pcic.c

讲述linux的初始化过程

static void
pcic_fill_irq(struct linux_pcic *pcic, struct pci_dev *dev, int node)
{
	struct pcic_ca2irq *p;
	int i, ivec;
	char namebuf[64];

	if (node == 0 || node == -1) {
		strcpy(namebuf, "???");
	} else {
		prom_getstring(node, "name", namebuf, sizeof(namebuf));
	}

	if ((p = pcic->pcic_imap) == 0) {
		dev->irq = 0;
		return;
	}
	for (i = 0; i < pcic->pcic_imdim; i++) {
		if (p->busno == dev->bus->number && p->devfn == dev->devfn)
			break;
		p++;
	}
	if (i >= pcic->pcic_imdim) {
		printk("PCIC: device %s devfn %02x:%02x not found in %d\n",
		    namebuf, dev->bus->number, dev->devfn, pcic->pcic_imdim);
		dev->irq = 0;
		return;
	}

	i = p->pin;
	if (i >= 0 && i < 4) {
		ivec = readw(pcic->pcic_regs+PCI_INT_SELECT_LO);
		dev->irq = ivec >> (i << 2) & 0xF;
	} else if (i >= 4 && i < 8) {
		ivec = readw(pcic->pcic_regs+PCI_INT_SELECT_HI);
		dev->irq = ivec >> ((i-4) << 2) & 0xF;
	} else {					/* Corrupted map */
		printk("PCIC: BAD PIN %d\n", i); for (;;) {}
	}
/* P3 */ /* printk("PCIC: device %s pin %d ivec 0x%x irq %x\n", namebuf, i, ivec, dev->irq); */

	/*
	 * dev->irq=0 means PROM did not bother to program the upper
	 * half of PCIC. This happens on JS-E with PROM 3.11, for instance.
	 */
	if (dev->irq == 0 || p->force) {
		if (p->irq == 0 || p->irq >= 15) {	/* Corrupted map */
			printk("PCIC: BAD IRQ %d\n", p->irq); for (;;) {}
		}
		printk("PCIC: setting irq %d at pin %d for device %02x:%02x\n",
		    p->irq, p->pin, dev->bus->number, dev->devfn);
		dev->irq = p->irq;

		i = p->pin;
		if (i >= 4) {
			ivec = readw(pcic->pcic_regs+PCI_INT_SELECT_HI);
			ivec &= ~(0xF << ((i - 4) << 2));
			ivec |= p->irq << ((i - 4) << 2);
			writew(ivec, pcic->pcic_regs+PCI_INT_SELECT_HI);
		} else {
			ivec = readw(pcic->pcic_regs+PCI_INT_SELECT_LO);
			ivec &= ~(0xF << (i << 2));
			ivec |= p->irq << (i << 2);
			writew(ivec, pcic->pcic_regs+PCI_INT_SELECT_LO);
		}
 	}

	return;
}

/*
 * Normally called from {do_}pci_scan_bus...
 */
void __init pcibios_fixup_bus(struct pci_bus *bus)
{
	struct list_head *walk;
	int i, has_io, has_mem;
	unsigned short cmd;
	struct linux_pcic *pcic;
	/* struct linux_pbm_info* pbm = &pcic->pbm; */
	int node;
	struct pcidev_cookie *pcp;

	if (!pcic0_up) {
		printk("pcibios_fixup_bus: no PCIC\n");
		return;
	}
	pcic = &pcic0;

	/*
	 * Next crud is an equivalent of pbm = pcic_bus_to_pbm(bus);
	 */
	if (bus->number != 0) {
		printk("pcibios_fixup_bus: nonzero bus 0x%x\n", bus->number);
		return;
	}

	walk = &bus->devices;
	for (walk = walk->next; walk != &bus->devices; walk = walk->next) {
		struct pci_dev *dev = pci_dev_b(walk);

		/*
		 * Comment from i386 branch:
		 *     There are buggy BIOSes that forget to enable I/O and memory
		 *     access to PCI devices. We try to fix this, but we need to
		 *     be sure that the BIOS didn't forget to assign an address
		 *     to the device. [mj]
		 * OBP is a case of such BIOS :-)
		 */
		has_io = has_mem = 0;
		for(i=0; i<6; i++) {
			unsigned long f = dev->resource[i].flags;
			if (f & IORESOURCE_IO) {
				has_io = 1;
			} else if (f & IORESOURCE_MEM)
				has_mem = 1;
		}
		pcic_read_config_word(dev, PCI_COMMAND, &cmd);
		if (has_io && !(cmd & PCI_COMMAND_IO)) {
			printk("PCIC: Enabling I/O for device %02x:%02x\n",
				dev->bus->number, dev->devfn);
			cmd |= PCI_COMMAND_IO;
			pcic_write_config_word(dev, PCI_COMMAND, cmd);
		}
		if (has_mem && !(cmd & PCI_COMMAND_MEMORY)) {
			printk("PCIC: Enabling memory for device %02x:%02x\n",
				dev->bus->number, dev->devfn);
			cmd |= PCI_COMMAND_MEMORY;
			pcic_write_config_word(dev, PCI_COMMAND, cmd);
		}    

		node = pdev_to_pnode(&pcic->pbm, dev);
		if(node == 0)
			node = -1;

