/*
	2005.11 yhlu add let the real sb to use small uintid

*/

#include <bitops.h>
#include <console/console.h>
#include <device/device.h>
#include <device/path.h>
#include <device/pci.h>
#include <device/pci_ids.h>
#include <device/hypertransport.h>
#include <part/hard_reset.h>
#include <part/fallback_boot.h>

#define OPT_HT_LINK 0
        
#if OPT_HT_LINK == 1
#include <cpu/amd/model_fxx_rev.h>
#endif

static device_t ht_scan_get_devs(device_t *old_devices)
{
	device_t first, last;
	first = *old_devices;
	last = first;
	/* Extract the chain of devices to (first through last)
	 * for the next hypertransport device.
	 */
	while(last && last->sibling && 
		(last->sibling->path.type == DEVICE_PATH_PCI) &&
		(last->sibling->path.u.pci.devfn > last->path.u.pci.devfn)) 
	{
		last = last->sibling;
	}
	if (first) {
		device_t child;
		/* Unlink the chain from the list of old devices */
		*old_devices = last->sibling;
		last->sibling = 0;

		/* Now add the device to the list of devices on the bus.
		 */
		/* Find the last child of our parent */
		for(child = first->bus->children; child && child->sibling; ) {
			child = child->sibling;
		}
		/* Place the chain on the list of children of their parent. */
		if (child) {
			child->sibling = first;
		} else {
			first->bus->children = first;
		}
	}
	return first;
}

#if OPT_HT_LINK == 1
static unsigned ht_read_freq_cap(device_t dev, unsigned pos)
{
	/* Handle bugs in valid hypertransport frequency reporting */
	unsigned freq_cap;

	freq_cap = pci_read_config16(dev, pos);
	freq_cap &= ~(1 << HT_FREQ_VENDOR); /* Ignore Vendor HT frequencies */

	/* AMD 8131 Errata 48 */
	if ((dev->vendor == PCI_VENDOR_ID_AMD) &&
		(dev->device == PCI_DEVICE_ID_AMD_8131_PCIX)) {
		freq_cap &= ~(1 << HT_FREQ_800Mhz);
	}
	/* AMD 8151 Errata 23 */
	if ((dev->vendor == PCI_VENDOR_ID_AMD) &&
		(dev->device == PCI_DEVICE_ID_AMD_8151_SYSCTRL)) {
		freq_cap &= ~(1 << HT_FREQ_800Mhz);
	}
	/* AMD K8 Unsupported 1Ghz? */
	if ((dev->vendor == PCI_VENDOR_ID_AMD) && (dev->device == 0x1100)) {
#if K8_HT_FREQ_1G_SUPPORT == 1 
	#if K8_REV_F_SUPPORT == 0 
		if (is_cpu_pre_e0()) { // only e0 later suupport 1GHz HT
			freq_cap &= ~(1 << HT_FREQ_1000Mhz);
		} 
	#endif
#else
		freq_cap &= ~(1 << HT_FREQ_1000Mhz);
#endif

	}
	return freq_cap;
}
#endif

struct ht_link {
	struct device *dev;
	unsigned pos;
	unsigned char ctrl_off, config_off, freq_off, freq_cap_off;
};

static int ht_setup_link(struct ht_link *prev, device_t dev, unsigned pos)
{
	static const uint8_t link_width_to_pow2[]= { 3, 4, 0, 5, 1, 2, 0, 0 };
	static const uint8_t pow2_to_link_width[] = { 0x7, 4, 5, 0, 1, 3 };
	struct ht_link cur[1];
	unsigned present_width_cap,    upstream_width_cap;
	unsigned present_freq_cap,     upstream_freq_cap;
	unsigned ln_present_width_in,  ln_upstream_width_in; 
	unsigned ln_present_width_out, ln_upstream_width_out;
	unsigned freq, old_freq;
	unsigned present_width, upstream_width, old_width;
	int reset_needed;
	int linkb_to_host;

