[PATCH] NAPI support for Sibyte MAC
From: Mark E Mason <hidden>
Date: 2007-03-23 18:08:26
Also in:
linux-mips
[ This is a re-post, but the patch still applies and works fine against
the linux-mips.org tip. We'd really like to get this in. -Mark ]
This patch completes the NAPI functionality for SB1250 MAC, including
making
NAPI a kernel option that can be turned on or off and adds the
"sbmac_poll"
routine.
Signed off by: Mark Mason (mason@broadcom.com)
Signed off by: Dan Krejsa (dan.krejsa@windriver.com)
Signed off by: Steve Yang (steve.yang@windriver.com)
Index: linux-2.6.14-cgl/drivers/net/Kconfig
===================================================================--- linux-2.6.14-cgl.orig/drivers/net/Kconfig 2006-09-2014:58:54.000000000 -0700
+++ linux-2.6.14-cgl/drivers/net/Kconfig 2006-09-2017:04:31.000000000 -0700
@@ -2031,6 +2031,23 @@ tristate "SB1250 Ethernet support" depends on SIBYTE_SB1xxx_SOC +config SBMAC_NAPI + bool "SBMAC: Use Rx Polling (NAPI) (EXPERIMENTAL)" + depends on NET_SB1250_MAC && EXPERIMENTAL + help + NAPI is a new driver API designed to reduce CPU and interrupt
load + when the driver is receiving lots of packets from the card. It is + still somewhat experimental and thus not yet enabled by default. + + If your estimated Rx load is 10kpps or more, or if the card will be + deployed on potentially unfriendly networks (e.g. in a firewall), + then say Y here. + + See <file:Documentation/networking/NAPI_HOWTO.txt> for more + information. + + If in doubt, say y. + config R8169_VLAN bool "VLAN support" depends on R8169 && VLAN_8021Q
@@ -2826,3 +2843,5 @@ def_bool NETPOLL endmenu + +
Index: linux-2.6.14-cgl/drivers/net/sb1250-mac.c ===================================================================
--- linux-2.6.14-cgl.orig/drivers/net/sb1250-mac.c 2006-09-2014:59:00.000000000 -0700
+++ linux-2.6.14-cgl/drivers/net/sb1250-mac.c 2006-09-2020:16:27.000000000 -0700
@@ -95,19 +95,28 @@ #endif #ifdef CONFIG_SBMAC_COALESCE -static int int_pktcnt = 0; -module_param(int_pktcnt, int, S_IRUGO); -MODULE_PARM_DESC(int_pktcnt, "Packet count"); - -static int int_timeout = 0; -module_param(int_timeout, int, S_IRUGO); -MODULE_PARM_DESC(int_timeout, "Timeout value"); +static int int_pktcnt_tx = 255; +module_param(int_pktcnt_tx, int, S_IRUGO); +MODULE_PARM_DESC(int_pktcnt_tx, "TX packet count"); + +static int int_timeout_tx = 255; +module_param(int_timeout_tx, int, S_IRUGO); +MODULE_PARM_DESC(int_timeout_tx, "TX timeout value"); + +static int int_pktcnt_rx = 64; +module_param(int_pktcnt_rx, int, S_IRUGO); +MODULE_PARM_DESC(int_pktcnt_rx, "RX packet count"); + +static int int_timeout_rx = 64; +module_param(int_timeout_rx, int, S_IRUGO); +MODULE_PARM_DESC(int_timeout_rx, "RX timeout value"); #endif #include <asm/sibyte/sb1250.h> #if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80) #include <asm/sibyte/bcm1480_regs.h> #include <asm/sibyte/bcm1480_int.h> +#define R_MAC_DMA_OODPKTLOST_RX R_MAC_DMA_OODPKTLOST #elif defined(CONFIG_SIBYTE_SB1250) || defined(CONFIG_SIBYTE_BCM112X) #include <asm/sibyte/sb1250_regs.h> #include <asm/sibyte/sb1250_int.h>
