diff options
Diffstat (limited to 'nuttx/arch/arm/src/arm/up_va2pte.c')
-rwxr-xr-x | nuttx/arch/arm/src/arm/up_va2pte.c | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/nuttx/arch/arm/src/arm/up_va2pte.c b/nuttx/arch/arm/src/arm/up_va2pte.c new file mode 100755 index 000000000..5f92ad821 --- /dev/null +++ b/nuttx/arch/arm/src/arm/up_va2pte.c @@ -0,0 +1,121 @@ +/**************************************************************************** + * arch/arm/src/arm/up_va2pte.c + * Utility to map a virtual address to a L2 page table entry. + * + * Copyright (C) 2010 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <spudmonkey@racsa.co.cr> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> + +#include <stdint.h> +#include <debug.h> + +#include <nuttx/sched.h> +#include <nuttx/page.h> + +#include "chip.h" +#include "pg_macros.h" +#include "up_internal.h" + +#ifdef CONFIG_PAGING + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: up_va2pte() + * + * Description: + * Convert a virtual address within the paged text region into a pointer to + * the corresponding page table entry. + * + * Input Parameters: + * vaddr - The virtual address within the paged text region. + * + * Returned Value: + * A pointer to the corresponding page table entry. + * + * Assumptions: + * - This function is called from the normal tasking context (but with + * interrupts disabled). The implementation must take whatever actions + * are necessary to assure that the operation is safe within this + * context. + * + ****************************************************************************/ + +uint32_t *up_va2pte(uintptr_t vaddr) +{ + uint32_t L1; + uint32_t *L2; + unsigned int ndx; + + /* The virtual address is expected to lie in the paged text region */ + + DEBUGASSERT(vaddr >= PG_PAGED_VBASE && vaddr < PG_PAGED_VEND); + + /* Get the L1 table entry associated with this virtual address */ + + L1 = *(uint32_t*)PG_POOL_VA2L1VADDR(vaddr); + + /* Get the address of the L2 page table from the L1 entry */ + + L2 = (uint32_t*)PG_POOL_L12VPTABLE(L1); + + /* Get the index into the L2 page table. Each L1 entry maps + * 256 x 4Kb or 1024 x 1Kb pages. + */ + + ndx = (vaddr & 0x000fffff) >> PAGESHIFT; + + /* Return true if this virtual address is mapped. */ + + return &L2[ndx]; +} + +#endif /* CONFIG_PAGING */ |