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qec.c revision 1.12.2.8
      1  1.12.2.5  nathanw /*	$NetBSD: qec.c,v 1.12.2.8 2002/12/11 06:38:43 thorpej Exp $ */
      2       1.1       pk 
      3       1.1       pk /*-
      4       1.1       pk  * Copyright (c) 1998 The NetBSD Foundation, Inc.
      5       1.1       pk  * All rights reserved.
      6       1.1       pk  *
      7       1.1       pk  * This code is derived from software contributed to The NetBSD Foundation
      8       1.1       pk  * by Paul Kranenburg.
      9       1.1       pk  *
     10       1.1       pk  * Redistribution and use in source and binary forms, with or without
     11       1.1       pk  * modification, are permitted provided that the following conditions
     12       1.1       pk  * are met:
     13       1.1       pk  * 1. Redistributions of source code must retain the above copyright
     14       1.1       pk  *    notice, this list of conditions and the following disclaimer.
     15       1.1       pk  * 2. Redistributions in binary form must reproduce the above copyright
     16       1.1       pk  *    notice, this list of conditions and the following disclaimer in the
     17       1.1       pk  *    documentation and/or other materials provided with the distribution.
     18       1.1       pk  * 3. All advertising materials mentioning features or use of this software
     19       1.1       pk  *    must display the following acknowledgement:
     20       1.1       pk  *        This product includes software developed by the NetBSD
     21       1.1       pk  *        Foundation, Inc. and its contributors.
     22       1.1       pk  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23       1.1       pk  *    contributors may be used to endorse or promote products derived
     24       1.1       pk  *    from this software without specific prior written permission.
     25       1.1       pk  *
     26       1.1       pk  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27       1.1       pk  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28       1.1       pk  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29       1.1       pk  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30       1.1       pk  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31       1.1       pk  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32       1.1       pk  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33       1.1       pk  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34       1.1       pk  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35       1.1       pk  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36       1.1       pk  * POSSIBILITY OF SUCH DAMAGE.
     37       1.1       pk  */
     38  1.12.2.2  nathanw 
     39  1.12.2.2  nathanw #include <sys/cdefs.h>
     40  1.12.2.5  nathanw __KERNEL_RCSID(0, "$NetBSD: qec.c,v 1.12.2.8 2002/12/11 06:38:43 thorpej Exp $");
     41       1.1       pk 
     42       1.1       pk #include <sys/param.h>
     43       1.1       pk #include <sys/systm.h>
     44       1.1       pk #include <sys/kernel.h>
     45       1.1       pk #include <sys/errno.h>
     46       1.1       pk #include <sys/device.h>
     47       1.1       pk #include <sys/malloc.h>
     48       1.1       pk 
     49       1.2       pk #include <machine/bus.h>
     50      1.11       pk #include <machine/intr.h>
     51       1.2       pk #include <machine/autoconf.h>
     52       1.1       pk 
     53       1.1       pk #include <dev/sbus/sbusvar.h>
     54       1.1       pk #include <dev/sbus/qecreg.h>
     55       1.1       pk #include <dev/sbus/qecvar.h>
     56       1.1       pk 
     57       1.1       pk static int	qecprint	__P((void *, const char *));
     58       1.1       pk static int	qecmatch	__P((struct device *, struct cfdata *, void *));
     59       1.1       pk static void	qecattach	__P((struct device *, struct device *, void *));
     60       1.7       pk void		qec_init	__P((struct qec_softc *));
     61       1.1       pk 
