drivers/scsi/a3000.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 #include <linux/types.h>
   3 #include <linux/mm.h>
   4 #include <linux/ioport.h>
   5 #include <linux/init.h>
   6 #include <linux/slab.h>
   7 #include <linux/spinlock.h>
   8 #include <linux/interrupt.h>
   9 #include <linux/platform_device.h>
  10 #include <linux/dma-mapping.h>
  11 #include <linux/module.h>
  12
  13 #include <asm/page.h>
  14 #include <asm/amigaints.h>
  15 #include <asm/amigahw.h>
  16
  17 #include <scsi/scsi.h>
  18 #include <scsi/scsi_cmnd.h>
  19 #include <scsi/scsi_device.h>
  20 #include <scsi/scsi_eh.h>
  21 #include <scsi/scsi_tcq.h>
  22 #include "wd33c93.h"
  23 #include "a3000.h"
  24
  25
  26 struct a3000_hostdata {
  27         struct WD33C93_hostdata wh;
  28         struct a3000_scsiregs *regs;
  29         struct device *dev;
  30 };
  31
  32 #define DMA_DIR(d)   ((d == DATA_OUT_DIR) ? DMA_TO_DEVICE : DMA_FROM_DEVICE)
  33
  34 static irqreturn_t a3000_intr(int irq, void *data)
  35 {
  36         struct Scsi_Host *instance = data;
  37         struct a3000_hostdata *hdata = shost_priv(instance);
  38         unsigned int status = hdata->regs->ISTR;
  39         unsigned long flags;
  40
  41         if (!(status & ISTR_INT_P))
  42                 return IRQ_NONE;
  43         if (status & ISTR_INTS) {
  44                 spin_lock_irqsave(instance->host_lock, flags);
  45                 wd33c93_intr(instance);
  46                 spin_unlock_irqrestore(instance->host_lock, flags);
  47                 return IRQ_HANDLED;
  48         }
  49         pr_warn("Non-serviced A3000 SCSI-interrupt? ISTR = %02x\n", status);
  50         return IRQ_NONE;
  51 }
  52
  53 static int dma_setup(struct scsi_cmnd *cmd, int dir_in)
  54 {
  55         struct scsi_pointer *scsi_pointer = WD33C93_scsi_pointer(cmd);
  56         unsigned long len = scsi_pointer->this_residual;
  57         struct Scsi_Host *instance = cmd->device->host;
  58         struct a3000_hostdata *hdata = shost_priv(instance);
  59         struct WD33C93_hostdata *wh = &hdata->wh;
  60         struct a3000_scsiregs *regs = hdata->regs;
  61         unsigned short cntr = CNTR_PDMD | CNTR_INTEN;
  62         dma_addr_t addr;
  63
  64         addr = dma_map_single(hdata->dev, scsi_pointer->ptr,
  65                               len, DMA_DIR(dir_in));
  66         if (dma_mapping_error(hdata->dev, addr)) {
  67                 dev_warn(hdata->dev, "cannot map SCSI data block %p\n",
  68                          scsi_pointer->ptr);
  69                 return 1;
  70         }
  71         scsi_pointer->dma_handle = addr;
  72
  73         /*
  74          * if the physical address has the wrong alignment, or if
  75          * physical address is bad, or if it is a write and at the
  76          * end of a physical memory chunk, then allocate a bounce
  77          * buffer
  78          * MSch 20220629 - only wrong alignment tested - bounce
  79          * buffer returned by kmalloc is guaranteed to be aligned
  80          */
  81         if (addr & A3000_XFER_MASK) {
  82                 WARN_ONCE(1, "Invalid alignment for DMA!");
  83                 /* drop useless mapping */
  84                 dma_unmap_single(hdata->dev, scsi_pointer->dma_handle,
  85                                  scsi_pointer->this_residual,
  86                                  DMA_DIR(dir_in));
  87
  88                 wh->dma_bounce_len = (scsi_pointer->this_residual + 511) & ~0x1ff;
  89                 wh->dma_bounce_buffer = kmalloc(wh->dma_bounce_len,
  90                                                 GFP_KERNEL);
  91
  92                 /* can't allocate memory; use PIO */
  93                 if (!wh->dma_bounce_buffer) {
  94                         wh->dma_bounce_len = 0;
  95                         scsi_pointer->dma_handle = (dma_addr_t) NULL;
  96                         return 1;
  97                 }
  98
  99                 if (!dir_in) {
 100                         /* copy to bounce buffer for a write */
 101                         memcpy(wh->dma_bounce_buffer, scsi_pointer->ptr,
