: update comments for generic idle conversion 2014-06-06 16:08:18 -07:00
frv sys_sgetmask/sys_ssetmask: add CONFIG_SGETMASK_SYSCALL 2014-06-04 16:54:14 -07:00
hexagon
ia64 ia64: arch/ia64/include/uapi/asm/fcntl.h needs personality.h 2014-06-23 16:47:44 -07:00
m32r
m68k m68k: Export mach_random_get_entropy to modules 2014-07-11 10:37:53 +02:00
metag Merge commit '3cf2f34' into sched/core, to fix build error 2014-06-12 13:46:37 +02:00
microblaze Microblaze patches for 3.16-rc1 2014-06-05 16:15:33 -07:00
mips A bunch of one-liners (except the s390 one). 2014-07-01 09:27:34 -07:00
mn10300 sys_sgetmask/sys_ssetmask: add CONFIG_SGETMASK_SYSCALL 2014-06-04 16:54:14 -07:00
openrisc DeviceTree for 3.16: 2014-06-04 10:02:38 -07:00
parisc Merge branch 'parisc-3.16-5' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2014-07-13 12:02:05 -07:00
powerpc powerpc/perf: Never program book3s PMCs with values >= 0x80000000 2014-07-11 13:50:47 +10:00
s390 A bunch of one-liners (except the s390 one). 2014-07-01 09:27:34 -07:00
score
sh Merge commit '3cf2f34' into sched/core, to fix build error 2014-06-12 13:46:37 +02:00
sparc nmi: provide the option to issue an NMI back trace to every cpu but current 2014-06-23 16:47:44 -07:00
tile Merge commit '3cf2f34' into sched/core, to fix build error 2014-06-12 13:46:37 +02:00
um Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2014-06-12 21:23:38 -07:00
unicore32 unicore32: Remove ARCH_HAS_CPUFREQ config option 2014-06-20 08:22:41 +08:00
x86 x86/xen: safely map and unmap grant frames when in atomic context 2014-07-14 15:28:02 -04:00
xtensa Merge commit '3cf2f34' into sched/core, to fix build error 2014-06-12 13:46:37 +02:00
.gitignore
Kconfig