18ef8f360SDave Martin/* SPDX-License-Identifier: GPL-2.0 */
28ef8f360SDave Martin#ifndef __ASM_MMAN_H__
38ef8f360SDave Martin#define __ASM_MMAN_H__
48ef8f360SDave Martin
58ef8f360SDave Martin#include <linux/compiler.h>
68ef8f360SDave Martin#include <linux/types.h>
78ef8f360SDave Martin#include <uapi/asm/mman.h>
88ef8f360SDave Martin
98ef8f360SDave Martinstatic inline unsigned long arch_calc_vm_prot_bits(unsigned long prot,
108ef8f360SDave Martin	unsigned long pkey __always_unused)
118ef8f360SDave Martin{
129f341931SCatalin Marinas	unsigned long ret = 0;
139f341931SCatalin Marinas
148ef8f360SDave Martin	if (system_supports_bti() && (prot & PROT_BTI))
159f341931SCatalin Marinas		ret |= VM_ARM64_BTI;
168ef8f360SDave Martin
179f341931SCatalin Marinas	if (system_supports_mte() && (prot & PROT_MTE))
189f341931SCatalin Marinas		ret |= VM_MTE;
199f341931SCatalin Marinas
209f341931SCatalin Marinas	return ret;
218ef8f360SDave Martin}
228ef8f360SDave Martin#define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)
238ef8f360SDave Martin
249f341931SCatalin Marinasstatic inline unsigned long arch_calc_vm_flag_bits(unsigned long flags)
259f341931SCatalin Marinas{
269f341931SCatalin Marinas	/*
279f341931SCatalin Marinas	 * Only allow MTE on anonymous mappings as these are guaranteed to be
289f341931SCatalin Marinas	 * backed by tags-capable memory. The vm_flags may be overridden by a
299f341931SCatalin Marinas	 * filesystem supporting MTE (RAM-based).
309f341931SCatalin Marinas	 */
319f341931SCatalin Marinas	if (system_supports_mte() && (flags & MAP_ANONYMOUS))
329f341931SCatalin Marinas		return VM_MTE_ALLOWED;
339f341931SCatalin Marinas
349f341931SCatalin Marinas	return 0;
359f341931SCatalin Marinas}
369f341931SCatalin Marinas#define arch_calc_vm_flag_bits(flags) arch_calc_vm_flag_bits(flags)
379f341931SCatalin Marinas
388ef8f360SDave Martinstatic inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
398ef8f360SDave Martin{
409f341931SCatalin Marinas	pteval_t prot = 0;
419f341931SCatalin Marinas
429f341931SCatalin Marinas	if (vm_flags & VM_ARM64_BTI)
439f341931SCatalin Marinas		prot |= PTE_GP;
449f341931SCatalin Marinas
459f341931SCatalin Marinas	/*
469f341931SCatalin Marinas	 * There are two conditions required for returning a Normal Tagged
479f341931SCatalin Marinas	 * memory type: (1) the user requested it via PROT_MTE passed to
489f341931SCatalin Marinas	 * mmap() or mprotect() and (2) the corresponding vma supports MTE. We
499f341931SCatalin Marinas	 * register (1) as VM_MTE in the vma->vm_flags and (2) as
509f341931SCatalin Marinas	 * VM_MTE_ALLOWED. Note that the latter can only be set during the
519f341931SCatalin Marinas	 * mmap() call since mprotect() does not accept MAP_* flags.
5200420905SCatalin Marinas	 * Checking for VM_MTE only is sufficient since arch_validate_flags()
5300420905SCatalin Marinas	 * does not permit (VM_MTE & !VM_MTE_ALLOWED).
549f341931SCatalin Marinas	 */
5500420905SCatalin Marinas	if (vm_flags & VM_MTE)
569f341931SCatalin Marinas		prot |= PTE_ATTRINDX(MT_NORMAL_TAGGED);
579f341931SCatalin Marinas
589f341931SCatalin Marinas	return __pgprot(prot);
598ef8f360SDave Martin}
608ef8f360SDave Martin#define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags)
618ef8f360SDave Martin
628ef8f360SDave Martinstatic inline bool arch_validate_prot(unsigned long prot,
638ef8f360SDave Martin	unsigned long addr __always_unused)
648ef8f360SDave Martin{
658ef8f360SDave Martin	unsigned long supported = PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM;
668ef8f360SDave Martin
678ef8f360SDave Martin	if (system_supports_bti())
688ef8f360SDave Martin		supported |= PROT_BTI;
698ef8f360SDave Martin
709f341931SCatalin Marinas	if (system_supports_mte())
719f341931SCatalin Marinas		supported |= PROT_MTE;
729f341931SCatalin Marinas
738ef8f360SDave Martin	return (prot & ~supported) == 0;
748ef8f360SDave Martin}
758ef8f360SDave Martin#define arch_validate_prot(prot, addr) arch_validate_prot(prot, addr)
768ef8f360SDave Martin
7700420905SCatalin Marinasstatic inline bool arch_validate_flags(unsigned long vm_flags)
7800420905SCatalin Marinas{
7900420905SCatalin Marinas	if (!system_supports_mte())
8000420905SCatalin Marinas		return true;
8100420905SCatalin Marinas
8200420905SCatalin Marinas	/* only allow VM_MTE if VM_MTE_ALLOWED has been set previously */
8300420905SCatalin Marinas	return !(vm_flags & VM_MTE) || (vm_flags & VM_MTE_ALLOWED);
8400420905SCatalin Marinas}
8500420905SCatalin Marinas#define arch_validate_flags(vm_flags) arch_validate_flags(vm_flags)
8600420905SCatalin Marinas
878ef8f360SDave Martin#endif /* ! __ASM_MMAN_H__ */
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