arch/powerpc/include/asm/sections.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_POWERPC_SECTIONS_H
   3 #define _ASM_POWERPC_SECTIONS_H
   4 #ifdef __KERNEL__
   5
   6 #include <linux/elf.h>
   7 #include <linux/uaccess.h>
   8
   9 #include <asm-generic/sections.h>
  10
  11 extern char __head_end[];
  12
  13 #ifdef __powerpc64__
  14
  15 extern char __start_interrupts[];
  16 extern char __end_interrupts[];
  17
  18 extern char __prom_init_toc_start[];
  19 extern char __prom_init_toc_end[];
  20
  21 #ifdef CONFIG_PPC_POWERNV
  22 extern char start_real_trampolines[];
  23 extern char end_real_trampolines[];
  24 extern char start_virt_trampolines[];
  25 extern char end_virt_trampolines[];
  26 #endif
  27
  28 static inline unsigned long kernel_toc_addr(void)
  29 {
  30         /* Defined by the linker, see vmlinux.lds.S */
  31         extern unsigned long __toc_start;
  32
  33         /*
  34          * The TOC register (r2) points 32kB into the TOC, so that 64kB of
  35          * the TOC can be addressed using a single machine instruction.
  36          */
  37         return (unsigned long)(&__toc_start) + 0x8000UL;
  38 }
  39
  40 static inline int overlaps_interrupt_vector_text(unsigned long start,
  41                                                         unsigned long end)
  42 {
  43         unsigned long real_start, real_end;
  44         real_start = __start_interrupts - _stext;
  45         real_end = __end_interrupts - _stext;
  46
  47         return start < (unsigned long)__va(real_end) &&
  48                 (unsigned long)__va(real_start) < end;
  49 }
  50
  51 static inline int overlaps_kernel_text(unsigned long start, unsigned long end)
  52 {
  53         return start < (unsigned long)__init_end &&
  54                 (unsigned long)_stext < end;
  55 }
  56
  57 #ifdef PPC64_ELF_ABI_v1
  58
  59 #define HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR 1
  60
  61 #undef dereference_function_descriptor
  62 static inline void *dereference_function_descriptor(void *ptr)
  63 {
  64         struct ppc64_opd_entry *desc = ptr;
  65         void *p;
  66
  67         if (!get_kernel_nofault(p, (void *)&desc->funcaddr))
  68                 ptr = p;
  69         return ptr;
  70 }
  71
  72 #undef dereference_kernel_function_descriptor
  73 static inline void *dereference_kernel_function_descriptor(void *ptr)
  74 {
  75         if (ptr < (void *)__start_opd || ptr >= (void *)__end_opd)
  76                 return ptr;
  77
  78         return dereference_function_descriptor(ptr);
  79 }
  80 #endif /* PPC64_ELF_ABI_v1 */
  81
  82 #endif
  83
  84 #endif /* __KERNEL__ */
  85 #endif  /* _ASM_POWERPC_SECTIONS_H */