src/cpu/emulation/qemu-x86/northbridge.c

#include <console/console.h>
#include <arch/io.h>
#include <stdint.h>
#include <device/device.h>
#include <device/pci.h>
#include <stdlib.h>
#include <string.h>
#include <bitops.h>
#include "chip.h"
#include "northbridge.h"

#define BRIDGE_IO_MASK (IORESOURCE_IO | IORESOURCE_MEM)

static void pci_domain_read_resources(device_t dev)
{
	struct resource *resource;

	/* Initialize the system wide io space constraints */
	resource = new_resource(dev, IOINDEX_SUBTRACTIVE(0,0));
	resource->limit = 0xffffUL;
	resource->flags = IORESOURCE_IO | IORESOURCE_SUBTRACTIVE | IORESOURCE_ASSIGNED;

	/* Initialize the system wide memory resources constraints */
	resource = new_resource(dev, IOINDEX_SUBTRACTIVE(1,0));
	resource->limit = 0xffffffffULL;
	resource->flags = IORESOURCE_MEM | IORESOURCE_SUBTRACTIVE | IORESOURCE_ASSIGNED;
}

static void ram_resource(device_t dev, unsigned long index,
	unsigned long basek, unsigned long sizek)
{
	struct resource *resource;

	if (!sizek) {
		return;
	}
	resource = new_resource(dev, index);
	resource->base	= ((resource_t)basek) << 10;
	resource->size	= ((resource_t)sizek) << 10;
	resource->flags =  IORESOURCE_MEM | IORESOURCE_CACHEABLE | \
		IORESOURCE_FIXED | IORESOURCE_STORED | IORESOURCE_ASSIGNED;
}

static void tolm_test(void *gp, struct device *dev, struct resource *new)
{
	struct resource **best_p = gp;
	struct resource *best;
	best = *best_p;
	if (!best || (best->base > new->base)) {
		best = new;
	}
	*best_p = best;
}

static uint32_t find_pci_tolm(struct bus *bus)
{
	struct resource *min;
	uint32_t tolm;
	min = 0;
	search_bus_resources(bus, IORESOURCE_MEM, IORESOURCE_MEM, tolm_test, &min);
	tolm = 0xffffffffUL;
	if (min && tolm > min->base) {
		tolm = min->base;
	}
	return tolm;
}

static void pci_domain_set_resources(device_t dev)
{
	static const uint8_t ramregs[] = {
		0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 0x56, 0x57
	};
	device_t mc_dev;
	uint32_t pci_tolm;

	pci_tolm = find_pci_tolm(&dev->link[0]);
	mc_dev = dev->link[0].children;
	if (mc_dev) {
		unsigned long tomk, tolmk;
		unsigned char rambits;
		int i, idx;

		for(rambits = 0, i = 0; i < ARRAY_SIZE(ramregs); i++) {
			unsigned char reg;
			reg = pci_read_config8(mc_dev, ramregs[i]);
			/* these are ENDING addresses, not sizes. 
			 * if there is memory in this slot, then reg will be > rambits.
			 * So we just take the max, that gives us total. 
			 * We take the highest one to cover for once and future coreboot
			 * bugs. We warn about bugs.
			 */
			if (reg > rambits)
				rambits = reg;
			if (reg < rambits)
				printk_err("ERROR! register 0x%x is not set!\n", 
					ramregs[i]);
		}
		if (rambits == 0) {
			printk_err("RAM size config registers are empty; defaulting to 64 MBytes\n");
			rambits = 8;
		}
		printk_debug("I would set ram size to 0x%x Kbytes\n", (rambits)*8*1024);
		tomk = rambits*8*1024;
		/* Compute the top of Low memory */
		tolmk = pci_tolm >> 10;
		if (tolmk >= tomk) {
			/* The PCI hole does not overlap memory.
			 */
			tolmk = tomk;
		}
		/* Report the memory regions */
		idx = 10;
		ram_resource(dev, idx++, 0, tolmk);
	}
	assign_resources(&dev->link[0]);
}

static unsigned int pci_domain_scan_bus(device_t dev, unsigned int max)
{
	max = pci_scan_bus(&dev->link[0], PCI_DEVFN(0, 0), 0xff, max);
	return max;
}

static struct device_operations pci_domain_ops = {
	.read_resources	  = pci_domain_read_resources,
	.set_resources	  = pci_domain_set_resources,
	.enable_resources = enable_childrens_resources,
	.init		  = 0,
	.scan_bus	  = pci_domain_scan_bus,
};  

static void enable_dev(struct device *dev)
{
	/* Set the operations if it is a special bus type */
	if (dev->path.type == DEVICE_PATH_PCI_DOMAIN) {
		dev->ops = &pci_domain_ops;
		pci_set_method(dev);
	}
}

struct chip_operations cpu_emulation_qemu_x86_ops = {
	CHIP_NAME("QEMU Northbridge")
	.enable_dev = enable_dev,
};

void udelay(int usecs)
{
	int i;
	for(i = 0; i < usecs; i++)
		inb(0x80);
}