@@ -155,8 +164,8 @@ #define NUMCACHEBLKS(x) (((x)+SMP_CACHE_BYTES-1)/SMP_CACHE_BYTES) -#define SBMAC_MAX_TXDESCR 32 -#define SBMAC_MAX_RXDESCR 32 +#define SBMAC_MAX_TXDESCR 256 +#define SBMAC_MAX_RXDESCR 256 #define ETHER_ALIGN 2 #define ETHER_ADDR_LEN 6
@@ -185,10 +194,10 @@ * associated with it. */ - struct sbmac_softc *sbdma_eth; /* back pointer to
associated MAC */ - int sbdma_channel; /* channel number */ + struct sbmac_softc *sbdma_eth; /* back pointer to associated MAC */ + int sbdma_channel; /* channel number */ int sbdma_txdir; /* direction (1=transmit) */ - int sbdma_maxdescr; /* total # of descriptors in ring */ + int sbdma_maxdescr; /* total # of descriptors in ring */ #ifdef CONFIG_SBMAC_COALESCE int sbdma_int_pktcnt; /* # descriptors rx/tx before interrupt*/ int sbdma_int_timeout; /* # usec rx/tx interrupt */
@@ -197,13 +206,16 @@ volatile void __iomem *sbdma_config0; /* DMA config register 0
*/ volatile void __iomem *sbdma_config1; /* DMA config register 1 */ volatile void __iomem *sbdma_dscrbase; /* Descriptor base address */ - volatile void __iomem *sbdma_dscrcnt; /* Descriptor count register */ + volatile void __iomem *sbdma_dscrcnt; /* Descriptor count register */ volatile void __iomem *sbdma_curdscr; /* current descriptor address */ + volatile void __iomem *sbdma_oodpktlost;/* pkt drop (rx only) */ + /* * This stuff is for maintenance of the ring */ + sbdmadscr_t *sbdma_dscrtable_unaligned; sbdmadscr_t *sbdma_dscrtable; /* base of descriptor table */ sbdmadscr_t *sbdma_dscrtable_end; /* end of descriptor table */
@@ -286,8 +298,8 @@ static int sbdma_add_txbuffer(sbmacdma_t *d,struct sk_buff *m); static void sbdma_emptyring(sbmacdma_t *d); static void sbdma_fillring(sbmacdma_t *d); -static void sbdma_rx_process(struct sbmac_softc *sc,sbmacdma_t *d); -static void sbdma_tx_process(struct sbmac_softc *sc,sbmacdma_t *d); +static int sbdma_rx_process(struct sbmac_softc *sc,sbmacdma_t *d, int
work_to_do, int poll); +static void sbdma_tx_process(struct sbmac_softc *sc,sbmacdma_t *d, int poll); static int sbmac_initctx(struct sbmac_softc *s); static void sbmac_channel_start(struct sbmac_softc *s); static void sbmac_channel_stop(struct sbmac_softc *s);
@@ -308,6 +320,10 @@ static void sbmac_set_rx_mode(struct net_device *dev); static int sbmac_mii_ioctl(struct net_device *dev, struct ifreq *rq,
int cmd); static int sbmac_close(struct net_device *dev); +#ifdef CONFIG_SBMAC_NAPI +static int sbmac_poll(struct net_device *poll_dev, int *budget); +#endif + static int sbmac_mii_poll(struct sbmac_softc *s,int noisy); static int sbmac_mii_probe(struct net_device *dev);
@@ -679,6 +695,10 @@ int txrx, int maxdescr) { +#ifdef CONFIG_SBMAC_COALESCE + int int_pktcnt, int_timeout; +#endif + /* * Save away interesting stuff in the structure */
@@ -728,6 +748,11 @@ s->sbm_base +
