lunaix-os/hal/ahci/ata.c

   1 #include <hal/ahci/hba.h>
   2 #include <hal/ahci/sata.h>
   3
   4 #include <lunaix/mm/valloc.h>
   5 #include <lunaix/spike.h>
   6
   7 int
   8 __sata_buffer_io(struct hba_port* port,
   9                  uint64_t lba,
  10                  void* buffer,
  11                  uint32_t size,
  12                  int write)
  13 {
  14     assert_msg(((uintptr_t)buffer & 0x3) == 0, "HBA: Bad buffer alignment");
  15
  16     struct hba_cmdh* header;
  17     struct hba_cmdt* table;
  18     int slot = hba_alloc_slot(port, &table, &header, 0);
  19     int bitmask = 1 << slot;
  20
  21     // 确保端口是空闲的
  22     wait_until(!(port->regs[HBA_RPxTFD] & (HBA_PxTFD_BSY)));
  23
  24     port->regs[HBA_RPxIS] = 0;
  25
  26     table->entries[0] =
  27       (struct hba_prdte){ .byte_count = size - 1, .data_base = buffer };
  28     header->prdt_len = 1;
  29     header->options |= HBA_CMDH_WRITE * (write == 1);
  30
  31     uint16_t count = size / port->device->block_size;
  32     if (count == 0 && size < port->device->block_size) {
  33         // 一个special case: 当count=0的时候，表示的是65536个区块会被传输
  34         // 如果这个0是因为不够除而导致的，那么说明size太小了
  35         goto fail;
  36     }
  37
  38     struct sata_reg_fis* fis = table->command_fis;
  39     if ((port->device->flags & HBA_DEV_FEXTLBA)) {
  40         // 如果该设备支持48位LBA寻址
  41         sata_create_fis(
  42           fis, write ? ATA_WRITE_DMA_EXT : ATA_READ_DMA_EXT, lba, count);
  43     } else {
  44         sata_create_fis(fis, write ? ATA_WRITE_DMA : ATA_READ_DMA, lba, count);
  45     }
  46
  47     port->regs[HBA_RPxCI] = bitmask;
  48
  49     wait_until(!(port->regs[HBA_RPxCI] & bitmask));
  50
  51     if ((port->regs[HBA_RPxTFD] & HBA_PxTFD_ERR)) {
  52         // 有错误
  53         sata_read_error(port);
  54         goto fail;
  55     }
  56
  57     vfree_dma(table);
  58     return 1;
  59
  60 fail:
  61     vfree_dma(table);
  62     return 0;
  63 }
  64
  65 int
  66 sata_read_buffer(struct hba_port* port,
  67                  uint64_t lba,
  68                  void* buffer,
  69                  uint32_t size)
  70 {
  71     return __sata_buffer_io(port, lba, buffer, size, 0);
  72 }
  73
  74 int
  75 sata_write_buffer(struct hba_port* port,
  76                   uint64_t lba,
  77                   void* buffer,
  78                   uint32_t size)
  79 {
  80     return __sata_buffer_io(port, lba, buffer, size, 1);
  81 }
  82
  83 void
  84 sata_read_error(struct hba_port* port)
  85 {
  86     uint32_t tfd = port->regs[HBA_RPxTFD];
  87     port->device->last_error = (tfd >> 8) & 0xff;
  88 }