Module Name: src
Committed By: simonb
Date: Sat May 30 03:12:52 UTC 2020
Modified Files:
src/sys/arch/mips/cavium/dev: octeon_rnm.c
Log Message:
CN70XX iobdma limit appears to be 128 words, so gather that many samples
as a time.
Gather the full 512 bytes of samples and process in a single call to
rnd_add_data_sync() - about 10% faster than 4 calls to rnd_add_data_sync().
Put sample buffer in the softc to save some stack usage.
To generate a diff of this commit:
cvs rdiff -u -r1.6 -r1.7 src/sys/arch/mips/cavium/dev/octeon_rnm.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/mips/cavium/dev/octeon_rnm.c
diff -u src/sys/arch/mips/cavium/dev/octeon_rnm.c:1.6 src/sys/arch/mips/cavium/dev/octeon_rnm.c:1.7
--- src/sys/arch/mips/cavium/dev/octeon_rnm.c:1.6 Mon May 18 16:05:09 2020
+++ src/sys/arch/mips/cavium/dev/octeon_rnm.c Sat May 30 03:12:52 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: octeon_rnm.c,v 1.6 2020/05/18 16:05:09 riastradh Exp $ */
+/* $NetBSD: octeon_rnm.c,v 1.7 2020/05/30 03:12:52 simonb Exp $ */
/*
* Copyright (c) 2007 Internet Initiative Japan, Inc.
@@ -99,7 +99,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: octeon_rnm.c,v 1.6 2020/05/18 16:05:09 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: octeon_rnm.c,v 1.7 2020/05/30 03:12:52 simonb Exp $");
#include <sys/param.h>
#include <sys/device.h>
@@ -123,6 +123,7 @@ __KERNEL_RCSID(0, "$NetBSD: octeon_rnm.c
#define RNG_FIFO_WORDS (512/sizeof(uint64_t))
struct octeon_rnm_softc {
+ uint64_t sc_sample[RNG_FIFO_WORDS];
bus_space_tag_t sc_bust;
bus_space_handle_t sc_regh;
kmutex_t sc_lock;
@@ -222,8 +223,8 @@ static void
octeon_rnm_rng(size_t nbytes, void *vsc)
{
const unsigned BPB = 256; /* bits of data per bit of entropy */
- uint64_t sample[32];
struct octeon_rnm_softc *sc = vsc;
+ uint64_t *samplepos;
size_t needed = NBBY*nbytes;
unsigned i;
@@ -244,20 +245,21 @@ octeon_rnm_rng(size_t nbytes, void *vsc)
octeon_rnm_raw_entropy(sc, sc->sc_rogroup);
/*
- * Gather half the FIFO at a time -- we are limited to
- * 256 bytes because of limits on the CVMSEG buffer.
+ * Gather quarter the FIFO at a time -- we are limited
+ * to 128 bytes because of limits on the CVMSEG buffer.
*/
- CTASSERT(sizeof sample == 256);
- CTASSERT(2*__arraycount(sample) == RNG_FIFO_WORDS);
- for (i = 0; i < 2; i++) {
- octeon_rnm_iobdma(sc, sample, __arraycount(sample));
+ CTASSERT(sizeof sc->sc_sample == 512);
+ CTASSERT(__arraycount(sc->sc_sample) == RNG_FIFO_WORDS);
+ for (samplepos = sc->sc_sample, i = 0; i < 4; i++) {
+ octeon_rnm_iobdma(sc, samplepos, RNG_FIFO_WORDS / 4);
+ samplepos += RNG_FIFO_WORDS / 4;
+ }
#ifdef OCTEON_RNM_DEBUG
- hexdump(printf, "rnm", sample, sizeof sample);
+ hexdump(printf, "rnm", sc->sc_sample, sizeof sc->sc_sample);
#endif
- rnd_add_data_sync(&sc->sc_rndsrc, sample,
- sizeof sample, NBBY*sizeof(sample)/BPB);
- needed -= MIN(needed, MAX(1, NBBY*sizeof(sample)/BPB));
- }
+ rnd_add_data_sync(&sc->sc_rndsrc, sc->sc_sample,
+ sizeof sc->sc_sample, NBBY*sizeof(sc->sc_sample)/BPB);
+ needed -= MIN(needed, MAX(1, NBBY*sizeof(sc->sc_sample)/BPB));
/* Yield if requested. */
if (__predict_false(curcpu()->ci_schedstate.spc_flags &
@@ -270,7 +272,7 @@ octeon_rnm_rng(size_t nbytes, void *vsc)
mutex_exit(&sc->sc_lock);
/* Zero the sample. */
- explicit_memset(sample, 0, sizeof sample);
+ explicit_memset(sc->sc_sample, 0, sizeof sc->sc_sample);
}
/*
@@ -366,7 +368,7 @@ octeon_rnm_iobdma(struct octeon_rnm_soft
__SHIFTIN(RNM_IOBDMA_MAJORDID, IOBDMA_MAJORDID) |
__SHIFTIN(RNM_IOBDMA_SUBDID, IOBDMA_SUBDID);
- KASSERT(nwords < 256); /* iobdma address restriction */
+ KASSERT(nwords < 128); /* iobdma address restriction */
KASSERT(nwords <= 32); /* octeon_cvmseg_map limitation */
octeon_iobdma_write_8(iobdma);
