X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Farch%2Fxtensa%2Finclude%2Fasm%2Ffixmap.h;fp=kernel%2Farch%2Fxtensa%2Finclude%2Fasm%2Ffixmap.h;h=62b507deea9da136cc26cf32388a5a3358efa251;hb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;hp=0000000000000000000000000000000000000000;hpb=98260f3884f4a202f9ca5eabed40b1354c489b29;p=kvmfornfv.git diff --git a/kernel/arch/xtensa/include/asm/fixmap.h b/kernel/arch/xtensa/include/asm/fixmap.h new file mode 100644 index 000000000..62b507dee --- /dev/null +++ b/kernel/arch/xtensa/include/asm/fixmap.h @@ -0,0 +1,80 @@ +/* + * fixmap.h: compile-time virtual memory allocation + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 1998 Ingo Molnar + * + * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 + */ + +#ifndef _ASM_FIXMAP_H +#define _ASM_FIXMAP_H + +#include +#ifdef CONFIG_HIGHMEM +#include +#include +#endif + +/* + * Here we define all the compile-time 'special' virtual + * addresses. The point is to have a constant address at + * compile time, but to set the physical address only + * in the boot process. We allocate these special addresses + * from the start of the consistent memory region upwards. + * Also this lets us do fail-safe vmalloc(), we + * can guarantee that these special addresses and + * vmalloc()-ed addresses never overlap. + * + * these 'compile-time allocated' memory buffers are + * fixed-size 4k pages. (or larger if used with an increment + * higher than 1) use fixmap_set(idx,phys) to associate + * physical memory with fixmap indices. + */ +enum fixed_addresses { +#ifdef CONFIG_HIGHMEM + /* reserved pte's for temporary kernel mappings */ + FIX_KMAP_BEGIN, + FIX_KMAP_END = FIX_KMAP_BEGIN + + (KM_TYPE_NR * NR_CPUS * DCACHE_N_COLORS) - 1, +#endif + __end_of_fixed_addresses +}; + +#define FIXADDR_TOP (VMALLOC_START - PAGE_SIZE) +#define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) +#define FIXADDR_START ((FIXADDR_TOP - FIXADDR_SIZE) & PMD_MASK) + +#define __fix_to_virt(x) (FIXADDR_START + ((x) << PAGE_SHIFT)) +#define __virt_to_fix(x) (((x) - FIXADDR_START) >> PAGE_SHIFT) + +#ifndef __ASSEMBLY__ +/* + * 'index to address' translation. If anyone tries to use the idx + * directly without translation, we catch the bug with a NULL-deference + * kernel oops. Illegal ranges of incoming indices are caught too. + */ +static __always_inline unsigned long fix_to_virt(const unsigned int idx) +{ + BUILD_BUG_ON(idx >= __end_of_fixed_addresses); + return __fix_to_virt(idx); +} + +static inline unsigned long virt_to_fix(const unsigned long vaddr) +{ + BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); + return __virt_to_fix(vaddr); +} + +#endif + +#define kmap_get_fixmap_pte(vaddr) \ + pte_offset_kernel( \ + pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), \ + (vaddr) \ + ) + +#endif