| // Copyright 2016 The Fuchsia Authors |
| // Copyright (c) 2014 Travis Geiselbrecht |
| // |
| // Use of this source code is governed by a MIT-style |
| // license that can be found in the LICENSE file or at |
| // https://opensource.org/licenses/MIT |
| |
| #include <vm/bootalloc.h> |
| |
| #include "vm_priv.h" |
| #include <stdint.h> |
| #include <stdlib.h> |
| #include <sys/types.h> |
| #include <trace.h> |
| #include <vm/vm.h> |
| #include <vm/physmap.h> |
| #include <vm/pmm.h> |
| |
| #define LOCAL_TRACE MAX(VM_GLOBAL_TRACE, 0) |
| |
| // Simple boot time allocator that starts by allocating physical memory off |
| // the end of wherever the kernel is loaded in physical space. |
| // |
| // Pointers are returned from the kernel's physmap |
| |
| // store the start and current pointer to the boot allocator in physical address |
| paddr_t boot_alloc_start; |
| paddr_t boot_alloc_end; |
| |
| // run in physical space without the mmu set up, so by computing the address of _end |
| // and saving it, we've effectively computed the physical address of the end of the |
| // kernel. |
| __NO_SAFESTACK |
| void boot_alloc_init() { |
| boot_alloc_start = reinterpret_cast<paddr_t>(_end); |
| boot_alloc_end = reinterpret_cast<paddr_t>(_end); |
| } |
| |
| void boot_alloc_reserve(paddr_t start, size_t len) { |
| uintptr_t end = ALIGN((start + len), PAGE_SIZE); |
| |
| if (end >= boot_alloc_start) { |
| if ((start > boot_alloc_start) && |
| ((start - boot_alloc_start) > (128 * 1024 * 1024))) { |
| // if we've got 128MB of space, that's good enough |
| // it's possible that the start may be *way* far up |
| // (gigabytes) and there may not be space after it... |
| return; |
| } |
| boot_alloc_start = boot_alloc_end = end; |
| } |
| } |
| |
| void* boot_alloc_mem(size_t len) { |
| uintptr_t ptr; |
| |
| ptr = ALIGN(boot_alloc_end, 8); |
| boot_alloc_end = (ptr + ALIGN(len, 8)); |
| |
| LTRACEF("len %zu, phys ptr %#" PRIxPTR " ptr %p\n", len, ptr, paddr_to_physmap(ptr)); |
| |
| return paddr_to_physmap(ptr); |
| } |
| |
| // called from arch start.S |
| // run in physical space without the mmu set up, so stick to basic, relocatable code |
| __NO_SAFESTACK |
| paddr_t boot_alloc_page_phys() { |
| paddr_t ptr = ALIGN(boot_alloc_end, PAGE_SIZE); |
| boot_alloc_end = ptr + PAGE_SIZE; |
| |
| return ptr; |
| } |
| |