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path: root/drivers/scsi/atari_dma_emul.c
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Diffstat (limited to 'drivers/scsi/atari_dma_emul.c')
-rw-r--r--drivers/scsi/atari_dma_emul.c468
1 files changed, 0 insertions, 468 deletions
diff --git a/drivers/scsi/atari_dma_emul.c b/drivers/scsi/atari_dma_emul.c
deleted file mode 100644
index cdc710ea00fa..000000000000
--- a/drivers/scsi/atari_dma_emul.c
+++ /dev/null
@@ -1,468 +0,0 @@
-/*
- * atari_dma_emul.c -- TT SCSI DMA emulator for the Hades.
- *
- * Copyright 1997 Wout Klaren <W.Klaren@inter.nl.net>
- *
- * This file is subject to the terms and conditions of the GNU General Public
- * License. See the file COPYING in the main directory of this archive
- * for more details.
- *
- * This code was written using the Hades TOS source code as a
- * reference. This source code can be found on the home page
- * of Medusa Computer Systems.
- *
- * Version 0.1, 1997-09-24.
- *
- * This code should be considered experimental. It has only been
- * tested on a Hades with a 68060. It might not work on a Hades
- * with a 68040. Make backups of your hard drives before using
- * this code.
- */
-
-#include <linux/compiler.h>
-#include <asm/thread_info.h>
-#include <asm/uaccess.h>
-
-#define hades_dma_ctrl (*(unsigned char *) 0xffff8717)
-#define hades_psdm_reg (*(unsigned char *) 0xffff8741)
-
-#define TRANSFER_SIZE 16
-
-struct m68040_frame {
- unsigned long effaddr; /* effective address */
- unsigned short ssw; /* special status word */
- unsigned short wb3s; /* write back 3 status */
- unsigned short wb2s; /* write back 2 status */
- unsigned short wb1s; /* write back 1 status */
- unsigned long faddr; /* fault address */
- unsigned long wb3a; /* write back 3 address */
- unsigned long wb3d; /* write back 3 data */
- unsigned long wb2a; /* write back 2 address */
- unsigned long wb2d; /* write back 2 data */
- unsigned long wb1a; /* write back 1 address */
- unsigned long wb1dpd0; /* write back 1 data/push data 0*/
- unsigned long pd1; /* push data 1*/
- unsigned long pd2; /* push data 2*/
- unsigned long pd3; /* push data 3*/
-};
-
-static void writeback (unsigned short wbs, unsigned long wba,
- unsigned long wbd, void *old_buserr)
-{
- mm_segment_t fs = get_fs();
- static void *save_buserr;
-
- __asm__ __volatile__ ("movec.l %%vbr,%%a0\n\t"
- "move.l %0,8(%%a0)\n\t"
- :
- : "r" (&&bus_error)
- : "a0" );
-
- save_buserr = old_buserr;
-
- set_fs (MAKE_MM_SEG(wbs & WBTM_040));
-
- switch (wbs & WBSIZ_040) {
- case BA_SIZE_BYTE:
- put_user (wbd & 0xff, (char *)wba);
- break;
- case BA_SIZE_WORD:
- put_user (wbd & 0xffff, (short *)wba);
- break;
- case BA_SIZE_LONG:
- put_user (wbd, (int *)wba);
- break;
- }
-
- set_fs (fs);
- return;
-
-bus_error:
- __asm__ __volatile__ ("cmp.l %0,2(%%sp)\n\t"
- "bcs.s .jump_old\n\t"
- "cmp.l %1,2(%%sp)\n\t"
- "bls.s .restore_old\n"
- ".jump_old:\n\t"
- "move.l %2,-(%%sp)\n\t"
- "rts\n"
- ".restore_old:\n\t"
- "move.l %%a0,-(%%sp)\n\t"
- "movec.l %%vbr,%%a0\n\t"
- "move.l %2,8(%%a0)\n\t"
- "move.l (%%sp)+,%%a0\n\t"
- "rte\n\t"
- :
- : "i" (writeback), "i" (&&bus_error),
- "m" (save_buserr) );
-}
-
-/*
- * static inline void set_restdata_reg(unsigned char *cur_addr)
- *
- * Set the rest data register if necessary.
- */
-
-static inline void set_restdata_reg(unsigned char *cur_addr)
-{
- if (((long) cur_addr & ~3) != 0)
- tt_scsi_dma.dma_restdata =
- *((unsigned long *) ((long) cur_addr & ~3));
-}
-
-/*
- * void hades_dma_emulator(int irq, void *dummy)
- *
- * This code emulates TT SCSI DMA on the Hades.
- *
- * Note the following:
- *
- * 1. When there is no byte available to read from the SCSI bus, or
- * when a byte cannot yet bet written to the SCSI bus, a bus
- * error occurs when reading or writing the pseudo DMA data
- * register (hades_psdm_reg). We have to catch this bus error
- * and try again to read or write the byte. If after several tries
- * we still get a bus error, the interrupt handler is left. When
- * the byte can be read or written, the interrupt handler is
- * called again.
- *
- * 2. The SCSI interrupt must be disabled in this interrupt handler.