R_MAC_DMA_REGISTER(txrx,chan,R_MAC_DMA_DSCR_CNT); d->sbdma_curdscr = s->sbm_base + R_MAC_DMA_REGISTER(txrx,chan,R_MAC_DMA_CUR_DSCRADDR); + if (d->sbdma_txdir) + d->sbdma_oodpktlost = NULL; + else + d->sbdma_oodpktlost = + s->sbm_base + R_MAC_DMA_REGISTER(txrx,chan,R_MAC_DMA_OODPKTLOST_RX); /* * Allocate memory for the ring
@@ -735,6 +760,7 @@ d->sbdma_maxdescr = maxdescr; + d->sbdma_dscrtable_unaligned = d->sbdma_dscrtable = (sbdmadscr_t *) kmalloc((d->sbdma_maxdescr+1)*sizeof(sbdmadscr_t),
GFP_KERNEL);
@@ -765,12 +791,14 @@ * Setup Rx/Tx DMA coalescing defaults */ + int_pktcnt = (txrx == DMA_TX) ? int_pktcnt_tx : int_pktcnt_rx; if ( int_pktcnt ) { d->sbdma_int_pktcnt = int_pktcnt; } else { d->sbdma_int_pktcnt = 1; } + int_timeout = (txrx == DMA_TX) ? int_timeout_tx :
int_timeout_rx;
if ( int_timeout ) {
d->sbdma_int_timeout = int_timeout;
} else {@@ -1130,30 +1158,41 @@ /********************************************************************** - * SBDMA_RX_PROCESS(sc,d) + * SBDMA_RX_PROCESS(sc,d,work_to_do,poll) * * Process "completed" receive buffers on the specified DMA channel. - * Note that this isn't really ideal for priority channels, since - * it processes all of the packets on a given channel before - * returning. * * Input parameters: - * sc - softc structure - * d - DMA channel context + * sc - softc structure + * d - DMA channel context + * work_to_do - no. of packets to process before enabling interrupt + * again (for NAPI) + * poll - 1: using polling (for NAPI) * * Return value: * nothing *********************************************************************
*/
-static void sbdma_rx_process(struct sbmac_softc *sc,sbmacdma_t *d)
+static int sbdma_rx_process(struct sbmac_softc *sc,sbmacdma_t *d,
+ int work_to_do, int poll)
{
int curidx;
int hwidx;
sbdmadscr_t *dsc;
struct sk_buff *sb;
int len;
+ int work_done = 0;
+ int dropped = 0;
- for (;;) {
+ prefetch(d);
+
+again:
+ /* Check if the HW dropped any frames */
+ sc->sbm_stats.rx_fifo_errors
+ += __raw_readq(sc->sbm_rxdma.sbdma_oodpktlost) & 0xffff;
+ __raw_writeq(0, sc->sbm_rxdma.sbdma_oodpktlost);
+
+ while (work_to_do-- > 0) {
/*
* figure out where we are (as an index) and where
* the hardware is (also as an index)@@ -1165,7 +1204,12 @@ * (sbdma_remptr) and the physical address
(sbdma_curdscr CSR) */ - curidx = d->sbdma_remptr - d->sbdma_dscrtable; + dsc = d->sbdma_remptr; + curidx = dsc - d->sbdma_dscrtable; + + prefetch(dsc); + prefetch(&d->sbdma_ctxtable[curidx]); + hwidx = (int) (((__raw_readq(d->sbdma_curdscr) & M_DMA_CURDSCR_ADDR) - d->sbdma_dscrtable_phys) / sizeof(sbdmadscr_t));
@@ -1176,13 +1220,12 @@ */ if (curidx == hwidx) - break; + goto done; /* * Otherwise, get the packet's sk_buff ptr back */ - dsc = &(d->sbdma_dscrtable[curidx]); sb = d->sbdma_ctxtable[curidx]; d->sbdma_ctxtable[curidx] = NULL;
@@ -1194,17 +1237,22 @@ * receive ring. */ - if (!(dsc->dscr_a & M_DMA_ETHRX_BAD)) { - + if (likely (!(dsc->dscr_a & M_DMA_ETHRX_BAD))) { + /* * Add a new buffer to replace the old one. If
we fail
* to allocate a buffer, we're going to drop
this
* packet and put it right back on the receive
ring.
