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e26a9e00af
linux/arch/arm/include/asm
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Russell King e26a9e00af ARM: Better virt_to_page() handling 
virt_to_page() is incredibly inefficient when virt-to-phys patching is
enabled.  This is because we end up with this calculation:

  page = &mem_map[asm virt_to_phys(addr) >> 12 - __pv_phys_offset >> 12]

in assembly.  The asm virt_to_phys() is equivalent this this operation:

  addr - PAGE_OFFSET + __pv_phys_offset

and we can see that because this is assembly, the compiler has no chance
to optimise some of that away.  This should reduce down to:

  page = &mem_map[(addr - PAGE_OFFSET) >> 12]

for the common cases.  Permit the compiler to make this optimisation by
giving it more of the information it needs - do this by providing a
virt_to_pfn() macro.

Another issue which makes this more complex is that __pv_phys_offset is
a 64-bit type on all platforms.  This is needlessly wasteful - if we
store the physical offset as a PFN, we can save a lot of work having
to deal with 64-bit values, which sometimes ends up producing incredibly
horrid code:

     a4c:       e3009000        movw    r9, #0
                        a4c: R_ARM_MOVW_ABS_NC  __pv_phys_offset
     a50:       e3409000        movt    r9, #0          ; r9 = &__pv_phys_offset
                        a50: R_ARM_MOVT_ABS     __pv_phys_offset
     a54:       e3002000        movw    r2, #0
                        a54: R_ARM_MOVW_ABS_NC  __pv_phys_offset
     a58:       e3402000        movt    r2, #0          ; r2 = &__pv_phys_offset
                        a58: R_ARM_MOVT_ABS     __pv_phys_offset
     a5c:       e5999004        ldr     r9, [r9, #4]    ; r9 = high word of __pv_phys_offset
     a60:       e3001000        movw    r1, #0
                        a60: R_ARM_MOVW_ABS_NC  mem_map
     a64:       e592c000        ldr     ip, [r2]        ; ip = low word of __pv_phys_offset

Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-04-03 22:46:34 +01:00
..
hardware ARM: 7922/1: l2x0: add Marvell Tauros3 support 2013-12-29 12:32:47 +00:00
mach ARM: implement basic NX support for kernel lowmem mappings 2013-12-11 09:53:16 +00:00
xen Features: 2014-01-22 22:00:18 -08:00
arch_timer.h ARM: arch_timer: add support to configure and enable event stream 2013-09-26 09:47:26 +01:00
asm-offsets.h
assembler.h ARM: 7990/1: asm: rename logical shift macros push pull into lspush lspull 2014-02-25 11:33:57 +00:00
atomic.h ARM: 7983/1: atomics: implement a better __atomic_add_unless for v6+ 2014-02-25 11:35:08 +00:00
barrier.h arch: Introduce smp_load_acquire(), smp_store_release() 2014-01-12 10:37:17 +01:00
bitops.h ARM: fix ffs/fls implementations to match x86 2014-01-13 23:34:56 +00:00
bL_switcher.h ARM: bL_switcher: Add query interface to discover CPU affinities 2013-09-23 18:47:31 -04:00
bug.h ARM: Correct BUG() assembly to ensure it is endian-agnostic 2013-10-19 20:46:35 +01:00
bugs.h
cache.h
cacheflush.h ARM: mm: Define set_memory_* functions for ARM 2013-12-11 09:53:19 +00:00
cachetype.h
checksum.h ARM: fix csum_tcpudp_magic() miscompilation 2013-12-29 12:32:41 +00:00
clkdev.h clk: Add common __clk_get(), __clk_put() implementations 2013-12-04 17:19:44 +01:00
cmpxchg.h ARM: 7984/1: prefetch: add prefetchw invocations for barriered atomics 2014-02-25 11:30:20 +00:00
compiler.h
cp15.h Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm 2013-07-03 09:46:29 -07:00
cpu.h ARM: kernel: add MIDR to per-CPU information data 2012-11-19 14:51:11 +00:00
cpuidle.h
cputype.h ARM: 7940/1: add support for the Cortex-A12 processor 2014-02-10 11:48:00 +00:00
cti.h ARM: coresight: common definition for (OS) Lock Access Register key value 2013-01-10 21:13:05 +00:00
delay.h ARM: 7685/1: delay: use private ticks_per_jiffy field for timer-based delay ops 2013-04-03 16:45:50 +01:00
device.h ARM: dma-mapping: Add macro to_dma_iommu_mapping() 2013-02-25 15:30:41 +01:00
div64.h ARM: 7705/1: use optimized do_div only for EABI 2013-05-15 19:35:53 +01:00
dma-contiguous.h drivers: dma-contiguous: clean source code and prepare for device tree 2013-08-27 09:18:29 +02:00
dma-iommu.h ARM: dma-mapping: Add arm_iommu_detach_device() 2013-02-25 15:30:41 +01:00
dma-mapping.h Features: 2013-11-15 13:34:37 +09:00
dma.h mm/memblock: add memblock memory allocation apis 2014-01-21 16:19:46 -08:00
domain.h
ecard.h
edac.h
elf.h Move the EM_ARM and EM_AARCH64 definitions to uapi/linux/elf-em.h 2013-09-02 16:35:50 +01:00
entry-macro-multi.S
exception.h
fb.h
fiq.h
firmware.h ARM: Add interface for registering and calling firmware-specific operations 2013-04-09 01:52:06 +09:00
fixmap.h
flat.h ARM: binfmt_flat: unused variable 'persistent' 2012-10-09 20:29:06 +02:00
floppy.h ARM: 7996/1: floppy.h: remove deprecated IRQF_DISABLED 2014-03-12 10:32:29 +00:00
fncpy.h
fpstate.h
ftrace.h
futex.h ARM: 7984/1: prefetch: add prefetchw invocations for barriered atomics 2014-02-25 11:30:20 +00:00
glue-cache.h Merge branch 'for-next' of git://git.pengutronix.de/git/ukl/linux into devel-stable 2013-05-22 10:52:24 +01:00
glue-df.h ARM: Add base support for ARMv7-M 2013-04-17 21:38:10 +02:00
glue-pf.h
glue-proc.h ARM SoC specific changes 2013-07-02 13:43:38 -07:00
glue.h
gpio.h ARM: make mach/gpio.h headers optional 2012-09-14 09:21:59 -05:00
hardirq.h Merge branch 'devel-stable' into for-next 2013-11-12 10:58:59 +00:00
highmem.h ARM: 7684/1: errata: Workaround for Cortex-A15 erratum 798181 (TLBI/DSB operations) 2013-04-03 16:45:49 +01:00
hugetlb-3level.h ARM: mm: HugeTLB support for LPAE systems. 2013-06-04 16:52:37 +01:00
hugetlb.h ARM: mm: HugeTLB support for LPAE systems. 2013-06-04 16:52:37 +01:00
hw_breakpoint.h ARM: 7948/1: hw_breakpoint: Add ARMv8 support 2014-02-10 11:48:05 +00:00