	/* Set the hypertransport link width and frequency */
	reset_needed = 0;
	/* See which side of the device our previous write to 
	 * set the unitid came from.
	 */
	cur->dev = dev;
	cur->pos = pos;
	linkb_to_host = (pci_read_config16(cur->dev, cur->pos + PCI_CAP_FLAGS) >> 10) & 1;
	if (!linkb_to_host) {
		cur->ctrl_off     = PCI_HT_CAP_SLAVE_CTRL0;
		cur->config_off   = PCI_HT_CAP_SLAVE_WIDTH0;
		cur->freq_off     = PCI_HT_CAP_SLAVE_FREQ0;
		cur->freq_cap_off = PCI_HT_CAP_SLAVE_FREQ_CAP0;
	}
	else {
		cur->ctrl_off     = PCI_HT_CAP_SLAVE_CTRL1;
		cur->config_off   = PCI_HT_CAP_SLAVE_WIDTH1;
		cur->freq_off     = PCI_HT_CAP_SLAVE_FREQ1;
		cur->freq_cap_off = PCI_HT_CAP_SLAVE_FREQ_CAP1;
	}
#if OPT_HT_LINK == 1
	/* Read the capabilities */
	present_freq_cap   = ht_read_freq_cap(cur->dev, cur->pos + cur->freq_cap_off);
	upstream_freq_cap  = ht_read_freq_cap(prev->dev, prev->pos + prev->freq_cap_off);
	present_width_cap  = pci_read_config8(cur->dev, cur->pos + cur->config_off);
	upstream_width_cap = pci_read_config8(prev->dev, prev->pos + prev->config_off);
	
	/* Calculate the highest useable frequency */
	freq = log2(present_freq_cap & upstream_freq_cap);

	/* Calculate the highest width */
	ln_upstream_width_in = link_width_to_pow2[upstream_width_cap & 7];
	ln_present_width_out = link_width_to_pow2[(present_width_cap >> 4) & 7];
	if (ln_upstream_width_in > ln_present_width_out) {
		ln_upstream_width_in = ln_present_width_out;
	}
	upstream_width = pow2_to_link_width[ln_upstream_width_in];
	present_width  = pow2_to_link_width[ln_upstream_width_in] << 4;

	ln_upstream_width_out = link_width_to_pow2[(upstream_width_cap >> 4) & 7];
	ln_present_width_in   = link_width_to_pow2[present_width_cap & 7];
	if (ln_upstream_width_out > ln_present_width_in) {
		ln_upstream_width_out = ln_present_width_in;
	}
	upstream_width |= pow2_to_link_width[ln_upstream_width_out] << 4;
	present_width  |= pow2_to_link_width[ln_upstream_width_out];

	/* Set the current device */
	old_freq = pci_read_config8(cur->dev, cur->pos + cur->freq_off);
	old_freq &= 0x0f;
	if (freq != old_freq) {
		unsigned new_freq;
		pci_write_config8(cur->dev, cur->pos + cur->freq_off, freq);
		reset_needed = 1;
		printk_spew("HyperT FreqP old %x new %x\n",old_freq,freq);
		new_freq = pci_read_config8(cur->dev, cur->pos + cur->freq_off);
		new_freq &= 0x0f;
		if (new_freq != freq) {
			printk_err("%s Hypertransport frequency would not set wanted: %x got: %x\n",
				dev_path(dev), freq, new_freq);
		}
	}
	old_width = pci_read_config8(cur->dev, cur->pos + cur->config_off + 1);
	if (present_width != old_width) {
		unsigned new_width;
		pci_write_config8(cur->dev, cur->pos + cur->config_off + 1,
			present_width);
		reset_needed = 1;
		printk_spew("HyperT widthP old %x new %x\n",old_width, present_width);
		new_width = pci_read_config8(cur->dev, cur->pos + cur->config_off + 1);
		if (new_width != present_width) {
			printk_err("%s Hypertransport width would not set wanted: %x got: %x\n",
				dev_path(dev), present_width, new_width);
		}
	}

