// SPDX-License-Identifier: GPL-2.0-or-later /* * * (c) Copyright 1998 Alan Cox <alan@lxorguk.ukuu.org.uk> * (c) Copyright 2000, 2001 Red Hat Inc * * Development of this driver was funded by Equiinet Ltd * http://www.equiinet.com * * ChangeLog: * * Asynchronous mode dropped for 2.2. For 2.5 we will attempt the * unification of all the Z85x30 asynchronous drivers for real. * * DMA now uses get_free_page as kmalloc buffers may span a 64K * boundary. * * Modified for SMP safety and SMP locking by Alan Cox * <alan@lxorguk.ukuu.org.uk> * * Performance * * Z85230: * Non DMA you want a 486DX50 or better to do 64Kbits. 9600 baud * X.25 is not unrealistic on all machines. DMA mode can in theory * handle T1/E1 quite nicely. In practice the limit seems to be about * 512Kbit->1Mbit depending on motherboard. * * Z85C30: * 64K will take DMA, 9600 baud X.25 should be ok. * * Z8530: * Synchronous mode without DMA is unlikely to pass about 2400 baud. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/module.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/net.h> #include <linux/skbuff.h> #include <linux/netdevice.h> #include <linux/if_arp.h> #include <linux/delay.h> #include <linux/hdlc.h> #include <linux/ioport.h> #include <linux/init.h> #include <linux/gfp.h> #include <asm/dma.h> #include <asm/io.h> #define RT_LOCK #define RT_UNLOCK #include <linux/spinlock.h> #include "z85230.h" /** * z8530_read_port - Architecture specific interface function * @p: port to read * * Provided port access methods. The Comtrol SV11 requires no delays * between accesses and uses PC I/O. Some drivers may need a 5uS delay * * In the longer term this should become an architecture specific * section so that this can become a generic driver interface for all * platforms. For now we only handle PC I/O ports with or without the * dread 5uS sanity delay. * * The caller must hold sufficient locks to avoid violating the horrible * 5uS delay rule. */ static inline int z8530_read_port(unsigned long p) { u8 r=inb(Z8530_PORT_OF(p)); if(p&Z8530_PORT_SLEEP) /* gcc should figure this out efficiently ! */ udelay(5); return r; } /** * z8530_write_port - Architecture specific interface function * @p: port to write * @d: value to write * * Write a value to a port with delays if need be. Note that the * caller must hold locks to avoid read/writes from other contexts * violating the 5uS rule * * In the longer term this should become an architecture specific * section so that this can become a generic driver interface for all * platforms. For now we only handle PC I/O ports with or without the * dread 5uS sanity delay. */ static inline void z8530_write_port(unsigned long p, u8 d) { outb(d,Z8530_PORT_OF(p)); if(p&Z8530_PORT_SLEEP) udelay(5); } static void z8530_rx_done(struct z8530_channel *c); static void z8530_tx_done(struct z8530_channel *c); /** * read_zsreg - Read a register from a Z85230 * @c: Z8530 channel to read from (2 per chip) * @reg: Register to read * FIXME: Use a spinlock. * * Most of the Z8530 registers are indexed off the control registers. * A read is done by writing to the control register and reading the * register back. The caller must hold the lock */ static inline u8 read_zsreg(struct z8530_channel *c, u8 reg) { if(reg) z8530_write_port(c->ctrlio, reg); return z8530_read_port(c->ctrlio); } /** * read_zsdata - Read the data port of a Z8530 channel * @c: The Z8530 channel to read the data port from * * The data port provides fast access to some things. We still * have all the 5uS delays to worry about. */ static inline u8 read_zsdata(struct z8530_channel *c) { u8 r; r=z8530_read_port(c->dataio); return r; } /** * write_zsreg - Write to a Z8530 channel register * @c: The Z8530 channel * @reg: Register number * @val: Value to write * * Write a value to an indexed register. The caller must hold the lock * to honour the irritating delay rules. We know about register 0 * being fast to access. * * Assumes c->lock is held. */ static inline void write_zsreg(struct z8530_channel *c, u8 reg, u8 val) { if(reg) z8530_write_port(c->ctrlio, reg); z8530_write_port(c->ctrlio, val); } /** * write_zsctrl - Write to a Z8530 control register * @c: The Z8530 channel * @val: Value to write * * Write directly to the control register on the Z8530 */ static inline void write_zsctrl(struct z8530_channel *c, u8 val) { z8530_write_port(c->ctrlio, val); } /** * write_zsdata - Write to a Z8530 control register * @c: The Z8530 channel * @val: Value to write * * Write directly to the data register on the Z8530 */ static inline void write_zsdata(struct z8530_channel *c, u8 val) { z8530_write_port(c->dataio, val); } /* * Register loading parameters for a dead port */ u8 z8530_dead_port[]= { 255 }; EXPORT_SYMBOL(z8530_dead_port); /* * Register loading parameters for currently supported circuit types */ /* * Data clocked by telco end. This is the correct data for the UK * "kilostream" service, and most other similar services. */ u8 z8530_hdlc_kilostream[]= { 4, SYNC_ENAB|SDLC|X1CLK, 2, 0, /* No vector */ 1, 0, 3, ENT_HM|RxCRC_ENAB|Rx8, 5, TxCRC_ENAB|RTS|TxENAB|Tx8|DTR, 9, 0, /* Disable interrupts */ 6, 0xFF, 7, FLAG, 10, ABUNDER|NRZ|CRCPS,/*MARKIDLE ??