KVM: arm64: Provide I-cache invalidation by virtual address at EL2

In preparation for handling cache maintenance of guest pages from within
the pKVM hypervisor at EL2, introduce an EL2 copy of icache_inval_pou()
which will later be plumbed into the stage-2 page-table cache
maintenance callbacks, ensuring that the initial contents of pages
mapped as executable into the guest stage-2 page-table is visible to the
instruction fetcher.

Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-17-will@kernel.org

arm64: clean up symbol aliasing

Now that we have SYM_FUNC_ALIAS() and SYM_FUNC_ALIAS_WEAK(), use those
to simplify and more consistently define function aliases across
arch/arm64.

Aliases are now defined in terms of a canonical function name. For
position-independent functions I've made the __pi_<func> name the
canonical name, and defined other alises in terms of this.

The SYM_FUNC_{START,END}_PI(func) macros obscure the __pi_<func> name,
and make this hard to seatch for. The SYM_FUNC_START_WEAK_PI() macro
also obscures the fact that the __pi_<func> fymbol is global and the
<func> symbol is weak. For clarity, I have removed these macros and used
SYM_FUNC_{START,END}() directly with the __pi_<func> name.

For example:

SYM_FUNC_START_WEAK_PI(func)
... asm insns ...
SYM_FUNC_END_PI(func)
EXPORT_SYMBOL(func)

... becomes:

SYM_FUNC_START(__pi_func)
... asm insns ...
SYM_FUNC_END(__pi_func)

SYM_FUNC_ALIAS_WEAK(func, __pi_func)
EXPORT_SYMBOL(func)

For clarity, where there are multiple annotations such as
EXPORT_SYMBOL(), I've tried to keep annotations grouped by symbol. For
example, where a function has a name and an alias which are both
exported, this is organised as:

SYM_FUNC_START(func)
... asm insns ...
SYM_FUNC_END(func)
EXPORT_SYMBOL(func)

SYM_FUNC_ALIAS(alias, func)
EXPORT_SYMBOL(alias)

For consistency with the other string functions, I've defined strrchr as
a position-independent function, as it can safely be used as such even
though we have no users today.

As we no longer use SYM_FUNC_{START,END}_ALIAS(), our local copies are
removed. The common versions will be removed by a subsequent patch.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Mark Brown <broonie@kernel.org>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Will Deacon <will@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220216162229.1076788-3-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

arm64: Rename arm64-internal cache maintenance functions

Although naming across the codebase isn't that consistent, it
tends to follow certain patterns. Moreover, the term "flush"
isn't defined in the Arm Architecture reference manual, and might
be interpreted to mean clean, invalidate, or both for a cache.

Rename arm64-internal functions to make the naming internally
consistent, as well as making it consistent with the Arm ARM, by
specifying whether it applies to the instruction, data, or both
caches, whether the operation is a clean, invalidate, or both.
Also specify which point the operation applies to, i.e., to the
point of unification (PoU), coherency (PoC), or persistence
(PoP).

This commit applies the following sed transformation to all files
under arch/arm64:

"s/\b__flush_cache_range\b/caches_clean_inval_pou_macro/g;"\
"s/\b__flush_icache_range\b/caches_clean_inval_pou/g;"\
"s/\binvalidate_icache_range\b/icache_inval_pou/g;"\
"s/\b__flush_dcache_area\b/dcache_clean_inval_poc/g;"\
"s/\b__inval_dcache_area\b/dcache_inval_poc/g;"\
"s/__clean_dcache_area_poc\b/dcache_clean_poc/g;"\
"s/\b__clean_dcache_area_pop\b/dcache_clean_pop/g;"\
"s/\b__clean_dcache_area_pou\b/dcache_clean_pou/g;"\
"s/\b__flush_cache_user_range\b/caches_clean_inval_user_pou/g;"\
"s/\b__flush_icache_all\b/icache_inval_all_pou/g;"

Note that __clean_dcache_area_poc is deliberately missing a word
boundary check at the beginning in order to match the efistub
symbols in image-vars.h.

Also note that, despite its name, __flush_icache_range operates
on both instruction and data caches. The name change here
reflects that.

No functional change intended.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20210524083001.2586635-19-tabba@google.com
Signed-off-by: Will Deacon <will@kernel.org>

arm64: __flush_dcache_area to take end parameter instead of size

To be consistent with other functions with similar names and
functionality in cacheflush.h, cache.S, and cachetlb.rst, change
to specify the range in terms of start and end, as opposed to
start and size.

No functional change intended.

Reported-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20210524083001.2586635-13-tabba@google.com
Signed-off-by: Will Deacon <will@kernel.org>

arm64: dcache_by_line_op to take end parameter instead of size

To be consistent with other functions with similar names and
functionality in cacheflush.h, cache.S, and cachetlb.rst, change
to specify the range in terms of start and end, as opposed to
start and size.

No functional change intended.

Reported-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20210524083001.2586635-12-tabba@google.com
Signed-off-by: Will Deacon <will@kernel.org>

KVM: arm64: Provide __flush_dcache_area at EL2

We will need to do cache maintenance at EL2 soon, so compile a copy of
__flush_dcache_area at EL2, and provide a copy of arm64_ftr_reg_ctrel0
as it is needed by the read_ctr macro.

Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210319100146.1149909-15-qperret@google.com