ARM: Delete ARM11MPCore (ARM11 ARMv6K SMP) support

This ARM11 SMP configuration was one of the first SMP configurations
the ARM kernel supported, but it has the downside of odd DMA handling,
odd cache tagging, and often (as of recent) completely broken cache
handling on the ARM RealView PB11MPCore test chips. To boot the
platform it was necessary to completely disable the cache.
When it comes to the EB 11MPCore it is unclear if this ever worked.

These reference designs are now the only ARMv6K SMP platforms.

As only reference designs of purely academic interest remain, and
since the special-cased DMA and PMU code is hard to maintain and
doesn't really work, it is not really worth our time.

Delete the ARM11MPCore support along with:

- The special DMA quirk CONFIG_DMA_CACHE_RWFO that is only used
on ARMv6K SMP, and we are the last ARMV6K system leaving the
building and the cache handling is awkward, so good-bye.

- The special PMU handling that was only used by ARM11MPCore.

The following is left behind:

- TIMER_OF_DECLARE(arm_twd_11mp, "arm,arm11mp-twd-timer", ...)
in arch/arm/kernel/smp_twd.c, this is still in use by Marvell MMP3
arch/arm/boot/dts/marvell/mmp3.dtsi

- IRQCHIP_DECLARE(arm11mp_gic, "arm,arm11mp-gic", ...)
in drivers/irqchip/irq-gic.c, this is still in use by Marvell MMP3
arch/arm/boot/dts/marvell/mmp3.dtsi

- A compatible for the arm11mpcore SCU, since this was mistakedly
used for the Cortex-A9 version of RealView EB.

These are unfortunate but will need to be kept around for
compatibility. New Marvell-specific compatibles should however probably
be added.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://lore.kernel.org/r/20231207-drop-11mpcore-v2-1-560b396f3bf5@linaro.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

ARM: 9263/1: use .arch directives instead of assembler command line flags

Similar to commit a6c30873ee4a ("ARM: 8989/1: use .fpu assembler
directives instead of assembler arguments").

GCC and GNU binutils support setting the "sub arch" via -march=,
-Wa,-march, target function attribute, and .arch assembler directive.

Clang was missing support for -Wa,-march=, but this was implemented in
clang-13.

The behavior of both GCC and Clang is to
prefer -Wa,-march= over -march= for assembler and assembler-with-cpp
sources, but Clang will warn about the -march= being unused.

clang: warning: argument unused during compilation: '-march=armv6k'
[-Wunused-command-line-argument]

Since most assembler is non-conditionally assembled with one sub arch
(modulo arch/arm/delay-loop.S which conditionally is assembled as armv4
based on CONFIG_ARCH_RPC, and arch/arm/mach-at91/pm-suspend.S which is
conditionally assembled as armv7-a based on CONFIG_CPU_V7), prefer the
.arch assembler directive.

Add a few more instances found in compile testing as found by Arnd and
Nathan.

Link: https://github.com/llvm/llvm-project/commit/1d51c699b9e2ebc5bcfdbe85c74cc871426333d4
Link: https://bugs.llvm.org/show_bug.cgi?id=48894
Link: https://github.com/ClangBuiltLinux/linux/issues/1195
Link: https://github.com/ClangBuiltLinux/linux/issues/1315

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ARM: 8844/1: use unified assembler in assembly files

Use unified assembler syntax (UAL) in assembly files. Divided
syntax is considered deprecated. This will also allow to build
the kernel using LLVM's integrated assembler.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+

ARMv6 and greater introduced a new instruction ("bx") which can be used
to return from function calls. Recent CPUs perform better when the
"bx lr" instruction is used rather than the "mov pc, lr" instruction,
and this sequence is strongly recommended to be used by the ARM
architecture manual (section A.4.1.1).

We provide a new macro "ret" with all its variants for the condition
code which will resolve to the appropriate instruction.

Rather than doing this piecemeal, and miss some instances, change all
the "mov pc" instances to use the new macro, with the exception of
the "movs" instruction and the kprobes code. This allows us to detect
the "mov pc, lr" case and fix it up - and also gives us the possibility
of deploying this for other registers depending on the CPU selection.

Reported-by: Will Deacon <will.deacon@arm.com>
Tested-by: Stephen Warren <swarren@nvidia.com> # Tegra Jetson TK1
Tested-by: Robert Jarzmik <robert.jarzmik@free.fr> # mioa701_bootresume.S
Tested-by: Andrew Lunn <andrew@lunn.ch> # Kirkwood
Tested-by: Shawn Guo <shawn.guo@freescale.com>
Tested-by: Tony Lindgren <tony@atomide.com> # OMAPs
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com> # Armada XP, 375, 385
Acked-by: Sekhar Nori <nsekhar@ti.com> # DaVinci
Acked-by: Christoffer Dall <christoffer.dall@linaro.org> # kvm/hyp
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com> # PXA3xx
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> # Xen
Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> # ARMv7M
Tested-by: Simon Horman <horms+renesas@verge.net.au> # Shmobile
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: mm: implement LoUIS API for cache maintenance ops

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: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>

ARM: 7408/1: cacheflush: return error to userspace when flushing syscall fails

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: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: mm: cache-v6: Use the new processor struct macros

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

ARM: 6941/1: cache: ensure MVA is cacheline aligned in flush_kern_dcache_area

The v6 and v7 implementations of flush_kern_dcache_area do not align
the passed MVA to the size of a cacheline in the data cache. If a
misaligned address is used, only a subset of the requested area will
be flushed. This has been observed to cause failures in SMP boot where
the secondary_data initialised by the primary CPU is not cacheline
aligned, causing the secondary CPUs to read incorrect values for their
pgd and stack pointers.