*/ 11, TCTRxCP, 14, DISDPLL, 15, DCDIE|SYNCIE|CTSIE|TxUIE|BRKIE, 1, EXT_INT_ENAB|TxINT_ENAB|INT_ALL_Rx, 9, NV|MIE|NORESET, 255 }; EXPORT_SYMBOL(z8530_hdlc_kilostream); /* * As above but for enhanced chips. */ u8 z8530_hdlc_kilostream_85230[]= { 4, SYNC_ENAB|SDLC|X1CLK, 2, 0, /* No vector */ 1, 0, 3, ENT_HM|RxCRC_ENAB|Rx8, 5, TxCRC_ENAB|RTS|TxENAB|Tx8|DTR, 9, 0, /* Disable interrupts */ 6, 0xFF, 7, FLAG, 10, ABUNDER|NRZ|CRCPS, /* MARKIDLE?? */ 11, TCTRxCP, 14, DISDPLL, 15, DCDIE|SYNCIE|CTSIE|TxUIE|BRKIE, 1, EXT_INT_ENAB|TxINT_ENAB|INT_ALL_Rx, 9, NV|MIE|NORESET, 23, 3, /* Extended mode AUTO TX and EOM*/ 255 }; EXPORT_SYMBOL(z8530_hdlc_kilostream_85230); /** * z8530_flush_fifo - Flush on chip RX FIFO * @c: Channel to flush * * Flush the receive FIFO. There is no specific option for this, we * blindly read bytes and discard them. Reading when there is no data * is harmless. The 8530 has a 4 byte FIFO, the 85230 has 8 bytes. * * All locking is handled for the caller. On return data may still be * present if it arrived during the flush. */ static void z8530_flush_fifo(struct z8530_channel *c) { read_zsreg(c, R1); read_zsreg(c, R1); read_zsreg(c, R1); read_zsreg(c, R1); if(c->dev->type==Z85230) { read_zsreg(c, R1); read_zsreg(c, R1); read_zsreg(c, R1); read_zsreg(c, R1); } } /** * z8530_rtsdtr - Control the outgoing DTS/RTS line * @c: The Z8530 channel to control; * @set: 1 to set, 0 to clear * * Sets or clears DTR/RTS on the requested line. All locking is handled * by the caller. For now we assume all boards use the actual RTS/DTR * on the chip. Apparently one or two don't. We'll scream about them * later. */ static void z8530_rtsdtr(struct z8530_channel *c, int set) { if (set) c->regs[5] |= (RTS | DTR); else c->regs[5] &= ~(RTS | DTR); write_zsreg(c, R5, c->regs[5]); } /** * z8530_rx - Handle a PIO receive event * @c: Z8530 channel to process * * Receive handler for receiving in PIO mode. This is much like the * async one but not quite the same or as complex * * Note: Its intended that this handler can easily be separated from * the main code to run realtime. That'll be needed for some machines * (eg to ever clock 64kbits on a sparc ;)). * * The RT_LOCK macros don't do anything now. Keep the code covered * by them as short as possible in all circumstances - clocks cost * baud. The interrupt handler is assumed to be atomic w.r.t. to * other code - this is true in the RT case too. * * We only cover the sync cases for this. If you want 2Mbit async * do it yourself but consider medical assistance first. This non DMA * synchronous mode is portable code. The DMA mode assumes PCI like * ISA DMA * * Called with the device lock held */ static void z8530_rx(struct z8530_channel *c) { u8 ch,stat; while(1) { /* FIFO empty ? */ if(!(read_zsreg(c, R0)&1)) break; ch=read_zsdata(c); stat=read_zsreg(c, R1); /* * Overrun ? */ if(c->count < c->max) { *c->dptr++=ch; c->count++; } if(stat&END_FR) { /* * Error ? */ if(stat&(Rx_OVR|CRC_ERR)) { /* Rewind the buffer and return */ if(c->skb) c->dptr=c->skb->data; c->count=0; if(stat&Rx_OVR) { pr_warn("%s: overrun\n", c->dev->name); c->rx_overrun++; } if(stat&CRC_ERR) { c->rx_crc_err++; /* printk("crc error\n"); */ } /* Shove the frame upstream */ } else { /* * Drop the lock for RX processing, or * there are deadlocks */ z8530_rx_done(c); write_zsctrl(c, RES_Rx_CRC); } } } /* * Clear irq */ write_zsctrl(c, ERR_RES); write_zsctrl(c, RES_H_IUS); } /** * z8530_tx - Handle a PIO transmit event * @c: Z8530 channel to process * * Z8530 transmit interrupt handler for the PIO mode. The basic * idea is to attempt to keep the FIFO fed. We fill as many bytes * in as possible, its quite possible that we won't keep up with the * data rate otherwise. */ static void z8530_tx(struct z8530_channel *c) { while(c->txcount) { /* FIFO full ? */ if(!