MIPS: Fix typos

Fix typos, most reported by "codespell arch/mips". Only touches comments,
no code changes.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-mips@vger.kernel.org
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: vdso: Invalid GIC access through VDSO

Accessing raw timers (currently only CLOCK_MONOTONIC_RAW) through VDSO
doesn't return the correct time when using the GIC as clock source.
The address of the GIC mapped page is in this case not calculated
correctly. The GIC mapped page is calculated from the VDSO data by
subtracting PAGE_SIZE:

void *get_gic(const struct vdso_data *data) {
return (void __iomem *)data - PAGE_SIZE;
}

However, the data pointer is not page aligned for raw clock sources.
This is because the VDSO data for raw clock sources (CS_RAW = 1) is
stored after the VDSO data for coarse clock sources (CS_HRES_COARSE = 0).
Therefore, only the VDSO data for CS_HRES_COARSE is page aligned:

+--------------------+
| |
| vd[CS_RAW] | ---+
| vd[CS_HRES_COARSE] | |
+--------------------+ | -PAGE_SIZE
| | |
| GIC mapped page | <--+
| |
+--------------------+

When __arch_get_hw_counter() is called with &vd[CS_RAW], get_gic returns
the wrong address (somewhere inside the GIC mapped page). The GIC counter
values are not returned which results in an invalid time.

Fixes: a7f4df4e21dd ("MIPS: VDSO: Add implementations of gettimeofday() and clock_gettime()")
Signed-off-by: Martin Fäcknitz <faecknitz@hotsplots.de>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

mips: fix vdso32 build, again

The generic vdso support adds the same #if hack in two places,
asm/vdso/vdso.h and config-n32-o32-env.c, but only the second
is actually used. The result lacks the BUILD_VDSO32_64 macro,
and that triggers a build error:

./include/linux/page-flags-layout.h:95:2: error: #error "Not enough bits in page flags"

Move the macro into the other place, and remove the duplicated
bits.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Fixes: ee38d94a0ad8 ("page flags: prioritize kasan bits over last-cpuid")
Fixes: 24640f233b46 ("mips: Add support for generic vDSO")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

mips: Add support for generic vDSO

The mips vDSO library requires some adaptations to take advantage of the
newly introduced generic vDSO library.

Introduce the following changes:
- Modification of vdso.c to be compliant with the common vdso datapage
- Use of lib/vdso for gettimeofday

Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
[paul.burton@mips.com: Prepend $(src) to config-n32-o32-env.c path.]
Signed-off-by: Paul Burton <paul.burton@mips.com>