Pull ar-k0-usage into release branch
This commit is contained in:
commit
0ace57a96b
@ -244,28 +244,31 @@ find_initrd (void)
|
||||
static void __init
|
||||
io_port_init (void)
|
||||
{
|
||||
extern unsigned long ia64_iobase;
|
||||
unsigned long phys_iobase;
|
||||
|
||||
/*
|
||||
* Set `iobase' to the appropriate address in region 6 (uncached access range).
|
||||
* Set `iobase' based on the EFI memory map or, failing that, the
|
||||
* value firmware left in ar.k0.
|
||||
*
|
||||
* The EFI memory map is the "preferred" location to get the I/O port space base,
|
||||
* rather the relying on AR.KR0. This should become more clear in future SAL
|
||||
* specs. We'll fall back to getting it out of AR.KR0 if no appropriate entry is
|
||||
* found in the memory map.
|
||||
* Note that in ia32 mode, IN/OUT instructions use ar.k0 to compute
|
||||
* the port's virtual address, so ia32_load_state() loads it with a
|
||||
* user virtual address. But in ia64 mode, glibc uses the
|
||||
* *physical* address in ar.k0 to mmap the appropriate area from
|
||||
* /dev/mem, and the inX()/outX() interfaces use MMIO. In both
|
||||
* cases, user-mode can only use the legacy 0-64K I/O port space.
|
||||
*
|
||||
* ar.k0 is not involved in kernel I/O port accesses, which can use
|
||||
* any of the I/O port spaces and are done via MMIO using the
|
||||
* virtual mmio_base from the appropriate io_space[].
|
||||
*/
|
||||
phys_iobase = efi_get_iobase();
|
||||
if (phys_iobase)
|
||||
/* set AR.KR0 since this is all we use it for anyway */
|
||||
ia64_set_kr(IA64_KR_IO_BASE, phys_iobase);
|
||||
else {
|
||||
if (!phys_iobase) {
|
||||
phys_iobase = ia64_get_kr(IA64_KR_IO_BASE);
|
||||
printk(KERN_INFO "No I/O port range found in EFI memory map, falling back "
|
||||
"to AR.KR0\n");
|
||||
printk(KERN_INFO "I/O port base = 0x%lx\n", phys_iobase);
|
||||
printk(KERN_INFO "No I/O port range found in EFI memory map, "
|
||||
"falling back to AR.KR0 (0x%lx)\n", phys_iobase);
|
||||
}
|
||||
ia64_iobase = (unsigned long) ioremap(phys_iobase, 0);
|
||||
ia64_set_kr(IA64_KR_IO_BASE, __pa(ia64_iobase));
|
||||
|
||||
/* setup legacy IO port space */
|
||||
io_space[0].mmio_base = ia64_iobase;
|
||||
|
Loading…
Reference in New Issue
Block a user