/* * I/O Processor (IOP) management * Written and (C) 1999 by Joshua M. Thompson (funaho@jurai.org) * * 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 and this list of conditions. * 2. Redistributions in binary form must reproduce the above copyright * notice and this list of conditions in the documentation and/or other * materials provided with the distribution. */ /* * The IOP chips are used in the IIfx and some Quadras (900, 950) to manage * serial and ADB. They are actually a 6502 processor and some glue logic. * * 990429 (jmt) - Initial implementation, just enough to knock the SCC IOP * into compatible mode so nobody has to fiddle with the * Serial Switch control panel anymore. * 990603 (jmt) - Added code to grab the correct ISM IOP interrupt for OSS * and non-OSS machines (at least I hope it's correct on a * non-OSS machine -- someone with a Q900 or Q950 needs to * check this.) * 990605 (jmt) - Rearranged things a bit wrt IOP detection; iop_present is * gone, IOP base addresses are now in an array and the * globally-visible functions take an IOP number instead of an * an actual base address. * 990610 (jmt) - Finished the message passing framework and it seems to work. * Sending _definitely_ works; my adb-bus.c mods can send * messages and receive the MSG_COMPLETED status back from the * IOP. The trick now is figuring out the message formats. * 990611 (jmt) - More cleanups. Fixed problem where unclaimed messages on a * receive channel were never properly acknowledged. Bracketed * the remaining debug printk's with #ifdef's and disabled * debugging. I can now type on the console. * 990612 (jmt) - Copyright notice added. Reworked the way replies are handled. * It turns out that replies are placed back in the send buffer * for that channel; messages on the receive channels are always * unsolicited messages from the IOP (and our replies to them * should go back in the receive channel.) Also added tracking * of device names to the listener functions ala the interrupt * handlers. * 990729 (jmt) - Added passing of pt_regs structure to IOP handlers. This is * used by the new unified ADB driver. * * TODO: * * o Something should be periodically checking iop_alive() to make sure the * IOP hasn't died. * o Some of the IOP manager routines need better error checking and * return codes. Nothing major, just prettying up. */ /* * ----------------------- * IOP Message Passing 101 * ----------------------- * * The host talks to the IOPs using a rather simple message-passing scheme via * a shared memory area in the IOP RAM. Each IOP has seven "channels"; each * channel is conneced to a specific software driver on the IOP. For example * on the SCC IOP there is one channel for each serial port. Each channel has * an incoming and and outgoing message queue with a depth of one. * * A message is 32 bytes plus a state byte for the channel (MSG_IDLE, MSG_NEW, * MSG_RCVD, MSG_COMPLETE). To send a message you copy the message into the * buffer, set the state to MSG_NEW and signal the IOP by setting the IRQ flag * in the IOP control to 1. The IOP will move the state to MSG_RCVD when it * receives the message and then to MSG_COMPLETE when the message processing * has completed. It is the host's responsibility at that point to read the * reply back out of the send channel buffer and reset the channel state back * to MSG_IDLE. * * To receive message from the IOP the same procedure is used except the roles * are reversed. That is, the IOP puts message in the channel with a state of * MSG_NEW, and the host receives the message and move its state to MSG_RCVD * and then to MSG_COMPLETE when processing is completed and the reply (if any) * has been placed back in the receive channel. The IOP will then reset the * channel state to MSG_IDLE. * * Two sets of host interrupts are provided, INT0 and INT1. Both appear on one * interrupt level; they are distinguished by a pair of bits in the IOP status * register. The IOP will raise INT0 when one or more messages in the send * channels have gone to the MSG_COMPLETE state and it will raise INT1 when one * or more messages on the receive channels have gone to the MSG_NEW state. * * Since each channel handles only one message we have to implement a small * interrupt-driven queue on