	/* Set the upstream device */
	old_freq = pci_read_config8(prev->dev, prev->pos + prev->freq_off);
	old_freq &= 0x0f;
	if (freq != old_freq) {
		unsigned new_freq;
		pci_write_config8(prev->dev, prev->pos + prev->freq_off, freq);
		reset_needed = 1;
		printk_spew("HyperT freqU old %x new %x\n", old_freq, freq);
		new_freq = pci_read_config8(prev->dev, prev->pos + prev->freq_off);
		new_freq &= 0x0f;
		if (new_freq != freq) {
			printk_err("%s Hypertransport frequency would not set wanted: %x got: %x\n",
				dev_path(prev->dev), freq, new_freq);
		}
	}
	old_width = pci_read_config8(prev->dev, prev->pos + prev->config_off + 1);
	if (upstream_width != old_width) {
		unsigned new_width;
		pci_write_config8(prev->dev, prev->pos + prev->config_off + 1, upstream_width);
		reset_needed = 1;
		printk_spew("HyperT widthU old %x new %x\n", old_width, upstream_width);
		new_width = pci_read_config8(prev->dev, prev->pos + prev->config_off + 1);
		if (new_width != upstream_width) {
			printk_err("%s Hypertransport width would not set wanted: %x got: %x\n",
				dev_path(prev->dev), upstream_width, new_width);
		}
	}
#endif
	
	/* Remember the current link as the previous link,
	 * But look at the other offsets.
	 */
	prev->dev = cur->dev;
	prev->pos = cur->pos;
	if (cur->ctrl_off == PCI_HT_CAP_SLAVE_CTRL0) {
		prev->ctrl_off     = PCI_HT_CAP_SLAVE_CTRL1;
		prev->config_off   = PCI_HT_CAP_SLAVE_WIDTH1;
		prev->freq_off     = PCI_HT_CAP_SLAVE_FREQ1;
		prev->freq_cap_off = PCI_HT_CAP_SLAVE_FREQ_CAP1;
	} else {
		prev->ctrl_off     = PCI_HT_CAP_SLAVE_CTRL0;
		prev->config_off   = PCI_HT_CAP_SLAVE_WIDTH0;
		prev->freq_off     = PCI_HT_CAP_SLAVE_FREQ0;
		prev->freq_cap_off = PCI_HT_CAP_SLAVE_FREQ_CAP0;
	}

	return reset_needed;
		
}

static unsigned ht_lookup_slave_capability(struct device *dev)
{
	unsigned pos;
	pos = 0;
	do {
		pos = pci_find_next_capability(dev, PCI_CAP_ID_HT, pos);
		if (pos) {
			unsigned flags;
			flags = pci_read_config16(dev, pos + PCI_CAP_FLAGS);
			printk_spew("flags: 0x%04x\n", flags);
			if ((flags >> 13) == 0) {
				/* Entry is a Slave secondary, success... */
				break;
			}
		}
	} while(pos);
	return pos;
}

static void ht_collapse_early_enumeration(struct bus *bus, unsigned offset_unitid)
{
	unsigned int devfn;
	struct ht_link prev;
	unsigned ctrl;

	/* Initialize the hypertransport enumeration state */
	prev.dev = bus->dev;
	prev.pos = bus->cap;
	prev.ctrl_off     = PCI_HT_CAP_HOST_CTRL;
	prev.config_off   = PCI_HT_CAP_HOST_WIDTH;
	prev.freq_off     = PCI_HT_CAP_HOST_FREQ;
	prev.freq_cap_off = PCI_HT_CAP_HOST_FREQ_CAP;