     62       1.1       pk static int qec_bus_map __P((
     63       1.1       pk 		bus_space_tag_t,
     64  1.12.2.5  nathanw 		bus_addr_t,		/*coded slot+offset*/
     65       1.1       pk 		bus_size_t,		/*size*/
     66       1.1       pk 		int,			/*flags*/
     67       1.4       pk 		vaddr_t,		/*preferred virtual address */
     68       1.1       pk 		bus_space_handle_t *));
     69       1.8       pk static void *qec_intr_establish __P((
     70       1.8       pk 		bus_space_tag_t,
     71      1.11       pk 		int,			/*bus interrupt priority*/
     72      1.11       pk 		int,			/*`device class' interrupt level*/
     73       1.8       pk 		int (*) __P((void *)),	/*handler*/
     74  1.12.2.8  thorpej 		void *,			/*arg*/
     75  1.12.2.8  thorpej 		void (*) __P((void))));	/*optional fast trap handler*/
     76       1.1       pk 
     77  1.12.2.7  nathanw CFATTACH_DECL(qec, sizeof(struct qec_softc),
     78  1.12.2.7  nathanw     qecmatch, qecattach, NULL, NULL);
     79       1.1       pk 
     80       1.1       pk int
     81       1.1       pk qecprint(aux, busname)
     82       1.1       pk 	void *aux;
     83       1.1       pk 	const char *busname;
     84       1.1       pk {
     85       1.1       pk 	struct sbus_attach_args *sa = aux;
     86       1.1       pk 	bus_space_tag_t t = sa->sa_bustag;
     87       1.1       pk 	struct qec_softc *sc = t->cookie;
     88       1.1       pk 
     89       1.1       pk 	sa->sa_bustag = sc->sc_bustag;	/* XXX */
     90       1.1       pk 	sbus_print(aux, busname);	/* XXX */
     91       1.1       pk 	sa->sa_bustag = t;		/* XXX */
     92       1.1       pk 	return (UNCONF);
     93       1.1       pk }
     94       1.1       pk 
     95       1.1       pk int
     96       1.1       pk qecmatch(parent, cf, aux)
     97       1.1       pk 	struct device *parent;
     98       1.1       pk 	struct cfdata *cf;
     99       1.1       pk 	void *aux;
    100       1.1       pk {
    101       1.1       pk 	struct sbus_attach_args *sa = aux;
    102       1.1       pk 
    103  1.12.2.7  nathanw 	return (strcmp(cf->cf_name, sa->sa_name) == 0);
    104       1.1       pk }
    105       1.1       pk 
    106       1.1       pk /*
    107       1.1       pk  * Attach all the sub-devices we can find
    108       1.1       pk  */
    109       1.1       pk void
    110       1.1       pk qecattach(parent, self, aux)
    111       1.1       pk 	struct device *parent, *self;
    112       1.1       pk 	void *aux;
    113       1.1       pk {
    114       1.1       pk 	struct sbus_attach_args *sa = aux;
    115       1.1       pk 	struct qec_softc *sc = (void *)self;
    116       1.1       pk 	int node;
    117       1.1       pk 	int sbusburst;
    118       1.1       pk 	bus_space_tag_t sbt;
    119       1.1       pk 	bus_space_handle_t bh;
    120       1.1       pk 	int error;
    121       1.1       pk 
    122       1.1       pk 	sc->sc_bustag = sa->sa_bustag;
    123       1.1       pk 	sc->sc_dmatag = sa->sa_dmatag;
    124       1.1       pk 	node = sa->sa_node;
    125       1.1       pk 
    126       1.6       pk 	if (sa->sa_nreg < 2) {
    127       1.6       pk 		printf("%s: only %d register sets\n",
    128       1.6       pk 			self->dv_xname, sa->sa_nreg);
    129       1.1       pk 		return;
    130       1.1       pk 	}
    131       1.1       pk 
    132       1.1       pk 	if (sbus_bus_map(sa->sa_bustag,
    133  1.12.2.6  nathanw 			 sa->sa_reg[0].oa_space,
    134  1.12.2.6  nathanw 			 sa->sa_reg[0].oa_base,
    135  1.12.2.6  nathanw 			 sa->sa_reg[0].oa_size,
    136  1.12.2.5  nathanw 			 0, &sc->sc_regs) != 0) {
    137       1.1       pk 		printf("%s: attach: cannot map registers\n", self->dv_xname);
    138       1.1       pk 		return;
    139       1.1       pk 	}
    140       1.1       pk 
    141       1.1       pk 	/*
    142       1.1       pk 	 * This device's "register space 1" is just a buffer where the
    143       1.1       pk 	 * Lance ring-buffers can be stored. Note the buffer's location
    144       1.1       pk 	 * and size, so the child driver can pick them up.
