LXR linux/arch/powerpc/include/asm/nohash/32/kup-8xx.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _ASM_POWERPC_KUP_8XX_H_
   3#define _ASM_POWERPC_KUP_8XX_H_
   4
   5#include <asm/bug.h>
   6#include <asm/mmu.h>
   7
   8#ifdef CONFIG_PPC_KUAP
   9
  10#ifdef __ASSEMBLY__
  11
  12.macro kuap_save_and_lock       sp, thread, gpr1, gpr2, gpr3
  13        lis     \gpr2, MD_APG_KUAP@h    /* only APG0 and APG1 are used */
  14        mfspr   \gpr1, SPRN_MD_AP
  15        mtspr   SPRN_MD_AP, \gpr2
  16        stw     \gpr1, STACK_REGS_KUAP(\sp)
  17.endm
  18
  19.macro kuap_restore     sp, current, gpr1, gpr2, gpr3
  20        lwz     \gpr1, STACK_REGS_KUAP(\sp)
  21        mtspr   SPRN_MD_AP, \gpr1
  22.endm
  23
  24.macro kuap_check       current, gpr
  25#ifdef CONFIG_PPC_KUAP_DEBUG
  26        mfspr   \gpr, SPRN_MD_AP
  27        rlwinm  \gpr, \gpr, 16, 0xffff
  28999:    twnei   \gpr, MD_APG_KUAP@h
  29        EMIT_BUG_ENTRY 999b, __FILE__, __LINE__, (BUGFLAG_WARNING | BUGFLAG_ONCE)
  30#endif
  31.endm
  32
  33#else /* !__ASSEMBLY__ */
  34
  35#include <asm/reg.h>
  36
  37static inline void allow_user_access(void __user *to, const void __user *from,
  38                                     unsigned long size, unsigned long dir)
  39{
  40        mtspr(SPRN_MD_AP, MD_APG_INIT);
  41}
  42
  43static inline void prevent_user_access(void __user *to, const void __user *from,
  44                                       unsigned long size, unsigned long dir)
  45{
  46        mtspr(SPRN_MD_AP, MD_APG_KUAP);
  47}
  48
  49static inline unsigned long prevent_user_access_return(void)
  50{
  51        unsigned long flags = mfspr(SPRN_MD_AP);
  52
  53        mtspr(SPRN_MD_AP, MD_APG_KUAP);
  54
  55        return flags;
  56}
  57
  58static inline void restore_user_access(unsigned long flags)
  59{
  60        mtspr(SPRN_MD_AP, flags);
  61}
  62
  63static inline bool
  64bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
  65{
  66        return WARN(!((regs->kuap ^ MD_APG_KUAP) & 0xf0000000),
  67                    "Bug: fault blocked by AP register !");
  68}
  69
  70#endif /* !__ASSEMBLY__ */
  71
  72#endif /* CONFIG_PPC_KUAP */
  73
  74#endif /* _ASM_POWERPC_KUP_8XX_H_ */
  75