Introduce superpages support for ARMv6/v7.

Promoting base pages to superpages can increase TLB coverage and allow for
efficient use of page table entries.  This development provides FreeBSD/ARM
with superpages management mechanism roughly equivalent to what we have for
i386 and amd64 architectures.

1. Add mechanism for automatic promotion of 4KB page mappings to 1MB section
   mappings (and demotion when not needed, respectively).

2. Managed and non-kernel mappings are now superpages-aware.

3. The functionality can be enabled by setting "vm.pmap.sp_enabled" tunable to
   a non-zero value (either in loader.conf or by modifying "sp_enabled"
   variable in pmap-v6.c file).  By default, automatic promotion is currently
   disabled.

Submitted by:	Zbigniew Bodek <zbb@semihalf.com>
Reviewed by:	alc
Sponsored by:	The FreeBSD Foundation, Semihalf
This commit is contained in:
Rafal Jaworowski 2013-08-26 17:12:30 +00:00
parent 0c4367400d
commit b949475db0
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=254918
4 changed files with 1144 additions and 128 deletions

File diff suppressed because it is too large Load diff

View file

@ -108,9 +108,10 @@
#define PDR_SHIFT 20 /* log2(NBPDR) */
#define NBPDR (1 << PDR_SHIFT)
#define PDRMASK (NBPDR - 1)
#define NPDEPG (1 << (32 - PDR_SHIFT))
#define MAXPAGESIZES 1 /* maximum number of supported page sizes */
#define MAXPAGESIZES 2 /* maximum number of supported page sizes */
#ifndef KSTACK_PAGES
#define KSTACK_PAGES 2
@ -133,8 +134,8 @@
*/
#define trunc_page(x) ((x) & ~PAGE_MASK)
#define round_page(x) (((x) + PAGE_MASK) & ~PAGE_MASK)
#define trunc_4mpage(x) ((unsigned)(x) & ~PDRMASK)
#define round_4mpage(x) ((((unsigned)(x)) + PDRMASK) & ~PDRMASK)
#define trunc_1mpage(x) ((unsigned)(x) & ~PDRMASK)
#define round_1mpage(x) ((((unsigned)(x)) + PDRMASK) & ~PDRMASK)
#define atop(x) ((unsigned)(x) >> PAGE_SHIFT)
#define ptoa(x) ((unsigned)(x) << PAGE_SHIFT)