- *
- * 3. If we set the EOP signal, the SCSI controller still expects one
- * byte to be read or written. Therefore the last byte is transferred
- * separately, after setting the EOP signal.
- *
- * 4. When this function is left, the address pointer (start_addr) is
- * converted to a physical address. Because it points one byte
- * further than the last transferred byte, it can point outside the
- * current page. If virt_to_phys() is called with this address we
- * might get an access error. Therefore virt_to_phys() is called with
- * start_addr - 1 if the count has reached zero. The result is
- * increased with one.
- */
-
-static irqreturn_t hades_dma_emulator(int irq, void *dummy)
-{
- unsigned long dma_base;
- register unsigned long dma_cnt asm ("d3");
- static long save_buserr;
- register unsigned long save_sp asm ("d4");
- register int tries asm ("d5");
- register unsigned char *start_addr asm ("a3"), *end_addr asm ("a4");
- register unsigned char *eff_addr;
- register unsigned char *psdm_reg;
- unsigned long rem;
-
- atari_disable_irq(IRQ_TT_MFP_SCSI);
-
- /*
- * Read the dma address and count registers.
- */
-
- dma_base = SCSI_DMA_READ_P(dma_addr);
- dma_cnt = SCSI_DMA_READ_P(dma_cnt);
-
- /*
- * Check if DMA is still enabled.
- */
-
- if ((tt_scsi_dma.dma_ctrl & 2) == 0)
- {
- atari_enable_irq(IRQ_TT_MFP_SCSI);
- return IRQ_HANDLED;
- }
-
- if (dma_cnt == 0)
- {
- printk(KERN_NOTICE "DMA emulation: count is zero.\n");
- tt_scsi_dma.dma_ctrl &= 0xfd; /* DMA ready. */
- atari_enable_irq(IRQ_TT_MFP_SCSI);
- return IRQ_HANDLED;
- }
-
- /*
- * Install new bus error routine.
- */
-
- __asm__ __volatile__ ("movec.l %%vbr,%%a0\n\t"
- "move.l 8(%%a0),%0\n\t"
- "move.l %1,8(%%a0)\n\t"
- : "=&r" (save_buserr)
- : "r" (&&scsi_bus_error)
- : "a0" );
-
- hades_dma_ctrl &= 0xfc; /* Bus error and EOP off. */
-
- /*
- * Save the stack pointer.
- */
-
- __asm__ __volatile__ ("move.l %%sp,%0\n\t"
- : "=&r" (save_sp) );
-
- tries = 100; /* Maximum number of bus errors. */
- start_addr = phys_to_virt(dma_base);
- end_addr = start_addr + dma_cnt;
-
-scsi_loop:
- dma_cnt--;
- rem = dma_cnt & (TRANSFER_SIZE - 1);
- dma_cnt &= ~(TRANSFER_SIZE - 1);
- psdm_reg = &hades_psdm_reg;
-
- if (tt_scsi_dma.dma_ctrl & 1) /* Read or write? */
- {
- /*
- * SCSI write. Abort when count is zero.
- */
-
- switch (rem)
- {
- case 0:
- while (dma_cnt > 0)
- {
- dma_cnt -= TRANSFER_SIZE;
-
- *psdm_reg = *start_addr++;
- case 15:
- *psdm_reg = *start_addr++;
- case 14:
- *psdm_reg = *start_addr++;
- case 13:
- *psdm_reg = *start_addr++;
- case 12:
- *psdm_reg = *start_addr++;
- case 11:
- *psdm_reg = *start_addr++;
- case 10:
- *psdm_reg = *start_addr++;
- case 9:
- *psdm_reg = *start_addr++;
- case 8:
- *psdm_reg = *start_addr++;
- case 7:
- *psdm_reg = *start_addr++;
- case 6:
- *psdm_reg = *start_addr++;
- case 5:
- *psdm_reg = *start_addr++;
- case 4:
- *psdm_reg = *start_addr++;
- case 3:
- *psdm_reg = *start_addr++;
- case 2:
- *psdm_reg = *start_addr++;
- case 1:
- *psdm_reg = *start_addr++;
- }
- }
-
- hades_dma_ctrl |= 1; /* Set EOP. */
- udelay(10);
- *psdm_reg = *start_addr++; /* Dummy byte. */
- tt_scsi_dma.dma_ctrl &= 0xfd; /* DMA ready. */
- }
- else
- {
- /*
- * SCSI read. Abort when count is zero.
