1// SPDX-License-Identifier: GPL-3.0-or-later
2
3#include "mos/lib/sync/spinlock.hpp"
4#define pr_fmt(fmt) "dma: " fmt
5
6#include "mos/mm/dma.hpp"
7#include "mos/mm/mm.hpp"
8#include "mos/mm/paging/paging.hpp"
9#include "mos/mm/physical/pmm.hpp"
10#include "mos/platform/platform.hpp"
11#include "mos/syslog/printk.hpp"
12
13#include <mos_string.hpp>
14
15static pfn_t dmabuf_do_allocate(size_t n_pages, bool do_ref)
16{
17 phyframe_t *frames = pmm_allocate_frames(n_frames: n_pages, flags: PMM_ALLOC_NORMAL);
18 if (do_ref)
19 pmm_ref(frame: frames, npages: n_pages);
20 memset(s: (void *) phyframe_va(frames), c: 0, n: n_pages * MOS_PAGE_SIZE);
21 return phyframe_pfn(frames);
22}
23
24pfn_t dmabuf_allocate(size_t n_pages, ptr_t *vaddr)
25{
26 const pfn_t pfn = dmabuf_do_allocate(n_pages, do_ref: true);
27 auto vmap = mm_map_user_pages(current_mm, MOS_ADDR_USER_MMAP, pfn, npages: n_pages, flags: VM_USER_RW | VM_CACHE_DISABLED, type: VMAP_TYPE_SHARED, content: VMAP_DMA);
28 if (!vmap)
29 {
30 pmm_unref(pfn_start: pfn, npages: n_pages);
31 return 0;
32 }
33 *vaddr = vmap->vaddr;
34 pr_dinfo2(dma, "allocated %zu DMA pages at " PFN_FMT " and mapped them at " PTR_FMT, n_pages, pfn, *vaddr);
35 return pfn;
36}
37
38bool dmabuf_free(ptr_t vaddr, ptr_t paddr)
39{
40 MOS_UNUSED(paddr);
41 pr_dinfo2(dma, "freeing DMA pages at " PTR_FMT, vaddr);
42
43 SpinLocker lock(&current_mm->mm_lock);
44 vmap_t *vmap = vmap_obtain(current_mm, vaddr: (ptr_t) vaddr);
45 if (!vmap)
46 return false;
47
48 vmap_destroy(vmap);
49 return true;
50}
51
52pfn_t dmabuf_share(void *buf, size_t size)
53{
54 const size_t n_pages = ALIGN_UP_TO_PAGE(size) / MOS_PAGE_SIZE;
55 const pfn_t pfn = dmabuf_do_allocate(n_pages, do_ref: false);
56 pr_dinfo2(dma, "sharing %zu bytes at " PFN_FMT, size, pfn);
57
58 memcpy(dest: (void *) pfn_va(pfn), src: buf, n: size);
59 return pfn;
60}
61
62bool dmabuf_unshare(ptr_t phys, size_t size, void *buffer)
63{
64 const pfn_t pfn = phys / MOS_PAGE_SIZE;
65 pr_dinfo2(dma, "unsharing %zu bytes at " PFN_FMT, size, pfn);
66 memcpy(dest: buffer, src: (void *) pfn_va(pfn), n: size);
67 pmm_free_frames(pfn_phyframe(pfn), ALIGN_UP_TO_PAGE(size) / MOS_PAGE_SIZE);
68 return true;
69}
70