	/* Wait until the link initialization is complete */
	do {
		ctrl = pci_read_config16(prev.dev, prev.pos + prev.ctrl_off);
		/* Is this the end of the hypertransport chain */
		if (ctrl & (1 << 6)) {
			return;
		}
		/* Has the link failed? */
		if (ctrl & (1 << 4)) {
			/*
			 * Either the link has failed, or we have
			 * a CRC error.
			 * Sometimes this can happen due to link
			 * retrain, so lets knock it down and see
			 * if its transient
			 */
			ctrl |= ((1 << 4) | (1 <<8)); // Link fail + Crc
			pci_write_config16(prev.dev, prev.pos + prev.ctrl_off, ctrl);
			ctrl = pci_read_config16(prev.dev, prev.pos + prev.ctrl_off);
			if (ctrl & ((1 << 4) | (1 << 8))) {
				printk_alert("Detected error on Hypertransport Link\n");
				return;
			}
		}
	} while((ctrl & (1 << 5)) == 0);

	        //actually, only for one HT device HT chain, and unitid is 0
#if HT_CHAIN_UNITID_BASE == 0
        if(offset_unitid) {
                return;
        }
#endif

        /* Check if is already collapsed */
        if((!offset_unitid)|| (offset_unitid && (!((HT_CHAIN_END_UNITID_BASE == 0) && (HT_CHAIN_END_UNITID_BASE <HT_CHAIN_UNITID_BASE))))) {
                struct device dummy;
                uint32_t id;
                dummy.bus              = bus;
                dummy.path.type        = DEVICE_PATH_PCI;
                dummy.path.u.pci.devfn = PCI_DEVFN(0, 0);
                id = pci_read_config32(&dummy, PCI_VENDOR_ID);
                if ( ! ( (id == 0xffffffff) || (id == 0x00000000) ||
                    (id == 0x0000ffff) || (id == 0xffff0000) ) ) {
                             return;
                }
        }

	/* Spin through the devices and collapse any early
	 * hypertransport enumeration.
	 */
	for(devfn = PCI_DEVFN(1, 0); devfn <= 0xff; devfn += 8) {
		struct device dummy;
		uint32_t id;
		unsigned pos, flags;
		dummy.bus              = bus;
		dummy.path.type        = DEVICE_PATH_PCI;
		dummy.path.u.pci.devfn = devfn;
		id = pci_read_config32(&dummy, PCI_VENDOR_ID);
		if (	(id == 0xffffffff) || (id == 0x00000000) || 
			(id == 0x0000ffff) || (id == 0xffff0000)) {
			continue;
		}
		dummy.vendor = id & 0xffff;
		dummy.device = (id >> 16) & 0xffff;
		dummy.hdr_type = pci_read_config8(&dummy, PCI_HEADER_TYPE);
		pos = ht_lookup_slave_capability(&dummy);
		if (!pos){
			continue;
		}

		/* Clear the unitid */
		flags = pci_read_config16(&dummy, pos + PCI_CAP_FLAGS);
		flags &= ~0x1f;
		pci_write_config16(&dummy, pos + PCI_CAP_FLAGS, flags);
		printk_spew("Collapsing %s [%04x/%04x]\n", 
			dev_path(&dummy), dummy.vendor, dummy.device);
	}
}

unsigned int hypertransport_scan_chain(struct bus *bus, 
	unsigned min_devfn, unsigned max_devfn, unsigned int max, unsigned *ht_unitid_base, unsigned offset_unitid)
{
	//even HT_CHAIN_UNITID_BASE == 0, we still can go through this function, because of end_of_chain check, also We need it to optimize link
	unsigned next_unitid, last_unitid;
	device_t old_devices, dev, func;
	unsigned min_unitid = (offset_unitid) ? HT_CHAIN_UNITID_BASE:1;
	struct ht_link prev;
	device_t last_func = 0;
	int ht_dev_num = 0;

#if HT_CHAIN_END_UNITID_BASE < HT_CHAIN_UNITID_BASE
        //let't record the device of last ht device, So we can set the Unitid to HT_CHAIN_END_UNITID_BASE
        unsigned real_last_unitid; 
        uint8_t real_last_pos;
	device_t real_last_dev;
#endif