    145       1.1       pk 	 */
    146       1.1       pk 	if (sbus_bus_map(sa->sa_bustag,
    147  1.12.2.6  nathanw 			 sa->sa_reg[1].oa_space,
    148  1.12.2.6  nathanw 			 sa->sa_reg[1].oa_base,
    149  1.12.2.6  nathanw 			 sa->sa_reg[1].oa_size,
    150  1.12.2.5  nathanw 			 BUS_SPACE_MAP_LINEAR, &bh) != 0) {
    151       1.1       pk 		printf("%s: attach: cannot map registers\n", self->dv_xname);
    152       1.1       pk 		return;
    153       1.1       pk 	}
    154  1.12.2.5  nathanw 	sc->sc_buffer = (caddr_t)bus_space_vaddr(sa->sa_bustag, bh);
    155  1.12.2.6  nathanw 	sc->sc_bufsiz = (bus_size_t)sa->sa_reg[1].oa_size;
    156       1.1       pk 
    157       1.7       pk 	/* Get number of on-board channels */
    158  1.12.2.1  nathanw 	sc->sc_nchannels = PROM_getpropint(node, "#channels", -1);
    159       1.7       pk 	if (sc->sc_nchannels == -1) {
    160       1.7       pk 		printf(": no channels\n");
    161       1.7       pk 		return;
    162       1.7       pk 	}
    163       1.7       pk 
    164       1.1       pk 	/*
    165       1.1       pk 	 * Get transfer burst size from PROM
    166       1.1       pk 	 */
    167       1.1       pk 	sbusburst = ((struct sbus_softc *)parent)->sc_burst;
    168       1.1       pk 	if (sbusburst == 0)
    169       1.1       pk 		sbusburst = SBUS_BURST_32 - 1; /* 1->16 */
    170       1.1       pk 
    171  1.12.2.1  nathanw 	sc->sc_burst = PROM_getpropint(node, "burst-sizes", -1);
    172       1.1       pk 	if (sc->sc_burst == -1)
    173       1.1       pk 		/* take SBus burst sizes */
    174       1.1       pk 		sc->sc_burst = sbusburst;
    175       1.1       pk 
    176       1.1       pk 	/* Clamp at parent's burst sizes */
    177       1.1       pk 	sc->sc_burst &= sbusburst;
    178       1.1       pk 
    179       1.1       pk 	sbus_establish(&sc->sc_sd, &sc->sc_dev);
    180       1.1       pk 
    181       1.1       pk 	/*
    182       1.1       pk 	 * Collect address translations from the OBP.
    183       1.1       pk 	 */
    184  1.12.2.6  nathanw 	error = PROM_getprop(node, "ranges", sizeof(struct openprom_range),
    185       1.1       pk 			 &sc->sc_nrange, (void **)&sc->sc_range);
    186       1.1       pk 	switch (error) {
    187       1.1       pk 	case 0:
    188       1.1       pk 		break;
    189       1.1       pk 	case ENOENT:
    190       1.1       pk 	default:
    191       1.1       pk 		panic("%s: error getting ranges property", self->dv_xname);
    192       1.1       pk 	}
    193       1.1       pk 
    194       1.1       pk 	/* Allocate a bus tag */
    195  1.12.2.4  nathanw 	sbt = (bus_space_tag_t) malloc(sizeof(struct sparc_bus_space_tag),
    196  1.12.2.4  nathanw 	    M_DEVBUF, M_NOWAIT|M_ZERO);
    197       1.1       pk 	if (sbt == NULL) {
    198       1.1       pk 		printf("%s: attach: out of memory\n", self->dv_xname);
    199       1.1       pk 		return;
    200       1.1       pk 	}
    201       1.1       pk 
    202       1.1       pk 	sbt->cookie = sc;
    203       1.1       pk 	sbt->parent = sc->sc_bustag;
    204       1.1       pk 	sbt->sparc_bus_map = qec_bus_map;
    205       1.8       pk 	sbt->sparc_intr_establish = qec_intr_establish;
    206       1.8       pk 
    207       1.8       pk 	/*
    208       1.8       pk 	 * Save interrupt information for use in our qec_intr_establish()
    209       1.8       pk 	 * function below. Apparently, the intr level for the quad
    210  1.12.2.3  nathanw 	 * ethernet board (qe) is stored in the QEC node rather than
    211       1.8       pk 	 * separately in each of the QE nodes.