(read_zsreg(c, R0)&4)) return; c->txcount--; /* * Shovel out the byte */ write_zsreg(c, R8, *c->tx_ptr++); write_zsctrl(c, RES_H_IUS); /* We are about to underflow */ if(c->txcount==0) { write_zsctrl(c, RES_EOM_L); write_zsreg(c, R10, c->regs[10]&~ABUNDER); } } /* * End of frame TX - fire another one */ write_zsctrl(c, RES_Tx_P); z8530_tx_done(c); write_zsctrl(c, RES_H_IUS); } /** * z8530_status - Handle a PIO status exception * @chan: Z8530 channel to process * * A status event occurred in PIO synchronous mode. There are several * reasons the chip will bother us here. A transmit underrun means we * failed to feed the chip fast enough and just broke a packet. A DCD * change is a line up or down. */ static void z8530_status(struct z8530_channel *chan) { u8 status, altered; status = read_zsreg(chan, R0); altered = chan->status ^ status; chan->status = status; if (status & TxEOM) { /* printk("%s: Tx underrun.\n", chan->dev->name); */ chan->netdevice->stats.tx_fifo_errors++; write_zsctrl(chan, ERR_RES); z8530_tx_done(chan); } if (altered & chan->dcdcheck) { if (status & chan->dcdcheck) { pr_info("%s: DCD raised\n", chan->dev->name); write_zsreg(chan, R3, chan->regs[3] | RxENABLE); if (chan->netdevice) netif_carrier_on(chan->netdevice); } else { pr_info("%s: DCD lost\n", chan->dev->name); write_zsreg(chan, R3, chan->regs[3] & ~RxENABLE); z8530_flush_fifo(chan); if (chan->netdevice) netif_carrier_off(chan->netdevice); } } write_zsctrl(chan, RES_EXT_INT); write_zsctrl(chan, RES_H_IUS); } struct z8530_irqhandler z8530_sync = { .rx = z8530_rx, .tx = z8530_tx, .status = z8530_status, }; EXPORT_SYMBOL(z8530_sync); /** * z8530_dma_rx - Handle a DMA RX event * @chan: Channel to handle * * Non bus mastering DMA interfaces for the Z8x30 devices. This * is really pretty PC specific. The DMA mode means that most receive * events are handled by the DMA hardware. We get a kick here only if * a frame ended. */ static void z8530_dma_rx(struct z8530_channel *chan) { if(chan->rxdma_on) { /* Special condition check only */ u8 status; read_zsreg(chan, R7); read_zsreg(chan, R6); status=read_zsreg(chan, R1); if(status&END_FR) { z8530_rx_done(chan); /* Fire up the next one */ } write_zsctrl(chan, ERR_RES); write_zsctrl(chan, RES_H_IUS); } else { /* DMA is off right now, drain the slow way */ z8530_rx(chan); } } /** * z8530_dma_tx - Handle a DMA TX event * @chan: The Z8530 channel to handle * * We have received an interrupt while doing DMA transmissions. It * shouldn't happen. Scream loudly if it does. */ static void z8530_dma_tx(struct z8530_channel *chan) { if(!chan->dma_tx) { pr_warn("Hey who turned the DMA off?\n"); z8530_tx(chan); return; } /* This shouldn't occur in DMA mode */ pr_err("DMA tx - bogus event!\n"); z8530_tx(chan); } /** * z8530_dma_status - Handle a DMA status exception * @chan: Z8530 channel to process * * A status event occurred on the Z8530. We receive these for two reasons * when in DMA mode. Firstly if we finished a packet transfer we get one * and kick the next packet out. Secondly we may see a DCD change. * */ static void z8530_dma_status(struct z8530_channel *chan) { u8 status, altered; status=read_zsreg(chan, R0); altered=chan->status^status; chan->status=status; if(chan->dma_tx) { if(status&TxEOM) { unsigned long flags; flags=claim_dma_lock(); disable_dma(chan->txdma); clear_dma_ff(chan->txdma); chan->txdma_on=0; release_dma_lock(flags); z8530_tx_done(chan); } } if (altered & chan->dcdcheck) { if (status & chan->dcdcheck) { pr_info("%s: DCD raised\n", chan->dev->name); write_zsreg(chan, R3, chan->regs[3] | RxENABLE); if (chan->netdevice) netif_carrier_on(chan->netdevice); } else { pr_info("%s: DCD lost\n", chan->dev->name); write_zsreg(chan, R3, chan->regs[3] & ~RxENABLE); z8530_flush_fifo(chan); if (chan->netdevice) netif_carrier_off(chan->netdevice); } } write_zsctrl(chan, RES_EXT_INT); write_zsctrl(chan, RES_H_IUS); } static struct z8530_irqhandler z8530_dma_sync = { .rx = z8530_dma_rx, .tx = z8530_dma_tx, .status = z8530_dma_status, }; static struct z8530_irqhandler z8530_txdma_sync = { .rx = z8530_rx, .tx = z8530_dma_tx, .status = z8530_dma_status, }; /** * z8530_rx_clear - Handle RX events from a stopped chip * @c: Z8530 channel to shut up * * Receive interrupt vectors for a Z8530 that is in 'parked' mode. * For machines with PCI Z85x30 cards, or level triggered interrupts * (eg the MacII) we must clear the interrupt cause or die. */ static void z8530_rx_clear(struct z8530_channel *c) { /* * Data and status bytes */ u8 stat; read_zsdata(c); stat=read_zsreg(c, R1); if(stat&END_FR) write_zsctrl(c, RES_Rx_CRC); /* * Clear irq */ write_zsctrl(c, ERR_RES); write_zsctrl(c, RES_H_IUS); } /** * z8530_tx_clear - Handle TX events from a stopped chip * @c: Z8530 channel to shut up * * Transmit interrupt vectors for a Z8530 that is in 'parked' mode. * For machines with PCI Z85x30 cards, or level triggered interrupts * (eg the MacII) we must clear the interrupt cause or die. */ static void