		/* cookies */
		pcp = pci_devcookie_alloc();
		pcp->pbm = &pcic->pbm;
		pcp->prom_node = node;
		dev->sysdata = pcp;

		/* fixing I/O to look like memory */
		if ((dev->class>>16) != PCI_BASE_CLASS_BRIDGE)
			pcic_map_pci_device(pcic, dev, node);

		pcic_fill_irq(pcic, dev, node);
	}
}

/*
 * pcic_pin_to_irq() is exported to ebus.c.
 */
unsigned int
pcic_pin_to_irq(unsigned int pin, char *name)
{
	struct linux_pcic *pcic = &pcic0;
	unsigned int irq;
	unsigned int ivec;

	if (pin < 4) {
		ivec = readw(pcic->pcic_regs+PCI_INT_SELECT_LO);
		irq = ivec >> (pin << 2) & 0xF;
	} else if (pin < 8) {
		ivec = readw(pcic->pcic_regs+PCI_INT_SELECT_HI);
		irq = ivec >> ((pin-4) << 2) & 0xF;
	} else {					/* Corrupted map */
		printk("PCIC: BAD PIN %d FOR %s\n", pin, name);
		for (;;) {}	/* XXX Cannot panic properly in case of PROLL */
	}
/* P3 */ /* printk("PCIC: dev %s pin %d ivec 0x%x irq %x\n", name, pin, ivec, irq); */
	return irq;
}

/* Makes compiler happy */
static volatile int pcic_timer_dummy;

static void pcic_clear_clock_irq(void)
{
	pcic_timer_dummy = readl(pcic0.pcic_regs+PCI_SYS_LIMIT);
}

static void pcic_timer_handler (int irq, void *h, struct pt_regs *regs)
{
	pcic_clear_clock_irq();
	do_timer(regs);
}

#define USECS_PER_JIFFY  10000  /* We have 100HZ "standard" timer for sparc */
#define TICK_TIMER_LIMIT ((100*1000000/4)/100)

void __init pci_time_init(void)
{
	struct linux_pcic *pcic = &pcic0;
	unsigned long v;
	int timer_irq, irq;

	do_get_fast_time = pci_do_gettimeofday;
	/* A hack until do_gettimeofday prototype is moved to arch specific headers
	   and btfixupped. Patch do_gettimeofday with ba pci_do_gettimeofday; nop */
	((unsigned int *)do_gettimeofday)[0] = 
	    0x10800000 | ((((unsigned long)pci_do_gettimeofday -
	     (unsigned long)do_gettimeofday) >> 2) & 0x003fffff);
	((unsigned int *)do_gettimeofday)[1] = 0x01000000;
	BTFIXUPSET_CALL(bus_do_settimeofday, pci_do_settimeofday, BTFIXUPCALL_NORM);
	btfixup();

	writel (TICK_TIMER_LIMIT, pcic->pcic_regs+PCI_SYS_LIMIT);
	/* PROM should set appropriate irq */
	v = readb(pcic->pcic_regs+PCI_COUNTER_IRQ);
	timer_irq = PCI_COUNTER_IRQ_SYS(v);
	writel (PCI_COUNTER_IRQ_SET(timer_irq, 0),
		pcic->pcic_regs+PCI_COUNTER_IRQ);
	irq = request_irq(timer_irq, pcic_timer_handler,
			  (SA_INTERRUPT | SA_STATIC_ALLOC), "timer", NULL);
	if (irq) {
		prom_printf("time_init: unable to attach IRQ%d\n", timer_irq);
		prom_halt();
	}
	__sti();
}

static __inline__ unsigned long do_gettimeoffset(void)
{
	struct tasklet_struct *t;
	unsigned long offset = 0;

