/*
* Search for the biggest gap in the low 32 bits of the e820
* memory space. We pass this space to PCI to assign MMIO resources
* for hotplug or unconfigured devices in.
* Hopefully the BIOS let enough space left.
*/
__init void e820_setup_gap(void)
{
unsigned long gapstart, gapsize, round;
int found;
gapstart = 0x10000000;
gapsize = 0x400000;
found = e820_search_gap(&gapstart, &gapsize, 0, MAX_GAP_END);
#ifdef CONFIG_X86_64
if (!found) {
gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024;
printk(KERN_ERR "PCI: Warning: Cannot find a gap in the 32bit "
"address range\n"
KERN_ERR "PCI: Unassigned devices with 32bit resource "
"registers may break!\n");
}
#endif
/*
* See how much we want to round up: start off with
* rounding to the next 1MB area.
*/
round = 0x100000;
while ((gapsize >> 4) > round)
round += round;
/* Fun with two's complement */
pci_mem_start = (gapstart + round) & -round;
printk(KERN_INFO
"Allocating PCI resources starting at %lx (gap: %lx:%lx)\n",
pci_mem_start, gapstart, gapsize);
}
__init void e820_setup_gap(void)
{
unsigned long gapstart, gapsize;
int found;
gapstart = 0x10000000;
gapsize = 0x400000;
found = e820_search_gap(&gapstart, &gapsize, 0, MAX_GAP_END);
#ifdef CONFIG_X86_64
if (!found) {
gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024;
printk(KERN_ERR
"PCI: Warning: Cannot find a gap in the 32bit address range\n"
"PCI: Unassigned devices with 32bit resource registers may break!\n");
}
#endif
pci_mem_start = gapstart;
printk(KERN_INFO
"Allocating PCI resources starting at %lx (gap: %lx:%lx)\n",
pci_mem_start, gapstart, gapsize);
}