z8530_tx_clear(struct z8530_channel *c) { write_zsctrl(c, RES_Tx_P); write_zsctrl(c, RES_H_IUS); } /** * z8530_status_clear - Handle status events from a stopped chip * @chan: Z8530 channel to shut up * * Status interrupt vectors for a Z8530 that is in 'parked' mode. * For machines with PCI Z85x30 cards, or level triggered interrupts * (eg the MacII) we must clear the interrupt cause or die. */ static void z8530_status_clear(struct z8530_channel *chan) { u8 status=read_zsreg(chan, R0); if(status&TxEOM) write_zsctrl(chan, ERR_RES); write_zsctrl(chan, RES_EXT_INT); write_zsctrl(chan, RES_H_IUS); } struct z8530_irqhandler z8530_nop = { .rx = z8530_rx_clear, .tx = z8530_tx_clear, .status = z8530_status_clear, }; EXPORT_SYMBOL(z8530_nop); /** * z8530_interrupt - Handle an interrupt from a Z8530 * @irq: Interrupt number * @dev_id: The Z8530 device that is interrupting. * * A Z85[2]30 device has stuck its hand in the air for attention. * We scan both the channels on the chip for events and then call * the channel specific call backs for each channel that has events. * We have to use callback functions because the two channels can be * in different modes. * * Locking is done for the handlers. Note that locking is done * at the chip level (the 5uS delay issue is per chip not per * channel). c->lock for both channels points to dev->lock */ irqreturn_t z8530_interrupt(int irq, void *dev_id) { struct z8530_dev *dev=dev_id; u8 uninitialized_var(intr); static volatile int locker=0; int work=0; struct z8530_irqhandler *irqs; if(locker) { pr_err("IRQ re-enter\n"); return IRQ_NONE; } locker=1; spin_lock(&dev->lock); while(++work<5000) { intr = read_zsreg(&dev->chanA, R3); if(!(intr & (CHARxIP|CHATxIP|CHAEXT|CHBRxIP|CHBTxIP|CHBEXT))) break; /* This holds the IRQ status. On the 8530 you must read it from chan A even though it applies to the whole chip */ /* Now walk the chip and see what it is wanting - it may be an IRQ for someone else remember */ irqs=dev->chanA.irqs; if(intr & (CHARxIP|CHATxIP|CHAEXT)) { if(intr&CHARxIP) irqs->rx(&dev->chanA); if(intr&CHATxIP) irqs->tx(&dev->chanA); if(intr&CHAEXT) irqs->status(&dev->chanA); } irqs=dev->chanB.irqs; if(intr & (CHBRxIP|CHBTxIP|CHBEXT)) { if(intr&CHBRxIP) irqs->rx(&dev->chanB); if(intr&CHBTxIP) irqs->tx(&dev->chanB); if(intr&CHBEXT) irqs->status(&dev->chanB); } } spin_unlock(&dev->lock); if(work==5000) pr_err("%s: interrupt jammed - abort(0x%X)!\n", dev->name, intr); /* Ok all done */ locker=0; return IRQ_HANDLED; } EXPORT_SYMBOL(z8530_interrupt); static const u8 reg_init[16]= { 0,0,0,0, 0,0,0,0, 0,0,0,0, 0x55,0,0,0 }; /** * z8530_sync_open - Open a Z8530 channel for PIO * @dev: The network interface we are using * @c: The Z8530 channel to open in synchronous PIO mode * * Switch a Z8530 into synchronous mode without DMA assist. We * raise the RTS/DTR and commence network operation. */ int z8530_sync_open(struct net_device *dev, struct z8530_channel *c) { unsigned long flags; spin_lock_irqsave(c->lock, flags); c->sync = 1; c->mtu = dev->mtu+64; c->count = 0; c->skb = NULL; c->skb2 = NULL; c->irqs = &z8530_sync; /* This loads the double buffer up */ z8530_rx_done(c); /* Load the frame ring */ z8530_rx_done(c); /* Load the backup frame */ z8530_rtsdtr(c,1); c->dma_tx = 0; c->regs[R1]|=TxINT_ENAB; write_zsreg(c, R1, c->regs[R1]); write_zsreg(c, R3, c->regs[R3]|RxENABLE); spin_unlock_irqrestore(c->lock, flags); return 0; } EXPORT_SYMBOL(z8530_sync_open); /** * z8530_sync_close - Close a PIO Z8530 channel * @dev: Network device to close * @c: Z8530 channel to disassociate and move to idle * * Close down a Z8530 interface and switch its interrupt handlers * to discard future events. */ int z8530_sync_close(struct net_device *dev, struct z8530_channel *c) { u8 chk; unsigned long flags; spin_lock_irqsave(c->lock, flags); c->irqs = &z8530_nop; c->max = 0; c->sync = 0; chk=read_zsreg(c,R0); write_zsreg(c, R3, c->regs[R3]); z8530_rtsdtr(c,0); spin_unlock_irqrestore(c->lock, flags); return 0; } EXPORT_SYMBOL(z8530_sync_close); /** * z8530_sync_dma_open - Open a Z8530 for DMA I/O * @dev: The network device to attach * @c: The Z8530 channel to configure in sync DMA mode. * * Set up a Z85x30 device for synchronous DMA in both directions. Two * ISA DMA channels must be available for this to work. We assume ISA * DMA driven I/O and PC limits on access. */ int z8530_sync_dma_open(struct net_device *dev, struct z8530_channel *c) { unsigned long cflags, dflags; c->sync = 1; c->mtu = dev->mtu+64; c->count = 0; c->skb = NULL; c->skb2 = NULL; /* * Load the DMA interfaces up */ c->rxdma_on = 0; c->txdma_on = 0; /* * Allocate the DMA flip buffers. Limit by page