 102                                scsi_pointer->this_residual);
 103                 }
 104
 105                 addr = dma_map_single(hdata->dev, scsi_pointer->ptr,
 106                                       len, DMA_DIR(dir_in));
 107                 if (dma_mapping_error(hdata->dev, addr)) {
 108                         dev_warn(hdata->dev,
 109                                  "cannot map SCSI data block %p\n",
 110                                  scsi_pointer->ptr);
 111                         return 1;
 112                 }
 113                 scsi_pointer->dma_handle = addr;
 114         }
 115
 116         /* setup dma direction */
 117         if (!dir_in)
 118                 cntr |= CNTR_DDIR;
 119
 120         /* remember direction */
 121         wh->dma_dir = dir_in;
 122
 123         regs->CNTR = cntr;
 124
 125         /* setup DMA *physical* address */
 126         regs->ACR = addr;
 127
 128         /* no more cache flush here - dma_map_single() takes care */
 129
 130         /* start DMA */
 131         mb();                   /* make sure setup is completed */
 132         regs->ST_DMA = 1;
 133         mb();                   /* make sure DMA has started before next IO */
 134
 135         /* return success */
 136         return 0;
 137 }
 138
 139 static void dma_stop(struct Scsi_Host *instance, struct scsi_cmnd *SCpnt,
 140                      int status)
 141 {
 142         struct scsi_pointer *scsi_pointer = WD33C93_scsi_pointer(SCpnt);
 143         struct a3000_hostdata *hdata = shost_priv(instance);
 144         struct WD33C93_hostdata *wh = &hdata->wh;
 145         struct a3000_scsiregs *regs = hdata->regs;
 146
 147         /* disable SCSI interrupts */
 148         unsigned short cntr = CNTR_PDMD;
 149
 150         if (!wh->dma_dir)
 151                 cntr |= CNTR_DDIR;
 152
 153         regs->CNTR = cntr;
 154         mb();                   /* make sure CNTR is updated before next IO */
 155
 156         /* flush if we were reading */
 157         if (wh->dma_dir) {
 158                 regs->FLUSH = 1;
 159                 mb();           /* don't allow prefetch */
 160                 while (!(regs->ISTR & ISTR_FE_FLG))
 161                         barrier();
 162                 mb();           /* no IO until FLUSH is done */
 163         }
 164
 165         /* clear a possible interrupt */
 166         /* I think that this CINT is only necessary if you are
 167          * using the terminal count features.   HM 7 Mar 1994
 168          */
 169         regs->CINT = 1;
 170
 171         /* stop DMA */
 172         regs->SP_DMA = 1;
 173         mb();                   /* make sure DMA is stopped before next IO */
 174
 175         /* restore the CONTROL bits (minus the direction flag) */
 176         regs->CNTR = CNTR_PDMD | CNTR_INTEN;
 177         mb();                   /* make sure CNTR is updated before next IO */
 178
 179         dma_unmap_single(hdata->dev, scsi_pointer->dma_handle,
 180                          scsi_pointer->this_residual,
 181                          DMA_DIR(wh->dma_dir));
 182
 183         /* copy from a bounce buffer, if necessary */
 184         if (status && wh->dma_bounce_buffer) {
 185                 if (SCpnt) {
 186                         if (wh->dma_dir && SCpnt)
 187                                 memcpy(scsi_pointer->ptr, wh->dma_bounce_buffer,
 188                                        scsi_pointer->this_residual);
 189                         kfree(wh->dma_bounce_buffer);
 190                         wh->dma_bounce_buffer = NULL;
 191                         wh->dma_bounce_len = 0;
 192                 } else {
 193                         kfree(wh->dma_bounce_buffer);
 194                         wh->dma_bounce_buffer = NULL;
 195                         wh->dma_bounce_len = 0;
 196                 }
 197         }
 198 }
 199
 200 static const struct scsi_host_template amiga_a3000_scsi_template = {
 201         .module                 = THIS_MODULE,
 202         .name                   = "Amiga 3000 built-in SCSI",
 203         .show_info              = wd33c93_show_info,