	/* Restore the hypertransport chain to it's unitialized state */
	ht_collapse_early_enumeration(bus, offset_unitid);

	/* See which static device nodes I have */
	old_devices = bus->children;
	bus->children = 0;

	/* Initialize the hypertransport enumeration state */
	prev.dev = bus->dev;
	prev.pos = bus->cap;
	prev.ctrl_off     = PCI_HT_CAP_HOST_CTRL;
	prev.config_off   = PCI_HT_CAP_HOST_WIDTH;
	prev.freq_off     = PCI_HT_CAP_HOST_FREQ;
	prev.freq_cap_off = PCI_HT_CAP_HOST_FREQ_CAP;
	
	/* If present assign unitid to a hypertransport chain */
	last_unitid = min_unitid -1;
	next_unitid = min_unitid;
	do {
		uint8_t pos;
		uint16_t flags;
		unsigned count, static_count;
		unsigned ctrl;

		last_unitid = next_unitid;

		/* Wait until the link initialization is complete */
		do {
			ctrl = pci_read_config16(prev.dev, prev.pos + prev.ctrl_off);

			if (ctrl & (1 << 6))
				goto end_of_chain;	// End of chain

			if (ctrl & ((1 << 4) | (1 << 8))) {
				/*
				 * Either the link has failed, or we have
				 * a CRC error.
				 * Sometimes this can happen due to link
				 * retrain, so lets knock it down and see
				 * if its transient
				 */
				ctrl |= ((1 << 4) | (1 <<8)); // Link fail + Crc
				pci_write_config16(prev.dev, prev.pos + prev.ctrl_off, ctrl);
				ctrl = pci_read_config16(prev.dev, prev.pos + prev.ctrl_off);
				if (ctrl & ((1 << 4) | (1 << 8))) {
					printk_alert("Detected error on Hypertransport Link\n");
					goto end_of_chain;
				}
			}
		} while((ctrl & (1 << 5)) == 0);
		

		/* Get and setup the device_structure */
		dev = ht_scan_get_devs(&old_devices);

		/* See if a device is present and setup the
		 * device structure.
		 */
		dev = pci_probe_dev(dev, bus, 0);
		if (!dev || !dev->enabled) {
			break;
		}

		/* Find the hypertransport link capability */
		pos = ht_lookup_slave_capability(dev);
		if (pos == 0) {
			printk_err("%s Hypertransport link capability not found", 
				dev_path(dev));
			break;
		}
		
		/* Update the Unitid of the current device */
		flags = pci_read_config16(dev, pos + PCI_CAP_FLAGS);
        
		/* If the devices has a unitid set and is at devfn 0 we are done. 
		 * This can happen with shadow hypertransport devices,
		 * or if we have reached the bottom of a
		 * hypertransport device chain.
		 */
		if (flags & 0x1f) {
			break;
		}

		flags &= ~0x1f; /* mask out base Unit ID */
                flags |= next_unitid & 0x1f;
                pci_write_config16(dev, pos + PCI_CAP_FLAGS, flags);

		/* Update the Unitd id in the device structure */
		static_count = 1;
		for(func = dev; func; func = func->sibling) {
			func->path.u.pci.devfn += (next_unitid << 3);
			static_count = (func->path.u.pci.devfn >> 3) 
				- (dev->path.u.pci.devfn >> 3) + 1;
			last_func = func;
		}

		/* Compute the number of unitids consumed */
		count = (flags >> 5) & 0x1f; /* get unit count */
		printk_spew("%s count: %04x static_count: %04x\n", 
			dev_path(dev), count, static_count);
		if (count < static_count) {
			count = static_count;
		}

		/* Update the Unitid of the next device */
		ht_unitid_base[ht_dev_num] = next_unitid;
		ht_dev_num++;
#if HT_CHAIN_END_UNITID_BASE < HT_CHAIN_UNITID_BASE
		if(offset_unitid) {
	                real_last_unitid = next_unitid;
        	        real_last_pos = pos;
			real_last_dev = dev;
		}
#endif
		next_unitid += count;

