x86: add LongModeAddressSize function to cpuid
LongModeAddressSize was used by kernel 2.6.28.4 for physical address
validation, if not properly implemented, PCI resource allocation may
failed because of ioremap failed:
- linux-2.6.28.4/arch/x86/mm/ioremap.c:27-30
27 static inline int phys_addr_valid(unsigned long addr)
28 {
29 return addr < (1UL << boot_cpu_data.x86_phys_bits);
30 }
- linux-2.6.28.4/arch/x86/kernel/cpu/common.c:475-482
475 #ifdef CONFIG_X86_64
476 if (c->extended_cpuid_level >= 0x80000008) {
477 u32 eax = cpuid_eax(0x80000008);
478
479 c->x86_virt_bits = (eax >> 8) & 0xff;
480 c->x86_phys_bits = eax & 0xff;
481 }
482 #endif
- linux-2.6.28.4/arch/x86/mm/ioremap.c:209-214
209 if (!phys_addr_valid(phys_addr)) {
210 printk(KERN_WARNING "ioremap: invalid physical address %llx\n",
211 (unsigned long long)phys_addr);
212 WARN_ON_ONCE(1);
213 return NULL;
214 }
This patch return 0x0000ffff for LongModeAddressSize, which guarantee phys_addr_valid never failed.
Committed by: Nilay Vaish <nilay@cs.wisc.edu>