size. * Everyone runs 1500 mtu or less on wan links so this * should be fine. */ if(c->mtu > PAGE_SIZE/2) return -EMSGSIZE; c->rx_buf[0]=(void *)get_zeroed_page(GFP_KERNEL|GFP_DMA); if(c->rx_buf[0]==NULL) return -ENOBUFS; c->rx_buf[1]=c->rx_buf[0]+PAGE_SIZE/2; c->tx_dma_buf[0]=(void *)get_zeroed_page(GFP_KERNEL|GFP_DMA); if(c->tx_dma_buf[0]==NULL) { free_page((unsigned long)c->rx_buf[0]); c->rx_buf[0]=NULL; return -ENOBUFS; } c->tx_dma_buf[1]=c->tx_dma_buf[0]+PAGE_SIZE/2; c->tx_dma_used=0; c->dma_tx = 1; c->dma_num=0; c->dma_ready=1; /* * Enable DMA control mode */ spin_lock_irqsave(c->lock, cflags); /* * TX DMA via DIR/REQ */ c->regs[R14]|= DTRREQ; write_zsreg(c, R14, c->regs[R14]); c->regs[R1]&= ~TxINT_ENAB; write_zsreg(c, R1, c->regs[R1]); /* * RX DMA via W/Req */ c->regs[R1]|= WT_FN_RDYFN; c->regs[R1]|= WT_RDY_RT; c->regs[R1]|= INT_ERR_Rx; c->regs[R1]&= ~TxINT_ENAB; write_zsreg(c, R1, c->regs[R1]); c->regs[R1]|= WT_RDY_ENAB; write_zsreg(c, R1, c->regs[R1]); /* * DMA interrupts */ /* * Set up the DMA configuration */ dflags=claim_dma_lock(); disable_dma(c->rxdma); clear_dma_ff(c->rxdma); set_dma_mode(c->rxdma, DMA_MODE_READ|0x10); set_dma_addr(c->rxdma, virt_to_bus(c->rx_buf[0])); set_dma_count(c->rxdma, c->mtu); enable_dma(c->rxdma); disable_dma(c->txdma); clear_dma_ff(c->txdma); set_dma_mode(c->txdma, DMA_MODE_WRITE); disable_dma(c->txdma); release_dma_lock(dflags); /* * Select the DMA interrupt handlers */ c->rxdma_on = 1; c->txdma_on = 1; c->tx_dma_used = 1; c->irqs = &z8530_dma_sync; z8530_rtsdtr(c,1); write_zsreg(c, R3, c->regs[R3]|RxENABLE); spin_unlock_irqrestore(c->lock, cflags); return 0; } EXPORT_SYMBOL(z8530_sync_dma_open); /** * z8530_sync_dma_close - Close down DMA I/O * @dev: Network device to detach * @c: Z8530 channel to move into discard mode * * Shut down a DMA mode synchronous interface. Halt the DMA, and * free the buffers. */ int z8530_sync_dma_close(struct net_device *dev, struct z8530_channel *c) { u8 chk; unsigned long flags; c->irqs = &z8530_nop; c->max = 0; c->sync = 0; /* * Disable the PC DMA channels */ flags=claim_dma_lock(); disable_dma(c->rxdma); clear_dma_ff(c->rxdma); c->rxdma_on = 0; disable_dma(c->txdma); clear_dma_ff(c->txdma); release_dma_lock(flags); c->txdma_on = 0; c->tx_dma_used = 0; spin_lock_irqsave(c->lock, flags); /* * Disable DMA control mode */ c->regs[R1]&= ~WT_RDY_ENAB; write_zsreg(c, R1, c->regs[R1]); c->regs[R1]&= ~(WT_RDY_RT|WT_FN_RDYFN|INT_ERR_Rx); c->regs[R1]|= INT_ALL_Rx; write_zsreg(c, R1, c->regs[R1]); c->regs[R14]&= ~DTRREQ; write_zsreg(c, R14, c->regs[R14]); if(c->rx_buf[0]) { free_page((unsigned long)c->rx_buf[0]); c->rx_buf[0]=NULL; } if(c->tx_dma_buf[0]) { free_page((unsigned long)c->tx_dma_buf[0]); c->tx_dma_buf[0]=NULL; } chk=read_zsreg(c,R0); write_zsreg(c, R3, c->regs[R3]); z8530_rtsdtr(c,0); spin_unlock_irqrestore(c->lock, flags); return 0; } EXPORT_SYMBOL(z8530_sync_dma_close); /** * z8530_sync_txdma_open - Open a Z8530 for TX driven DMA * @dev: The network device to attach * @c: The Z8530 channel to configure in sync DMA mode. * * Set up a Z85x30 device for synchronous DMA transmission. One * ISA DMA channel must be available for this to work. The receive * side is run in PIO mode, but then it has the bigger FIFO. */ int z8530_sync_txdma_open(struct net_device *dev, struct z8530_channel *c) { unsigned long cflags, dflags; printk("Opening sync interface for TX-DMA\n"); c->sync = 1; c->mtu = dev->mtu+64; c->count = 0; c->skb = NULL; c->skb2 = NULL; /* * Allocate the DMA flip buffers. Limit by page size. * Everyone runs 1500 mtu or less on wan links so this * should be fine. */ if(c->mtu > PAGE_SIZE/2) return -EMSGSIZE; c->tx_dma_buf[0]=(void *)get_zeroed_page(GFP_KERNEL|GFP_DMA); if(c->tx_dma_buf[0]==NULL) return -ENOBUFS; c->tx_dma_buf[1] = c->tx_dma_buf[0] + PAGE_SIZE/2; spin_lock_irqsave(c->lock, cflags); /* * Load the PIO receive ring */ z8530_rx_done(c); z8530_rx_done(c); /* * Load the DMA interfaces up */ c->rxdma_on = 0; c->txdma_on = 0; c->tx_dma_used=0; c->dma_num=0; c->dma_ready=1; c->dma_tx = 1; /* * Enable DMA control mode */ /* * TX DMA via DIR/REQ */ c->regs[R14]|= DTRREQ; write_zsreg(c, R14, c->regs[R14]); c->regs[R1]&= ~TxINT_ENAB; write_zsreg(c, R1, c->regs[R1]); /* * Set up the DMA configuration */ dflags = claim_dma_lock(); disable_dma(c->txdma); clear_dma_ff(c->txdma); set_dma_mode(c->txdma, DMA_MODE_WRITE); disable_dma(c->txdma); release_dma_lock(dflags); /* * Select the DMA interrupt handlers */ c->rxdma_on = 0; c->txdma_on = 1; c->tx_dma_used = 1; c->irqs = &z8530_txdma_sync; z8530_rtsdtr(c,1); write_zsreg(c, R3, c->regs[R3]|RxENABLE); spin_unlock_irqrestore(c->lock, cflags); return 