| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | /* |
| 3 | * highmem.h: virtual kernel memory mappings for high memory |
| 4 | * |
| 5 | * PowerPC version, stolen from the i386 version. |
| 6 | * |
| 7 | * Used in CONFIG_HIGHMEM systems for memory pages which |
| 8 | * are not addressable by direct kernel virtual addresses. |
| 9 | * |
| 10 | * Copyright (C) 1999 Gerhard Wichert, Siemens AG |
| 11 | * Gerhard.Wichert@pdb.siemens.de |
| 12 | * |
| 13 | * |
| 14 | * Redesigned the x86 32-bit VM architecture to deal with |
| 15 | * up to 16 Terrabyte physical memory. With current x86 CPUs |
| 16 | * we now support up to 64 Gigabytes physical RAM. |
| 17 | * |
| 18 | * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com> |
| 19 | */ |
| 20 | |
| 21 | #ifndef _ASM_HIGHMEM_H |
| 22 | #define _ASM_HIGHMEM_H |
| 23 | |
| 24 | #ifdef __KERNEL__ |
| 25 | |
| 26 | #include <linux/interrupt.h> |
| 27 | #include <asm/kmap_types.h> |
| 28 | #include <asm/cacheflush.h> |
| 29 | #include <asm/page.h> |
| 30 | #include <asm/fixmap.h> |
| 31 | |
| 32 | extern pte_t *kmap_pte; |
| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 33 | extern pte_t *pkmap_page_table; |
| 34 | |
| 35 | /* |
| 36 | * Right now we initialize only a single pte table. It can be extended |
| 37 | * easily, subsequent pte tables have to be allocated in one physical |
| 38 | * chunk of RAM. |
| 39 | */ |
| 40 | /* |
| 41 | * We use one full pte table with 4K pages. And with 16K/64K/256K pages pte |
| 42 | * table covers enough memory (32MB/512MB/2GB resp.), so that both FIXMAP |
| 43 | * and PKMAP can be placed in a single pte table. We use 512 pages for PKMAP |
| 44 | * in case of 16K/64K/256K page sizes. |
| 45 | */ |
| 46 | #ifdef CONFIG_PPC_4K_PAGES |
| 47 | #define PKMAP_ORDER PTE_SHIFT |
| 48 | #else |
| 49 | #define PKMAP_ORDER 9 |
| 50 | #endif |
| 51 | #define LAST_PKMAP (1 << PKMAP_ORDER) |
| 52 | #ifndef CONFIG_PPC_4K_PAGES |
| 53 | #define PKMAP_BASE (FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1)) |
| 54 | #else |
| 55 | #define PKMAP_BASE ((FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1)) & PMD_MASK) |
| 56 | #endif |
| 57 | #define LAST_PKMAP_MASK (LAST_PKMAP-1) |
| 58 | #define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT) |
| 59 | #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) |
| 60 | |
| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 61 | #define flush_cache_kmaps() flush_cache_all() |
| 62 | |
| 63 | #endif /* __KERNEL__ */ |
| 64 | |
| 65 | #endif /* _ASM_HIGHMEM_H */ |