hash-4k.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_POWERPC_BOOK3S_64_HASH_4K_H
#define _ASM_POWERPC_BOOK3S_64_HASH_4K_H

#define H_PTE_INDEX_SIZE  9  // size: 8B << 9 = 4KB, maps: 2^9 x   4KB =   2MB
#define H_PMD_INDEX_SIZE  7  // size: 8B << 7 = 1KB, maps: 2^7 x   2MB = 256MB
#define H_PUD_INDEX_SIZE  9  // size: 8B << 9 = 4KB, maps: 2^9 x 256MB = 128GB
#define H_PGD_INDEX_SIZE  9  // size: 8B << 9 = 4KB, maps: 2^9 x 128GB =  64TB

/*
 * Each context is 512TB. But on 4k we restrict our max TASK size to 64TB
 * Hence also limit max EA bits to 64TB.
 */
#define MAX_EA_BITS_PER_CONTEXT		46


/*
 * Our page table limit us to 64TB. For 64TB physical memory, we only need 64GB
 * of vmemmap space. To better support sparse memory layout, we use 61TB
 * linear map range, 1TB of vmalloc, 1TB of I/O and 1TB of vmememmap.
 */
#define REGION_SHIFT		(40)
#define H_KERN_MAP_SIZE		(ASM_CONST(1) << REGION_SHIFT)

/*
 * Limits the linear mapping range
 */
#define H_MAX_PHYSMEM_BITS	46

/*
 * Define the address range of the kernel non-linear virtual area (61TB)
 */
#define H_KERN_VIRT_START	ASM_CONST(0xc0003d0000000000)

#ifndef __ASSEMBLY__
#define H_PTE_TABLE_SIZE	(sizeof(pte_t) << H_PTE_INDEX_SIZE)
#define H_PMD_TABLE_SIZE	(sizeof(pmd_t) << H_PMD_INDEX_SIZE)
#define H_PUD_TABLE_SIZE	(sizeof(pud_t) << H_PUD_INDEX_SIZE)
#define H_PGD_TABLE_SIZE	(sizeof(pgd_t) << H_PGD_INDEX_SIZE)

#define H_PAGE_F_GIX_SHIFT	_PAGE_PA_MAX
#define H_PAGE_F_SECOND		_RPAGE_PKEY_BIT0 /* HPTE is in 2ndary HPTEG */
#define H_PAGE_F_GIX		(_RPAGE_RPN43 | _RPAGE_RPN42 | _RPAGE_RPN41)
#define H_PAGE_BUSY		_RPAGE_RSV1
#define H_PAGE_HASHPTE		_RPAGE_PKEY_BIT4

/* PTE flags to conserve for HPTE identification */
#define _PAGE_HPTEFLAGS (H_PAGE_BUSY | H_PAGE_HASHPTE | \
			 H_PAGE_F_SECOND | H_PAGE_F_GIX)
/*
 * Not supported by 4k linux page size
 */
#define H_PAGE_4K_PFN	0x0
#define H_PAGE_THP_HUGE 0x0
#define H_PAGE_COMBO	0x0

/* 8 bytes per each pte entry */
#define H_PTE_FRAG_SIZE_SHIFT  (H_PTE_INDEX_SIZE + 3)
#define H_PTE_FRAG_NR	(PAGE_SIZE >> H_PTE_FRAG_SIZE_SHIFT)
#define H_PMD_FRAG_SIZE_SHIFT  (H_PMD_INDEX_SIZE + 3)
#define H_PMD_FRAG_NR	(PAGE_SIZE >> H_PMD_FRAG_SIZE_SHIFT)

/* memory key bits, only 8 keys supported */
#define H_PTE_PKEY_BIT4	0
#define H_PTE_PKEY_BIT3	0
#define H_PTE_PKEY_BIT2	_RPAGE_PKEY_BIT3
#define H_PTE_PKEY_BIT1	_RPAGE_PKEY_BIT2
#define H_PTE_PKEY_BIT0	_RPAGE_PKEY_BIT1


/*
 * On all 4K setups, remap_4k_pfn() equates to remap_pfn_range()
 */
#define remap_4k_pfn(vma, addr, pfn, prot)	\
	remap_pfn_range((vma), (addr), (pfn), PAGE_SIZE, (prot))

/*
 * With 4K page size the real_pte machinery is all nops.
 */
static inline real_pte_t __real_pte(pte_t pte, pte_t *ptep, int offset)
{
	return (real_pte_t){pte};
}

#define __rpte_to_pte(r)	((r).pte)

static inline unsigned long __rpte_to_hidx(real_pte_t rpte, unsigned long index)
{
	return pte_val(__rpte_to_pte(rpte)) >> H_PAGE_F_GIX_SHIFT;
}

#define pte_iterate_hashed_subpages(rpte, psize, va, index, shift)       \
	do {							         \
		index = 0;					         \
		shift = mmu_psize_defs[psize].shift;		         \

#define pte_iterate_hashed_end() } while(0)

/*
 * We expect this to be called only for user addresses or kernel virtual
 * addresses other than the linear mapping.
 */
#define pte_pagesize_index(mm, addr, pte)	MMU_PAGE_4K

/*
 * 4K PTE format is different from 64K PTE format. Saving the hash_slot is just
 * a matter of returning the PTE bits that need to be modified. On 64K PTE,
 * things are a little more involved and hence needs many more parameters to
 * accomplish the same. However we want to abstract this out from the caller by
 * keeping the prototype consistent across the two formats.
 */
static inline unsigned long pte_set_hidx(pte_t *ptep, real_pte_t rpte,
					 unsigned int subpg_index, unsigned long hidx,
					 int offset)
{
	return (hidx << H_PAGE_F_GIX_SHIFT) &
		(H_PAGE_F_SECOND | H_PAGE_F_GIX);
}

#ifdef CONFIG_TRANSPARENT_HUGEPAGE

static inline char *get_hpte_slot_array(pmd_t *pmdp)
{
	BUG();
	return NULL;
}

static inline unsigned int hpte_valid(unsigned char *hpte_slot_array, int index)
{
	BUG();
	return 0;
}

static inline unsigned int hpte_hash_index(unsigned char *hpte_slot_array,
					   int index)
{
	BUG();
	return 0;
}

static inline void mark_hpte_slot_valid(unsigned char *hpte_slot_array,
					unsigned int index, unsigned int hidx)
{
	BUG();
}

static inline int hash__pmd_trans_huge(pmd_t pmd)
{
	return 0;
}

static inline pmd_t hash__pmd_mkhuge(pmd_t pmd)
{
	BUG();
	return pmd;
}

extern unsigned long hash__pmd_hugepage_update(struct mm_struct *mm,
					   unsigned long addr, pmd_t *pmdp,
					   unsigned long clr, unsigned long set);
extern pmd_t hash__pmdp_collapse_flush(struct vm_area_struct *vma,
				   unsigned long address, pmd_t *pmdp);
extern void hash__pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
					 pgtable_t pgtable);
extern pgtable_t hash__pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
extern pmd_t hash__pmdp_huge_get_and_clear(struct mm_struct *mm,
				       unsigned long addr, pmd_t *pmdp);
extern int hash__has_transparent_hugepage(void);
#endif

#endif /* !__ASSEMBLY__ */

#endif /* _ASM_POWERPC_BOOK3S_64_HASH_4K_H */