v4.19.13 snapshot.
diff --git a/drivers/scsi/atari_scsi.c b/drivers/scsi/atari_scsi.c
new file mode 100644
index 0000000..89f5154
--- /dev/null
+++ b/drivers/scsi/atari_scsi.c
@@ -0,0 +1,894 @@
+/*
+ * atari_scsi.c -- Device dependent functions for the Atari generic SCSI port
+ *
+ * Copyright 1994 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
+ *
+ * Loosely based on the work of Robert De Vries' team and added:
+ * - working real DMA
+ * - Falcon support (untested yet!) ++bjoern fixed and now it works
+ * - lots of extensions and bug fixes.
+ *
+ * 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.
+ *
+ */
+
+/*
+ * Notes for Falcon SCSI DMA
+ *
+ * The 5380 device is one of several that all share the DMA chip. Hence
+ * "locking" and "unlocking" access to this chip is required.
+ *
+ * Two possible schemes for ST DMA acquisition by atari_scsi are:
+ * 1) The lock is taken for each command separately (i.e. can_queue == 1).
+ * 2) The lock is taken when the first command arrives and released
+ * when the last command is finished (i.e. can_queue > 1).
+ *
+ * The first alternative limits SCSI bus utilization, since interleaving
+ * commands is not possible. The second gives better performance but is
+ * unfair to other drivers needing to use the ST DMA chip. In order to
+ * allow the IDE and floppy drivers equal access to the ST DMA chip
+ * the default is can_queue == 1.
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/blkdev.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/nvram.h>
+#include <linux/bitops.h>
+#include <linux/wait.h>
+#include <linux/platform_device.h>
+
+#include <asm/setup.h>
+#include <asm/atarihw.h>
+#include <asm/atariints.h>
+#include <asm/atari_stdma.h>
+#include <asm/atari_stram.h>
+#include <asm/io.h>
+
+#include <scsi/scsi_host.h>
+
+#define DMA_MIN_SIZE 32
+
+/* Definitions for the core NCR5380 driver. */
+
+#define NCR5380_implementation_fields /* none */
+
+static u8 (*atari_scsi_reg_read)(unsigned int);
+static void (*atari_scsi_reg_write)(unsigned int, u8);
+
+#define NCR5380_read(reg) atari_scsi_reg_read(reg)
+#define NCR5380_write(reg, value) atari_scsi_reg_write(reg, value)
+
+#define NCR5380_queue_command atari_scsi_queue_command
+#define NCR5380_abort atari_scsi_abort
+#define NCR5380_info atari_scsi_info
+
+#define NCR5380_dma_xfer_len atari_scsi_dma_xfer_len
+#define NCR5380_dma_recv_setup atari_scsi_dma_recv_setup
+#define NCR5380_dma_send_setup atari_scsi_dma_send_setup
+#define NCR5380_dma_residual atari_scsi_dma_residual
+
+#define NCR5380_acquire_dma_irq(instance) falcon_get_lock(instance)
+#define NCR5380_release_dma_irq(instance) falcon_release_lock()
+
+#include "NCR5380.h"
+
+
+#define IS_A_TT() ATARIHW_PRESENT(TT_SCSI)
+
+#define SCSI_DMA_WRITE_P(elt,val) \
+ do { \
+ unsigned long v = val; \
+ tt_scsi_dma.elt##_lo = v & 0xff; \
+ v >>= 8; \
+ tt_scsi_dma.elt##_lmd = v & 0xff; \
+ v >>= 8; \
+ tt_scsi_dma.elt##_hmd = v & 0xff; \
+ v >>= 8; \
+ tt_scsi_dma.elt##_hi = v & 0xff; \
+ } while(0)
+
+#define SCSI_DMA_READ_P(elt) \
+ (((((((unsigned long)tt_scsi_dma.elt##_hi << 8) | \
+ (unsigned long)tt_scsi_dma.elt##_hmd) << 8) | \
+ (unsigned long)tt_scsi_dma.elt##_lmd) << 8) | \
+ (unsigned long)tt_scsi_dma.elt##_lo)
+
+
+static inline void SCSI_DMA_SETADR(unsigned long adr)
+{
+ st_dma.dma_lo = (unsigned char)adr;
+ MFPDELAY();
+ adr >>= 8;
+ st_dma.dma_md = (unsigned char)adr;
+ MFPDELAY();
+ adr >>= 8;
+ st_dma.dma_hi = (unsigned char)adr;
+ MFPDELAY();
+}
+
+static inline unsigned long SCSI_DMA_GETADR(void)
+{
+ unsigned long adr;
+ adr = st_dma.dma_lo;
+ MFPDELAY();
+ adr |= (st_dma.dma_md & 0xff) << 8;
+ MFPDELAY();
+ adr |= (st_dma.dma_hi & 0xff) << 16;
+ MFPDELAY();
+ return adr;
+}
+
+static void atari_scsi_fetch_restbytes(void);
+
+static unsigned long atari_dma_residual, atari_dma_startaddr;
+static short atari_dma_active;
+/* pointer to the dribble buffer */
+static char *atari_dma_buffer;
+/* precalculated physical address of the dribble buffer */
+static unsigned long atari_dma_phys_buffer;
+/* != 0 tells the Falcon int handler to copy data from the dribble buffer */
+static char *atari_dma_orig_addr;
+/* size of the dribble buffer; 4k seems enough, since the Falcon cannot use
+ * scatter-gather anyway, so most transfers are 1024 byte only. In the rare
+ * cases where requests to physical contiguous buffers have been merged, this
+ * request is <= 4k (one page). So I don't think we have to split transfers
+ * just due to this buffer size...
