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- /*
- * isa_dma.c
- *
- * Copyright (C) 2013 Aleksandar Andrejevic <theflash@sdf.lonestar.org>
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License as
- * published by the Free Software Foundation, either version 3 of the
- * License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
- #include <isa_dma.h>
- #include <lock.h>
- static dword_t isa_dma_bitmap[1 + ((ISA_DMA_MEM_BLOCKS - 1) / 32)] = { 0 };
- static DECLARE_LOCK(dma_lock);
- void *isa_dma_alloc(void)
- {
- dword_t i;
- for (i = 0; i < ISA_DMA_MEM_BLOCKS; i++) if (!test_bit(isa_dma_bitmap, i))
- {
- set_bit(isa_dma_bitmap, i);
- return (void*)(ISA_DMA_MEM_START + (i * ISA_DMA_MEM_ALIGNMENT));
- }
- return NULL;
- }
- void isa_dma_free(void *dma_buffer)
- {
- clear_bit(isa_dma_bitmap, ((dword_t)dma_buffer - ISA_DMA_MEM_START) / ISA_DMA_MEM_ALIGNMENT);
- }
- void isa_dma_read(dword_t channel, void *buffer, word_t count)
- {
- channel &= 7;
- if (count == 0) return;
- else count--;
- lock_acquire(&dma_lock);
- cpu_write_port_byte(ISA_DMA_SINGLE_MASK_REG(channel), ISA_DMA_MASK_ON | (channel & 3));
- cpu_write_port_byte(ISA_DMA_FF_RESET_REG(channel), 0xFF);
- cpu_write_port_byte(ISA_DMA_SAR(channel), (dword_t)buffer & 0xFF);
- cpu_write_port_byte(ISA_DMA_SAR(channel), ((dword_t)buffer >> 8) & 0xFF);
- cpu_write_port_byte(ISA_DMA_PAR(channel), ((dword_t)buffer >> 16) & 0xFF);
- cpu_write_port_byte(ISA_DMA_FF_RESET_REG(channel), 0xFF);
- cpu_write_port_byte(ISA_DMA_CNT(channel), count & 0xFF);
- cpu_write_port_byte(ISA_DMA_CNT(channel), count >> 8);
- cpu_write_port_byte(ISA_DMA_MODE_REG(channel), 0x48 | (channel & 3));
- cpu_write_port_byte(ISA_DMA_SINGLE_MASK_REG(channel), (channel & 3));
- lock_release(&dma_lock);
- }
- void isa_dma_write(dword_t channel, void *buffer, dword_t count)
- {
- channel &= 7;
- if (count == 0) return;
- else count--;
- lock_acquire(&dma_lock);
- cpu_write_port_byte(ISA_DMA_SINGLE_MASK_REG(channel), ISA_DMA_MASK_ON | (channel & 3));
- cpu_write_port_byte(ISA_DMA_FF_RESET_REG(channel), 0xFF);
- cpu_write_port_byte(ISA_DMA_SAR(channel), (dword_t)buffer & 0xFF);
- cpu_write_port_byte(ISA_DMA_SAR(channel), ((dword_t)buffer >> 8) & 0xFF);
- cpu_write_port_byte(ISA_DMA_PAR(channel), ((dword_t)buffer >> 16) & 0xFF);
- cpu_write_port_byte(ISA_DMA_FF_RESET_REG(channel), 0xFF);
- cpu_write_port_byte(ISA_DMA_CNT(channel), count & 0xFF);
- cpu_write_port_byte(ISA_DMA_CNT(channel), count >> 8);
- cpu_write_port_byte(ISA_DMA_MODE_REG(channel), 0x44 | (channel & 3));
- cpu_write_port_byte(ISA_DMA_SINGLE_MASK_REG(channel), (channel & 3));
- lock_release(&dma_lock);
- }
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