1 // Copyright 2018 The Fuchsia Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include <ddk/mmio-buffer.h>
6
7 #include <string.h>
8
9 #include <ddk/driver.h>
10 #include <zircon/process.h>
11 #include <zircon/syscalls.h>
12 #include <zircon/types.h>
13
mmio_buffer_init(mmio_buffer_t * buffer,zx_off_t offset,size_t size,zx_handle_t vmo,uint32_t cache_policy)14 zx_status_t mmio_buffer_init(mmio_buffer_t* buffer, zx_off_t offset, size_t size,
15 zx_handle_t vmo, uint32_t cache_policy) {
16 zx_status_t status = zx_vmo_set_cache_policy(vmo, cache_policy);
17 if (status != ZX_OK) {
18 zx_handle_close(vmo);
19 return status;
20 }
21
22 uintptr_t vaddr;
23 const size_t vmo_offset = ROUNDDOWN(offset, ZX_PAGE_SIZE);
24 const size_t page_offset = offset - vmo_offset;
25 const size_t vmo_size = ROUNDUP(size + page_offset, ZX_PAGE_SIZE);
26
27 status = zx_vmar_map(zx_vmar_root_self(),
28 ZX_VM_PERM_READ | ZX_VM_PERM_WRITE | ZX_VM_MAP_RANGE,
29 0, vmo, vmo_offset, vmo_size, &vaddr);
30 if (status != ZX_OK) {
31 zx_handle_close(vmo);
32 return status;
33 }
34
35 buffer->vmo = vmo;
36 buffer->vaddr = (void*)(vaddr + page_offset);
37 buffer->offset = offset;
38 buffer->size = size;
39
40 return ZX_OK;
41 }
42
mmio_buffer_init_physical(mmio_buffer_t * buffer,zx_paddr_t base,size_t size,zx_handle_t resource,uint32_t cache_policy)43 zx_status_t mmio_buffer_init_physical(mmio_buffer_t* buffer, zx_paddr_t base, size_t size,
44 zx_handle_t resource, uint32_t cache_policy) {
45 zx_handle_t vmo;
46 zx_status_t status = zx_vmo_create_physical(resource, base, size, &vmo);
47 if (status != ZX_OK) {
48 return status;
49 }
50
51 // |base| is guaranteed to be page aligned.
52 return mmio_buffer_init(buffer, 0, size, vmo, cache_policy);
53 }
54
mmio_buffer_release(mmio_buffer_t * buffer)55 void mmio_buffer_release(mmio_buffer_t* buffer) {
56 if (buffer->vmo != ZX_HANDLE_INVALID) {
57 zx_vmar_unmap(zx_vmar_root_self(), (uintptr_t)buffer->vaddr, buffer->size);
58 zx_handle_close(buffer->vmo);
59 buffer->vmo = ZX_HANDLE_INVALID;
60 }
61 }
62
mmio_buffer_pin(mmio_buffer_t * buffer,zx_handle_t bti,mmio_pinned_buffer_t * out)63 zx_status_t mmio_buffer_pin(mmio_buffer_t* buffer, zx_handle_t bti, mmio_pinned_buffer_t* out) {
64 zx_paddr_t paddr;
65 zx_handle_t pmt;
66 const uint32_t options = ZX_BTI_PERM_WRITE | ZX_BTI_PERM_READ | ZX_BTI_CONTIGUOUS;
67 const size_t vmo_offset = ROUNDDOWN(buffer->offset, ZX_PAGE_SIZE);
68 const size_t page_offset = buffer->offset - vmo_offset;
69 const size_t vmo_size = ROUNDUP(buffer->size + page_offset, ZX_PAGE_SIZE);
70
71 zx_status_t status = zx_bti_pin(bti, options, buffer->vmo, vmo_offset, vmo_size,
72 &paddr, 1, &pmt);
73 if (status != ZX_OK) {
74 return status;
75 }
76
77 out->mmio = buffer;
78 out->paddr = paddr + page_offset;
79 out->pmt = pmt;
80
81 return ZX_OK;
82 }
83
mmio_buffer_unpin(mmio_pinned_buffer_t * buffer)84 void mmio_buffer_unpin(mmio_pinned_buffer_t* buffer) {
85 if (buffer->pmt != ZX_HANDLE_INVALID) {
86 zx_pmt_unpin(buffer->pmt);
87 buffer->pmt = ZX_HANDLE_INVALID;
88 }
89 }
90