- */
-
- switch (rem)
- {
- case 0:
- while (dma_cnt > 0)
- {
- dma_cnt -= TRANSFER_SIZE;
-
- *start_addr++ = *psdm_reg;
- case 15:
- *start_addr++ = *psdm_reg;
- case 14:
- *start_addr++ = *psdm_reg;
- case 13:
- *start_addr++ = *psdm_reg;
- case 12:
- *start_addr++ = *psdm_reg;
- case 11:
- *start_addr++ = *psdm_reg;
- case 10:
- *start_addr++ = *psdm_reg;
- case 9:
- *start_addr++ = *psdm_reg;
- case 8:
- *start_addr++ = *psdm_reg;
- case 7:
- *start_addr++ = *psdm_reg;
- case 6:
- *start_addr++ = *psdm_reg;
- case 5:
- *start_addr++ = *psdm_reg;
- case 4:
- *start_addr++ = *psdm_reg;
- case 3:
- *start_addr++ = *psdm_reg;
- case 2:
- *start_addr++ = *psdm_reg;
- case 1:
- *start_addr++ = *psdm_reg;
- }
- }
-
- hades_dma_ctrl |= 1; /* Set EOP. */
- udelay(10);
- *start_addr++ = *psdm_reg;
- tt_scsi_dma.dma_ctrl &= 0xfd; /* DMA ready. */
-
- set_restdata_reg(start_addr);
- }
-
- if (start_addr != end_addr)
- printk(KERN_CRIT "DMA emulation: FATAL: Count is not zero at end of transfer.\n");
-
- dma_cnt = end_addr - start_addr;
-
-scsi_end:
- dma_base = (dma_cnt == 0) ? virt_to_phys(start_addr - 1) + 1 :
- virt_to_phys(start_addr);
-
- SCSI_DMA_WRITE_P(dma_addr, dma_base);
- SCSI_DMA_WRITE_P(dma_cnt, dma_cnt);
-
- /*
- * Restore old bus error routine.
- */
-
- __asm__ __volatile__ ("movec.l %%vbr,%%a0\n\t"
- "move.l %0,8(%%a0)\n\t"
- :
- : "r" (save_buserr)
- : "a0" );
-
- atari_enable_irq(IRQ_TT_MFP_SCSI);
-
- return IRQ_HANDLED;
-
-scsi_bus_error:
- /*
- * First check if the bus error is caused by our code.
- * If not, call the original handler.
- */
-
- __asm__ __volatile__ ("cmp.l %0,2(%%sp)\n\t"
- "bcs.s .old_vector\n\t"
- "cmp.l %1,2(%%sp)\n\t"
- "bls.s .scsi_buserr\n"
- ".old_vector:\n\t"
- "move.l %2,-(%%sp)\n\t"
- "rts\n"
- ".scsi_buserr:\n\t"
- :
- : "i" (&&scsi_loop), "i" (&&scsi_end),
- "m" (save_buserr) );
-
- if (CPU_IS_060)
- {
- /*
- * Get effective address and restore the stack.
- */
-
- __asm__ __volatile__ ("move.l 8(%%sp),%0\n\t"
- "move.l %1,%%sp\n\t"
- : "=a&" (eff_addr)
- : "r" (save_sp) );
- }
- else
- {
- register struct m68040_frame *frame;
-
- __asm__ __volatile__ ("lea 8(%%sp),%0\n\t"
- : "=a&" (frame) );
-
- if (tt_scsi_dma.dma_ctrl & 1)
- {
- /*
- * Bus error while writing.
- */
-
- if (frame->wb3s & WBV_040)
- {
- if (frame->wb3a == (long) &hades_psdm_reg)
- start_addr--;
- else
- writeback(frame->wb3s, frame->wb3a,
- frame->wb3d, &&scsi_bus_error);
- }
-
- if (frame->wb2s & WBV_040)
- {
- if (frame->wb2a == (long) &hades_psdm_reg)
- start_addr--;
- else
- writeback(frame->wb2s, frame->wb2a,
- frame->wb2d, &&scsi_bus_error);
- }
-
- if (frame->wb1s & WBV_040)
- {
- if (frame->wb1a == (long) &hades_psdm_reg)
- start_addr--;
- }
- }
- else
- {
- /*
- * Bus error while reading.
- */
-
- if (frame->wb3s & WBV_040)
- writeback(frame->wb3s, frame->wb3a,
- frame->wb3d, &&scsi_bus_error);
- }
-
- eff_addr = (unsigned char *) frame->faddr;
-
- __asm__ __volatile__ ("move.l %0,%%sp\n\t"
- :
- : "r" (save_sp) );
- }
-
- dma_cnt = end_addr - start_addr;
-
- if (eff_addr == &hades_psdm_reg)
- {
- /*
- * Bus error occurred while reading the pseudo
- * DMA register. Time out.
- */
-
- tries--;
-
- if (tries <= 0)
- {
- if ((tt_scsi_dma.dma_ctrl & 1) == 0) /* Read or write? */
- set_restdata_reg(start_addr);
-
- if (dma_cnt <= 1)
- printk(KERN_CRIT "DMA emulation: Fatal "
- "error while %s the last byte.\n",
- (tt_scsi_dma.dma_ctrl & 1)
- ? "writing" : "reading");
-
- goto scsi_end;
- }
- else
- goto scsi_loop;
- }
- else
- {
- /*
- * Bus error during pseudo DMA transfer.
- * Terminate the DMA transfer.
- */
-
- hades_dma_ctrl |= 3; /* Set EOP and bus error. */
- if ((tt_scsi_dma.dma_ctrl & 1) == 0) /* Read or write? */
- set_restdata_reg(start_addr);
- goto scsi_end;
- }
-}
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