    212       1.8       pk 	 *
    213       1.8       pk 	 * XXX - qe.c should call bus_intr_establish() with `level = 0'..
    214       1.8       pk 	 * XXX - maybe we should have our own attach args for all that.
    215       1.8       pk 	 */
    216       1.8       pk 	sc->sc_intr = sa->sa_intr;
    217       1.1       pk 
    218       1.1       pk 	printf(": %dK memory\n", sc->sc_bufsiz / 1024);
    219       1.1       pk 
    220       1.7       pk 	qec_init(sc);
    221       1.7       pk 
    222       1.1       pk 	/* search through children */
    223       1.1       pk 	for (node = firstchild(node); node; node = nextsibling(node)) {
    224       1.1       pk 		struct sbus_attach_args sa;
    225       1.1       pk 		sbus_setup_attach_args((struct sbus_softc *)parent,
    226      1.10       pk 				       sbt, sc->sc_dmatag, node, &sa);
    227       1.1       pk 		(void)config_found(&sc->sc_dev, (void *)&sa, qecprint);
    228       1.3       pk 		sbus_destroy_attach_args(&sa);
    229       1.1       pk 	}
    230       1.1       pk }
    231       1.1       pk 
    232       1.1       pk int
    233  1.12.2.5  nathanw qec_bus_map(t, baddr, size, flags, va, hp)
    234       1.1       pk 	bus_space_tag_t t;
    235  1.12.2.5  nathanw 	bus_addr_t baddr;
    236       1.1       pk 	bus_size_t size;
    237       1.1       pk 	int	flags;
    238  1.12.2.5  nathanw 	vaddr_t va;	/* Ignored */
    239       1.1       pk 	bus_space_handle_t *hp;
    240       1.1       pk {
    241       1.1       pk 	struct qec_softc *sc = t->cookie;
    242  1.12.2.5  nathanw 	int slot = BUS_ADDR_IOSPACE(baddr);
    243       1.1       pk 	int i;
    244       1.1       pk 
    245       1.1       pk 	for (i = 0; i < sc->sc_nrange; i++) {
    246  1.12.2.6  nathanw 		struct openprom_range *rp = &sc->sc_range[i];
    247       1.1       pk 
    248  1.12.2.6  nathanw 		if (sc->sc_range[i].or_child_space != slot)
    249       1.1       pk 			continue;
    250       1.1       pk 
    251       1.1       pk 		/* We've found the connection to the parent bus */
    252  1.12.2.5  nathanw 		return (bus_space_map(sc->sc_bustag,
    253  1.12.2.6  nathanw 		    BUS_ADDR(rp->or_parent_space,
    254  1.12.2.6  nathanw 			     rp->or_parent_base + BUS_ADDR_PADDR(baddr)),
    255  1.12.2.6  nathanw 		    size, flags, hp));
    256       1.1       pk 	}
    257       1.1       pk 
    258       1.1       pk 	return (EINVAL);
    259       1.7       pk }
    260       1.7       pk 
    261       1.8       pk void *
    262  1.12.2.8  thorpej qec_intr_establish(t, pri, level, handler, arg, fastvec)
    263       1.8       pk 	bus_space_tag_t t;
    264      1.11       pk 	int pri;
    265      1.11       pk 	int level;
    266      1.11       pk 	int (*handler) __P((void *));
    267      1.11       pk 	void *arg;
    268  1.12.2.8  thorpej 	void (*fastvec) __P((void));	/* ignored */
    269       1.8       pk {
    270       1.8       pk 	struct qec_softc *sc = t->cookie;
    271       1.8       pk 
    272      1.11       pk 	if (pri == 0) {
    273       1.8       pk 		/*
    274      1.11       pk 		 * qe.c calls bus_intr_establish() with `pri == 0'
    275       1.8       pk 		 * XXX - see also comment in qec_attach().