+ */
+#define STRAM_BUFFER_SIZE (4096)
+/* mask for address bits that can't be used with the ST-DMA */
+static unsigned long atari_dma_stram_mask;
+#define STRAM_ADDR(a) (((a) & atari_dma_stram_mask) == 0)
+
+static int setup_can_queue = -1;
+module_param(setup_can_queue, int, 0);
+static int setup_cmd_per_lun = -1;
+module_param(setup_cmd_per_lun, int, 0);
+static int setup_sg_tablesize = -1;
+module_param(setup_sg_tablesize, int, 0);
+static int setup_hostid = -1;
+module_param(setup_hostid, int, 0);
+static int setup_toshiba_delay = -1;
+module_param(setup_toshiba_delay, int, 0);
+
+
+static int scsi_dma_is_ignored_buserr(unsigned char dma_stat)
+{
+ int i;
+ unsigned long addr = SCSI_DMA_READ_P(dma_addr), end_addr;
+
+ if (dma_stat & 0x01) {
+
+ /* A bus error happens when DMA-ing from the last page of a
+ * physical memory chunk (DMA prefetch!), but that doesn't hurt.
+ * Check for this case:
+ */
+
+ for (i = 0; i < m68k_num_memory; ++i) {
+ end_addr = m68k_memory[i].addr + m68k_memory[i].size;
+ if (end_addr <= addr && addr <= end_addr + 4)
+ return 1;
+ }
+ }
+ return 0;
+}
+
+
+static irqreturn_t scsi_tt_intr(int irq, void *dev)
+{
+ struct Scsi_Host *instance = dev;
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+ int dma_stat;
+
+ dma_stat = tt_scsi_dma.dma_ctrl;
+
+ dsprintk(NDEBUG_INTR, instance, "NCR5380 interrupt, DMA status = %02x\n",
+ dma_stat & 0xff);
+
+ /* Look if it was the DMA that has interrupted: First possibility
+ * is that a bus error occurred...
+ */
+ if (dma_stat & 0x80) {
+ if (!scsi_dma_is_ignored_buserr(dma_stat)) {
+ printk(KERN_ERR "SCSI DMA caused bus error near 0x%08lx\n",
+ SCSI_DMA_READ_P(dma_addr));
+ printk(KERN_CRIT "SCSI DMA bus error -- bad DMA programming!");
+ }
+ }
+
+ /* If the DMA is active but not finished, we have the case
+ * that some other 5380 interrupt occurred within the DMA transfer.
+ * This means we have residual bytes, if the desired end address
+ * is not yet reached. Maybe we have to fetch some bytes from the
+ * rest data register, too. The residual must be calculated from
+ * the address pointer, not the counter register, because only the
+ * addr reg counts bytes not yet written and pending in the rest
+ * data reg!