0; } EXPORT_SYMBOL(z8530_sync_txdma_open); /** * z8530_sync_txdma_close - Close down a TX driven DMA channel * @dev: Network device to detach * @c: Z8530 channel to move into discard mode * * Shut down a DMA/PIO split mode synchronous interface. Halt the DMA, * and free the buffers. */ int z8530_sync_txdma_close(struct net_device *dev, struct z8530_channel *c) { unsigned long dflags, cflags; u8 chk; spin_lock_irqsave(c->lock, cflags); c->irqs = &z8530_nop; c->max = 0; c->sync = 0; /* * Disable the PC DMA channels */ dflags = claim_dma_lock(); disable_dma(c->txdma); clear_dma_ff(c->txdma); c->txdma_on = 0; c->tx_dma_used = 0; release_dma_lock(dflags); /* * Disable DMA control mode */ c->regs[R1]&= ~WT_RDY_ENAB; write_zsreg(c, R1, c->regs[R1]); c->regs[R1]&= ~(WT_RDY_RT|WT_FN_RDYFN|INT_ERR_Rx); c->regs[R1]|= INT_ALL_Rx; write_zsreg(c, R1, c->regs[R1]); c->regs[R14]&= ~DTRREQ; write_zsreg(c, R14, c->regs[R14]); if(c->tx_dma_buf[0]) { free_page((unsigned long)c->tx_dma_buf[0]); c->tx_dma_buf[0]=NULL; } chk=read_zsreg(c,R0); write_zsreg(c, R3, c->regs[R3]); z8530_rtsdtr(c,0); spin_unlock_irqrestore(c->lock, cflags); return 0; } EXPORT_SYMBOL(z8530_sync_txdma_close); /* * Name strings for Z8530 chips. SGI claim to have a 130, Zilog deny * it exists... */ static const char *z8530_type_name[]={ "Z8530", "Z85C30", "Z85230" }; /** * z8530_describe - Uniformly describe a Z8530 port * @dev: Z8530 device to describe * @mapping: string holding mapping type (eg "I/O" or "Mem") * @io: the port value in question * * Describe a Z8530 in a standard format. We must pass the I/O as * the port offset isn't predictable. The main reason for this function * is to try and get a common format of report. */ void z8530_describe(struct z8530_dev *dev, char *mapping, unsigned long io) { pr_info("%s: %s found at %s 0x%lX, IRQ %d\n", dev->name, z8530_type_name[dev->type], mapping, Z8530_PORT_OF(io), dev->irq); } EXPORT_SYMBOL(z8530_describe); /* * Locked operation part of the z8530 init code */ static inline int do_z8530_init(struct z8530_dev *dev) { /* NOP the interrupt handlers first - we might get a floating IRQ transition when we reset the chip */ dev->chanA.irqs=&z8530_nop; dev->chanB.irqs=&z8530_nop; dev->chanA.dcdcheck=DCD; dev->chanB.dcdcheck=DCD; /* Reset the chip */ write_zsreg(&dev->chanA, R9, 0xC0); udelay(200); /* Now check its valid */ write_zsreg(&dev->chanA, R12, 0xAA); if(read_zsreg(&dev->chanA, R12)!=0xAA) return -ENODEV; write_zsreg(&dev->chanA, R12, 0x55); if(read_zsreg(&dev->chanA, R12)!=0x55) return -ENODEV; dev->type=Z8530; /* * See the application note. */ write_zsreg(&dev->chanA, R15, 0x01); /* * If we can set the low bit of R15 then * the chip is enhanced. */ if(read_zsreg(&dev->chanA, R15)==0x01) { /* This C30 versus 230 detect is from Klaus Kudielka's dmascc */ /* Put a char in the fifo */ write_zsreg(&dev->chanA, R8, 0); if(read_zsreg(&dev->chanA, R0)&Tx_BUF_EMP) dev->type = Z85230; /* Has a FIFO */ else dev->type = Z85C30; /* Z85C30, 1 byte FIFO */ } /* * The code assumes R7' and friends are * off. Use write_zsext() for these and keep * this bit clear. */ write_zsreg(&dev->chanA, R15, 0); /* * At this point it looks like the chip is behaving */ memcpy(dev->chanA.regs, reg_init, 16); memcpy(dev->chanB.regs, reg_init ,16); return 0; } /** * z8530_init - Initialise a Z8530 device * @dev: Z8530 device to initialise. * * Configure up a Z8530/Z85C30 or Z85230 chip. We check the device * is present, identify the type and then program it to hopefully * keep quite and behave. This matters a lot, a Z8530 in the wrong * state will sometimes get into stupid modes generating 10Khz * interrupt streams and the like. * * We set the interrupt handler up to discard any events, in case * we get them during reset or setp. * * Return 0 for success, or a negative value indicating the problem * in errno form. */ int z8530_init(struct z8530_dev *dev) { unsigned long flags; int ret; /* Set up the chip level lock */ spin_lock_init(&dev->lock); dev->chanA.lock = &dev->lock; dev->chanB.lock = &dev->lock; spin_lock_irqsave(&dev->lock, flags); ret = do_z8530_init(dev); spin_unlock_irqrestore(&dev->lock, flags); return ret; } EXPORT_SYMBOL(z8530_init); /** * z8530_shutdown - Shutdown a Z8530 device * @dev: The Z8530 chip to shutdown * * We set the interrupt handlers to silence any interrupts. We then * reset the chip and wait 100uS to be sure the reset completed. Just * in case the caller then tries to do stuff. * * This is called without the lock held */ int z8530_shutdown(struct z8530_dev *dev) { unsigned long flags; /* Reset the chip */ spin_lock_irqsave(&dev->lock, flags); dev->chanA.irqs=&z8530_nop; dev->chanB.irqs=&z8530_nop; write_zsreg(&dev->chanA, R9, 0xC0); /* We must lock the udelay, the chip is offlimits here */ udelay(100); spin_unlock_irqrestore(&dev->lock, flags); return 0; } EXPORT_SYMBOL(z8530_shutdown); /** * z8530_channel_load - Load channel data * @c: Z8530 channel to configure * @rtable: table of register, value pairs * FIXME: ioctl to allow user uploaded tables * * Load a Z8530 channel up from the system data. We use +16 to * indicate the "prime" registers. The value 255 terminates the * table. */ int z8530_channel_load(struct z8530_channel *c, u8 *rtable) { unsigned long flags; spin_lock_irqsave(c->lock, flags); while(*rtable!