/* SPDX-License-Identifier: GPL-2.0-only *//* * Page table support for the Hexagon architecture * * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved. */ #ifndef _ASM_PGALLOC_H#define _ASM_PGALLOC_H #include <asm/mem-layout.h>#include <asm/atomic.h> #include <asm-generic/pgalloc.h> extern unsigned long long kmap_generation; /* * Page table creation interface */static inline pgd_t *pgd_alloc(struct mm_struct *mm){	pgd_t *pgd; 	pgd = __pgd_alloc(mm, 0); 	/*	 * There may be better ways to do this, but to ensure	 * that new address spaces always contain the kernel	 * base mapping, and to ensure that the user area is	 * initially marked invalid, initialize the new map	 * map with a copy of the kernel's persistent map.	 */ 	memcpy(pgd, swapper_pg_dir, PTRS_PER_PGD*sizeof(pgd_t));	mm->context.generation = kmap_generation; 	/* Physical version is what is passed to virtual machine on switch */	mm->context.ptbase = __pa(pgd); 	return pgd;} static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,				pgtable_t pte){	/*	 * Conveniently, zero in 3 LSB means indirect 4K page table.	 * Not so convenient when you're trying to vary the page size.	 */	set_pmd(pmd, __pmd(((unsigned long)page_to_pfn(pte) << PAGE_SHIFT) |		HEXAGON_L1_PTE_SIZE));} /* * Other architectures seem to have ways of making all processes * share the same pmd's for their kernel mappings, but the v0.3 * Hexagon VM spec has a "monolithic" L1 table for user and kernel * segments.  We track "generations" of the kernel map to minimize * overhead, and update the "slave" copies of the kernel mappings * as part of switch_mm.  However, we still need to update the * kernel map of the active thread who's calling pmd_populate_kernel... */static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,				       pte_t *pte){	extern spinlock_t kmap_gen_lock;	pmd_t *ppmd;	int pmdindex; 	spin_lock(&kmap_gen_lock);	kmap_generation++;	mm->context.generation = kmap_generation;	current->active_mm->context.generation = kmap_generation;	spin_unlock(&kmap_gen_lock); 	set_pmd(pmd, __pmd(((unsigned long)__pa(pte)) | HEXAGON_L1_PTE_SIZE)); 	/*	 * Now the "slave" copy of the current thread.	 * This is pointer arithmetic, not byte addresses!	 */	pmdindex = (pgd_t *)pmd - mm->pgd;	ppmd = (pmd_t *)current->active_mm->pgd + pmdindex;	set_pmd(ppmd, __pmd(((unsigned long)__pa(pte)) | HEXAGON_L1_PTE_SIZE));	if (pmdindex > max_kernel_seg)		max_kernel_seg = pmdindex;} #define __pte_free_tlb(tlb, pte, addr)	\	tlb_remove_ptdesc((tlb), page_ptdesc(pte)) #endif