+ */
+ if ((dma_stat & 0x02) && !(dma_stat & 0x40)) {
+ atari_dma_residual = hostdata->dma_len -
+ (SCSI_DMA_READ_P(dma_addr) - atari_dma_startaddr);
+
+ dprintk(NDEBUG_DMA, "SCSI DMA: There are %ld residual bytes.\n",
+ atari_dma_residual);
+
+ if ((signed int)atari_dma_residual < 0)
+ atari_dma_residual = 0;
+ if ((dma_stat & 1) == 0) {
+ /*
+ * After read operations, we maybe have to
+ * transport some rest bytes
+ */
+ atari_scsi_fetch_restbytes();
+ } else {
+ /*
+ * There seems to be a nasty bug in some SCSI-DMA/NCR
+ * combinations: If a target disconnects while a write
+ * operation is going on, the address register of the
+ * DMA may be a few bytes farer than it actually read.
+ * This is probably due to DMA prefetching and a delay
+ * between DMA and NCR. Experiments showed that the
+ * dma_addr is 9 bytes to high, but this could vary.
+ * The problem is, that the residual is thus calculated
+ * wrong and the next transfer will start behind where
+ * it should. So we round up the residual to the next
+ * multiple of a sector size, if it isn't already a
+ * multiple and the originally expected transfer size
+ * was. The latter condition is there to ensure that
+ * the correction is taken only for "real" data
+ * transfers and not for, e.g., the parameters of some
+ * other command. These shouldn't disconnect anyway.
+ */
+ if (atari_dma_residual & 0x1ff) {
+ dprintk(NDEBUG_DMA, "SCSI DMA: DMA bug corrected, "
+ "difference %ld bytes\n",
+ 512 - (atari_dma_residual & 0x1ff));
+ atari_dma_residual = (atari_dma_residual + 511) & ~0x1ff;
+ }
+ }
+ tt_scsi_dma.dma_ctrl = 0;
+ }
+
+ /* If the DMA is finished, fetch the rest bytes and turn it off */
+ if (dma_stat & 0x40) {
+ atari_dma_residual = 0;
+ if ((dma_stat & 1) == 0)
+ atari_scsi_fetch_restbytes();
+ tt_scsi_dma.dma_ctrl = 0;
+ }
+
+ NCR5380_intr(irq, dev);
+
+ return IRQ_HANDLED;
+}
+
+
+static irqreturn_t scsi_falcon_intr(int irq, void *dev)
+{
+ struct Scsi_Host *instance = dev;
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+ int dma_stat;
+
+ /* Turn off DMA and select sector counter register before
+ * accessing the status register (Atari recommendation!)
+ */
+ st_dma.dma_mode_status = 0x90;
+ dma_stat = st_dma.dma_mode_status;
+
+ /* Bit 0 indicates some error in the DMA process... don't know
+ * what happened exactly (no further docu).
+ */
+ if (!(dma_stat & 0x01)) {
+ /* DMA error */
+ printk(KERN_CRIT "SCSI DMA error near 0x%08lx!\n", SCSI_DMA_GETADR());
+ }
+
+ /* If the DMA was active, but now bit 1 is not clear, it is some
+ * other 5380 interrupt that finishes the DMA transfer. We have to
+ * calculate the number of residual bytes and give a warning if
+ * bytes are stuck in the ST-DMA fifo (there's no way to reach them!)
+ */
+ if (atari_dma_active && (dma_stat & 0x02)) {
+ unsigned long transferred;
+
+ transferred = SCSI_DMA_GETADR() - atari_dma_startaddr;
+ /* The ST-DMA address is incremented in 2-byte steps, but the
+ * data are written only in 16-byte chunks. If the number of
+ * transferred bytes is not divisible by 16, the remainder is
+ * lost somewhere in outer space.
+ */
+ if (transferred & 15)
+ printk(KERN_ERR "SCSI DMA error: %ld bytes lost in "
+ "ST-DMA fifo\n", transferred & 15);
+
+ atari_dma_residual = hostdata->dma_len - transferred;
+ dprintk(NDEBUG_DMA, "SCSI DMA: There are %ld residual bytes.\n",
+ atari_dma_residual);
+ } else
+ atari_dma_residual = 0;
+ atari_dma_active = 0;
+
+ if (atari_dma_orig_addr) {
+ /* If the dribble buffer was used on a read operation, copy the DMA-ed
+ * data to the original destination address.
