forked from luck/tmp_suning_uos_patched
e6331a321a
Emulation of the tlbwr instruction, which writes a TLB entry to a random
index in the TLB, currently uses get_random_bytes() to generate a 4 byte
random number which we then mask to form the index. This is overkill in
a couple of ways:
- We don't need 4 bytes here since we mask the value to form a 6 bit
number anyway, so we waste /dev/random entropy generating 3 random
bytes that are unused.
- We don't need crypto-grade randomness here - the architecture spec
allows implementations to use any algorithm & merely encourages that
some pseudo-randomness be used rather than a simple counter. The
fast prandom_u32() function fits that criteria well.
So rather than using get_random_bytes() & consuming /dev/random entropy,
switch to using the faster prandom_u32_max() which provides what we need
here whilst also performing the masking/modulo for us.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Reported-by: George Spelvin <lkml@sdf.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
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| .. | ||
| 00README.txt | ||
| callback.c | ||
| commpage.c | ||
| commpage.h | ||
| dyntrans.c | ||
| emulate.c | ||
| entry.c | ||
| fpu.S | ||
| hypcall.c | ||
| interrupt.c | ||
| interrupt.h | ||
| Kconfig | ||
| Makefile | ||
| mips.c | ||
| mmu.c | ||
| msa.S | ||
| stats.c | ||
| tlb.c | ||
| trace.h | ||
| trap_emul.c | ||
| vz.c | ||