our end. Messages to be sent are placed on the * queue for sending and contain a pointer to an optional callback function. * The handler for a message is called when the message state goes to * MSG_COMPLETE. * * For receiving message we maintain a list of handler functions to call when * a message is received on that IOP/channel combination. The handlers are * called much like an interrupt handler and are passed a copy of the message * from the IOP. The message state will be in MSG_RCVD while the handler runs; * it is the handler's responsibility to call iop_complete_message() when * finished; this function moves the message state to MSG_COMPLETE and signals * the IOP. This two-step process is provided to allow the handler to defer * message processing to a bottom-half handler if the processing will take * a significant amount of time (handlers are called at interrupt time so they * should execute quickly.) */ #include <linux/types.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/delay.h> #include <linux/init.h> #include <linux/interrupt.h> #include <asm/macintosh.h> #include <asm/macints.h> #include <asm/mac_iop.h> /*#define DEBUG_IOP*/ /* Non-zero if the IOPs are present */ int iop_scc_present, iop_ism_present; /* structure for tracking channel listeners */ struct listener { const char *devname; void (*handler)(struct iop_msg *); }; /* * IOP structures for the two IOPs * * The SCC IOP controls both serial ports (A and B) as its two functions. * The ISM IOP controls the SWIM (floppy drive) and ADB. */ static volatile struct mac_iop *iop_base[NUM_IOPS]; /* * IOP message queues */ static struct iop_msg iop_msg_pool[NUM_IOP_MSGS]; static struct iop_msg *iop_send_queue[NUM_IOPS][NUM_IOP_CHAN]; static struct listener iop_listeners[NUM_IOPS][NUM_IOP_CHAN]; irqreturn_t iop_ism_irq(int, void *); /* * Private access functions */ static __inline__ void iop_loadaddr(volatile struct mac_iop *iop, __u16 addr) { iop->ram_addr_lo = addr; iop->ram_addr_hi = addr >> 8; } static __inline__ __u8 iop_readb(volatile struct mac_iop *iop, __u16 addr) { iop->ram_addr_lo = addr; iop->ram_addr_hi = addr >> 8; return iop->ram_data; } static __inline__ void iop_writeb(volatile struct mac_iop *iop, __u16 addr, __u8 data) { iop->ram_addr_lo = addr; iop->ram_addr_hi = addr >> 8; iop->ram_data = data; } static __inline__ void iop_stop(volatile struct mac_iop *iop) { iop->status_ctrl &= ~IOP_RUN; } static __inline__ void iop_start(volatile struct mac_iop *iop) { iop->status_ctrl = IOP_RUN | IOP_AUTOINC; } static __inline__ void iop_bypass(volatile struct mac_iop *iop) { iop->status_ctrl |= IOP_BYPASS; } static __inline__ void iop_interrupt(volatile struct mac_iop *iop) { iop->status_ctrl |= IOP_IRQ; } static int iop_alive(volatile struct mac_iop *iop) { int retval; retval = (iop_readb(iop, IOP_ADDR_ALIVE) == 0xFF); iop_writeb(iop, IOP_ADDR_ALIVE, 0); return retval; } static struct iop_msg *iop_alloc_msg(void) { int i; unsigned long flags; local_irq_save(flags); for (i = 0 ; i < NUM_IOP_MSGS ; i++) { if (iop_msg_pool[i].status == IOP_MSGSTATUS_UNUSED) { iop_msg_pool[i].status = IOP_MSGSTATUS_WAITING; local_irq_restore(flags); return &iop_msg_pool[i]; } } local_irq_restore(flags); return NULL; } static void iop_free_msg(struct iop_msg *msg) { msg->status = IOP_MSGSTATUS_UNUSED; } /* * This is called by the startup code before anything else. Its purpose * is to find and initialize the IOPs early in the boot sequence, so that * the serial IOP can be placed into bypass mode _before_ we try to * initialize the serial console. */ void __init iop_preinit(void) { if (macintosh_config->scc_type == MAC_SCC_IOP) { if (macintosh_config->ident == MAC_MODEL_IIFX) { iop_base[IOP_NUM_SCC] = (struct mac_iop *) SCC_IOP_BASE_IIFX; } else { iop_base[IOP_NUM_SCC] = (struct mac_iop *) SCC_IOP_BASE_QUADRA; } iop_base[IOP_NUM_SCC]->status_ctrl = 0x87; iop_scc_present = 1; } else { iop_base[IOP_NUM_SCC] = NULL; iop_scc_present = 0; } if (macintosh_config->adb_type == MAC_ADB_IOP) { if (macintosh_config->ident == MAC_MODEL_IIFX) { iop_base[IOP_NUM_ISM] = (struct mac_iop *) ISM_IOP_BASE_IIFX; } else { iop_base[IOP_NUM_ISM] = (struct mac_iop *) ISM_IOP_BASE_QUADRA; } iop_base[IOP_NUM_ISM]->status_ctrl = 0; iop_ism_present = 1; } else { iop_base[IOP_NUM_ISM] = NULL; iop_ism_present = 0; } } /* * Initialize the IOPs, if present. */ void __init iop_init(void) { int i; if (iop_scc_present) { printk("IOP: detected SCC IOP at %p\n", iop_base[IOP_NUM_SCC]); } if (iop_ism_present) { printk("IOP: detected ISM IOP at %p\n", iop_base[IOP_NUM_ISM]); iop_start(iop_base[IOP_NUM_ISM]); iop_alive(iop_base[IOP_NUM_ISM]); /* clears the alive flag */ } /* Make the whole pool available and empty the queues */ for (i = 0 ; i < NUM_IOP_MSGS ; i++) { iop_msg_pool[i].status = IOP_MSGSTATUS_UNUSED; } for (i = 0 ; i < NUM_IOP_CHAN ; i++) { iop_send_queue[IOP_NUM_SCC][i] = NULL; iop_send_queue[IOP_NUM_ISM][i] = NULL; iop_listeners[IOP_NUM_SCC][i].devname = NULL; iop_listeners[IOP_NUM_SCC][i].handler = NULL; iop_listeners[IOP_NUM_ISM][i].devname = NULL; iop_listeners[IOP_NUM_ISM][i].handler = NULL; } } /* * Register the interrupt handler for the IOPs. * TODO: might be wrong for non-OSS machines. Anyone? */ void __init iop_register_interrupts(void) { if (iop_ism_present) { if (macintosh_config->ident == MAC_MODEL_IIFX) { if (request_irq(IRQ_MAC_ADB, iop_ism_irq, 0, "ISM IOP", (void *)IOP_NUM_ISM)) pr_err("Couldn't register ISM IOP interrupt\n"); } else { if (request_irq(IRQ_VIA2_0, iop_ism_irq, 0, "ISM IOP", (void *)IOP_NUM_ISM)) pr_err("Couldn't register ISM IOP interrupt\n"); } if (!iop_alive(iop_base[IOP_NUM_ISM])) { printk("IOP: oh my god, they killed the ISM IOP!\n"); } else { printk("IOP: the ISM IOP seems to be alive.\n"); } } } /* * Register or unregister a listener for a specific IOP and channel * * If the handler pointer is NULL the current listener (if any) is * unregistered. Otherwise the new listener is registered provided * there is no existing listener registered. */ int iop_listen(uint iop_num, uint chan, void (*handler)(struct iop_msg *), const char *devname) { if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return -EINVAL; if (chan >= NUM_IOP_CHAN) return -EINVAL; if (iop_listeners[iop_num][chan].handler && handler) return -EINVAL; iop_listeners[iop_num][chan].devname = devname; iop_listeners[iop_num][chan].handler = handler; return 0; } /* * Complete reception of a message, which just means copying the reply * into the buffer, setting the channel state to MSG_COMPLETE and * notifying the IOP. */ void iop_complete_message(struct iop_msg *msg) { int iop_num = msg->iop_num; int chan = msg->channel; int i,offset; #ifdef DEBUG_IOP printk("iop_complete(%p): iop %d chan %d\n", msg, msg->iop_num, msg->channel); #endif offset = IOP_ADDR_RECV_MSG + (msg->channel * IOP_MSG_LEN); for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) { iop_writeb(iop_base[iop_num], offset, msg->reply[i]); } iop_writeb(iop_base[iop_num], IOP_ADDR_RECV_STATE + chan, IOP_MSG_COMPLETE); iop_interrupt(iop_base[msg->iop_num]); iop_free_msg(msg); } /* * Actually put a message into a send channel buffer */ static void iop_do_send(struct iop_msg *msg) { volatile struct mac_iop *iop = iop_base[msg->iop_num]; int i,offset; offset = IOP_ADDR_SEND_MSG + (msg->channel * IOP_MSG_LEN); for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) { iop_writeb(iop, offset, msg->message[i]); } iop_writeb(iop, IOP_ADDR_SEND_STATE + msg->channel, IOP_MSG_NEW); iop_interrupt(iop); } /* * Handle sending a message on a channel that * has gone into the IOP_MSG_COMPLETE state. */ static void iop_handle_send(uint iop_num, uint chan) { volatile struct mac_iop *iop = iop_base[iop_num]; struct iop_msg *msg,*msg2; int i,offset; #ifdef DEBUG_IOP printk("iop_handle_send: iop %d channel %d\n", iop_num, chan); #endif iop_writeb(iop, IOP_ADDR_SEND_STATE + chan, IOP_MSG_IDLE); if (!(msg = iop_send_queue[iop_num][chan])) return; msg->status = IOP_MSGSTATUS_COMPLETE; offset = IOP_ADDR_SEND_MSG + (chan * IOP_MSG_LEN); for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) { msg->reply[i] = iop_readb(iop, offset); } if (msg->handler) (*msg->handler)(msg); msg2 = msg; msg = msg->next; iop_free_msg(msg2); iop_send_queue[iop_num][chan] = msg; if (msg) iop_do_send(msg); } /* * Handle reception of a message on a channel that has * gone into the IOP_MSG_NEW state. */ static void iop_handle_recv(uint iop_num, uint chan) { volatile struct mac_iop *iop = iop_base[iop_num]; int i,offset; struct iop_msg *msg; #ifdef DEBUG_IOP