+ */
+ memcpy(atari_dma_orig_addr, phys_to_virt(atari_dma_startaddr),
+ hostdata->dma_len - atari_dma_residual);
+ atari_dma_orig_addr = NULL;
+ }
+
+ NCR5380_intr(irq, dev);
+
+ return IRQ_HANDLED;
+}
+
+
+static void atari_scsi_fetch_restbytes(void)
+{
+ int nr;
+ char *src, *dst;
+ unsigned long phys_dst;
+
+ /* fetch rest bytes in the DMA register */
+ phys_dst = SCSI_DMA_READ_P(dma_addr);
+ nr = phys_dst & 3;
+ if (nr) {
+ /* there are 'nr' bytes left for the last long address
+ before the DMA pointer */
+ phys_dst ^= nr;
+ dprintk(NDEBUG_DMA, "SCSI DMA: there are %d rest bytes for phys addr 0x%08lx",
+ nr, phys_dst);
+ /* The content of the DMA pointer is a physical address! */
+ dst = phys_to_virt(phys_dst);
+ dprintk(NDEBUG_DMA, " = virt addr %p\n", dst);
+ for (src = (char *)&tt_scsi_dma.dma_restdata; nr != 0; --nr)
+ *dst++ = *src++;
+ }
+}
+
+
+/* This function releases the lock on the DMA chip if there is no
+ * connected command and the disconnected queue is empty.
+ */
+
+static void falcon_release_lock(void)
+{
+ if (IS_A_TT())
+ return;
+
+ if (stdma_is_locked_by(scsi_falcon_intr))
+ stdma_release();
+}
+
+/* This function manages the locking of the ST-DMA.
+ * If the DMA isn't locked already for SCSI, it tries to lock it by
+ * calling stdma_lock(). But if the DMA is locked by the SCSI code and
+ * there are other drivers waiting for the chip, we do not issue the
+ * command immediately but tell the SCSI mid-layer to defer.
+ */
+
+static int falcon_get_lock(struct Scsi_Host *instance)
+{
+ if (IS_A_TT())
+ return 1;
+
+ if (stdma_is_locked_by(scsi_falcon_intr) &&
+ instance->hostt->can_queue > 1)
+ return 1;
+
+ if (in_interrupt())
+ return stdma_try_lock(scsi_falcon_intr, instance);
+
+ stdma_lock(scsi_falcon_intr, instance);
+ return 1;
+}
+
+#ifndef MODULE
+static int __init atari_scsi_setup(char *str)
+{
+ /* Format of atascsi parameter is:
+ * atascsi=<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
+ * Defaults depend on TT or Falcon, determined at run time.
+ * Negative values mean don't change.
+ */
+ int ints[8];
+
+ get_options(str, ARRAY_SIZE(ints), ints);
+
+ if (ints[0] < 1) {
+ printk("atari_scsi_setup: no arguments!\n");
+ return 0;
+ }
+ if (ints[0] >= 1)
+ setup_can_queue = ints[1];
+ if (ints[0] >= 2)
+ setup_cmd_per_lun = ints[2];
+ if (ints[0] >= 3)
+ setup_sg_tablesize = ints[3];
+ if (ints[0] >= 4)
+ setup_hostid = ints[4];
+ /* ints[5] (use_tagged_queuing) is ignored */
+ /* ints[6] (use_pdma) is ignored */
+ if (ints[0] >= 7)
+ setup_toshiba_delay = ints[7];
+
+ return 1;
+}
+
+__setup("atascsi=", atari_scsi_setup);
+#endif /* !MODULE */
+
+static unsigned long atari_scsi_dma_setup(struct NCR5380_hostdata *hostdata,
+ void *data, unsigned long count,
+ int dir)
+{
+ unsigned long addr = virt_to_phys(data);
+
+ dprintk(NDEBUG_DMA, "scsi%d: setting up dma, data = %p, phys = %lx, count = %ld, dir = %d\n",
+ hostdata->host->host_no, data, addr, count, dir);
+
+ if (!IS_A_TT() && !STRAM_ADDR(addr)) {
+ /* If we have a non-DMAable address on a Falcon, use the dribble
+ * buffer; 'orig_addr' != 0 in the read case tells the interrupt
+ * handler to copy data from the dribble buffer to the originally
+ * wanted address.
+ */
+ if (dir)
+ memcpy(atari_dma_buffer, data, count);
+ else
+ atari_dma_orig_addr = data;
+ addr = atari_dma_phys_buffer;
+ }
+
+ atari_dma_startaddr = addr; /* Needed for calculating residual later. */
+
+ /* Cache cleanup stuff: On writes, push any dirty cache out before sending
+ * it to the peripheral. (Must be done before DMA setup, since at least
+ * the ST-DMA begins to fill internal buffers right after setup. For
+ * reads, invalidate any cache, may be altered after DMA without CPU
+ * knowledge.
