ARM v7 architecture introduced the concept of cache levels and related
control registers. New processors like A7 and A15 embed an L2 unified cache
controller that becomes part of the cache level hierarchy. Some operations in
the kernel like cpu_suspend and __cpu_disable do not require a flush of the
entire cache hierarchy to DRAM but just the cache levels belonging to the
Level of Unification Inner Shareable (LoUIS), which in most of ARM v7 systems
correspond to L1.

The current cache flushing API used in cpu_suspend and __cpu_disable,
flush_cache_all(), ends up flushing the whole cache hierarchy since for
v7 it cleans and invalidates all cache levels up to Level of Coherency
(LoC) which cripples system performance when used in hot paths like hotplug
and cpuidle.

Therefore a new kernel cache maintenance API must be added to cope with
latest ARM system requirements.

This patch adds flush_cache_louis() to the ARM kernel cache maintenance API.

This function cleans and invalidates all data cache levels up to the
Level of Unification Inner Shareable (LoUIS) and invalidates the instruction
cache for processors that support it (> v7).

This patch also creates an alias of the cache LoUIS function to flush_kern_all
for all processor versions prior to v7, so that the current cache flushing
behaviour is unchanged for those processors.

v7 cache maintenance code implements a cache LoUIS function that cleans and
invalidates the D-cache up to LoUIS and invalidates the I-cache, according
to the new API.
Reviewed-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: NNicolas Pitre <nico@linaro.org>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: NShawn Guo <shawn.guo@linaro.org>

The cacheflush syscall can fail for two reasons:

(1) The arguments are invalid (nonsensical address range or no VMA)

(2) The region generates a translation fault on a VIPT or PIPT cache

This patch allows do_cache_op to return an error code to userspace in
the case of the above. The various coherent_user_range implementations
are modified to return 0 in the case of VIVT caches or -EFAULT in the
case of an abort on v6/v7 cores.
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The CPU reset functions disable the MMU and therefore must be executed
with an identity mapping in place.

This patch places the CPU reset functions into the .idmap.text section,
causing the idmap code to include them as part of the identity mapping.
Acked-by: NDave Martin <dave.martin@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Signed-off-by: NDave Martin <dave.martin@linaro.org>

This adds core support for saving and restoring CPU coprocessor
registers for suspend/resume support.  This contains support for suspend
with ARM920, ARM926, SA11x0, PXA25x, PXA27x, PXA3xx, V6 and V7 CPUs.
Tested on Assabet and Tegra 2.
Tested-by: NColin Cross <ccross@android.com>
Tested-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Commit 81d11955 ("ARM: 6405/1: Handle __flush_icache_all for
CONFIG_SMP_ON_UP") added a new function to struct cpu_cache_fns:
flush_icache_all(). It also implemented this for v6 and v7 but not
for v5 and backwards. Without the function pointer in place, we
will be calling wrong cache functions.

For example with ep93xx we get following:

    Unable to handle kernel paging request at virtual address ee070f38
    pgd = c0004000
    [ee070f38] *pgd=00000000
    Internal error: Oops: 80000005 [#1] PREEMPT
    last sysfs file:
    Modules linked in:
    CPU: 0    Not tainted  (2.6.36+ #1)
    PC is at 0xee070f38
    LR is at __dma_alloc+0x11c/0x2d0
    pc : [<ee070f38>]    lr : [<c0032c8c>]    psr: 60000013
    sp : c581bde0  ip : 00000000  fp : c0472000
    r10: c0472000  r9 : 000000d0  r8 : 00020000
    r7 : 0001ffff  r6 : 00000000  r5 : c0472400  r4 : c5980000
    r3 : c03ab7e0  r2 : 00000000  r1 : c59a0000  r0 : c5980000
    Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
    Control: c000717f  Table: c0004000  DAC: 00000017
    Process swapper (pid: 1, stack limit = 0xc581a270)
    [<c0032c8c>] (__dma_alloc+0x11c/0x2d0)
    [<c0032e5c>] (dma_alloc_writecombine+0x1c/0x24)
    [<c0204148>] (ep93xx_pcm_preallocate_dma_buffer+0x44/0x60)
    [<c02041c0>] (ep93xx_pcm_new+0x5c/0x88)
    [<c01ff188>] (snd_soc_instantiate_cards+0x8a8/0xbc0)
    [<c01ff59c>] (soc_probe+0xfc/0x134)
    [<c01adafc>] (platform_drv_probe+0x18/0x1c)
    [<c01acca4>] (driver_probe_device+0xb0/0x16c)
    [<c01ac284>] (bus_for_each_drv+0x48/0x84)
    [<c01ace90>] (device_attach+0x50/0x68)
    [<c01ac0f8>] (bus_probe_device+0x24/0x44)
    [<c01aad7c>] (device_add+0x2fc/0x44c)
    [<c01adfa8>] (platform_device_add+0x104/0x15c)
    [<c0015eb8>] (simone_init+0x60/0x94)
    [<c0021410>] (do_one_initcall+0xd0/0x1a4)