	/* 
	 * We devide all to 100
	 * to have microsecond resolution and to avoid overflow
	 */
	unsigned long count = 
	    readl(pcic0.pcic_regs+PCI_SYS_COUNTER) & ~PCI_SYS_COUNTER_OVERFLOW;
	count = ((count/100)*USECS_PER_JIFFY) / (TICK_TIMER_LIMIT/100);

	t = &bh_task_vec[TIMER_BH];
	if (test_bit(TASKLET_STATE_SCHED, &t->state))
		offset = 1000000;
	return offset + count;
}

extern volatile unsigned long wall_jiffies;

static void pci_do_gettimeofday(struct timeval *tv)
{
 	unsigned long flags;

	save_and_cli(flags);
	*tv = xtime;
	tv->tv_usec += do_gettimeoffset();

	/*
	 * xtime is atomically updated in timer_bh. The difference
	 * between jiffies and wall_jiffies is nonzero if the timer
	 * bottom half hasnt executed yet.
	 */
	if ((jiffies - wall_jiffies) != 0)
		tv->tv_usec += USECS_PER_JIFFY;

	restore_flags(flags);

	if (tv->tv_usec >= 1000000) {
		tv->tv_usec -= 1000000;
		tv->tv_sec++;
	}       
}

static void pci_do_settimeofday(struct timeval *tv)
{
	cli();
	tv->tv_usec -= do_gettimeoffset();
	if(tv->tv_usec < 0) {
		tv->tv_usec += 1000000;
		tv->tv_sec--;
	}
	xtime = *tv;
	time_adjust = 0;		/* stop active adjtime() */
	time_status |= STA_UNSYNC;
	time_maxerror = NTP_PHASE_LIMIT;
	time_esterror = NTP_PHASE_LIMIT;
	sti();
}

#if 0
static void watchdog_reset() {
	writeb(0, pcic->pcic_regs+PCI_SYS_STATUS);
}
#endif

/*
 * Other archs parse arguments here.
 */
char * __init pcibios_setup(char *str)
{
	return str;
}

/*
 */
void pcibios_update_resource(struct pci_dev *pdev, struct resource *res1,
			     struct resource *res2, int index)
{
}

void pcibios_align_resource(void *data, struct resource *res, unsigned long size)
{
}

int pcibios_enable_device(struct pci_dev *pdev)
{
	return 0;
}

/*
 * NMI
 */
void pcic_nmi(unsigned int pend, struct pt_regs *regs)
{

	pend = flip_dword(pend);

	if (!pcic_speculative || (pend & PCI_SYS_INT_PENDING_PIO) == 0) {
		/*
		 * XXX On CP-1200 PCI #SERR may happen, we do not know
		 * what to do about it yet.
		 */
		printk("Aiee, NMI pend 0x%x pc 0x%x spec %d, hanging\n",
		    pend, (int)regs->pc, pcic_speculative);
		for (;;) { }
	}
	pcic_speculative = 0;
	pcic_trapped = 1;
	regs->pc = regs->npc;
	regs->npc += 4;
}

/*
 * XXX  Gleb wrote me that he needs this for X server (only).
 * Since we successfuly use XF86_FBDev, we do not need these anymore.
 *
 *  Following code added to handle extra PCI-related system calls 
 */
asmlinkage int sys_pciconfig_read(unsigned long bus,
				  unsigned long dfn,
				  unsigned long off,
				  unsigned long len,
				  unsigned char *buf)
{
	unsigned char ubyte;
	unsigned short ushort;
	unsigned int uint;
	int err = 0;

	if(!suser())
		return -EPERM;

	switch(len) {
	case 1:
		pcibios_read_config_byte(bus, dfn, off, &ubyte);
		put_user(ubyte, (unsigned char *)buf);
		break;
	case 2:
		pcibios_read_config_word(bus, dfn, off, &ushort);
		put_user(ushort, (unsigned short *)buf);
		break;
	case 4:
		pcibios_read_config_dword(bus, dfn, off, &uint);
		put_user(uint, (unsigned int *)buf);
		break;

	default:
		err = -EINVAL;
		break;
	};

	return err;
}

asmlinkage int sys_pciconfig_write(unsigned long bus,
				   unsigned long dfn,
				   unsigned long off,
				   unsigned long len,
				   unsigned char *buf)
{
	unsigned char ubyte;
	unsigned short ushort;
	unsigned int uint;
	int err = 0;

	if(!suser())
		return -EPERM;

	switch(len) {
	case 1:
		err = get_user(ubyte, (unsigned char *)buf);
		if(err)
			break;
		pcibios_write_config_byte(bus, dfn, off, ubyte);
		break;

	case 2:
		err = get_user(ushort, (unsigned short *)buf);
		if(err)
			break;
		pcibios_write_config_byte(bus, dfn, off, ushort);
		break;

	case 4:
		err = get_user(uint, (unsigned int *)buf);
		if(err)
			break;
		pcibios_write_config_byte(bus, dfn, off, uint);
		break;

	default:
		err = -EINVAL;
		break;

