linux/drivers/macintosh/adb-iop.c

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/*
* I/O Processor (IOP) ADB Driver
* Written and (C) 1999 by Joshua M. Thompson (funaho@jurai.org)
* Based on via-cuda.c by Paul Mackerras.
*
* 1999-07-01 (jmt) - First implementation for new driver architecture.
*
* 1999-07-31 (jmt) - First working version.
*
* TODO:
*
* o Implement SRQ handling.
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <asm/macintosh.h>
#include <asm/macints.h>
#include <asm/mac_iop.h>
#include <asm/mac_oss.h>
#include <asm/adb_iop.h>
#include <linux/adb.h>
/*#define DEBUG_ADB_IOP*/
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:55:46 +02:00
extern void iop_ism_irq(int, void *);
static struct adb_request *current_req;
static struct adb_request *last_req;
#if 0
static unsigned char reply_buff[16];
static unsigned char *reply_ptr;
#endif
static enum adb_iop_state {
idle,
sending,
awaiting_reply
} adb_iop_state;
static void adb_iop_start(void);
static int adb_iop_probe(void);
static int adb_iop_init(void);
static int adb_iop_send_request(struct adb_request *, int);
static int adb_iop_write(struct adb_request *);
static int adb_iop_autopoll(int);
static void adb_iop_poll(void);
static int adb_iop_reset_bus(void);
struct adb_driver adb_iop_driver = {
"ISM IOP",
adb_iop_probe,
adb_iop_init,
adb_iop_send_request,
adb_iop_autopoll,
adb_iop_poll,
adb_iop_reset_bus
};
static void adb_iop_end_req(struct adb_request *req, int state)
{
req->complete = 1;
current_req = req->next;
if (req->done) (*req->done)(req);
adb_iop_state = state;
}
/*
* Completion routine for ADB commands sent to the IOP.
*
* This will be called when a packet has been successfully sent.
*/
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:55:46 +02:00
static void adb_iop_complete(struct iop_msg *msg)
{
struct adb_request *req;
unsigned long flags;
local_irq_save(flags);
req = current_req;
if ((adb_iop_state == sending) && req && req->reply_expected) {
adb_iop_state = awaiting_reply;
}
local_irq_restore(flags);
}
/*
* Listen for ADB messages from the IOP.
*
* This will be called when unsolicited messages (usually replies to TALK
* commands or autopoll packets) are received.
*/
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:55:46 +02:00
static void adb_iop_listen(struct iop_msg *msg)
{
struct adb_iopmsg *amsg = (struct adb_iopmsg *) msg->message;
struct adb_request *req;
unsigned long flags;
#ifdef DEBUG_ADB_IOP
int i;
#endif
local_irq_save(flags);
req = current_req;
#ifdef DEBUG_ADB_IOP
printk("adb_iop_listen %p: rcvd packet, %d bytes: %02X %02X", req,
(uint) amsg->count + 2, (uint) amsg->flags, (uint) amsg->cmd);
for (i = 0; i < amsg->count; i++)
printk(" %02X", (uint) amsg->data[i]);
printk("\n");
#endif
/* Handle a timeout. Timeout packets seem to occur even after */
/* we've gotten a valid reply to a TALK, so I'm assuming that */
/* a "timeout" is actually more like an "end-of-data" signal. */
/* We need to send back a timeout packet to the IOP to shut */
/* it up, plus complete the current request, if any. */
if (amsg->flags & ADB_IOP_TIMEOUT) {
msg->reply[0] = ADB_IOP_TIMEOUT | ADB_IOP_AUTOPOLL;
msg->reply[1] = 0;
msg->reply[2] = 0;
if (req && (adb_iop_state != idle)) {
adb_iop_end_req(req, idle);
}
} else {
/* TODO: is it possible for more than one chunk of data */
/* to arrive before the timeout? If so we need to */
/* use reply_ptr here like the other drivers do. */
if ((adb_iop_state == awaiting_reply) &&
(amsg->flags & ADB_IOP_EXPLICIT)) {
req->reply_len = amsg->count + 1;
memcpy(req->reply, &amsg->cmd, req->reply_len);
} else {
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:55:46 +02:00
adb_input(&amsg->cmd, amsg->count + 1,
amsg->flags & ADB_IOP_AUTOPOLL);
}
memcpy(msg->reply, msg->message, IOP_MSG_LEN);
}
iop_complete_message(msg);
local_irq_restore(flags);
}
/*
* Start sending an ADB packet, IOP style
*
* There isn't much to do other than hand the packet over to the IOP
* after encapsulating it in an adb_iopmsg.
*/
static void adb_iop_start(void)
{
unsigned long flags;
struct adb_request *req;
struct adb_iopmsg amsg;
#ifdef DEBUG_ADB_IOP
int i;
#endif
/* get the packet to send */
req = current_req;
if (!req) return;
local_irq_save(flags);
#ifdef DEBUG_ADB_IOP
printk("adb_iop_start %p: sending packet, %d bytes:", req, req->nbytes);
for (i = 0 ; i < req->nbytes ; i++)
printk(" %02X", (uint) req->data[i]);
printk("\n");
#endif
/* The IOP takes MacII-style packets, so */
/* strip the initial ADB_PACKET byte. */
amsg.flags = ADB_IOP_EXPLICIT;
amsg.count = req->nbytes - 2;
/* amsg.data immediately follows amsg.cmd, effectively making */
/* amsg.cmd a pointer to the beginning of a full ADB packet. */
memcpy(&amsg.cmd, req->data + 1, req->nbytes - 1);
req->sent = 1;
adb_iop_state = sending;
local_irq_restore(flags);
/* Now send it. The IOP manager will call adb_iop_complete */
/* when the packet has been sent. */
iop_send_message(ADB_IOP, ADB_CHAN, req,
sizeof(amsg), (__u8 *) &amsg, adb_iop_complete);
}
int adb_iop_probe(void)
{
if (!iop_ism_present) return -ENODEV;
return 0;
}
int adb_iop_init(void)
{
printk("adb: IOP ISM driver v0.4 for Unified ADB.\n");
iop_listen(ADB_IOP, ADB_CHAN, adb_iop_listen, "ADB");
return 0;
}
int adb_iop_send_request(struct adb_request *req, int sync)
{
int err;
err = adb_iop_write(req);
if (err) return err;
if (sync) {
while (!req->complete) adb_iop_poll();
}
return 0;
}
static int adb_iop_write(struct adb_request *req)
{
unsigned long flags;
if ((req->nbytes < 2) || (req->data[0] != ADB_PACKET)) {
req->complete = 1;
return -EINVAL;
}
local_irq_save(flags);
req->next = NULL;
req->sent = 0;
req->complete = 0;
req->reply_len = 0;
if (current_req != 0) {
last_req->next = req;
last_req = req;
} else {
current_req = req;
last_req = req;
}
local_irq_restore(flags);
if (adb_iop_state == idle) adb_iop_start();
return 0;
}
int adb_iop_autopoll(int devs)
{
/* TODO: how do we enable/disable autopoll? */
return 0;
}
void adb_iop_poll(void)
{
if (adb_iop_state == idle) adb_iop_start();
iop_ism_irq(0, (void *) ADB_IOP);
}
int adb_iop_reset_bus(void)
{
struct adb_request req = {
.reply_expected = 0,
.nbytes = 2,
.data = { ADB_PACKET, 0 },
};
adb_iop_write(&req);
while (!req.complete) {
adb_iop_poll();
schedule();
}
return 0;
}