diff options
Diffstat (limited to 'rtemsbsd/rtems/rtems-kernel-pager.c')
| -rw-r--r-- | rtemsbsd/rtems/rtems-kernel-pager.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/rtemsbsd/rtems/rtems-kernel-pager.c b/rtemsbsd/rtems/rtems-kernel-pager.c new file mode 100644 index 00000000..5a48c2e8 --- /dev/null +++ b/rtemsbsd/rtems/rtems-kernel-pager.c @@ -0,0 +1,171 @@ +/** + * @file + * + * @ingroup rtems_bsd_rtems + * + * @brief TODO. + */ + +/* + * Copyright (c) 2020 Chris Johns <chris@contemporary.software> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <machine/rtems-bsd-kernel-space.h> + +#include <sys/param.h> +#include <sys/buf.h> +#include <sys/kernel.h> +#include <sys/vmem.h> + +#include <vm/vm.h> +#include <vm/uma.h> +#include <vm/vm_extern.h> + +#define B_MAXPHYS 0x00200000 /* nitems(b_pages[]) = atop(MAXPHYS). */ +#define PBUF_PAGES (atop(maxphys) + 1) +#define MAXPHYS (128 * 1024) +#define NSWBUF_MIN 16 + +static u_long maxphys; /* max raw I/O transfer size */ +static int nswbuf_max; + +vmem_t *kernel_arena; +uma_zone_t pbuf_zone; +uma_zone_t ncl_pbuf_zone; + +vm_offset_t +kva_alloc(vm_size_t size) +{ + vm_offset_t addr; + + size = round_page(size); + if (vmem_alloc(kernel_arena, size, M_BESTFIT | M_NOWAIT, &addr)) + return (0); + + return (addr); +} + +static int +pbuf_ctor(void *mem, int size, void *arg, int flags) +{ + struct buf *bp = mem; + + bp->b_vp = NULL; + bp->b_bufobj = NULL; + + /* copied from initpbuf() */ + bp->b_rcred = NOCRED; + bp->b_wcred = NOCRED; + bp->b_qindex = 0; /* On no queue (QUEUE_NONE) */ + bp->b_data = bp->b_kvabase; + bp->b_xflags = 0; + bp->b_flags = B_MAXPHYS; + bp->b_ioflags = 0; + bp->b_iodone = NULL; + bp->b_error = 0; + BUF_LOCK(bp, LK_EXCLUSIVE, NULL); + + return (0); +} + +static void +pbuf_dtor(void *mem, int size, void *arg) +{ + struct buf *bp = mem; + + if (bp->b_rcred != NOCRED) { + crfree(bp->b_rcred); + bp->b_rcred = NOCRED; + } + if (bp->b_wcred != NOCRED) { + crfree(bp->b_wcred); + bp->b_wcred = NOCRED; + } + + BUF_UNLOCK(bp); +} + +static int +pbuf_init(void *mem, int size, int flags) +{ + struct buf *bp = mem; + + bp->b_kvabase = (void *)kva_alloc(ptoa(PBUF_PAGES)); + if (bp->b_kvabase == NULL) + return (ENOMEM); + bp->b_kvasize = ptoa(PBUF_PAGES); + BUF_LOCKINIT(bp); + LIST_INIT(&bp->b_dep); + bp->b_rcred = bp->b_wcred = NOCRED; + bp->b_xflags = 0; + + return (0); +} + +void +vm_pager_bufferinit(void) +{ + /* Main zone for paging bufs. */ + pbuf_zone = uma_zcreate("pbuf", + sizeof(struct buf) + PBUF_PAGES * sizeof(vm_page_t), pbuf_ctor, + pbuf_dtor, pbuf_init, NULL, UMA_ALIGN_CACHE, UMA_ZONE_NOFREE); + /* Few systems may still use this zone directly, so it needs a limit. */ + nswbuf_max += uma_zone_set_max(pbuf_zone, NSWBUF_MIN); +} + +uma_zone_t +pbuf_zsecond_create(char *name, int max) +{ + uma_zone_t zone; + + zone = uma_zsecond_create( + name, pbuf_ctor, pbuf_dtor, NULL, NULL, pbuf_zone); + /* + * uma_prealloc() rounds up to items per slab. If we would prealloc + * immediately on every pbuf_zsecond_create(), we may accumulate too + * much of difference between hard limit and prealloced items, which + * means wasted memory. + */ + if (nswbuf_max > 0) + nswbuf_max += uma_zone_set_max(zone, max); + else + uma_prealloc(pbuf_zone, uma_zone_set_max(zone, max)); + + return (zone); +} + +struct buf * +getpbuf(int *pfreecnt) +{ + (void)pfreecnt; + return uma_zalloc(ncl_pbuf_zone, M_WAITOK); +} + +void +relpbuf(struct buf *bp, int *pfreecnt) +{ + (void)pfreecnt; + uma_zfree(ncl_pbuf_zone, bp); +} |