*/
- if (sbdma_add_rcvbuffer(d,NULL) == -ENOBUFS) {
- sc->sbm_stats.rx_dropped++;
+ if (unlikely (sbdma_add_rcvbuffer(d,NULL) ==
+ -ENOBUFS)) {
+ sc->sbm_stats.rx_dropped++;
sbdma_add_rcvbuffer(d,sb); /* re-add old
buffer */
+ /* No point in continuing at the moment
*/
+ printk(KERN_ERR "dropped packet (1)\n");
+ d->sbdma_remptr =
SBDMA_NEXTBUF(d,sbdma_remptr);
+ goto done;
} else {
/*
* Set length into the packet@@ -1216,8 +1264,6 @@ * receive ring. Pass the buffer to * the kernel */ - sc->sbm_stats.rx_bytes += len; - sc->sbm_stats.rx_packets++; sb->protocol =
eth_type_trans(sb,d->sbdma_eth->sbm_dev);
/* Check hw IPv4/TCP checksum if
supported */
if (sc->rx_hw_checksum == ENABLE) {@@ -1229,8 +1275,24 @@ sb->ip_summed =
CHECKSUM_NONE;
}
}
-
- netif_rx(sb);
+ prefetch(sb->data);
+ prefetch((const void *)(((char
*)sb->data)+32));
+#ifdef CONFIG_SBMAC_NAPI
+ if (poll)
+ dropped = netif_receive_skb(sb);
+ else
+#endif
+ dropped = netif_rx(sb);
+
+ if (dropped == NET_RX_DROP) {
+ sc->sbm_stats.rx_dropped++;
+ d->sbdma_remptr =
SBDMA_NEXTBUF(d,sbdma_remptr);
+ goto done;
+ }
+ else {
+ sc->sbm_stats.rx_bytes += len;
+ sc->sbm_stats.rx_packets++;
+ }
}
} else {
/*@@ -1247,12 +1309,16 @@ */ d->sbdma_remptr = SBDMA_NEXTBUF(d,sbdma_remptr); - + work_done++; + } + if (!poll) { + work_to_do = 32; + goto again; /* collect fifo drop statistics again */ } +done: + return work_done; } - - /********************************************************************** * SBDMA_TX_PROCESS(sc,d) *
@@ -1264,22 +1330,30 @@ * * Input parameters: * sc - softc structure - * d - DMA channel context + * d - DMA channel context + * poll - 1: using polling (for NAPI) * * Return value: * nothing *********************************************************************
*/
-static void sbdma_tx_process(struct sbmac_softc *sc,sbmacdma_t *d)
+static void sbdma_tx_process(struct sbmac_softc *sc,sbmacdma_t *d, int
poll)
{
int curidx;
int hwidx;
sbdmadscr_t *dsc;
struct sk_buff *sb;
unsigned long flags;
+ int packets_handled = 0;
spin_lock_irqsave(&(sc->sbm_lock), flags);
+ if (d->sbdma_remptr == d->sbdma_addptr)
+ goto end_unlock;
+
+ hwidx = (int) (((__raw_readq(d->sbdma_curdscr) &
M_DMA_CURDSCR_ADDR) -
+ d->sbdma_dscrtable_phys) / sizeof(sbdmadscr_t));
+
for (;;) {
/*
* figure out where we are (as an index) and where@@ -1293,8 +1367,6 @@ */ curidx = d->sbdma_remptr - d->sbdma_dscrtable; - hwidx = (int) (((__raw_readq(d->sbdma_curdscr) &
M_DMA_CURDSCR_ADDR) - - d->sbdma_dscrtable_phys) / sizeof(sbdmadscr_t)); /* * If they're the same, that means we've processed all
@@ -1332,6 +1404,8 @@ d->sbdma_remptr = SBDMA_NEXTBUF(d,sbdma_remptr); + packets_handled++; + } /*
