xtensa: add alternative kernel memory layouts

MMUv3 is able to support low memory bigger than 128MB.
Implement 256MB and 512MB KSEG layouts:

- add Kconfig selector for KSEG layout;
- add KSEG base address, size and alignment definitions to
  arch/xtensa/include/asm/kmem_layout.h;
- use new definitions in TLB initialization;
- add build time memory map consistency checks.

See Documentation/xtensa/mmu.txt for the details of new memory layouts.

Signed-off-by: Max Filippov <[email protected]>
This commit is contained in:
Max Filippov 2016-04-11 21:14:17 +03:00
commit d39af90265
9 changed files with 249 additions and 10 deletions

View file

@ -62,3 +62,127 @@ limitations apply:
6. The IO area covers the entire 256MB segment of parent-bus-address; the
"ranges" triplet length field is ignored
MMUv3 address space layouts.
============================
Default MMUv2-compatible layout.
Symbol VADDR Size
+------------------+
| Userspace | 0x00000000 TASK_SIZE
+------------------+ 0x40000000
+------------------+
| Page table | 0x80000000
+------------------+ 0x80400000
+------------------+
| KMAP area | PKMAP_BASE PTRS_PER_PTE *
| | DCACHE_N_COLORS *
| | PAGE_SIZE
| | (4MB * DCACHE_N_COLORS)
+------------------+
| Atomic KMAP area | FIXADDR_START KM_TYPE_NR *
| | NR_CPUS *
| | DCACHE_N_COLORS *
| | PAGE_SIZE
+------------------+ FIXADDR_TOP 0xbffff000
+------------------+
| VMALLOC area | VMALLOC_START 0xc0000000 128MB - 64KB
+------------------+ VMALLOC_END
| Cache aliasing | TLBTEMP_BASE_1 0xc7ff0000 DCACHE_WAY_SIZE
| remap area 1 |
+------------------+
| Cache aliasing | TLBTEMP_BASE_2 DCACHE_WAY_SIZE
| remap area 2 |
+------------------+
+------------------+
| Cached KSEG | XCHAL_KSEG_CACHED_VADDR 0xd0000000 128MB
+------------------+
| Uncached KSEG | XCHAL_KSEG_BYPASS_VADDR 0xd8000000 128MB
+------------------+
| Cached KIO | XCHAL_KIO_CACHED_VADDR 0xe0000000 256MB
+------------------+
| Uncached KIO | XCHAL_KIO_BYPASS_VADDR 0xf0000000 256MB
+------------------+
256MB cached + 256MB uncached layout.
Symbol VADDR Size
+------------------+
| Userspace | 0x00000000 TASK_SIZE
+------------------+ 0x40000000
+------------------+
| Page table | 0x80000000
+------------------+ 0x80400000
+------------------+
| KMAP area | PKMAP_BASE PTRS_PER_PTE *
| | DCACHE_N_COLORS *
| | PAGE_SIZE
| | (4MB * DCACHE_N_COLORS)
+------------------+
| Atomic KMAP area | FIXADDR_START KM_TYPE_NR *
| | NR_CPUS *
| | DCACHE_N_COLORS *
| | PAGE_SIZE
+------------------+ FIXADDR_TOP 0x9ffff000
+------------------+
| VMALLOC area | VMALLOC_START 0xa0000000 128MB - 64KB
+------------------+ VMALLOC_END
| Cache aliasing | TLBTEMP_BASE_1 0xa7ff0000 DCACHE_WAY_SIZE
| remap area 1 |
+------------------+
| Cache aliasing | TLBTEMP_BASE_2 DCACHE_WAY_SIZE
| remap area 2 |
+------------------+
+------------------+
| Cached KSEG | XCHAL_KSEG_CACHED_VADDR 0xb0000000 256MB
+------------------+
| Uncached KSEG | XCHAL_KSEG_BYPASS_VADDR 0xc0000000 256MB
+------------------+
+------------------+
| Cached KIO | XCHAL_KIO_CACHED_VADDR 0xe0000000 256MB
+------------------+
| Uncached KIO | XCHAL_KIO_BYPASS_VADDR 0xf0000000 256MB
+------------------+
512MB cached + 512MB uncached layout.
Symbol VADDR Size
+------------------+
| Userspace | 0x00000000 TASK_SIZE
+------------------+ 0x40000000
+------------------+
| Page table | 0x80000000
+------------------+ 0x80400000
+------------------+
| KMAP area | PKMAP_BASE PTRS_PER_PTE *
| | DCACHE_N_COLORS *
| | PAGE_SIZE
| | (4MB * DCACHE_N_COLORS)
+------------------+
| Atomic KMAP area | FIXADDR_START KM_TYPE_NR *
| | NR_CPUS *
| | DCACHE_N_COLORS *
| | PAGE_SIZE
+------------------+ FIXADDR_TOP 0x8ffff000
+------------------+
| VMALLOC area | VMALLOC_START 0x90000000 128MB - 64KB
+------------------+ VMALLOC_END
| Cache aliasing | TLBTEMP_BASE_1 0x97ff0000 DCACHE_WAY_SIZE
| remap area 1 |
+------------------+
| Cache aliasing | TLBTEMP_BASE_2 DCACHE_WAY_SIZE
| remap area 2 |
+------------------+
+------------------+
| Cached KSEG | XCHAL_KSEG_CACHED_VADDR 0xa0000000 512MB
+------------------+
| Uncached KSEG | XCHAL_KSEG_BYPASS_VADDR 0xc0000000 512MB
+------------------+
| Cached KIO | XCHAL_KIO_CACHED_VADDR 0xe0000000 256MB
+------------------+
| Uncached KIO | XCHAL_KIO_BYPASS_VADDR 0xf0000000 256MB
+------------------+