 204         .write_info             = wd33c93_write_info,
 205         .proc_name              = "A3000",
 206         .queuecommand           = wd33c93_queuecommand,
 207         .eh_abort_handler       = wd33c93_abort,
 208         .eh_host_reset_handler  = wd33c93_host_reset,
 209         .can_queue              = CAN_QUEUE,
 210         .this_id                = 7,
 211         .sg_tablesize           = SG_ALL,
 212         .cmd_per_lun            = CMD_PER_LUN,
 213         .cmd_size               = sizeof(struct scsi_pointer),
 214 };
 215
 216 static int __init amiga_a3000_scsi_probe(struct platform_device *pdev)
 217 {
 218         struct resource *res;
 219         struct Scsi_Host *instance;
 220         int error;
 221         struct a3000_scsiregs *regs;
 222         wd33c93_regs wdregs;
 223         struct a3000_hostdata *hdata;
 224
 225         if (dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32))) {
 226                 dev_warn(&pdev->dev, "cannot use 32 bit DMA\n");
 227                 return -ENODEV;
 228         }
 229
 230         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 231         if (!res)
 232                 return -ENODEV;
 233
 234         if (!request_mem_region(res->start, resource_size(res), "wd33c93"))
 235                 return -EBUSY;
 236
 237         instance = scsi_host_alloc(&amiga_a3000_scsi_template,
 238                                    sizeof(struct a3000_hostdata));
 239         if (!instance) {
 240                 error = -ENOMEM;
 241                 goto fail_alloc;
 242         }
 243
 244         instance->irq = IRQ_AMIGA_PORTS;
 245
 246         regs = ZTWO_VADDR(res->start);
 247         regs->DAWR = DAWR_A3000;
 248
 249         wdregs.SASR = &regs->SASR;
 250         wdregs.SCMD = &regs->SCMD;
 251
 252         hdata = shost_priv(instance);
 253         hdata->dev = &pdev->dev;
 254         hdata->wh.no_sync = 0xff;
 255         hdata->wh.fast = 0;
 256         hdata->wh.dma_mode = CTRL_DMA;
 257         hdata->regs = regs;
 258
 259         wd33c93_init(instance, wdregs, dma_setup, dma_stop, WD33C93_FS_12_15);
 260         error = request_irq(IRQ_AMIGA_PORTS, a3000_intr, IRQF_SHARED,
 261                             "A3000 SCSI", instance);
 262         if (error)
 263                 goto fail_irq;
 264
 265         regs->CNTR = CNTR_PDMD | CNTR_INTEN;
 266
 267         error = scsi_add_host(instance, NULL);
 268         if (error)
 269                 goto fail_host;
 270
 271         platform_set_drvdata(pdev, instance);
 272
 273         scsi_scan_host(instance);
 274         return 0;
 275
 276 fail_host:
 277         free_irq(IRQ_AMIGA_PORTS, instance);
 278 fail_irq:
 279         scsi_host_put(instance);
 280 fail_alloc:
 281         release_mem_region(res->start, resource_size(res));
 282         return error;
 283 }
 284
 285 static void __exit amiga_a3000_scsi_remove(struct platform_device *pdev)
 286 {
 287         struct Scsi_Host *instance = platform_get_drvdata(pdev);
 288         struct a3000_hostdata *hdata = shost_priv(instance);
 289         struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 290
 291         hdata->regs->CNTR = 0;
 292         scsi_remove_host(instance);
 293         free_irq(IRQ_AMIGA_PORTS, instance);
 294         scsi_host_put(instance);
 295         release_mem_region(res->start, resource_size(res));
 296 }
 297
 298 /*
 299  * amiga_a3000_scsi_remove() lives in .exit.text. For drivers registered via
 300  * module_platform_driver_probe() this is ok because they cannot get unbound at
 301  * runtime. So mark the driver struct with __refdata to prevent modpost
 302  * triggering a section mismatch warning.
 303  */
 304 static struct platform_driver amiga_a3000_scsi_driver __refdata = {
 305         .remove_new = __exit_p(amiga_a3000_scsi_remove),
 306         .driver   = {
 307                 .name   = "amiga-a3000-scsi",
 308         },
 309 };
 310
 311 module_platform_driver_probe(amiga_a3000_scsi_driver, amiga_a3000_scsi_probe);
 312
 313 MODULE_DESCRIPTION("Amiga 3000 built-in SCSI");
 314 MODULE_LICENSE("GPL");
 315 MODULE_ALIAS("platform:amiga-a3000-scsi");