+ *
+ * ++roman: For the Medusa, there's no need at all for that cache stuff,
+ * because the hardware does bus snooping (fine!).
+ */
+ dma_cache_maintenance(addr, count, dir);
+
+ if (IS_A_TT()) {
+ tt_scsi_dma.dma_ctrl = dir;
+ SCSI_DMA_WRITE_P(dma_addr, addr);
+ SCSI_DMA_WRITE_P(dma_cnt, count);
+ tt_scsi_dma.dma_ctrl = dir | 2;
+ } else { /* ! IS_A_TT */
+
+ /* set address */
+ SCSI_DMA_SETADR(addr);
+
+ /* toggle direction bit to clear FIFO and set DMA direction */
+ dir <<= 8;
+ st_dma.dma_mode_status = 0x90 | dir;
+ st_dma.dma_mode_status = 0x90 | (dir ^ 0x100);
+ st_dma.dma_mode_status = 0x90 | dir;
+ udelay(40);
+ /* On writes, round up the transfer length to the next multiple of 512
+ * (see also comment at atari_dma_xfer_len()). */
+ st_dma.fdc_acces_seccount = (count + (dir ? 511 : 0)) >> 9;
+ udelay(40);
+ st_dma.dma_mode_status = 0x10 | dir;
+ udelay(40);
+ /* need not restore value of dir, only boolean value is tested */
+ atari_dma_active = 1;
+ }
+
+ return count;
+}
+
+static inline int atari_scsi_dma_recv_setup(struct NCR5380_hostdata *hostdata,
+ unsigned char *data, int count)
+{
+ return atari_scsi_dma_setup(hostdata, data, count, 0);
+}
+
+static inline int atari_scsi_dma_send_setup(struct NCR5380_hostdata *hostdata,
+ unsigned char *data, int count)
+{
+ return atari_scsi_dma_setup(hostdata, data, count, 1);
+}
+
+static int atari_scsi_dma_residual(struct NCR5380_hostdata *hostdata)
+{
+ return atari_dma_residual;
+}
+
+
+#define CMD_SURELY_BLOCK_MODE 0
+#define CMD_SURELY_BYTE_MODE 1
+#define CMD_MODE_UNKNOWN 2
+
+static int falcon_classify_cmd(struct scsi_cmnd *cmd)
+{
+ unsigned char opcode = cmd->cmnd[0];
+
+ if (opcode == READ_DEFECT_DATA || opcode == READ_LONG ||
+ opcode == READ_BUFFER)
+ return CMD_SURELY_BYTE_MODE;
+ else if (opcode == READ_6 || opcode == READ_10 ||
+ opcode == 0xa8 /* READ_12 */ || opcode == READ_REVERSE ||
+ opcode == RECOVER_BUFFERED_DATA) {
+ /* In case of a sequential-access target (tape), special care is
+ * needed here: The transfer is block-mode only if the 'fixed' bit is
+ * set! */
+ if (cmd->device->type == TYPE_TAPE && !(cmd->cmnd[1] & 1))
+ return CMD_SURELY_BYTE_MODE;
+ else
+ return CMD_SURELY_BLOCK_MODE;
+ } else
+ return CMD_MODE_UNKNOWN;
+}
+
+
+/* This function calculates the number of bytes that can be transferred via
+ * DMA. On the TT, this is arbitrary, but on the Falcon we have to use the
+ * ST-DMA chip. There are only multiples of 512 bytes possible and max.
+ * 255*512 bytes :-( This means also, that defining READ_OVERRUNS is not
+ * possible on the Falcon, since that would require to program the DMA for
+ * n*512 - atari_read_overrun bytes. But it seems that the Falcon doesn't have
+ * the overrun problem, so this question is academic :-)
+ */
+
+static int atari_scsi_dma_xfer_len(struct NCR5380_hostdata *hostdata,
+ struct scsi_cmnd *cmd)
+{
+ int wanted_len = cmd->SCp.this_residual;
+ int possible_len, limit;
+
+ if (wanted_len < DMA_MIN_SIZE)
+ return 0;
+
+ if (IS_A_TT())
+ /* TT SCSI DMA can transfer arbitrary #bytes */
+ return wanted_len;
+
+ /* ST DMA chip is stupid -- only multiples of 512 bytes! (and max.