		/* Setup the hypetransport link */
		bus->reset_needed |= ht_setup_link(&prev, dev, pos);

		printk_debug("%s [%04x/%04x] %s next_unitid: %04x\n",
			dev_path(dev),
			dev->vendor, dev->device, 
			(dev->enabled? "enabled": "disabled"), next_unitid);

	} while((last_unitid != next_unitid) && (next_unitid <= (max_devfn >> 3)));
 end_of_chain:
#if OPT_HT_LINK == 1
	if(bus->reset_needed) {
		printk_info("HyperT reset needed\n");
	}
	else {
		printk_debug("HyperT reset not needed\n");
	}
#endif

#if HT_CHAIN_END_UNITID_BASE < HT_CHAIN_UNITID_BASE
        if(offset_unitid && (ht_dev_num>0)) {
                uint16_t flags;
                int i;
		device_t last_func = 0;
                flags = pci_read_config16(real_last_dev, real_last_pos + PCI_CAP_FLAGS);
                flags &= ~0x1f;
                flags |= HT_CHAIN_END_UNITID_BASE & 0x1f;
                pci_write_config16(real_last_dev, real_last_pos + PCI_CAP_FLAGS, flags);

                for(func = real_last_dev; func; func = func->sibling) {
                        func->path.u.pci.devfn -= ((real_last_unitid - HT_CHAIN_END_UNITID_BASE) << 3);
			last_func = func;
                }
		
		ht_unitid_base[ht_dev_num-1] = HT_CHAIN_END_UNITID_BASE; // update last one
		
                next_unitid = real_last_unitid;
        }
#endif

	if (next_unitid > 0x1f) {
		next_unitid = 0x1f;
	}

	/* Die if any leftover Static devices are are found.  
	 * There's probably a problem in the Config.lb.
	 */
	if(old_devices) {
		device_t left;
		for(left = old_devices; left; left = left->sibling) {
			printk_debug("%s\n", dev_path(left));
		}
		printk_err("HT: Left over static devices.  Check your Config.lb\n");
		if(last_func  && !last_func->sibling) // put back the left over static device, and let pci_scan_bus disable it
			last_func->sibling = old_devices; 
	}

	/* Now that nothing is overlapping it is safe to scan the
	 * children. 
	 */
	max = pci_scan_bus(bus, 0x00, (next_unitid << 3)|7, max); 
	return max; 
}

/**
 * @brief Scan a PCI bridge and the buses behind the bridge.
 *
 * Determine the existence of buses behind the bridge. Set up the bridge
 * according to the result of the scan.
 *
 * This function is the default scan_bus() method for PCI bridge devices.
 *
 * @param dev pointer to the bridge device
 * @param max the highest bus number assgined up to now
 *
 * @return The maximum bus number found, after scanning all subordinate busses
 */
unsigned int hypertransport_scan_chain_x(struct bus *bus,
        unsigned min_devfn, unsigned max_devfn, unsigned int max)
{
	unsigned ht_unitid_base[4];
	unsigned offset_unitid = 1;
	return hypertransport_scan_chain(bus, min_devfn, max_devfn, max, ht_unitid_base, offset_unitid);
}

unsigned int ht_scan_bridge(struct device *dev, unsigned int max)
{
	return do_pci_scan_bridge(dev, max, hypertransport_scan_chain_x);
}


/** Default device operations for hypertransport bridges */
static struct pci_operations ht_bus_ops_pci = {
	.set_subsystem = 0,
};

struct device_operations default_ht_ops_bus = {
	.read_resources   = pci_bus_read_resources,
	.set_resources    = pci_dev_set_resources,
	.enable_resources = pci_bus_enable_resources,
	.init		  = 0,
	.scan_bus	  = ht_scan_bridge,
	.enable           = 0,
	.reset_bus        = pci_bus_reset,
	.ops_pci          = &ht_bus_ops_pci,
};