@@ -1340,8 +1414,10 @@ * watermark on the transmit queue. */ - netif_wake_queue(d->sbdma_eth->sbm_dev); + if (packets_handled) + netif_wake_queue(d->sbdma_eth->sbm_dev); +end_unlock: spin_unlock_irqrestore(&(sc->sbm_lock), flags); }
@@ -1415,9 +1491,9 @@ static void sbdma_uninitctx(struct sbmacdma_s *d) { - if (d->sbdma_dscrtable) { - kfree(d->sbdma_dscrtable); - d->sbdma_dscrtable = NULL; + if (d->sbdma_dscrtable_unaligned) { + kfree(d->sbdma_dscrtable_unaligned); + d->sbdma_dscrtable_unaligned = d->sbdma_dscrtable =
NULL;
}
if (d->sbdma_ctxtable) {@@ -1615,15 +1691,9 @@ #endif #ifdef CONFIG_SBMAC_COALESCE - /* - * Accept any TX interrupt and EOP count/timer RX interrupts on
ch 0 - */ __raw_writeq(((M_MAC_INT_EOP_COUNT | M_MAC_INT_EOP_TIMER) << S_MAC_TX_CH0) | ((M_MAC_INT_EOP_COUNT | M_MAC_INT_EOP_TIMER) << S_MAC_RX_CH0), s->sbm_imr); #else - /* - * Accept any kind of interrupt on TX and RX DMA channel 0 - */ __raw_writeq((M_MAC_INT_CHANNEL << S_MAC_TX_CH0) | (M_MAC_INT_CHANNEL << S_MAC_RX_CH0), s->sbm_imr); #endif
@@ -2056,8 +2126,7 @@ uint64_t isr; int handled = 0; - for (;;) { - +#ifdef CONFIG_SBMAC_NAPI /* * Read the ISR (this clears the bits in the real * register, except for counter addr)
@@ -2066,8 +2135,7 @@ isr = __raw_readq(sc->sbm_isr) & ~M_MAC_COUNTER_ADDR; if (isr == 0) - break; - + return IRQ_RETVAL(0); handled = 1; /*
@@ -2075,12 +2143,52 @@ */ if (isr & (M_MAC_INT_CHANNEL << S_MAC_TX_CH0)) { - sbdma_tx_process(sc,&(sc->sbm_txdma)); + sbdma_tx_process(sc,&(sc->sbm_txdma), 0); +#ifdef CONFIG_NETPOLL_TRAP + if (netpoll_trap()) { + if (test_and_clear_bit(__LINK_STATE_XOFF,
&dev->state))
+ __netif_schedule(dev);
+ }
+#endif
}
+ if (isr & (M_MAC_INT_CHANNEL << S_MAC_RX_CH0)) {
+ if (netif_rx_schedule_prep(dev)) {
+ __raw_writeq(0, sc->sbm_imr);
+ __netif_rx_schedule(dev);
+ /* Depend on the exit from poll to reenable intr
*/
+ }
+ else {
+ /* may leave some packets behind */
+ sbdma_rx_process(sc,&(sc->sbm_rxdma),
+ SBMAC_MAX_RXDESCR * 2, 0);
+ }
+ }
+#else
+ /* Non NAPI */
+ for (;;) {
+
/*
- * Receives on channel 0
+ * Read the ISR (this clears the bits in the real
+ * register, except for counter addr)
*/
+ isr = __raw_readq(sc->sbm_isr) & ~M_MAC_COUNTER_ADDR;
+
+ if (isr == 0)
+ break;
+
+ handled = 1;
+
+ if (isr & (M_MAC_INT_CHANNEL << S_MAC_TX_CH0)) {
+ sbdma_tx_process(sc,&(sc->sbm_txdma),
+ SBMAC_MAX_RXDESCR * 2);
+#ifdef CONFIG_NETPOLL_TRAP
+ if (netpoll_trap()) {
+ if (test_and_clear_bit(__LINK_STATE_XOFF,
&dev->state))
+ __netif_schedule(dev);
+ }
+#endif
+ }
/*
* It's important to test all the bits (or at least the@@ -2097,16 +2205,15 @@ * EOP_SEEN here takes care of this case. * (EOP_SEEN is part of M_MAC_INT_CHANNEL <<