+ * 255*512 bytes, but this should be enough)
+ *
+ * ++roman: Aaargl! Another Falcon-SCSI problem... There are some commands
+ * that return a number of bytes which cannot be known beforehand. In this
+ * case, the given transfer length is an "allocation length". Now it
+ * can happen that this allocation length is a multiple of 512 bytes and
+ * the DMA is used. But if not n*512 bytes really arrive, some input data
+ * will be lost in the ST-DMA's FIFO :-( Thus, we have to distinguish
+ * between commands that do block transfers and those that do byte
+ * transfers. But this isn't easy... there are lots of vendor specific
+ * commands, and the user can issue any command via the
+ * SCSI_IOCTL_SEND_COMMAND.
+ *
+ * The solution: We classify SCSI commands in 1) surely block-mode cmd.s,
+ * 2) surely byte-mode cmd.s and 3) cmd.s with unknown mode. In case 1)
+ * and 3), the thing to do is obvious: allow any number of blocks via DMA
+ * or none. In case 2), we apply some heuristic: Byte mode is assumed if
+ * the transfer (allocation) length is < 1024, hoping that no cmd. not
+ * explicitly known as byte mode have such big allocation lengths...
+ * BTW, all the discussion above applies only to reads. DMA writes are
+ * unproblematic anyways, since the targets aborts the transfer after
+ * receiving a sufficient number of bytes.
+ *
+ * Another point: If the transfer is from/to an non-ST-RAM address, we
+ * use the dribble buffer and thus can do only STRAM_BUFFER_SIZE bytes.
+ */
+
+ if (cmd->sc_data_direction == DMA_TO_DEVICE) {
+ /* Write operation can always use the DMA, but the transfer size must
+ * be rounded up to the next multiple of 512 (atari_dma_setup() does
+ * this).
+ */
+ possible_len = wanted_len;
+ } else {
+ /* Read operations: if the wanted transfer length is not a multiple of
+ * 512, we cannot use DMA, since the ST-DMA cannot split transfers
+ * (no interrupt on DMA finished!)
+ */
+ if (wanted_len & 0x1ff)
+ possible_len = 0;
+ else {
+ /* Now classify the command (see above) and decide whether it is
+ * allowed to do DMA at all */
+ switch (falcon_classify_cmd(cmd)) {
+ case CMD_SURELY_BLOCK_MODE:
+ possible_len = wanted_len;
+ break;
+ case CMD_SURELY_BYTE_MODE:
+ possible_len = 0; /* DMA prohibited */
+ break;
+ case CMD_MODE_UNKNOWN:
+ default:
+ /* For unknown commands assume block transfers if the transfer
+ * size/allocation length is >= 1024 */
+ possible_len = (wanted_len < 1024) ? 0 : wanted_len;
+ break;
+ }
+ }
+ }
+
+ /* Last step: apply the hard limit on DMA transfers */
+ limit = (atari_dma_buffer && !STRAM_ADDR(virt_to_phys(cmd->SCp.ptr))) ?
+ STRAM_BUFFER_SIZE : 255*512;
+ if (possible_len > limit)
+ possible_len = limit;
+
+ if (possible_len != wanted_len)
+ dprintk(NDEBUG_DMA, "DMA transfer now %d bytes instead of %d\n",
+ possible_len, wanted_len);
+
+ return possible_len;
+}
+
+
+/* NCR5380 register access functions
+ *
+ * There are separate functions for TT and Falcon, because the access
+ * methods are quite different. The calling macros NCR5380_read and
+ * NCR5380_write call these functions via function pointers.