    276       1.8       pk 		 */
    277       1.8       pk 		if (sc->sc_intr == NULL) {
    278       1.8       pk 			printf("%s: warning: no interrupts\n",
    279       1.8       pk 				sc->sc_dev.dv_xname);
    280       1.8       pk 			return (NULL);
    281       1.8       pk 		}
    282  1.12.2.6  nathanw 		pri = sc->sc_intr->oi_pri;
    283       1.8       pk 	}
    284       1.8       pk 
    285  1.12.2.8  thorpej 	return (bus_intr_establish(t->parent, pri, level, handler, arg));
    286       1.8       pk }
    287       1.8       pk 
    288       1.7       pk void
    289       1.7       pk qec_init(sc)
    290       1.7       pk 	struct qec_softc *sc;
    291       1.7       pk {
    292       1.7       pk 	bus_space_tag_t t = sc->sc_bustag;
    293       1.7       pk 	bus_space_handle_t qr = sc->sc_regs;
    294       1.9       pk 	u_int32_t v, burst = 0, psize;
    295       1.9       pk 	int i;
    296       1.9       pk 
    297       1.9       pk 	/* First, reset the controller */
    298       1.9       pk 	bus_space_write_4(t, qr, QEC_QRI_CTRL, QEC_CTRL_RESET);
    299       1.9       pk 	for (i = 0; i < 1000; i++) {
    300       1.9       pk 		DELAY(100);
    301       1.9       pk 		v = bus_space_read_4(t, qr, QEC_QRI_CTRL);
    302       1.9       pk 		if ((v & QEC_CTRL_RESET) == 0)
    303       1.9       pk 			break;
    304       1.9       pk 	}
    305       1.7       pk 
    306       1.7       pk 	/*
    307       1.7       pk 	 * Cut available buffer size into receive and transmit buffers.
    308       1.7       pk 	 * XXX - should probably be done in be & qe driver...
    309       1.7       pk 	 */
    310       1.7       pk 	v = sc->sc_msize = sc->sc_bufsiz / sc->sc_nchannels;
    311       1.7       pk 	bus_space_write_4(t, qr, QEC_QRI_MSIZE, v);
    312       1.7       pk 
    313       1.7       pk 	v = sc->sc_rsize = sc->sc_bufsiz / (sc->sc_nchannels * 2);
    314       1.7       pk 	bus_space_write_4(t, qr, QEC_QRI_RSIZE, v);
    315       1.7       pk 	bus_space_write_4(t, qr, QEC_QRI_TSIZE, v);
    316       1.7       pk 
    317       1.9       pk 	psize = sc->sc_nchannels == 1 ? QEC_PSIZE_2048 : 0;
    318       1.9       pk 	bus_space_write_4(t, qr, QEC_QRI_PSIZE, psize);
    319       1.7       pk 
    320       1.7       pk 	if (sc->sc_burst & SBUS_BURST_64)
    321       1.7       pk 		burst = QEC_CTRL_B64;
    322       1.7       pk 	else if (sc->sc_burst & SBUS_BURST_32)
    323       1.7       pk 		burst = QEC_CTRL_B32;
    324       1.7       pk 	else
    325       1.7       pk 		burst = QEC_CTRL_B16;
    326       1.7       pk 
    327       1.7       pk 	v = bus_space_read_4(t, qr, QEC_QRI_CTRL);
    328       1.7       pk 	v = (v & QEC_CTRL_MODEMASK) | burst;
    329       1.7       pk 	bus_space_write_4(t, qr, QEC_QRI_CTRL, v);
    330       1.8       pk }
    331       1.8       pk 
    332       1.8       pk /*
    333       1.8       pk  * Common routine to initialize the QEC packet ring buffer.
    334       1.8       pk  * Called from be & qe drivers.
