Module Name: src
Committed By: isaki
Date: Sat Aug 13 06:47:41 UTC 2022
Modified Files:
src/sys/dev/audio: audio.c audiodef.h
Log Message:
audio: Rework about usrbuf allocation.
- Allocate the usrbuf from kmem(9) instead of uvm(9). The usrbuf has used
uvm(9), in case mmap(2) might be issued later. However, despite the most
apps don't use mmap(2), allocating (and reallocating) uvm(9) every time
would be expensive. In addition, uvm(9) for recording usrbuf was totally
pointless now.
- For playback, the usrbuf memory will be allocated in pages. Because the
usrbuf for playback is mostly near 64KB for backward compatibility.
This will reduce reallocation especially from the initial ulaw to the most
commonly used format like slinear16/2ch/48kHz.
- When mmap(2) is called, it will replace the playback usrbuf from kmem(9) to
uvm(9).
- Prohibit changing playback format once mmap(2) is called.
It follows netbsd-7.
- For recording, the usrbuf memory will be allocated in the requested size
every time as before. Because the usrbuf for recording is only one block
and is enough small to the page in the most case.
Inspired by PR kern/56947.
To generate a diff of this commit:
cvs rdiff -u -r1.134 -r1.135 src/sys/dev/audio/audio.c
cvs rdiff -u -r1.19 -r1.20 src/sys/dev/audio/audiodef.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/audio/audio.c
diff -u src/sys/dev/audio/audio.c:1.134 src/sys/dev/audio/audio.c:1.135
--- src/sys/dev/audio/audio.c:1.134 Wed Jul 6 01:12:45 2022
+++ src/sys/dev/audio/audio.c Sat Aug 13 06:47:41 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: audio.c,v 1.134 2022/07/06 01:12:45 riastradh Exp $ */
+/* $NetBSD: audio.c,v 1.135 2022/08/13 06:47:41 isaki Exp $ */
/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -181,7 +181,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: audio.c,v 1.134 2022/07/06 01:12:45 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: audio.c,v 1.135 2022/08/13 06:47:41 isaki Exp $");
#ifdef _KERNEL_OPT
#include "audio.h"
@@ -234,7 +234,7 @@ __KERNEL_RCSID(0, "$NetBSD: audio.c,v 1.
/*
* 0: No debug logs
- * 1: action changes like open/close/set_format...
+ * 1: action changes like open/close/set_format/mmap...
* 2: + normal operations like read/write/ioctl...
* 3: + TRACEs except interrupt
* 4: + TRACEs including interrupt
@@ -645,7 +645,6 @@ static void audio_print_format2(const ch
#endif
static void *audio_realloc(void *, size_t);
-static int audio_realloc_usrbuf(audio_track_t *, int);
static void audio_free_usrbuf(audio_track_t *);
static audio_track_t *audio_track_create(struct audio_softc *,
@@ -3559,10 +3558,13 @@ audio_mmap(struct audio_softc *sc, off_t
audio_file_t *file)
{
audio_track_t *track;
+ struct uvm_object *uobj;
+ vaddr_t vstart;
vsize_t vsize;
int error;
- TRACEF(2, file, "off=%lld, prot=%d", (long long)(*offp), prot);
+ TRACEF(1, file, "off=%jd, len=%ju, prot=%d",
+ (intmax_t)(*offp), (uintmax_t)len, prot);
KASSERT(len > 0);
@@ -3595,36 +3597,69 @@ audio_mmap(struct audio_softc *sc, off_t
if (track == NULL)
return EACCES;
+ /* XXX TODO: what happens when mmap twice. */
+ if (track->mmapped)
+ return EIO;
+
+ /* Create a uvm anonymous object */
vsize = roundup2(MAX(track->usrbuf.capacity, PAGE_SIZE), PAGE_SIZE);
- if (len > vsize)
- return EOVERFLOW;
- if (*offp > (uint)(vsize - len))
+ if (*offp + len > vsize)
return EOVERFLOW;
+ uobj = uao_create(vsize, 0);
- /* XXX TODO: what happens when mmap twice. */
- if (!track->mmapped) {
- track->mmapped = true;
+ /* Map it into the kernel virtual address space */
+ vstart = 0;
+ error = uvm_map(kernel_map, &vstart, vsize, uobj, 0, 0,
+ UVM_MAPFLAG(UVM_PROT_RW, UVM_PROT_RW, UVM_INH_NONE,
+ UVM_ADV_RANDOM, 0));
+ if (error) {
+ device_printf(sc->sc_dev, "uvm_map failed: errno=%d\n", error);
+ uao_detach(uobj); /* release reference */
+ return error;
+ }
- if (!track->is_pause) {
- error = audio_exlock_mutex_enter(sc);
- if (error)
- return error;
- if (sc->sc_pbusy == false)
- audio_pmixer_start(sc, true);
- audio_exlock_mutex_exit(sc);
- }
- /* XXX mmapping record buffer is not supported */
+ error = uvm_map_pageable(kernel_map, vstart, vstart + vsize,
+ false, 0);
+ if (error) {
+ device_printf(sc->sc_dev, "uvm_map_pageable failed: errno=%d\n",
+ error);
+ goto abort;
}
- /* get ringbuffer */
- *uobjp = track->uobj;
+ error = audio_exlock_mutex_enter(sc);
+ if (error)
+ goto abort;
+
+ /*
+ * mmap() will start playing immediately. XXX Maybe we lack API...