This patch ensures that the base address is cacheline aligned before
flushing the d-cache.

Cc: <stable@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: 6535/1: V6 MPCore v6_dma_inv_range and v6_dma_flush_range RWFO fix

Cache ownership must be acquired by reading/writing data from the
cache line to make cache operation have the desired effect on the
SMP MPCore CPU. However, the ownership is never acquired in the
v6_dma_inv_range function when cleaning the first line and
flushing the last one, in case the address is not aligned
to D_CACHE_LINE_SIZE boundary.
Fix this by reading/writing data if needed, before performing
cache operations.
While at it, fix v6_dma_flush_range to prevent RWFO outside
the buffer.

Cc: stable@kernel.org
Signed-off-by: Valentine Barshak <vbarshak@mvista.com>
Signed-off-by: George G. Davis <gdavis@mvista.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: 6405/1: Handle __flush_icache_all for CONFIG_SMP_ON_UP

Do this by adding flush_icache_all to cache_fns for ARMv6 and 7.
As flush_icache_all may neeed to be called from flush_kern_cache_all,
add it as the first entry in the cache_fns.

Note that now we can remove the ARM_ERRATA_411920 dependency
to !SMP so it can be selected on UP ARMv6 processors, such
as omap2.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: 6188/1: Add a config option for the ARM11MPCore DMA cache maintenance workaround

Commit f4d6477f introduced a workaround for the lack of hardware
broadcasting of the cache maintenance operations on ARM11MPCore.
However, the workaround is only valid on CPUs that do not do speculative
loads into the D-cache.

This patch adds a Kconfig option with the corresponding help to make the
above clear. When the DMA_CACHE_RWFO option is disabled, the kernel
behaviour is that prior to the f4d6477f commit. This also allows ARMv6
UP processors with speculative loads to work correctly.

For other processors, a different workaround may be needed.

Cc: Ronen Shitrit <rshitrit@marvell.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: 6187/1: The v6_dma_inv_range() function must preserve data on SMP

A recent patch for DMA cache maintenance on ARM11MPCore added a write
for ownership trick to the v6_dma_inv_range() function. Such operation
destroys data already present in the buffer. However, this function is
used with with dma_sync_single_for_device() which is supposed to
preserve the existing data transfered into the buffer. This patch adds a
combination of read/write for ownership to preserve the original data.

Reported-by: Ronen Shitrit <rshitrit@marvell.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: 6111/1: Implement read/write for ownership in the ARMv6 DMA cache ops

The Snoop Control Unit on the ARM11MPCore hardware does not detect the
cache operations and the dma_cache_maint*() functions may leave stale
cache entries on other CPUs. The solution implemented in this patch
performs a Read or Write For Ownership in the ARMv6 DMA cache
maintenance functions. These LDR/STR instructions change the cache line
state to shared or exclusive so that the cache maintenance operation has
the desired effect.

Tested-by: George G. Davis <gdavis@mvista.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: dma-mapping: fix for speculative prefetching

ARMv6 and ARMv7 CPUs can perform speculative prefetching, which makes
DMA cache coherency handling slightly more interesting. Rather than
being able to rely upon the CPU not accessing the DMA buffer until DMA
has completed, we now must expect that the cache could be loaded with
possibly stale data from the DMA buffer.

Where DMA involves data being transferred to the device, we clean the
cache before handing it over for DMA, otherwise we invalidate the buffer
to get rid of potential writebacks. On DMA Completion, if data was
transferred from the device, we invalidate the buffer to get rid of
any stale speculative prefetches.

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

ARM: dma-mapping: remove dmac_clean_range and dmac_inv_range

These are now unused, and so can be removed.

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

ARM: dma-mapping: provide per-cpu type map/unmap functions

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

ARM: add size argument to __cpuc_flush_dcache_page

... and rename the function since it no longer operates on just
pages.

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

ARM: 5746/1: Handle possible translation errors in ARMv6/v7 coherent_user_range

This is needed because applications using the sys_cacheflush system call
can pass a memory range which isn't mapped yet even though the
corresponding vma is valid. The patch also adds unwinding annotations
for correct backtraces from the coherent_user_range() functions.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

[ARM] 5488/1: ARM errata: Invalidation of the Instruction Cache operation can fail

This patch implements the recommended workaround for erratum 411920
(ARM1136, ARM1156, ARM1176).

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

[ARM] 3356/1: Workaround for the ARM1136 I-cache invalidation problem

Patch from Catalin Marinas

ARM1136 erratum 371025 (category 2) specifies that, under rare
conditions, an invalidate I-cache by MVA (line or range) operation can
fail to invalidate a cache line. The recommended workaround is to
either invalidate the entire I-cache or invalidate the range by
set/way rather than MVA.

Note that for a 16K cache size, invalidating a 4K page by set/way is
equivalent to invalidating the entire I-cache.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

[ARM] 3294/1: don't invalidate individual BTB entries on ARMv6

Patch from Nicolas Pitre

Doing so adds a much larger cost to the loop than the cost implied by
simply invalidating the whole BTB at once.

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

[ARM] 2940/1: Fix BTB entry flush in arch/arm/mm/cache-v6.S

Patch from Gen FUKATSU

Invalidate BTB entry instruction flushes two instruction
at a time. Therefore this instruction should be done four
times after invalidate instruction cache line.

Signed-off-by: Gen Fukatsu
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!