	};

	return err;
}			   

static inline unsigned long get_irqmask(int irq_nr)
{
	return 1 << irq_nr;
}

static inline char *pcic_irq_itoa(unsigned int irq)
{
	static char buff[16];
	sprintf(buff, "%d", irq);
	return buff;
}

static void pcic_disable_irq(unsigned int irq_nr)
{
	unsigned long mask, flags;

	mask = get_irqmask(irq_nr);
	save_and_cli(flags);
	writel(mask, pcic0.pcic_regs+PCI_SYS_INT_TARGET_MASK_SET);
	restore_flags(flags);
}

static void pcic_enable_irq(unsigned int irq_nr)
{
	unsigned long mask, flags;

	mask = get_irqmask(irq_nr);
	save_and_cli(flags);
	writel(mask, pcic0.pcic_regs+PCI_SYS_INT_TARGET_MASK_CLEAR);
	restore_flags(flags);
}

static void pcic_clear_profile_irq(int cpu)
{
	printk("PCIC: unimplemented code: FILE=%s LINE=%d", __FILE__, __LINE__);
}

static void pcic_load_profile_irq(int cpu, unsigned int limit)
{
	printk("PCIC: unimplemented code: FILE=%s LINE=%d", __FILE__, __LINE__);
}

/* We assume the caller is local cli()'d when these are called, or else
 * very bizarre behavior will result.
 */
static void pcic_disable_pil_irq(unsigned int pil)
{
	writel(get_irqmask(pil), pcic0.pcic_regs+PCI_SYS_INT_TARGET_MASK_SET);
}

static void pcic_enable_pil_irq(unsigned int pil)
{
	writel(get_irqmask(pil), pcic0.pcic_regs+PCI_SYS_INT_TARGET_MASK_CLEAR);
}

void __init sun4m_pci_init_IRQ(void)
{
	BTFIXUPSET_CALL(enable_irq, pcic_enable_irq, BTFIXUPCALL_NORM);
	BTFIXUPSET_CALL(disable_irq, pcic_disable_irq, BTFIXUPCALL_NORM);
	BTFIXUPSET_CALL(enable_pil_irq, pcic_enable_pil_irq, BTFIXUPCALL_NORM);
	BTFIXUPSET_CALL(disable_pil_irq, pcic_disable_pil_irq, BTFIXUPCALL_NORM);
	BTFIXUPSET_CALL(clear_clock_irq, pcic_clear_clock_irq, BTFIXUPCALL_NORM);
	BTFIXUPSET_CALL(clear_profile_irq, pcic_clear_profile_irq, BTFIXUPCALL_NORM);
	BTFIXUPSET_CALL(load_profile_irq, pcic_load_profile_irq, BTFIXUPCALL_NORM);
	BTFIXUPSET_CALL(__irq_itoa, pcic_irq_itoa, BTFIXUPCALL_NORM);
}

int pcibios_assign_resource(struct pci_dev *pdev, int resource)
{
	return -ENXIO;
}

/*
 * This probably belongs here rather than ioport.c because
 * we do not want this crud linked into SBus kernels.
 * Also, think for a moment about likes of floppy.c that
 * include architecture specific parts. They may want to redefine ins/outs.
 *
 * We do not use horroble macroses here because we want to
 * advance pointer by sizeof(size).
 */
void outsb(unsigned long addr, const void *src, unsigned long count) {
	while (count) {
		count -= 1;
		writeb(*(const char *)src, addr);
		src += 1;
		addr += 1;
	}
}

void outsw(unsigned long addr, const void *src, unsigned long count) {
	while (count) {
		count -= 2;
		writew(*(const short *)src, addr);
		src += 2;
		addr += 2;
	}
}

void outsl(unsigned long addr, const void *src, unsigned long count) {
	while (count) {
		count -= 4;
		writel(*(const long *)src, addr);
		src += 4;
		addr += 4;
	}
}

void insb(unsigned long addr, void *dst, unsigned long count) {
	while (count) {
		count -= 1;
		*(unsigned char *)dst = readb(addr);
		dst += 1;
		addr += 1;
	}
}

void insw(unsigned long addr, void *dst, unsigned long count) {
	while (count) {
		count -= 2;
		*(unsigned short *)dst = readw(addr);
		dst += 2;
		addr += 2;
	}
}

void insl(unsigned long addr, void *dst, unsigned long count) {
	while (count) {
		count -= 4;
		/*
		 * XXX I am sure we are in for an unaligned trap here.
		 */
		*(unsigned long *)dst = readl(addr);
		dst += 4;
		addr += 4;
	}
}

#endif