+ * If no one has played yet, start pmixer here.
+ */
+ if (sc->sc_pbusy == false)
+ audio_pmixer_start(sc, true);
+ audio_exlock_mutex_exit(sc);
+
+ /* Finally, replace the usrbuf from kmem to uvm. */
+ audio_track_lock_enter(track);
+ kmem_free(track->usrbuf.mem, track->usrbuf_allocsize);
+ track->usrbuf.mem = (void *)vstart;
+ track->usrbuf_allocsize = vsize;
+ memset(track->usrbuf.mem, 0, vsize);
+ track->mmapped = true;
+ audio_track_lock_exit(track);
/* Acquire a reference for the mmap. munmap will release. */
- uao_reference(*uobjp);
+ uao_reference(uobj);
+ *uobjp = uobj;
*maxprotp = prot;
*advicep = UVM_ADV_RANDOM;
*flagsp = MAP_SHARED;
+
return 0;
+
+abort:
+ uvm_unmap(kernel_map, vstart, vstart + vsize);
+ /* uvm_unmap also detach uobj */
+ return error;
}
/*
@@ -3698,80 +3733,6 @@ audio_realloc(void *memblock, size_t byt
}
/*
- * (Re)allocate usrbuf with 'newbufsize' bytes.
- * Use this function for usrbuf because only usrbuf can be mmapped.
- * If successful, it updates track->usrbuf.mem, track->usrbuf.capacity and
- * returns 0. Otherwise, it clears track->usrbuf.mem, track->usrbuf.capacity
- * and returns errno.
- * It must be called before updating usrbuf.capacity.
- */
-static int
-audio_realloc_usrbuf(audio_track_t *track, int newbufsize)
-{
- struct audio_softc *sc;
- vaddr_t vstart;
- vsize_t oldvsize;
- vsize_t newvsize;
- int error;
-
- KASSERT(newbufsize > 0);
- sc = track->mixer->sc;
-
- /* Get a nonzero multiple of PAGE_SIZE */
- newvsize = roundup2(MAX(newbufsize, PAGE_SIZE), PAGE_SIZE);
-
- if (track->usrbuf.mem != NULL) {
- oldvsize = roundup2(MAX(track->usrbuf.capacity, PAGE_SIZE),
- PAGE_SIZE);
- if (oldvsize == newvsize) {
- track->usrbuf.capacity = newbufsize;
- return 0;
- }
- vstart = (vaddr_t)track->usrbuf.mem;
- uvm_unmap(kernel_map, vstart, vstart + oldvsize);
- /* uvm_unmap also detach uobj */
- track->uobj = NULL; /* paranoia */
- track->usrbuf.mem = NULL;
- }
-
- /* Create a uvm anonymous object */
- track->uobj = uao_create(newvsize, 0);
-
- /* Map it into the kernel virtual address space */
- vstart = 0;
- error = uvm_map(kernel_map, &vstart, newvsize, track->uobj, 0, 0,
- UVM_MAPFLAG(UVM_PROT_RW, UVM_PROT_RW, UVM_INH_NONE,
- UVM_ADV_RANDOM, 0));
- if (error) {
- device_printf(sc->sc_dev, "uvm_map failed: errno=%d\n", error);
- uao_detach(track->uobj); /* release reference */
- goto abort;
- }
-
- error = uvm_map_pageable(kernel_map, vstart, vstart + newvsize,
- false, 0);
- if (error) {
- device_printf(sc->sc_dev, "uvm_map_pageable failed: errno=%d\n",
- error);
- uvm_unmap(kernel_map, vstart, vstart + newvsize);
- /* uvm_unmap also detach uobj */
- goto abort;
- }
-
- track->usrbuf.mem = (void *)vstart;
- track->usrbuf.capacity = newbufsize;
- memset(track->usrbuf.mem, 0, newvsize);
- return 0;
-
- /* failure */
-abort:
- track->uobj = NULL; /* paranoia */
- track->usrbuf.mem = NULL;
- track->usrbuf.capacity = 0;
- return error;
-}
-
-/*
* Free usrbuf (if available).
*/
static void
@@ -3780,21 +3741,25 @@ audio_free_usrbuf(audio_track_t *track)
vaddr_t vstart;
vsize_t vsize;
- vstart = (vaddr_t)track->usrbuf.mem;
- vsize = roundup2(MAX(track->usrbuf.capacity, PAGE_SIZE), PAGE_SIZE);
- if (track->usrbuf.mem != NULL) {
- /*
- * Unmap the kernel mapping. uvm_unmap releases the
- * reference to the uvm object, and this should be the
- * last virtual mapping of the uvm object, so no need
- * to explicitly release (`detach') the object.