+ */
+
+static u8 atari_scsi_tt_reg_read(unsigned int reg)
+{
+ return tt_scsi_regp[reg * 2];
+}
+
+static void atari_scsi_tt_reg_write(unsigned int reg, u8 value)
+{
+ tt_scsi_regp[reg * 2] = value;
+}
+
+static u8 atari_scsi_falcon_reg_read(unsigned int reg)
+{
+ unsigned long flags;
+ u8 result;
+
+ reg += 0x88;
+ local_irq_save(flags);
+ dma_wd.dma_mode_status = (u_short)reg;
+ result = (u8)dma_wd.fdc_acces_seccount;
+ local_irq_restore(flags);
+ return result;
+}
+
+static void atari_scsi_falcon_reg_write(unsigned int reg, u8 value)
+{
+ unsigned long flags;
+
+ reg += 0x88;
+ local_irq_save(flags);
+ dma_wd.dma_mode_status = (u_short)reg;
+ dma_wd.fdc_acces_seccount = (u_short)value;
+ local_irq_restore(flags);
+}
+
+
+#include "NCR5380.c"
+
+static int atari_scsi_host_reset(struct scsi_cmnd *cmd)
+{
+ int rv;
+ unsigned long flags;
+
+ local_irq_save(flags);
+
+ /* Abort a maybe active DMA transfer */
+ if (IS_A_TT()) {
+ tt_scsi_dma.dma_ctrl = 0;
+ } else {
+ if (stdma_is_locked_by(scsi_falcon_intr))
+ st_dma.dma_mode_status = 0x90;
+ atari_dma_active = 0;
+ atari_dma_orig_addr = NULL;
+ }
+
+ rv = NCR5380_host_reset(cmd);
+
+ /* The 5380 raises its IRQ line while _RST is active but the ST DMA
+ * "lock" has been released so this interrupt may end up handled by
+ * floppy or IDE driver (if one of them holds the lock). The NCR5380
+ * interrupt flag has been cleared already.
+ */
+
+ local_irq_restore(flags);
+
+ return rv;
+}
+
+#define DRV_MODULE_NAME "atari_scsi"
+#define PFX DRV_MODULE_NAME ": "
+
+static struct scsi_host_template atari_scsi_template = {
+ .module = THIS_MODULE,
+ .proc_name = DRV_MODULE_NAME,
+ .name = "Atari native SCSI",
+ .info = atari_scsi_info,
+ .queuecommand = atari_scsi_queue_command,
+ .eh_abort_handler = atari_scsi_abort,
+ .eh_host_reset_handler = atari_scsi_host_reset,
+ .this_id = 7,
+ .cmd_per_lun = 2,
+ .use_clustering = DISABLE_CLUSTERING,
+ .cmd_size = NCR5380_CMD_SIZE,
+};
+
+static int __init atari_scsi_probe(struct platform_device *pdev)
+{
+ struct Scsi_Host *instance;
+ int error;
+ struct resource *irq;
+ int host_flags = 0;
+
+ irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+ if (!irq)
+ return -ENODEV;
+
+ if (ATARIHW_PRESENT(TT_SCSI)) {
+ atari_scsi_reg_read = atari_scsi_tt_reg_read;
+ atari_scsi_reg_write = atari_scsi_tt_reg_write;
+ } else {
+ atari_scsi_reg_read = atari_scsi_falcon_reg_read;
+ atari_scsi_reg_write = atari_scsi_falcon_reg_write;
+ }
+
+ if (ATARIHW_PRESENT(TT_SCSI)) {
+ atari_scsi_template.can_queue = 16;
+ atari_scsi_template.sg_tablesize = SG_ALL;
+ } else {
+ atari_scsi_template.can_queue = 1;
+ atari_scsi_template.sg_tablesize = SG_NONE;
+ }
+
+ if (setup_can_queue > 0)
+ atari_scsi_template.can_queue = setup_can_queue;
+
+ if (setup_cmd_per_lun > 0)
+ atari_scsi_template.cmd_per_lun = setup_cmd_per_lun;
+
+ /* Leave sg_tablesize at 0 on a Falcon! */
+ if (ATARIHW_PRESENT(TT_SCSI) && setup_sg_tablesize >= 0)
+ atari_scsi_template.sg_tablesize = setup_sg_tablesize;
+
+ if (setup_hostid >= 0) {
+ atari_scsi_template.this_id = setup_hostid & 7;
+ } else {
+ /* Test if a host id is set in the NVRam */
+ if (ATARIHW_PRESENT(TT_CLK) && nvram_check_checksum()) {
+ unsigned char b = nvram_read_byte(16);
+
+ /* Arbitration enabled? (for TOS)
+ * If yes, use configured host ID
+ */
+ if (b & 0x80)
+ atari_scsi_template.this_id = b & 7;
+ }
+ }
+
+ /* If running on a Falcon and if there's TT-Ram (i.e., more than one
+ * memory block, since there's always ST-Ram in a Falcon), then
+ * allocate a STRAM_BUFFER_SIZE byte dribble buffer for transfers
+ * from/to alternative Ram.