S_MAC_RX_CH0)
*/
-
-
if (isr & (M_MAC_INT_CHANNEL << S_MAC_RX_CH0)) {
- sbdma_rx_process(sc,&(sc->sbm_rxdma));
+ sbdma_rx_process(sc,&(sc->sbm_rxdma),
+ SBMAC_MAX_RXDESCR * 2, 0);
}
}
+#endif
return IRQ_RETVAL(handled);
}
-
/**********************************************************************
* SBMAC_START_TX(skb,dev)
*@@ -2236,8 +2343,6 @@ } } - - #if defined(SBMAC_ETH0_HWADDR) || defined(SBMAC_ETH1_HWADDR) ||
defined(SBMAC_ETH2_HWADDR) || defined(SBMAC_ETH3_HWADDR) /********************************************************************** * SBMAC_PARSE_XDIGIT(str)
@@ -2400,9 +2505,12 @@ dev->do_ioctl = sbmac_mii_ioctl; dev->tx_timeout = sbmac_tx_timeout; dev->watchdog_timeo = TX_TIMEOUT; - dev->change_mtu = sb1250_change_mtu; - +#ifdef CONFIG_SBMAC_NAPI + dev->poll = sbmac_poll; + dev->weight = 16; +#endif + /* This is needed for PASS2 for Rx H/W checksum feature */ sbmac_set_iphdr_offset(sc);
@@ -2808,7 +2916,41 @@ return 0; } +#ifdef CONFIG_SBMAC_NAPI +static int sbmac_poll(struct net_device *dev, int *budget) +{ + int work_to_do; + int work_done; + struct sbmac_softc *sc = netdev_priv(dev); + + work_to_do = min(*budget, dev->quota); + work_done = sbdma_rx_process(sc, &(sc->sbm_rxdma), work_to_do,
1);
+
+ if (work_done > work_to_do)
+ printk(KERN_ERR "%s exceeded work_to_do budget=%d
quota=%d work-done=%d\n",
+ sc->sbm_dev->name, *budget, dev->quota,
work_done);
+
+ sbdma_tx_process(sc, &(sc->sbm_txdma), 1);
+ *budget -= work_done;
+ dev->quota -= work_done;
+
+ if (work_done < work_to_do) {
+ netif_rx_complete(dev);
+
+#ifdef CONFIG_SBMAC_COALESCE
+ __raw_writeq(((M_MAC_INT_EOP_COUNT |
M_MAC_INT_EOP_TIMER) << S_MAC_TX_CH0) |
+ ((M_MAC_INT_EOP_COUNT |
M_MAC_INT_EOP_TIMER) << S_MAC_RX_CH0),
+ sc->sbm_imr);
+#else
+ __raw_writeq((M_MAC_INT_CHANNEL << S_MAC_TX_CH0) |
+ (M_MAC_INT_CHANNEL << S_MAC_RX_CH0),
sc->sbm_imr);
+#endif
+ }
+
+ return (work_done >= work_to_do);
+}
+#endif
#if defined(SBMAC_ETH0_HWADDR) || defined(SBMAC_ETH1_HWADDR) ||
defined(SBMAC_ETH2_HWADDR) || defined(SBMAC_ETH3_HWADDR)
static void
Index: linux-2.6.14-cgl/arch/mips/sibyte/bcm1480/irq.c
===================================================================--- linux-2.6.14-cgl.orig/arch/mips/sibyte/bcm1480/irq.c2006-09-20 14:58:41.000000000 -0700
+++ linux-2.6.14-cgl/arch/mips/sibyte/bcm1480/irq.c 2006-09-2015:58:33.000000000 -0700
@@ -144,11 +144,11 @@ unsigned long flags; unsigned int irq_dirty; - i = first_cpu(mask); - if (next_cpu(i, mask) <= NR_CPUS) { + if (cpus_weight(mask) != 1) { printk("attempted to set irq affinity for irq %d to
multiple CPUs\n", irq); return; } + i = first_cpu(mask); /* Convert logical CPU to physical CPU */ cpu = cpu_logical_map(i);