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Diffstat (limited to 'src/dmem.c')
| -rw-r--r-- | src/dmem.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/src/dmem.c b/src/dmem.c new file mode 100644 index 0000000..bbabe09 --- /dev/null +++ b/src/dmem.c @@ -0,0 +1,154 @@ +/* SPDX-License-Identifier: copyleft-next-0.3.1 */ +/* Copyright 2021 - 2022, Kim Kuparinen < kimi.h.kuparinen@gmail.com > */ + +/** + * @file dmem.c + * Handle device memory, i.e. anything outside the physical RAM. + * + * \todo Handle NUMA. + */ + +#include <kmi/assert.h> +#include <kmi/dmem.h> + +/** Region before RAM. */ +static struct mem_region_root pre_ram = { 0 }; + +/** Region after RAM. */ +static struct mem_region_root post_ram = { 0 }; + +pm_t __pre_base = 0; +pm_t __pre_top = 0; +pm_t __post_base = 0; +pm_t __post_top = 0; + +stat_t init_devmem(pm_t ram_base, pm_t ram_top) +{ + pm_t mem_top = (pm_t)-1; + + __pre_base = 0; + __pre_top = ram_base - 1; + + __post_base = ram_top; + __post_top = mem_top; + + size_t pre_pages = __pages(__pre_top); + size_t post_pages = __pages(__post_top) - __pages(__post_base); + + init_region(&pre_ram, __pre_base, pre_pages); + init_region(&post_ram, __post_base, post_pages); + + return OK; +} + +/** + * Device virtual memory worker callback for \ref map_fill_region(). + * + * @param b Virtual memory to work in. + * @param offset Hint for \ref alloc_page(). + * @param vaddr Current virtual address. + * @param flags Flags of region. + * @param order Suggested page order. + * @param data Pointer to \ref stat_t. + * @return \see alloc_uvmem_wrapper(). + * + * \see alloc_uvmem_wrapper(). + */ +static stat_t dev_alloc_wrapper(struct vmem *b, pm_t *offset, vm_t vaddr, + vmflags_t flags, enum mm_order order, + void *data) +{ + stat_t *status = (stat_t *)data; + /** \todo remember to do something with this status info */ + *status = map_vpage(b, *offset, vaddr, flags, order); + *offset += order_size(order); + return OK; +} + +/** + * Device virtual memory freeing worker callback for \ref map_fill_region(). + * + * @param b Virtual memory to work in. + * @param offset Hint for \ref alloc_page(). + * @param vaddr Current virtual address. + * @param flags Flags of region. + * @param order Suggested page order. + * @param data Pointer to \ref stat_t. + * @return \see alloc_uvmem_wrapper(). + * + * \see alloc_uvmem_wrapper(). + */ +static stat_t dev_free_wrapper(struct vmem *b, pm_t *offset, vm_t vaddr, + vmflags_t flags, enum mm_order order, void *data) +{ + UNUSED(offset); + UNUSED(flags); + pm_t paddr = 0; + enum mm_order v_order = 0; + stat_vpage(b, vaddr, &paddr, &v_order, 0); + if (order != v_order) + return INFO_TRGN; + + stat_t *status = (stat_t *)data; + *status = unmap_vpage(b, vaddr); + return OK; +} + +vm_t alloc_devmem(struct tcb *t, pm_t dev_start, size_t bytes, vmflags_t flags) +{ + hard_assert(t && is_proc(t), ERR_INVAL); + + vm_t region = 0; + if (dev_start < __pre_top) + region = alloc_region(&pre_ram, bytes, 0, flags); + + if (dev_start > __post_base) + region = alloc_region(&post_ram, bytes, 0, flags); + + if (!region) + return NULL; + + stat_t status = OK; + const vm_t w = map_fill_region(t->proc.vmem, &dev_alloc_wrapper, + dev_start, region, + bytes, flags, &status); + + if (status) + return NULL; + + return w; +} + +stat_t free_devmem(struct tcb *t, vm_t dev_start) +{ + hard_assert(t && is_proc(t), ERR_INVAL); + + pm_t dev_paddr = 0; + stat_vpage(t->proc.vmem, dev_start, &dev_paddr, 0, 0); + + if (dev_paddr >= __pre_top && dev_paddr <= __post_base) + return ERR_ADDR; + + struct mem_region *m = 0; + if (dev_paddr < __pre_top) + m = find_used_region(&pre_ram, dev_paddr); + + if (dev_paddr > __post_base) + m = find_used_region(&post_ram, dev_paddr); + + if (!m) + return ERR_NF; + + size_t region_size = __addr(m->end - m->start); + stat_t status = OK; + map_fill_region(t->proc.vmem, &dev_free_wrapper, dev_paddr, dev_start, + region_size, 0, &status); + + if (dev_paddr < __pre_top) + free_region(&pre_ram, dev_paddr); + + if (dev_paddr > __post_base) + free_region(&post_ram, dev_paddr); + + return status; +} |