=255) { int reg=*rtable++; if(reg>0x0F) write_zsreg(c, R15, c->regs[15]|1); write_zsreg(c, reg&0x0F, *rtable); if(reg>0x0F) write_zsreg(c, R15, c->regs[15]&~1); c->regs[reg]=*rtable++; } c->rx_function=z8530_null_rx; c->skb=NULL; c->tx_skb=NULL; c->tx_next_skb=NULL; c->mtu=1500; c->max=0; c->count=0; c->status=read_zsreg(c, R0); c->sync=1; write_zsreg(c, R3, c->regs[R3]|RxENABLE); spin_unlock_irqrestore(c->lock, flags); return 0; } EXPORT_SYMBOL(z8530_channel_load); /** * z8530_tx_begin - Begin packet transmission * @c: The Z8530 channel to kick * * This is the speed sensitive side of transmission. If we are called * and no buffer is being transmitted we commence the next buffer. If * nothing is queued we idle the sync. * * Note: We are handling this code path in the interrupt path, keep it * fast or bad things will happen. * * Called with the lock held. */ static void z8530_tx_begin(struct z8530_channel *c) { unsigned long flags; if(c->tx_skb) return; c->tx_skb=c->tx_next_skb; c->tx_next_skb=NULL; c->tx_ptr=c->tx_next_ptr; if(c->tx_skb==NULL) { /* Idle on */ if(c->dma_tx) { flags=claim_dma_lock(); disable_dma(c->txdma); /* * Check if we crapped out. */ if (get_dma_residue(c->txdma)) { c->netdevice->stats.tx_dropped++; c->netdevice->stats.tx_fifo_errors++; } release_dma_lock(flags); } c->txcount=0; } else { c->txcount=c->tx_skb->len; if(c->dma_tx) { /* * FIXME. DMA is broken for the original 8530, * on the older parts we need to set a flag and * wait for a further TX interrupt to fire this * stage off */ flags=claim_dma_lock(); disable_dma(c->txdma); /* * These two are needed by the 8530/85C30 * and must be issued when idling. */ if(c->dev->type!=Z85230) { write_zsctrl(c, RES_Tx_CRC); write_zsctrl(c, RES_EOM_L); } write_zsreg(c, R10, c->regs[10]&~ABUNDER); clear_dma_ff(c->txdma); set_dma_addr(c->txdma, virt_to_bus(c->tx_ptr)); set_dma_count(c->txdma, c->txcount); enable_dma(c->txdma); release_dma_lock(flags); write_zsctrl(c, RES_EOM_L); write_zsreg(c, R5, c->regs[R5]|TxENAB); } else { /* ABUNDER off */ write_zsreg(c, R10, c->regs[10]); write_zsctrl(c, RES_Tx_CRC); while(c->txcount && (read_zsreg(c,R0)&Tx_BUF_EMP)) { write_zsreg(c, R8, *c->tx_ptr++); c->txcount--; } } } /* * Since we emptied tx_skb we can ask for more */ netif_wake_queue(c->netdevice); } /** * z8530_tx_done - TX complete callback * @c: The channel that completed a transmit. * * This is called when we complete a packet send. We wake the queue, * start the next packet going and then free the buffer of the existing * packet. This code is fairly timing sensitive. * * Called with the register lock held. */ static void z8530_tx_done(struct z8530_channel *c) { struct sk_buff *skb; /* Actually this can happen.*/ if (c->tx_skb == NULL) return; skb = c->tx_skb; c->tx_skb = NULL; z8530_tx_begin(c); c->netdevice->stats.tx_packets++; c->netdevice->stats.tx_bytes += skb->len; dev_consume_skb_irq(skb); } /** * z8530_null_rx - Discard a packet * @c: The channel the packet arrived on * @skb: The buffer * * We point the receive handler at this function when idle. Instead * of processing the frames we get to throw them away. */ void z8530_null_rx(struct z8530_channel *c, struct sk_buff *skb) { dev_kfree_skb_any(skb); } EXPORT_SYMBOL(z8530_null_rx); /** * z8530_rx_done - Receive completion callback * @c: The channel that completed a receive * * A new packet is complete. Our goal here is to get back into receive * mode as fast as possible. On the Z85230 we could change to using * ESCC mode, but on the older chips we have no choice. We flip to the * new buffer immediately in DMA mode so that the DMA of the next * frame can occur while we are copying the previous buffer to an sk_buff * * Called with the lock held */ static void z8530_rx_done(struct z8530_channel *c) { struct sk_buff *skb; int ct; /* * Is our receive engine in DMA mode */ if(c->rxdma_on) { /* * Save the ready state and the buffer currently * being used as the DMA target */ int ready=c->dma_ready; unsigned char *rxb=c->rx_buf[c->dma_num]; unsigned long flags; /* * Complete this DMA. Necessary to find the length */ flags=claim_dma_lock(); disable_dma(c->rxdma); clear_dma_ff(c->rxdma); c->rxdma_on=0; ct=c->mtu-get_dma_residue(c->rxdma); if(ct<0) ct=2; /* Shit happens.. */ c->dma_ready=0; /* * Normal case: the other slot is free, start the next DMA * into it immediately. */ if(ready) { c->dma_num^=1; set_dma_mode(c->rxdma, DMA_MODE_READ|0x10); set_dma_addr(c->rxdma, virt_to_bus(c->rx_buf[c->dma_num])); set_dma_count(c->rxdma, c->mtu); c->rxdma_on = 1; enable_dma(c->rxdma); /* Stop any frames that we missed the head of from passing */ write_zsreg(c, R0, RES_Rx_CRC); } else /* Can't occur as we dont reenable the DMA irq until after the flip is done */ netdev_warn(c->netdevice, "DMA flip overrun!\n"); release_dma_lock(flags); /* * Shove the old buffer into an sk_buff. We can't DMA * directly into one on a PC - it might be above the 16Mb * boundary. Optimisation - we could check to see if we * can avoid the copy. Optimisation 2 - make the memcpy * a copychecksum. */ skb = dev_alloc_skb(ct); if (skb == NULL) { c->netdevice->stats.rx_dropped++; netdev_warn(c->netdevice, "Memory squeeze\n"); } else { skb_put(skb, ct); skb_copy_to_linear_data(skb, rxb, ct); c->netdevice->stats.rx_packets++; c->netdevice->stats.rx_bytes += ct; } c->dma_ready = 1; } else { RT_LOCK; skb = c->skb; /* * The game we play for non DMA is similar. We want to * get the controller set up for the next packet as fast * as possible. We potentially only have one byte + the * fifo length for this. Thus we want to flip to the new * buffer and then mess around copying and allocating * things. For the current case it doesn't matter but * if you build a system where the sync irq isn't blocked * by the kernel IRQ disable then you need only block the * sync IRQ for the RT_LOCK area. * */ ct=c->count; c->skb = c->skb2; c->count = 0; c->max = c->mtu; if (c->skb) { c->dptr = c->skb->data; c->max = c->mtu; } else { c->count = 0; c->max = 0; } RT_UNLOCK; c->skb2 = dev_alloc_skb(c->mtu); if (c->skb2 == NULL) netdev_warn(c->netdevice, "memory squeeze\n"); else skb_put(c->skb2, c->mtu); c->netdevice->stats.rx_packets++; c->netdevice->stats.rx_bytes += ct; } /* * If we received a frame we must now process it. */ if (skb) { skb_trim(skb, ct); c->rx_function(c, skb); } else { c->netdevice->stats.rx_dropped++; netdev_err(c->netdevice, "Lost a frame\n"); } } /** * spans_boundary - Check a packet can be ISA DMA'd * @skb: The buffer to check * * Returns true if the buffer cross a DMA boundary on a PC. The poor * thing can only DMA within a 64K block not across the edges of it. */ static inline int spans_boundary(struct sk_buff *skb) { unsigned long a=(unsigned long)skb->data; a^=(a+skb->len); if(a&0x00010000) /* If the 64K bit is different.. */ return 1; return 0; } /** * z8530_queue_xmit - Queue a packet * @c: The channel to use * @skb: The packet to kick down the channel * * Queue a packet for transmission. Because we have rather * hard to hit interrupt latencies for the Z85230 per packet * even in DMA mode we do the flip to DMA buffer if needed here * not in the IRQ. * * Called from the network code. The lock is not held at this * point. */ netdev_tx_t z8530_queue_xmit(struct z8530_channel *c, struct sk_buff *skb) { unsigned long flags; netif_stop_queue(c->netdevice); if(c->tx_next_skb) return NETDEV_TX_BUSY; /* PC SPECIFIC - DMA limits */ /* * If we will DMA the transmit and its gone over the ISA bus * limit, then copy to the flip buffer */ if(c->dma_tx && ((unsigned long)(virt_to_bus(skb->data+skb->len))>=16*1024*1024 || spans_boundary(skb))) { /* * Send the flip buffer, and flip the flippy bit. * We don't care which is used when just so long as * we never use the same buffer twice in a row. Since * only one buffer can be going out at a time the other * has to be safe. */ c->tx_next_ptr=c->tx_dma_buf[c->tx_dma_used]; c->tx_dma_used^=1; /* Flip temp buffer */ skb_copy_from_linear_data(skb, c->tx_next_ptr, skb->len); } else c->tx_next_ptr=skb->data; RT_LOCK; c->tx_next_skb=skb; RT_UNLOCK; spin_lock_irqsave(c->lock, flags); z8530_tx_begin(c); spin_unlock_irqrestore(c->lock, flags); return NETDEV_TX_OK; } EXPORT_SYMBOL(z8530_queue_xmit); /* * Module support */ static const char banner[] __initconst = KERN_INFO "Generic Z85C30/Z85230 interface driver v0.02\n"; static int __init z85230_init_driver(void) { printk(banner); return 0; } module_init(z85230_init_driver); static void __exit z85230_cleanup_driver(void) { } module_exit(z85230_cleanup_driver); MODULE_AUTHOR("Red Hat Inc."); MODULE_DESCRIPTION("Z85x30 synchronous driver core"); MODULE_LICENSE("GPL");