hw_irq.h
hwcap.h ARM: 7981/1: add support for AT_HWCAP2 ELF auxv entry 2014-02-25 11:40:48 +00:00
hypervisor.h arm: initial Xen support 2012-09-14 13:53:39 +00:00
ide.h
idmap.h ARM: KVM: move to a KVM provided HYP idmap 2013-04-28 22:23:08 -07:00
io.h ARM: 7930/1: Introduce atomic MMIO modify 2014-01-28 14:06:25 +00:00
irq.h arm: Move the set_handle_irq and handle_arch_irq declarations to asm/irq.h 2013-03-26 16:11:20 +00:00
irqflags.h ARM: Add base support for ARMv7-M 2013-04-17 21:38:10 +02:00
jump_label.h ARM: 7989/1: Delete asm/system.h 2014-02-25 11:33:37 +00:00
Kbuild lib: Add missing arch generic-y entries for asm-generic/hash.h 2013-12-17 21:26:19 -05:00
kexec.h
kgdb.h ARM: kdgb: use <asm/opcodes.h> for data to be assembled as intruction 2013-10-19 20:46:35 +01:00
kmap_types.h arm: remove km_type definitions 2012-07-24 15:27:28 +08:00
kprobes.h
kvm_arm.h KVM: ARM: Update comments for kvm_handle_wfi 2013-10-17 15:26:50 -07:00
kvm_asm.h KVM: ARM: Add support for Cortex-A7 2013-10-12 17:45:30 -07:00
kvm_coproc.h KVM: ARM: User space API for getting/setting co-proc registers 2013-01-23 13:29:14 -05:00
kvm_emulate.h A handful of fixes for KVM/arm64: 2013-11-11 12:05:20 +01:00
kvm_host.h ARM/KVM: save and restore generic timer registers 2013-12-21 10:00:15 -08:00
kvm_mmio.h KVM: ARM: Handle I/O aborts 2013-01-23 13:29:17 -05:00
kvm_mmu.h arm/arm64: kvm: Use virt_to_idmap instead of virt_to_phys for idmap mappings 2013-12-11 09:49:31 -08:00
kvm_psci.h KVM: ARM: Power State Coordination Interface implementation 2013-01-23 13:29:18 -05:00
limits.h
linkage.h
mach-types.h
mc146818rtc.h
mcpm.h Merge branch 'devel-stable' into for-next 2013-11-12 10:58:59 +00:00
memblock.h ARM: constify machine_desc structure uses 2013-07-26 14:55:59 +01:00
memory.h ARM: Better virt_to_page() handling 2014-04-03 22:46:34 +01:00
mmu_context.h ARM: 7790/1: Fix deferred mm switch on VIVT processors 2013-07-26 12:02:09 +01:00
mmu.h ARM: tlb: ASID macro should give 32bit result for BE correct operation 2013-10-19 20:46:36 +01:00
module.h ARM: 7829/1: Add ".text.unlikely" and ".text.hot" to arm unwind tables 2013-09-02 13:49:47 +01:00
mpu.h ARM: mpu: protect the vectors page with an MPU region 2013-06-17 15:13:18 +01:00
mtd-xip.h
mutex.h ARM: 7495/1: mutex: use generic atomic_dec-based implementation for ARMv6+ 2012-08-25 09:22:31 +01:00
neon.h ARM: add support for kernel mode NEON 2013-07-08 22:08:51 +01:00
nwflash.h
opcodes-sec.h ARM: opcodes: add opcodes definitions for ARM security extensions 2013-01-10 21:10:20 +00:00
opcodes-virt.h ARM: opcodes: add __ERET/__MSR_ELR_HYP instruction encoding 2012-09-19 08:32:49 +01:00
opcodes.h ARM: opcodes: add missing include of linux/linkage.h 2013-01-10 21:10:20 +00:00
outercache.h ARM: move outer_cache declaration out of ifdef 2013-08-22 20:48:41 -05:00
page-nommu.h
page.h ARM: make vectors page inaccessible from userspace 2013-08-01 14:31:58 +01:00
pci.h ARM: PCI: add legacy IDE IRQ implementation 2013-12-29 12:44:10 +00:00
percpu.h ARM: 7747/1: pcpu: ensure __my_cpu_offset cannot be re-ordered across barrier() 2013-06-05 23:35:56 +01:00
perf_event.h ARM: 7584/1: perf: fix link error when CONFIG_HW_PERF_EVENTS is not selected 2012-11-23 13:01:30 +00:00
pgalloc.h arm: handle pgtable_page_ctor() fail 2013-11-15 09:32:16 +09:00
pgtable-2level-hwdef.h
pgtable-2level-types.h
pgtable-2level.h ARM: 7954/1: mm: remove remaining domain support from ARMv6 2014-02-10 11:48:13 +00:00
pgtable-3level-hwdef.h Merge branch 'for-rmk/lpae' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into devel-stable 2013-06-18 20:11:32 +01:00
pgtable-3level-types.h
pgtable-3level.h ARM: add support to dump the kernel page tables 2013-12-11 09:53:13 +00:00
pgtable-hwdef.h
