141 lines
4.1 KiB
C
141 lines
4.1 KiB
C
/*
|
|
* Copyright (c) 2020 Intel Corporation
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*
|
|
* Routines for managing virtual address spaces
|
|
*/
|
|
|
|
#include <stdint.h>
|
|
#include <kernel_arch_interface.h>
|
|
#include <spinlock.h>
|
|
|
|
#define LOG_LEVEL CONFIG_KERNEL_LOG_LEVEL
|
|
#include <logging/log.h>
|
|
LOG_MODULE_DECLARE(os);
|
|
|
|
/* Spinlock to protect any globals in this file and serialize page table
|
|
* updates in arch code
|
|
*/
|
|
static struct k_spinlock mm_lock;
|
|
|
|
/*
|
|
* Overall virtual memory map. System RAM is identity-mapped:
|
|
*
|
|
* +--------------+ <- CONFIG_SRAM_BASE_ADDRESS
|
|
* | Mapping for |
|
|
* | all RAM |
|
|
* | |
|
|
* | |
|
|
* +--------------+ <- CONFIG_SRAM_BASE_ADDRESS + CONFIG_SRAM_SIZE
|
|
* | Available | also the mapping limit as mappings grown downward
|
|
* | virtual mem |
|
|
* | |
|
|
* |..............| <- mapping_pos (grows downward as more mappings are made)
|
|
* | Mapping |
|
|
* +--------------+
|
|
* | Mapping |
|
|
* +--------------+
|
|
* | ... |
|
|
* +--------------+
|
|
* | Mapping |
|
|
* +--------------+ <- CONFIG_SRAM_BASE_ADDRESS + CONFIG_KERNEL_VM_SIZE
|
|
*
|
|
* At the moment we just have one area for mappings and they are permanent.
|
|
* This is under heavy development and may change.
|
|
*/
|
|
|
|
/* Current position for memory mappings in kernel memory.
|
|
* At the moment, all kernel memory mappings are permanent.
|
|
* z_mem_map() mappings start at the end of the address space, and grow
|
|
* downward.
|
|
*
|
|
* TODO: If we ever encounter a board with RAM in high enough memory
|
|
* such that there isn't room in the address space, define mapping_pos
|
|
* and mapping_limit such that we have mappings grow downward from the
|
|
* beginning of system RAM.
|
|
*/
|
|
static uint8_t *mapping_pos =
|
|
(uint8_t *)((uintptr_t)(CONFIG_SRAM_BASE_ADDRESS +
|
|
CONFIG_KERNEL_VM_SIZE));
|
|
|
|
/* Lower-limit of virtual address mapping. Immediately below this is the
|
|
* permanent identity mapping for all SRAM.
|
|
*/
|
|
static uint8_t *mapping_limit =
|
|
(uint8_t *)((uintptr_t)CONFIG_SRAM_BASE_ADDRESS +
|
|
KB((size_t)CONFIG_SRAM_SIZE));
|
|
|
|
size_t k_mem_region_align(uintptr_t *aligned_addr, size_t *aligned_size,
|
|
uintptr_t phys_addr, size_t size, size_t align)
|
|
{
|
|
size_t addr_offset;
|
|
|
|
/* The actual mapped region must be page-aligned. Round down the
|
|
* physical address and pad the region size appropriately
|
|
*/
|
|
*aligned_addr = ROUND_DOWN(phys_addr, align);
|
|
addr_offset = phys_addr - *aligned_addr;
|
|
*aligned_size = ROUND_UP(size + addr_offset, align);
|
|
|
|
return addr_offset;
|
|
}
|
|
|
|
void z_mem_map(uint8_t **virt_addr, uintptr_t phys_addr, size_t size,
|
|
uint32_t flags)
|
|
{
|
|
uintptr_t aligned_addr, addr_offset;
|
|
size_t aligned_size;
|
|
int ret;
|
|
k_spinlock_key_t key;
|
|
uint8_t *dest_virt;
|
|
|
|
addr_offset = k_mem_region_align(&aligned_addr, &aligned_size,
|
|
phys_addr, size,
|
|
CONFIG_MMU_PAGE_SIZE);
|
|
|
|
key = k_spin_lock(&mm_lock);
|
|
|
|
/* Carve out some unused virtual memory from the top of the
|
|
* address space
|
|
*/
|
|
if ((mapping_pos - aligned_size) < mapping_limit) {
|
|
LOG_ERR("insufficient kernel virtual address space");
|
|
goto fail;
|
|
}
|
|
mapping_pos -= aligned_size;
|
|
dest_virt = mapping_pos;
|
|
|
|
LOG_DBG("arch_mem_map(%p, 0x%lx, %zu, %x) offset %lu\n", dest_virt,
|
|
aligned_addr, aligned_size, flags, addr_offset);
|
|
__ASSERT(dest_virt != NULL, "NULL page memory mapping");
|
|
__ASSERT(aligned_size != 0, "0-length mapping at 0x%lx", aligned_addr);
|
|
__ASSERT((uintptr_t)dest_virt <
|
|
((uintptr_t)dest_virt + (aligned_size - 1)),
|
|
"wraparound for virtual address %p (size %zu)",
|
|
dest_virt, size);
|
|
__ASSERT(aligned_addr < (aligned_addr + (size - 1)),
|
|
"wraparound for physical address 0x%lx (size %zu)",
|
|
aligned_addr, size);
|
|
|
|
ret = arch_mem_map(dest_virt, aligned_addr, aligned_size, flags);
|
|
k_spin_unlock(&mm_lock, key);
|
|
|
|
if (ret == 0) {
|
|
*virt_addr = dest_virt + addr_offset;
|
|
} else {
|
|
/* This happens if there is an insurmountable problem
|
|
* with the selected cache modes or access flags
|
|
* with no safe fallback
|
|
*/
|
|
|
|
LOG_ERR("arch_mem_map() to %p returned %d", dest_virt, ret);
|
|
goto fail;
|
|
}
|
|
return;
|
|
fail:
|
|
LOG_ERR("memory mapping 0x%lx (size %zu, flags 0x%x) failed",
|
|
phys_addr, size, flags);
|
|
k_panic();
|
|
}
|