Conflicts:
	arch/arm/kernel/perf_event_cpu.c

The platforms selecting NEED_MACH_MEMORY_H defined the start address of
their physical memory in the respective <mach/memory.h>. With
ARM_PATCH_PHYS_VIRT=y (which is quite common today) this is useless
though because the definition isn't used but determined dynamically.

So remove the definitions from all <mach/memory.h> and provide the
Kconfig symbol PHYS_OFFSET with the respective defaults in case
ARM_PATCH_PHYS_VIRT isn't enabled.

This allows to drop the dependency of PHYS_OFFSET on !NEED_MACH_MEMORY_H
which prevents compiling an integrator nommu-kernel.
(CONFIG_PAGE_OFFSET which has "default PHYS_OFFSET if !MMU" expanded to
"0x" because CONFIG_PHYS_OFFSET doesn't exist as INTEGRATOR selects
NEED_MACH_MEMORY_H.)

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

With TASK_SIZE set to the maximal RAM address booting in some XIP
configurations fails (e.g. on efm32 DK3750). The problem is that
strncpy_from_user et al. check for the address not being above TASK_SIZE
(since 8c56cc8be5b3 (ARM: 7449/1: use generic strnlen_user and
strncpy_from_user functions)) and this makes booting fail if the XIP
flash is above the RAM address space.

This change is in line with blackfin, frv and m68k which also use
0xffffffff for TASK_SIZE with !MMU.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

It looks like the static mapping area for DMA was replaced by dynamic
allocation into the vmalloc area by commit e9da6e9905e6 but the
information in Documentation/arm/memory.txt was not removed accordingly.

CONSISTENT_END in arch/arm/include/asm/memory.h has no more users and
can be removed as well.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

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>

With noMMU, CONFIG_PAGE_OFFSET was not being set correctly.  As there's
no MMU, PAGE_OFFSET should be equal to PHYS_OFFSET in all cases.  This
commit makes that explicit.

Since we do this, we don't need to mess around in asm/memory.h with
ifdefs to sort this out, so let's get rid of that, and there's no point
offering the "Memory split" option for noMMU as that's meaningless
there.

Fixes: b9b32bf70f2f ("ARM: use linker magic for vectors and vector stubs")
Cc: <stable@vger.kernel.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The definition of virt_addr_valid is that virt_addr_valid should
return true if and only if virt_to_page returns a valid pointer.
The current definition of virt_addr_valid only checks against the
virtual address range. There's no guarantee that just because a
virtual address falls bewteen PAGE_OFFSET and high_memory the
associated physical memory has a valid backing struct page. Follow
the example of other architectures and convert to pfn_valid to
verify that the virtual address is actually valid. The check for
an address between PAGE_OFFSET and high_memory is still necessary
as vmalloc/highmem addresses are not valid with virt_to_page.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Nicolas Pitre <nico@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Jason Gunthorpe reports a build failure when ARM_PATCH_PHYS_VIRT is
not defined:

In file included from arch/arm/include/asm/page.h:163:0,
                 from include/linux/mm_types.h:16,
                 from include/linux/sched.h:24,
                 from arch/arm/kernel/asm-offsets.c:13:
arch/arm/include/asm/memory.h: In function '__virt_to_phys':
arch/arm/include/asm/memory.h:244:40: error: 'PHYS_OFFSET' undeclared (first use in this function)
arch/arm/include/asm/memory.h:244:40: note: each undeclared identifier is reported only once for each function it appears in
arch/arm/include/asm/memory.h: In function '__phys_to_virt':
arch/arm/include/asm/memory.h:249:13: error: 'PHYS_OFFSET' undeclared (first use in this function)

Fixes: ca5a45c06cd4 ("ARM: mm: use phys_addr_t appropriately in p2v and v2p conversions")
Tested-By: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Make sure that inline assembler that expects 'r' operand
receives 32 bit value.

Before this fix in case of CONFIG_ARCH_PHYS_ADDR_T_64BIT and
CONFIG_ARM_PATCH_PHYS_VIRT __phys_to_virt function passed 64 bit
value to __pv_stub inline assembler where 'r' operand is
expected. Compiler behavior in such case is not well specified.
It worked in little endian case, but in big endian case
incorrect code was generated, where compiler confused which
part of 64 bit value it needed to modify. For example BE
snippet looked like this:

N:0x80904E08 : MOV      r2,#0
N:0x80904E0C : SUB      r2,r2,#0x81000000

when LE similar code looked like this

N:0x808FCE2C : MOV      r2,r0
N:0x808FCE30 : SUB      r2,r2,#0xc0, 8 ; #0xc0000000

Note 'r0' register is va that have to be translated into phys

To avoid this situation use explicit cast to 'unsigned long',
which explicitly discard upper part of phys address and convert
value to 32 bit. Also add comment so such cast will not be
removed in the future.

Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>