target/linux/generic-2.6/patches-2.6.21/31-use_kbuild.h.patch

   1 [MIPS] Fix computation of {PGD,PMD,PTE}_T_LOG2.
   2
   3 For the generation of asm-offset.h to work these need to be evaulatable
   4 by gcc as a constant expression.  This issue did exist for a while but
   5 didn't bite because they're only in asm-offset.h for debugging purposes.
   6
   7 --- a/include/asm-mips/pgtable.h
   8 +++ b/include/asm-mips/pgtable.h
   9 @@ -168,9 +168,9 @@ static inline void pte_clear(struct mm_s
  10  #define set_pud(pudptr, pudval) do { *(pudptr) = (pudval); } while(0)
  11  #endif
  12
  13 -#define PGD_T_LOG2     ffz(~sizeof(pgd_t))
  14 -#define PMD_T_LOG2     ffz(~sizeof(pmd_t))
  15 -#define PTE_T_LOG2     ffz(~sizeof(pte_t))
  16 +#define PGD_T_LOG2     (__builtin_ffs(sizeof(pgd_t)) - 1)
  17 +#define PMD_T_LOG2     (__builtin_ffs(sizeof(pmd_t)) - 1)
  18 +#define PTE_T_LOG2     (__builtin_ffs(sizeof(pte_t)) - 1)
  19
  20  extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
  21