linux/arch/sparc/include/asm/pgtsrmmu.h
Will Deacon 8c8f3156dd sparc32: mm: Reduce allocation size for PMD and PTE tables
Now that the page table allocator can free page table allocations
smaller than PAGE_SIZE, reduce the size of the PMD and PTE allocations
to avoid needlessly wasting memory.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-13 15:32:00 -07:00

150 lines
4.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* pgtsrmmu.h: SRMMU page table defines and code.
*
* Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
*/
#ifndef _SPARC_PGTSRMMU_H
#define _SPARC_PGTSRMMU_H
#include <asm/page.h>
#ifdef __ASSEMBLY__
#include <asm/thread_info.h> /* TI_UWINMASK for WINDOW_FLUSH */
#endif
/* Number of contexts is implementation-dependent; 64k is the most we support */
#define SRMMU_MAX_CONTEXTS 65536
#define SRMMU_PTE_TABLE_SIZE (PTRS_PER_PTE*4)
#define SRMMU_PMD_TABLE_SIZE (PTRS_PER_PMD*4)
#define SRMMU_PGD_TABLE_SIZE (PTRS_PER_PGD*4)
/* Definition of the values in the ET field of PTD's and PTE's */
#define SRMMU_ET_MASK 0x3
#define SRMMU_ET_INVALID 0x0
#define SRMMU_ET_PTD 0x1
#define SRMMU_ET_PTE 0x2
#define SRMMU_ET_REPTE 0x3 /* AIEEE, SuperSparc II reverse endian page! */
/* Physical page extraction from PTP's and PTE's. */
#define SRMMU_CTX_PMASK 0xfffffff0
#define SRMMU_PTD_PMASK 0xfffffff0
#define SRMMU_PTE_PMASK 0xffffff00
/* The pte non-page bits. Some notes:
* 1) cache, dirty, valid, and ref are frobbable
* for both supervisor and user pages.
* 2) exec and write will only give the desired effect
* on user pages
* 3) use priv and priv_readonly for changing the
* characteristics of supervisor ptes
*/
#define SRMMU_CACHE 0x80
#define SRMMU_DIRTY 0x40
#define SRMMU_REF 0x20
#define SRMMU_NOREAD 0x10
#define SRMMU_EXEC 0x08
#define SRMMU_WRITE 0x04
#define SRMMU_VALID 0x02 /* SRMMU_ET_PTE */
#define SRMMU_PRIV 0x1c
#define SRMMU_PRIV_RDONLY 0x18
#define SRMMU_CHG_MASK (0xffffff00 | SRMMU_REF | SRMMU_DIRTY)
/* SRMMU swap entry encoding
*
* We use 5 bits for the type and 19 for the offset. This gives us
* 32 swapfiles of 4GB each. Encoding looks like:
*
* oooooooooooooooooootttttRRRRRRRR
* fedcba9876543210fedcba9876543210
*
* The bottom 7 bits are reserved for protection and status bits, especially
* PRESENT.
*/
#define SRMMU_SWP_TYPE_MASK 0x1f
#define SRMMU_SWP_TYPE_SHIFT 7
#define SRMMU_SWP_OFF_MASK 0xfffff
#define SRMMU_SWP_OFF_SHIFT (SRMMU_SWP_TYPE_SHIFT + 5)
/* Some day I will implement true fine grained access bits for
* user pages because the SRMMU gives us the capabilities to
* enforce all the protection levels that vma's can have.
* XXX But for now...
*/
#define SRMMU_PAGE_NONE __pgprot(SRMMU_CACHE | \
SRMMU_PRIV | SRMMU_REF)
#define SRMMU_PAGE_SHARED __pgprot(SRMMU_VALID | SRMMU_CACHE | \
SRMMU_EXEC | SRMMU_WRITE | SRMMU_REF)
#define SRMMU_PAGE_COPY __pgprot(SRMMU_VALID | SRMMU_CACHE | \
SRMMU_EXEC | SRMMU_REF)
#define SRMMU_PAGE_RDONLY __pgprot(SRMMU_VALID | SRMMU_CACHE | \
SRMMU_EXEC | SRMMU_REF)
#define SRMMU_PAGE_KERNEL __pgprot(SRMMU_VALID | SRMMU_CACHE | SRMMU_PRIV | \
SRMMU_DIRTY | SRMMU_REF)
/* SRMMU Register addresses in ASI 0x4. These are valid for all
* current SRMMU implementations that exist.
*/
#define SRMMU_CTRL_REG 0x00000000
#define SRMMU_CTXTBL_PTR 0x00000100
#define SRMMU_CTX_REG 0x00000200
#define SRMMU_FAULT_STATUS 0x00000300
#define SRMMU_FAULT_ADDR 0x00000400
#define WINDOW_FLUSH(tmp1, tmp2) \
mov 0, tmp1; \
98: ld [%g6 + TI_UWINMASK], tmp2; \
orcc %g0, tmp2, %g0; \
add tmp1, 1, tmp1; \
bne 98b; \
save %sp, -64, %sp; \
99: subcc tmp1, 1, tmp1; \
bne 99b; \
restore %g0, %g0, %g0;
#ifndef __ASSEMBLY__
extern unsigned long last_valid_pfn;
/* This makes sense. Honest it does - Anton */
/* XXX Yes but it's ugly as sin. FIXME. -KMW */
extern void *srmmu_nocache_pool;
#define __nocache_pa(VADDR) (((unsigned long)VADDR) - SRMMU_NOCACHE_VADDR + __pa((unsigned long)srmmu_nocache_pool))
#define __nocache_va(PADDR) (__va((unsigned long)PADDR) - (unsigned long)srmmu_nocache_pool + SRMMU_NOCACHE_VADDR)
#define __nocache_fix(VADDR) __va(__nocache_pa(VADDR))
/* Accessing the MMU control register. */
unsigned int srmmu_get_mmureg(void);
void srmmu_set_mmureg(unsigned long regval);
void srmmu_set_ctable_ptr(unsigned long paddr);
void srmmu_set_context(int context);
int srmmu_get_context(void);
unsigned int srmmu_get_fstatus(void);
unsigned int srmmu_get_faddr(void);
/* This is guaranteed on all SRMMU's. */
static inline void srmmu_flush_whole_tlb(void)
{
__asm__ __volatile__("sta %%g0, [%0] %1\n\t": :
"r" (0x400), /* Flush entire TLB!! */
"i" (ASI_M_FLUSH_PROBE) : "memory");
}
static inline int
srmmu_get_pte (unsigned long addr)
{
register unsigned long entry;
__asm__ __volatile__("\n\tlda [%1] %2,%0\n\t" :
"=r" (entry):
"r" ((addr & 0xfffff000) | 0x400), "i" (ASI_M_FLUSH_PROBE));
return entry;
}
#endif /* !(__ASSEMBLY__) */
#endif /* !(_SPARC_PGTSRMMU_H) */