- */
- uvm_unmap(kernel_map, vstart, vstart + vsize);
-
- track->uobj = NULL;
- track->usrbuf.mem = NULL;
- track->usrbuf.capacity = 0;
+ if (track->usrbuf_allocsize != 0) {
+ if (track->mmapped) {
+ /*
+ * Unmap the kernel mapping. uvm_unmap releases the
+ * reference to the uvm object, and this should be the
+ * last virtual mapping of the uvm object, so no need
+ * to explicitly release (`detach') the object.
+ */
+ vstart = (vaddr_t)track->usrbuf.mem;
+ vsize = track->usrbuf_allocsize;
+ uvm_unmap(kernel_map, vstart, vstart + vsize);
+ track->mmapped = false;
+ } else {
+ kmem_free(track->usrbuf.mem, track->usrbuf_allocsize);
+ }
}
+ track->usrbuf.mem = NULL;
+ track->usrbuf.capacity = 0;
+ track->usrbuf_allocsize = 0;
}
/*
@@ -4639,19 +4604,21 @@ audio_track_init_freq(audio_track_t *tra
static int
audio_track_set_format(audio_track_t *track, audio_format2_t *usrfmt)
{
- struct audio_softc *sc;
audio_ring_t *last_dst;
int is_playback;
u_int newbufsize;
- u_int oldblksize;
+ u_int newvsize;
u_int len;
int error;
KASSERT(track);
- sc = track->mixer->sc;
is_playback = audio_track_is_playback(track);
+ /* Once mmap is called, the track format cannot be changed. */
+ if (track->mmapped)
+ return EIO;
+
/* usrbuf is the closest buffer to the userland. */
track->usrbuf.fmt = *usrfmt;
@@ -4682,27 +4649,34 @@ audio_track_set_format(audio_track_t *tr
* newvsize = roundup2(61440, PAGE_SIZE) = 61440 (= 15 pages)
* Therefore it maps 15 * 4K pages and usrbuf->capacity = 61440.
*/
- oldblksize = track->usrbuf_blksize;
track->usrbuf_blksize = frametobyte(&track->usrbuf.fmt,
frame_per_block(track->mixer, &track->usrbuf.fmt));
track->usrbuf.head = 0;
track->usrbuf.used = 0;
if (is_playback) {
- if (track->usrbuf_blksize * AUMINNOBLK > 65536)
- newbufsize = track->usrbuf_blksize * AUMINNOBLK;
- else
+ newbufsize = track->usrbuf_blksize * AUMINNOBLK;
+ if (newbufsize < 65536)
newbufsize = rounddown(65536, track->usrbuf_blksize);
+ newvsize = roundup2(newbufsize, PAGE_SIZE);
} else {
newbufsize = track->usrbuf_blksize;
+ newvsize = track->usrbuf_blksize;
}
- if (track->usrbuf_blksize != oldblksize) {
- error = audio_realloc_usrbuf(track, newbufsize);
- if (error) {
- device_printf(sc->sc_dev, "malloc usrbuf(%d) failed\n",
- newbufsize);
- goto error;
+ /*
+ * Reallocate only if the number of pages changes.
+ * This is because we expect kmem to allocate memory on per page
+ * basis if the request size is about 64KB.
+ */
+ if (newvsize != track->usrbuf_allocsize) {
+ if (track->usrbuf_allocsize != 0) {
+ kmem_free(track->usrbuf.mem, track->usrbuf_allocsize);
}
+ TRACET(2, track, "usrbuf_allocsize %d -> %d",
+ track->usrbuf_allocsize, newvsize);
+ track->usrbuf.mem = kmem_alloc(newvsize, KM_SLEEP);
+ track->usrbuf_allocsize = newvsize;
}
+ track->usrbuf.capacity = newbufsize;
/* Recalc water mark. */
if (is_playback) {
Index: src/sys/dev/audio/audiodef.h
diff -u src/sys/dev/audio/audiodef.h:1.19 src/sys/dev/audio/audiodef.h:1.20
--- src/sys/dev/audio/audiodef.h:1.19 Sat Apr 23 07:55:07 2022
+++ src/sys/dev/audio/audiodef.h Sat Aug 13 06:47:41 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: audiodef.h,v 1.19 2022/04/23 07:55:07 isaki Exp $ */
+/* $NetBSD: audiodef.h,v 1.20 2022/08/13 06:47:41 isaki Exp $ */
/*
* Copyright (C) 2017 Tetsuya Isaki. All rights reserved.
@@ -119,7 +119,7 @@ struct audio_track {
audio_ring_t usrbuf; /* user i/o buffer */
u_int usrbuf_blksize; /* usrbuf block size in bytes */
- struct uvm_object *uobj;
+ u_int usrbuf_allocsize; /* allocation size in bytes */
bool mmapped; /* device is mmap()-ed */
u_int usrbuf_usedhigh;/* high water mark in bytes */
u_int usrbuf_usedlow; /* low water mark in bytes */