printk("iop_handle_recv: iop %d channel %d\n", iop_num, chan); #endif msg = iop_alloc_msg(); msg->iop_num = iop_num; msg->channel = chan; msg->status = IOP_MSGSTATUS_UNSOL; msg->handler = iop_listeners[iop_num][chan].handler; offset = IOP_ADDR_RECV_MSG + (chan * IOP_MSG_LEN); for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) { msg->message[i] = iop_readb(iop, offset); } iop_writeb(iop, IOP_ADDR_RECV_STATE + chan, IOP_MSG_RCVD); /* If there is a listener, call it now. Otherwise complete */ /* the message ourselves to avoid possible stalls. */ if (msg->handler) { (*msg->handler)(msg); } else { #ifdef DEBUG_IOP printk("iop_handle_recv: unclaimed message on iop %d channel %d\n", iop_num, chan); printk("iop_handle_recv:"); for (i = 0 ; i < IOP_MSG_LEN ; i++) { printk(" %02X", (uint) msg->message[i]); } printk("\n"); #endif iop_complete_message(msg); } } /* * Send a message * * The message is placed at the end of the send queue. Afterwards if the * channel is idle we force an immediate send of the next message in the * queue. */ int iop_send_message(uint iop_num, uint chan, void *privdata, uint msg_len, __u8 *msg_data, void (*handler)(struct iop_msg *)) { struct iop_msg *msg, *q; if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return -EINVAL; if (chan >= NUM_IOP_CHAN) return -EINVAL; if (msg_len > IOP_MSG_LEN) return -EINVAL; msg = iop_alloc_msg(); if (!msg) return -ENOMEM; msg->next = NULL; msg->status = IOP_MSGSTATUS_WAITING; msg->iop_num = iop_num; msg->channel = chan; msg->caller_priv = privdata; memcpy(msg->message, msg_data, msg_len); msg->handler = handler; if (!(q = iop_send_queue[iop_num][chan])) { iop_send_queue[iop_num][chan] = msg; } else { while (q->next) q = q->next; q->next = msg; } if (iop_readb(iop_base[iop_num], IOP_ADDR_SEND_STATE + chan) == IOP_MSG_IDLE) { iop_do_send(msg); } return 0; } /* * Upload code to the shared RAM of an IOP. */ void iop_upload_code(uint iop_num, __u8 *code_start, uint code_len, __u16 shared_ram_start) { if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return; iop_loadaddr(iop_base[iop_num], shared_ram_start); while (code_len--) { iop_base[iop_num]->ram_data = *code_start++; } } /* * Download code from the shared RAM of an IOP. */ void iop_download_code(uint iop_num, __u8 *code_start, uint code_len, __u16 shared_ram_start) { if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return; iop_loadaddr(iop_base[iop_num], shared_ram_start); while (code_len--) { *code_start++ = iop_base[iop_num]->ram_data; } } /* * Compare the code in the shared RAM of an IOP with a copy in system memory * and return 0 on match or the first nonmatching system memory address on * failure. */ __u8 *iop_compare_code(uint iop_num, __u8 *code_start, uint code_len, __u16 shared_ram_start) { if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return code_start; iop_loadaddr(iop_base[iop_num], shared_ram_start); while (code_len--) { if (*code_start != iop_base[iop_num]->ram_data) { return code_start; } code_start++; } return (__u8 *) 0; } /* * Handle an ISM IOP interrupt */ irqreturn_t iop_ism_irq(int irq, void *dev_id) { uint iop_num = (uint) dev_id; volatile struct mac_iop *iop = iop_base[iop_num]; int i,state; #ifdef DEBUG_IOP printk("iop_ism_irq: status = %02X\n", (uint) iop->status_ctrl); #endif /* INT0 indicates a state change on an outgoing message channel */ if (iop->status_ctrl & IOP_INT0) { iop->status_ctrl = IOP_INT0 | IOP_RUN | IOP_AUTOINC; #ifdef DEBUG_IOP printk("iop_ism_irq: new status = %02X, send states", (uint) iop->status_ctrl); #endif for (i = 0 ; i < NUM_IOP_CHAN ; i++) { state = iop_readb(iop, IOP_ADDR_SEND_STATE + i); #ifdef DEBUG_IOP printk(" %02X", state); #endif if (state == IOP_MSG_COMPLETE) { iop_handle_send(iop_num, i); } } #ifdef DEBUG_IOP printk("\n"); #endif } if (iop->status_ctrl & IOP_INT1) { /* INT1 for incoming msgs */ iop->status_ctrl = IOP_INT1 | IOP_RUN | IOP_AUTOINC; #ifdef DEBUG_IOP printk("iop_ism_irq: new status = %02X, recv states", (uint) iop->status_ctrl); #endif for (i = 0 ; i < NUM_IOP_CHAN ; i++) { state = iop_readb(iop, IOP_ADDR_RECV_STATE + i); #ifdef DEBUG_IOP printk(" %02X", state); #endif if (state == IOP_MSG_NEW) { iop_handle_recv(iop_num, i); } } #ifdef DEBUG_IOP printk("\n"); #endif } return IRQ_HANDLED; }