system/kernel/ke/dma.c

   1 /*
   2 Copyright (C) 2008  Mathias Gottschlag
   3
   4 Permission is hereby granted, free of charge, to any person obtaining a copy of
   5 this software and associated documentation files (the "Software"), to deal in the
   6 Software without restriction, including without limitation the rights to use,
   7 copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
   8 Software, and to permit persons to whom the Software is furnished to do so,
   9 subject to the following conditions:
  10
  11 The above copyright notice and this permission notice shall be included in all
  12 copies or substantial portions of the Software.
  13
  14 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
  15 INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
  16 PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  17 HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  18 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  19 SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  20 */
  21
  22 #include "ke/dma.h"
  23 #include "ke/errors.h"
  24 #include "ke/spinlock.h"
  25 #include "ke/ports.h"
  26 #include "mm/memory.h"
  27 #include <string.h>
  28
  29 typedef struct
  30 {
  31         uint8_t channel;
  32         uint8_t mode;
  33         void *buffer;
  34         uint32_t length;
  35         uintptr_t dmabuffer_phys;
  36         void *dmabuffer;
  37         KeSpinlock opened;
  38 } KeDMAChannel;
  39
  40 static KeDMAChannel channels[8];
  41
  42 //static uint16_t dma_status[8] = {0x08, 0x08, 0x08, 0x08, 0xD0, 0xD0, 0xD0, 0xD0};
  43 //static uint16_t dma_command[8] = {0x08, 0x08, 0x08, 0x08, 0xD0, 0xD0, 0xD0, 0xD0};
  44 //static uint16_t dma_request[8] = {0x09, 0x09, 0x09, 0x09, 0xD2, 0xD2, 0xD2, 0xD2};
  45 static uint16_t dma_channel_mask[8] = {0x0A, 0x0A, 0x0A, 0x0A, 0xD4, 0xD4, 0xD4, 0xD4};
  46 static uint16_t dma_mode[8] = {0x0B, 0x0B, 0x0B, 0x0B, 0xD6, 0xD6, 0xD6, 0xD6};
  47 static uint16_t dma_data[8] = {0x0C, 0x0C, 0x0C, 0x0C, 0xD8, 0xD8, 0xD8, 0xD8};
  48 //static uint16_t dma_intermediate[8] = {0x0D, 0x0D, 0x0D, 0x0D, 0xDA, 0xDA, 0xDA, 0xDA};
  49 //static uint16_t dma_mask[8] = {0x0F, 0x0F, 0x0F, 0x0F, 0xDE, 0xDE, 0xDE, 0xDE};
  50 static uint16_t dma_addr[8] = {0x00, 0x02, 0x04, 0x06, 0xC0, 0xC4, 0xC8, 0xCC};
  51 static uint16_t dma_page[8] = {0x87, 0x83, 0x81, 0x82, 0x8F, 0x8B, 0x89, 0x8A};
  52 static uint16_t dma_size[8] = {0x01, 0x03, 0x05, 0x07, 0xC2, 0xC6, 0xCA, 0xCE};
  53
  54 int keOpenDMA(uint8_t channel, uint8_t mode, void *buffer, uint32_t length)
  55 {
  56         // Open channel
  57         if (channel >= 8) return KE_ERROR_UNKNOWN;
  58         if (keTryLockSpinlock(&channels[channel].opened)) return KE_ERROR_UNKNOWN;
  59         channels[channel].channel = channel;
  60         channels[channel].mode = mode;
  61         channels[channel].buffer = buffer;
  62         channels[channel].length = length;
  63
  64         // Allocate buffer
  65         uint32_t pagecount = (length + 0xFFF) / 0x1000;
  66         uintptr_t dmabuffer_phys = mmAllocPhysicalMemory(MM_MEMORY_ALLOC_DMA,
  67                 0, pagecount * 0x1000);
  68         channels[channel].dmabuffer_phys = dmabuffer_phys;
  69         uintptr_t dmabuffer = mmFindFreeKernelPages(MM_MAX_KERNEL_PAGE,
  70                 MM_MIN_KERNEL_PAGE, 1, pagecount * 0x1000);
  71         uint32_t i;
  72         for (i = 0; i < pagecount; i++)
  73         {
  74                 mmMapKernelMemory(dmabuffer_phys + i * 0x1000, dmabuffer + i * 0x1000,
  75                         MM_MAP_READ | MM_MAP_WRITE);
  76         }
  77         memset((void*)dmabuffer, 0, length);
  78         channels[channel].dmabuffer = (void*)dmabuffer;
  79         // Setup DMA
  80         // Mask channel
  81         outb(dma_channel_mask[channel], channel | 0x4);
  82         // Set address
  83         outb(dma_data[channel], 0xFF);
  84         outb(dma_addr[channel], dmabuffer_phys & 0xFF);
  85         outb(dma_addr[channel], (dmabuffer_phys >> 8) & 0xFF);
  86         outb(dma_page[channel], (dmabuffer_phys >> 16) & 0xFF);
  87         // Set size
  88         outb(dma_data[channel], 0xFF);
  89         outb(dma_size[channel], length & 0xFF);
  90         outb(dma_size[channel], (length >> 8) & 0xFF);
  91         // Set mode
  92         outb(dma_mode[channel], (mode & 0xFC) + (channel & 0x3));
  93         // Unmask channel
  94         outb(dma_channel_mask[channel], channel);
  95
  96         return 0;
  97 }
  98 int keCloseDMA(uint8_t channel)
  99 {
 100         if (channel >= 8) return KE_ERROR_UNKNOWN;
 101         // Free buffer
 102         uint32_t pagecount = (channels[channel].length + 0xFFF) / 0x1000;
 103         mmFreePhysicalMemory(channels[channel].dmabuffer_phys, pagecount * 0x1000);
 104         uint32_t i;
 105         for (i = 0; i < pagecount; i++)
 106         {
 107                 mmMapKernelMemory(0, (uintptr_t)channels[channel].dmabuffer + i * 0x1000, 0);
 108         }
 109         // Close channel
 110         keUnlockSpinlock(&channels[channel].opened);
 111         return 0;
 112 }
 113
 114 int keReadDMA(uint8_t channel)
 115 {
 116         if (channel >= 8) return KE_ERROR_UNKNOWN;
 117         memcpy(channels[channel].buffer, channels[channel].dmabuffer,
 118                 channels[channel].length);
 119         return 0;
 120 }
 121 int keWriteDMA(uint8_t channel)
 122 {
 123         if (channel >= 8) return KE_ERROR_UNKNOWN;
 124         memcpy(channels[channel].dmabuffer, channels[channel].buffer,
 125                 channels[channel].length);
 126         return 0;
 127 }
 128