__dma_alloc() calls (inlined) __dma_alloc_buffer() which ends up
calling dmac_flush_range(). Now since the entries in the
arm920_cache_fns are shifted by one, we jump into address 0xee070f38
which is actually next instruction after the arm920_cache_fns
structure.

So implement flush_icache_all() for the rest of the supported CPUs
using a generic 'invalidate I cache' instruction.
Signed-off-by: NMika Westerberg <mika.westerberg@iki.fi>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

When hotplug CPU is enabled, we need to keep the list of supported CPUs,
their setup functions, and __lookup_processor_type in place so that we
can find and initialize secondary CPUs.  Move these into the __CPUINIT
section.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

All implementations of cpu_proc_fin() start by disabling interrupts
and then flush caches.  Rather than have every processors proc_fin()
implementation do this, move it out into generic code - and move the
cache flush past setup_mm_for_reboot() (so it can benefit from having
caches still enabled.)

This allows cpu_proc_fin() to become independent of the L1/L2 cache
types, and eventually move the L2 cache flushing into the L2 support
code.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

These are now unused, and so can be removed.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Tested-By: NSantosh Shilimkar <santosh.shilimkar@ti.com>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Tested-By: NSantosh Shilimkar <santosh.shilimkar@ti.com>

... and rename the function since it no longer operates on just
pages.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Instruction fault status register, IFSR, was introduced on ARMv6 to
provide status information about the last insturction fault. It
needed for proper prefetch abort handling.

Now we have three prefetch abort model:

  * legacy - for CPUs before ARMv6. They doesn't provide neither
    IFSR nor IFAR. We simulate IFSR with section translation fault
    status for them to generalize code;
  * ARMv6 - provides IFSR, but not IFAR;
  * ARMv7 - provides both IFSR and IFAR.
Signed-off-by: NKirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

asm code really wants asm/hwcap.h, so include that instead.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

... otherwise these fail to build.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The CPU's dma_flush_range() operation needs to clean+invalidate the
given memory area if the cache is in writeback mode, or do just the
invalidate part if the cache is in writethrough mode, but the current
proc-arm{925,926,940,946} (incorrectly) do a cache clean in the
latter case.  This patch fixes that.
Signed-off-by: NLennert Buytenhek <buytenh@marvell.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The proc-*.S files have the _prefetch_abort pointer placed at the end
of the processor structure but the cpu-multi32.h defines it in the
second position. The patch also fixes the support for XSC3 and the
MMU-less CPUs (740, 7tdmi, 940, 946 and 9tdmi).
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

These files want to provide/access ELF hwcap information, so should
be including asm/elf.h rather than asm/procinfo.h
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

There is no FSR/FAR register on no-CP15 or MPU cores. This patch adds a
dummy abort handler which returns zero for the base restored Data Abort
model !CPU_CP15_MMU cores. The abort-lv4t.S is still used with the fix-up
for the base updated Data Abort model cores.
Signed-off-by: NHyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This patch adds ARM940T core support which has 4KB D-cache, 4KB I-cache
and a MPU.
Signed-off-by: NHyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>