View file

@ -97,8 +97,12 @@ enum mem_type {
#endif
#define pmap_page_get_memattr(m) ((m)->md.pv_memattr)
#define pmap_page_is_mapped(m) (!TAILQ_EMPTY(&(m)->md.pv_list))
#define pmap_page_is_write_mapped(m) (((m)->aflags & PGA_WRITEABLE) != 0)
#if (ARM_MMU_V6 + ARM_MMU_V7) > 0
boolean_t pmap_page_is_mapped(vm_page_t);
#else
#define pmap_page_is_mapped(m) (!TAILQ_EMPTY(&(m)->md.pv_list))
#endif
void pmap_page_set_memattr(vm_page_t m, vm_memattr_t ma);
/*
@ -258,7 +262,9 @@ void *pmap_mapdev(vm_offset_t, vm_size_t);
void pmap_unmapdev(vm_offset_t, vm_size_t);
vm_page_t pmap_use_pt(pmap_t, vm_offset_t);
void pmap_debug(int);
#if (ARM_MMU_V6 + ARM_MMU_V7) == 0
void pmap_map_section(vm_offset_t, vm_offset_t, vm_offset_t, int, int);
#endif
void pmap_link_l2pt(vm_offset_t, vm_offset_t, struct pv_addr *);
vm_size_t pmap_map_chunk(vm_offset_t, vm_offset_t, vm_offset_t, vm_size_t, int, int);
void
@ -411,6 +417,24 @@ extern int pmap_needs_pte_sync;
#define L1_C_PROTO (L1_TYPE_C)
#define L2_S_PROTO (L2_TYPE_S)
/*
* Promotion to a 1MB (SECTION) mapping requires that the corresponding
* 4KB (SMALL) page mappings have identical settings for the following fields:
*/
#define L2_S_PROMOTE (L2_S_REF | L2_SHARED | L2_S_PROT_MASK | \
L2_XN | L2_S_PROTO)
/*
* In order to compare 1MB (SECTION) entry settings with the 4KB (SMALL)
* page mapping it is necessary to read and shift appropriate bits from
* L1 entry to positions of the corresponding bits in the L2 entry.
*/
#define L1_S_DEMOTE(l1pd) ((((l1pd) & L1_S_PROTO) >> 0) | \
(((l1pd) & L1_SHARED) >> 6) | \
(((l1pd) & L1_S_REF) >> 6) | \
(((l1pd) & L1_S_PROT_MASK) >> 6) | \
(((l1pd) & L1_S_XN) >> 4))
#ifndef SMP
#define ARM_L1S_STRONG_ORD (0)
#define ARM_L1S_DEVICE_NOSHARE (L1_S_TEX(2))
@ -497,11 +521,15 @@ extern int pmap_needs_pte_sync;
(((pr) & VM_PROT_WRITE) ? L2_S_PROT_W : 0))
#else
#define L1_S_PROT_U (L1_S_AP(AP_U))
#define L1_S_PROT_MASK (L1_S_APX|L1_S_AP(0x3))
#define L1_S_WRITABLE(pd) (!((pd) & L1_S_APX))
#define L1_S_PROT_W (L1_S_APX) /* Write disable */
#define L1_S_PROT_MASK (L1_S_PROT_W|L1_S_PROT_U)
#define L1_S_REF (L1_S_AP(AP_REF)) /* Reference flag */
#define L1_S_WRITABLE(pd) (!((pd) & L1_S_PROT_W))
#define L1_S_REFERENCED(pd) ((pd) & L1_S_REF)
#define L1_S_PROT(ku, pr) (L1_S_PROT_MASK & ~((((ku) == PTE_KERNEL) ? L1_S_PROT_U : 0) | \
(((pr) & VM_PROT_WRITE) ? L1_S_APX : 0)))
#define L1_S_PROT(ku, pr) (((((ku) == PTE_KERNEL) ? 0 : L1_S_PROT_U) | \
(((pr) & VM_PROT_WRITE) ? 0 : L1_S_PROT_W) | \
(((pr) & VM_PROT_EXECUTE) ? 0 : L1_S_XN)))
#define L2_L_PROT_MASK (L2_APX|L2_AP0(0x3))
#define L2_L_PROT(ku, pr) (L2_L_PROT_MASK & ~((((ku) == PTE_KERNEL) ? L2_S_PROT_U : 0) | \

View file

@ -159,6 +159,9 @@ typedef uint32_t pt_entry_t; /* page table entry */
*/
#define L2_TABLE_SIZE_REAL 0x400 /* 1K */
/* Total number of page table entries in L2 table */
#define L2_PTE_NUM_TOTAL (L2_TABLE_SIZE_REAL / sizeof(pt_entry_t))
/*
* ARM L1 Descriptors
*/
@ -173,6 +176,7 @@ typedef uint32_t pt_entry_t; /* page table entry */
#define L1_S_B 0x00000004 /* bufferable Section */
#define L1_S_C 0x00000008 /* cacheable Section */
#define L1_S_IMP 0x00000010 /* implementation defined */
#define L1_S_XN (1 << 4) /* execute not */
#define L1_S_DOM(x) ((x) << 5) /* domain */
#define L1_S_DOM_MASK L1_S_DOM(0xf)
#define L1_S_AP(x) ((x) << 10) /* access permissions */
@ -248,6 +252,7 @@ typedef uint32_t pt_entry_t; /* page table entry */
* Access Permissions for L1 and L2 Descriptors.
*/
#define AP_W 0x01 /* writable */
#define AP_REF 0x01 /* referenced flag */
#define AP_U 0x02 /* user */
/*