MIPS: Add support for XPA.

Add support for extended physical addressing (XPA) so that
32-bit platforms can access equal to or greater than 40 bits
of physical addresses.

NOTE:
      1) XPA and EVA are not the same and cannot be used
         simultaneously.
      2) If you configure your kernel for XPA, the PTEs
         and all address sizes become 64-bit.
      3) Your platform MUST have working HIGHMEM support.

Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9355/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Steven J. Hill
2015-02-26 18:16:38 -06:00
committed by Ralf Baechle
parent be0c37c985
commit c5b367835c
11 changed files with 173 additions and 44 deletions

View File

@@ -333,9 +333,17 @@ void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
ptep = pte_offset_map(pmdp, address);
#if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
#ifdef CONFIG_XPA
write_c0_entrylo0(pte_to_entrylo(ptep->pte_high));
writex_c0_entrylo0(ptep->pte_low & _PFNX_MASK);
ptep++;
write_c0_entrylo1(pte_to_entrylo(ptep->pte_high));
writex_c0_entrylo1(ptep->pte_low & _PFNX_MASK);
#else
write_c0_entrylo0(ptep->pte_high);
ptep++;
write_c0_entrylo1(ptep->pte_high);
#endif
#else
write_c0_entrylo0(pte_to_entrylo(pte_val(*ptep++)));
write_c0_entrylo1(pte_to_entrylo(pte_val(*ptep)));
@@ -355,6 +363,9 @@ void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
unsigned long entryhi, unsigned long pagemask)
{
#ifdef CONFIG_XPA
panic("Broken for XPA kernels");
#else
unsigned long flags;
unsigned long wired;
unsigned long old_pagemask;
@@ -383,6 +394,7 @@ void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
write_c0_pagemask(old_pagemask);
local_flush_tlb_all();
local_irq_restore(flags);
#endif
}
#ifdef CONFIG_TRANSPARENT_HUGEPAGE