    335       1.8       pk  */
    336       1.8       pk void
    337       1.8       pk qec_meminit(qr, pktbufsz)
    338       1.8       pk 	struct qec_ring *qr;
    339       1.8       pk 	unsigned int pktbufsz;
    340       1.8       pk {
    341       1.8       pk 	bus_addr_t txbufdma, rxbufdma;
    342       1.8       pk 	bus_addr_t dma;
    343       1.8       pk 	caddr_t p;
    344       1.8       pk 	unsigned int ntbuf, nrbuf, i;
    345       1.8       pk 
    346       1.8       pk 	p = qr->rb_membase;
    347       1.8       pk 	dma = qr->rb_dmabase;
    348       1.8       pk 
    349       1.8       pk 	ntbuf = qr->rb_ntbuf;
    350       1.8       pk 	nrbuf = qr->rb_nrbuf;
    351       1.8       pk 
    352       1.8       pk 	/*
    353       1.8       pk 	 * Allocate transmit descriptors
    354       1.8       pk 	 */
    355       1.8       pk 	qr->rb_txd = (struct qec_xd *)p;
    356       1.8       pk 	qr->rb_txddma = dma;
    357       1.8       pk 	p += QEC_XD_RING_MAXSIZE * sizeof(struct qec_xd);
    358       1.8       pk 	dma += QEC_XD_RING_MAXSIZE * sizeof(struct qec_xd);
    359       1.8       pk 
    360       1.8       pk 	/*
    361       1.8       pk 	 * Allocate receive descriptors
    362       1.8       pk 	 */
    363       1.8       pk 	qr->rb_rxd = (struct qec_xd *)p;
    364       1.8       pk 	qr->rb_rxddma = dma;
    365       1.8       pk 	p += QEC_XD_RING_MAXSIZE * sizeof(struct qec_xd);
    366       1.8       pk 	dma += QEC_XD_RING_MAXSIZE * sizeof(struct qec_xd);
    367       1.8       pk 
    368       1.8       pk 
    369       1.8       pk 	/*
    370       1.8       pk 	 * Allocate transmit buffers
    371       1.8       pk 	 */
    372       1.8       pk 	qr->rb_txbuf = p;
    373       1.8       pk 	txbufdma = dma;
    374       1.8       pk 	p += ntbuf * pktbufsz;
    375       1.8       pk 	dma += ntbuf * pktbufsz;
    376       1.8       pk 
    377       1.8       pk 	/*
    378       1.8       pk 	 * Allocate receive buffers
    379       1.8       pk 	 */
    380       1.8       pk 	qr->rb_rxbuf = p;
    381       1.8       pk 	rxbufdma = dma;
    382       1.8       pk 	p += nrbuf * pktbufsz;
    383       1.8       pk 	dma += nrbuf * pktbufsz;
    384       1.8       pk 
    385       1.8       pk 	/*
    386       1.8       pk 	 * Initialize transmit buffer descriptors
    387       1.8       pk 	 */
    388       1.8       pk 	for (i = 0; i < QEC_XD_RING_MAXSIZE; i++) {
    389       1.8       pk 		qr->rb_txd[i].xd_addr = (u_int32_t)
    390       1.8       pk 			(txbufdma + (i % ntbuf) * pktbufsz);
    391       1.8       pk 		qr->rb_txd[i].xd_flags = 0;
    392       1.8       pk 	}
    393       1.8       pk 
    394       1.8       pk 	/*
    395       1.8       pk 	 * Initialize receive buffer descriptors
    396       1.8       pk 	 */
    397       1.8       pk 	for (i = 0; i < QEC_XD_RING_MAXSIZE; i++) {
    398       1.8       pk 		qr->rb_rxd[i].xd_addr = (u_int32_t)
    399       1.8       pk 			(rxbufdma + (i % nrbuf) * pktbufsz);
    400       1.8       pk 		qr->rb_rxd[i].xd_flags = (i < nrbuf)
    401       1.8       pk 			? QEC_XD_OWN | (pktbufsz & QEC_XD_LENGTH)
    402       1.8       pk 			: 0;
    403       1.8       pk 	}
    404       1.8       pk 
    405       1.8       pk 	qr->rb_tdhead = qr->rb_tdtail = 0;
    406       1.8       pk 	qr->rb_td_nbusy = 0;
    407       1.8       pk 	qr->rb_rdtail = 0;
    408       1.1       pk }
    409