pgtable-nommu.h consolidate io_remap_pfn_range definitions 2013-06-29 12:46:35 +04:00
pgtable.h ARM: 7985/1: mm: implement pte_accessible for faulting mappings 2014-02-25 11:32:40 +00:00
pmu.h ARM: perf: consistently use arm_pmu->name for PMU name 2012-11-09 11:37:26 +00:00
proc-fns.h Merge branch 'for-rmk/lpae' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into devel-stable 2013-06-18 20:11:32 +01:00
processor.h ARM: prefetch: add support for prefetchw using pldw on SMP ARMv7+ CPUs 2013-09-30 16:42:55 +01:00
procinfo.h
prom.h of: remove HAVE_ARCH_DEVTREE_FIXUPS 2013-10-09 20:04:08 -05:00
psci.h arm: introduce psci_smp_ops 2013-05-21 14:24:11 +00:00
ptrace.h ARM: Add base support for ARMv7-M 2013-04-17 21:38:10 +02:00
scatterlist.h
seccomp.h
setup.h ARM: 7863/1: Let arm_add_memory() always use 64-bit arguments 2013-10-29 11:06:28 +00:00
shmparam.h
signal.h arm: switch to generic old sigaction() 2013-02-03 18:15:47 -05:00
smp_plat.h ARM: 7807/1: kexec: validate CPU hotplug support 2013-08-13 20:23:18 +01:00
smp_scu.h ARM: scu: provide inline dummy functions when SCU is not present 2013-07-04 05:10:51 -07:00
smp_twd.h ARM: smp_twd: convert to use CLKSRC_OF init 2013-03-11 08:42:08 -05:00
smp.h ARM: SMP: basic IPI triggered completion support 2013-09-23 18:47:26 -04:00
sparsemem.h
spinlock_types.h ARM: locks: prefetch the destination word for write prior to strex 2013-09-30 16:42:55 +01:00
spinlock.h Merge branch 'devel-stable' into for-next 2013-11-12 10:58:59 +00:00
stackprotector.h
stacktrace.h
string.h
suspend.h ARM: kernel: implement stack pointer save array through MPIDR hashing 2013-06-20 11:24:11 +01:00
swab.h UAPI: (Scripted) Disintegrate arch/arm/include/asm 2012-10-12 13:05:52 +01:00
switch_to.h ARM: spinlock: use inner-shareable dsb variant prior to sev instruction 2013-08-12 12:25:45 +01:00
sync_bitops.h ARM: 7989/1: Delete asm/system.h 2014-02-25 11:33:37 +00:00
syscall.h ARM: 7851/1: check for number of arguments in syscall_get/set_arguments() 2013-10-13 18:54:33 +01:00
system_info.h ARM: Add base support for ARMv7-M 2013-04-17 21:38:10 +02:00
system_misc.h reboot: arm: change reboot_mode to use enum reboot_mode 2013-07-09 10:33:29 -07:00
tcm.h
therm.h
thread_info.h preempt: Make PREEMPT_ACTIVE generic 2013-11-13 20:21:47 +01:00
thread_notify.h
timex.h Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm 2012-10-07 21:20:57 +09:00
tlb.h Fix TLB gather virtual address range invalidation corner cases 2013-08-16 08:52:46 -07:00
tlbflush.h ARM: 7855/1: Add check for Cortex-A15 errata 798181 ECO 2013-10-29 11:06:13 +00:00
tls.h ARM: 7735/2: Preserve the user r/w register TPIDRURW on context switch and fork 2013-06-24 15:21:59 +01:00
topology.h
traps.h
trusted_foundations.h ARM: add basic support for Trusted Foundations 2013-12-13 12:50:30 -07:00
types.h ARM: 7822/1: add workaround for ambiguous C99 stdint.h types 2013-08-25 17:09:46 +01:00
uaccess.h ARM: 7951/1: uaccess: use CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 2014-02-10 11:48:10 +00:00
ucontext.h
unified.h ARM: smp_on_up: move inline asm ALT_SMP patching macro out of spinlock.h 2013-09-30 16:42:55 +01:00
unistd.h sched: Add new scheduler syscalls to support an extended scheduling parameters ABI 2014-01-13 13:41:04 +01:00
unwind.h
user.h
v7m.h ARM: 7828/1: ARMv7-M: implement restart routine common to all v7-M machines 2013-09-02 13:49:29 +01:00
vfp.h
vfpmacros.h ARM: 7566/1: vfp: fix save and restore when running on pre-VFPv3 and CONFIG_VFPv3 set 2012-10-29 10:04:05 +00:00
vga.h
virt.h ARM: 7787/1: virt: ensure visibility of __boot_cpu_mode 2013-07-26 12:01:17 +01:00
word-at-a-time.h ARM: 7927/1: dcache: select DCACHE_WORD_ACCESS for big-endian CPUs 2013-12-29 12:46:50 +00:00
xor.h ARM: crypto: add NEON accelerated XOR implementation 2013-07-08 22:09:06 +01:00