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aaba098fe6
As we will exhaust the first 32 bits of AT_HWCAP let's start
exposing AT_HWCAP2 to userspace to give us up to 64 caps.
Whilst it's possible to use the remaining 32 bits of AT_HWCAP, we
prefer to expand into AT_HWCAP2 in order to provide a consistent
view to userspace between ILP32 and LP64. However internal to the
kernel we prefer to continue to use the full space of elf_hwcap.
To reduce complexity and allow for future expansion, we now
represent hwcaps in the kernel as ordinals and use a
KERNEL_HWCAP_ prefix. This allows us to support automatic feature
based module loading for all our hwcaps.
We introduce cpu_set_feature to set hwcaps which complements the
existing cpu_have_feature helper. These helpers allow us to clean
up existing direct uses of elf_hwcap and reduce any future effort
required to move beyond 64 caps.
For convenience we also introduce cpu_{have,set}_named_feature which
makes use of the cpu_feature macro to allow providing a hwcap name
without a {KERNEL_}HWCAP_ prefix.
Signed-off-by: Andrew Murray <andrew.murray@arm.com>
[will: use const_ilog2() and tweak documentation]
Signed-off-by: Will Deacon <will.deacon@arm.com>
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| .. | ||
| auxvec.h | ||
| bitsperlong.h | ||
| bpf_perf_event.h | ||
| byteorder.h | ||
| fcntl.h | ||
| hwcap.h | ||
| Kbuild | ||
| kvm.h | ||
| param.h | ||
| perf_regs.h | ||
| posix_types.h | ||
| ptrace.h | ||
| setup.h | ||
| sigcontext.h | ||
| signal.h | ||
| stat.h | ||
| statfs.h | ||
| sve_context.h | ||
| ucontext.h | ||
| unistd.h | ||