+ */
+ if (ATARIHW_PRESENT(ST_SCSI) && !ATARIHW_PRESENT(EXTD_DMA) &&
+ m68k_realnum_memory > 1) {
+ atari_dma_buffer = atari_stram_alloc(STRAM_BUFFER_SIZE, "SCSI");
+ if (!atari_dma_buffer) {
+ pr_err(PFX "can't allocate ST-RAM double buffer\n");
+ return -ENOMEM;
+ }
+ atari_dma_phys_buffer = atari_stram_to_phys(atari_dma_buffer);
+ atari_dma_orig_addr = NULL;
+ }
+
+ instance = scsi_host_alloc(&atari_scsi_template,
+ sizeof(struct NCR5380_hostdata));
+ if (!instance) {
+ error = -ENOMEM;
+ goto fail_alloc;
+ }
+
+ instance->irq = irq->start;
+
+ host_flags |= IS_A_TT() ? 0 : FLAG_LATE_DMA_SETUP;
+ host_flags |= setup_toshiba_delay > 0 ? FLAG_TOSHIBA_DELAY : 0;
+
+ error = NCR5380_init(instance, host_flags);
+ if (error)
+ goto fail_init;
+
+ if (IS_A_TT()) {
+ error = request_irq(instance->irq, scsi_tt_intr, 0,
+ "NCR5380", instance);
+ if (error) {
+ pr_err(PFX "request irq %d failed, aborting\n",
+ instance->irq);
+ goto fail_irq;
+ }
+ tt_mfp.active_edge |= 0x80; /* SCSI int on L->H */
+
+ tt_scsi_dma.dma_ctrl = 0;
+ atari_dma_residual = 0;
+
+ /* While the read overruns (described by Drew Eckhardt in
+ * NCR5380.c) never happened on TTs, they do in fact on the
+ * Medusa (This was the cause why SCSI didn't work right for
+ * so long there.) Since handling the overruns slows down
+ * a bit, I turned the #ifdef's into a runtime condition.
+ *
+ * In principle it should be sufficient to do max. 1 byte with
+ * PIO, but there is another problem on the Medusa with the DMA
+ * rest data register. So read_overruns is currently set
+ * to 4 to avoid having transfers that aren't a multiple of 4.
+ * If the rest data bug is fixed, this can be lowered to 1.
+ */
+ if (MACH_IS_MEDUSA) {
+ struct NCR5380_hostdata *hostdata =
+ shost_priv(instance);
+
+ hostdata->read_overruns = 4;
+ }
+ } else {
+ /* Nothing to do for the interrupt: the ST-DMA is initialized
+ * already.
+ */
+ atari_dma_residual = 0;
+ atari_dma_active = 0;
+ atari_dma_stram_mask = (ATARIHW_PRESENT(EXTD_DMA) ? 0x00000000
+ : 0xff000000);
+ }
+
+ NCR5380_maybe_reset_bus(instance);
+
+ error = scsi_add_host(instance, NULL);
+ if (error)
+ goto fail_host;
+
+ platform_set_drvdata(pdev, instance);
+
+ scsi_scan_host(instance);
+ return 0;
+
+fail_host:
+ if (IS_A_TT())
+ free_irq(instance->irq, instance);
+fail_irq:
+ NCR5380_exit(instance);
+fail_init:
+ scsi_host_put(instance);
+fail_alloc:
+ if (atari_dma_buffer)
+ atari_stram_free(atari_dma_buffer);
+ return error;
+}
+
+static int __exit atari_scsi_remove(struct platform_device *pdev)
+{
+ struct Scsi_Host *instance = platform_get_drvdata(pdev);
+
+ scsi_remove_host(instance);
+ if (IS_A_TT())
+ free_irq(instance->irq, instance);
+ NCR5380_exit(instance);
+ scsi_host_put(instance);
+ if (atari_dma_buffer)
+ atari_stram_free(atari_dma_buffer);
+ return 0;
+}
+
+static struct platform_driver atari_scsi_driver = {
+ .remove = __exit_p(atari_scsi_remove),
+ .driver = {
+ .name = DRV_MODULE_NAME,
+ },
+};
+
+module_platform_driver_probe(atari_scsi_driver, atari_scsi_probe);
+
+MODULE_ALIAS("platform:" DRV_MODULE_NAME);
+MODULE_LICENSE("GPL");