arch/arm/mach-ixp4xx/ixp4xx_qmgr.c

   1 /*
   2  * Intel IXP4xx Queue Manager driver for Linux
   3  *
   4  * Copyright (C) 2007 Krzysztof Halasa <khc@pm.waw.pl>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of version 2 of the GNU General Public License
   8  * as published by the Free Software Foundation.
   9  */
  10
  11 #include <linux/ioport.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <mach/qmgr.h>
  16
  17 struct qmgr_regs __iomem *qmgr_regs;
  18 static struct resource *mem_res;
  19 static spinlock_t qmgr_lock;
  20 static u32 used_sram_bitmap[4]; /* 128 16-dword pages */
  21 static void (*irq_handlers[QUEUES])(void *pdev);
  22 static void *irq_pdevs[QUEUES];
  23
  24 #if DEBUG_QMGR
  25 char qmgr_queue_descs[QUEUES][32];
  26 #endif
  27
  28 void qmgr_set_irq(unsigned int queue, int src,
  29                   void (*handler)(void *pdev), void *pdev)
  30 {
  31         unsigned long flags;
  32
  33         spin_lock_irqsave(&qmgr_lock, flags);
  34         if (queue < HALF_QUEUES) {
  35                 u32 __iomem *reg;
  36                 int bit;
  37                 BUG_ON(src > QUEUE_IRQ_SRC_NOT_FULL);
  38                 reg = &qmgr_regs->irqsrc[queue >> 3]; /* 8 queues per u32 */
  39                 bit = (queue % 8) * 4; /* 3 bits + 1 reserved bit per queue */
  40                 __raw_writel((__raw_readl(reg) & ~(7 << bit)) | (src << bit),
  41                              reg);
  42         } else
  43                 /* IRQ source for queues 32-63 is fixed */
  44                 BUG_ON(src != QUEUE_IRQ_SRC_NOT_NEARLY_EMPTY);
  45
  46         irq_handlers[queue] = handler;
  47         irq_pdevs[queue] = pdev;
  48         spin_unlock_irqrestore(&qmgr_lock, flags);
  49 }
  50
  51
  52 static irqreturn_t qmgr_irq1_a0(int irq, void *pdev)
  53 {
  54         int i, ret = 0;
  55         u32 en_bitmap, src, stat;
  56
  57         /* ACK - it may clear any bits so don't rely on it */
  58         __raw_writel(0xFFFFFFFF, &qmgr_regs->irqstat[0]);
  59
  60         en_bitmap = qmgr_regs->irqen[0];
  61         while (en_bitmap) {
  62                 i = __fls(en_bitmap); /* number of the last "low" queue */
  63                 en_bitmap &= ~BIT(i);
  64                 src = qmgr_regs->irqsrc[i >> 3];
  65                 stat = qmgr_regs->stat1[i >> 3];
  66                 if (src & 4) /* the IRQ condition is inverted */
  67                         stat = ~stat;
  68                 if (stat & BIT(src & 3)) {
  69                         irq_handlers[i](irq_pdevs[i]);
  70                         ret = IRQ_HANDLED;
  71                 }
  72         }
  73         return ret;
  74 }
  75
  76
  77 static irqreturn_t qmgr_irq2_a0(int irq, void *pdev)
  78 {
  79         int i, ret = 0;
  80         u32 req_bitmap;
  81
  82         /* ACK - it may clear any bits so don't rely on it */
  83         __raw_writel(0xFFFFFFFF, &qmgr_regs->irqstat[1]);
  84
  85         req_bitmap = qmgr_regs->irqen[1] & qmgr_regs->statne_h;
  86         while (req_bitmap) {
  87                 i = __fls(req_bitmap); /* number of the last "high" queue */
  88                 req_bitmap &= ~BIT(i);
  89                 irq_handlers[HALF_QUEUES + i](irq_pdevs[HALF_QUEUES + i]);
  90                 ret = IRQ_HANDLED;
  91         }
  92         return ret;
  93 }
  94
  95
  96 static irqreturn_t qmgr_irq(int irq, void *pdev)
  97 {
  98         int i, half = (irq == IRQ_IXP4XX_QM1 ? 0 : 1);
  99         u32 req_bitmap = __raw_readl(&qmgr_regs->irqstat[half]);
 100
 101         if (!req_bitmap)
 102                 return 0;
 103         __raw_writel(req_bitmap, &qmgr_regs->irqstat[half]); /* ACK */
 104
 105         while (req_bitmap) {
 106                 i = __fls(req_bitmap); /* number of the last queue */
 107                 req_bitmap &= ~BIT(i);
 108                 i += half * HALF_QUEUES;
 109                 irq_handlers[i](irq_pdevs[i]);
 110         }
 111         return IRQ_HANDLED;
 112 }
 113
 114
 115 void qmgr_enable_irq(unsigned int queue)
 116 {
 117         unsigned long flags;
 118         int half = queue / 32;
 119         u32 mask = 1 << (queue & (HALF_QUEUES - 1));
 120
 121         spin_lock_irqsave(&qmgr_lock, flags);
 122         __raw_writel(__raw_readl(&qmgr_regs->irqen[half]) | mask,
 123                      &qmgr_regs->irqen[half]);
 124         spin_unlock_irqrestore(&qmgr_lock, flags);
 125 }
 126
 127 void qmgr_disable_irq(unsigned int queue)
 128 {
 129         unsigned long flags;
 130         int half = queue / 32;
 131         u32 mask = 1 << (queue & (HALF_QUEUES - 1));
 132
 133         spin_lock_irqsave(&qmgr_lock, flags);
 134         __raw_writel(__raw_readl(&qmgr_regs->irqen[half]) & ~mask,
 135                      &qmgr_regs->irqen[half]);
 136         __raw_writel(mask, &qmgr_regs->irqstat[half]); /* clear */
 137         spin_unlock_irqrestore(&qmgr_lock, flags);
 138 }
 139
 140 static inline void shift_mask(u32 *mask)
 141 {
 142         mask[3] = mask[3] << 1 | mask[2] >> 31;
 143         mask[2] = mask[2] << 1 | mask[1] >> 31;
 144         mask[1] = mask[1] << 1 | mask[0] >> 31;
 145         mask[0] <<= 1;
 146 }
 147
 148 #if DEBUG_QMGR
 149 int qmgr_request_queue(unsigned int queue, unsigned int len /* dwords */,
 150                        unsigned int nearly_empty_watermark,
 151                        unsigned int nearly_full_watermark,
 152                        const char *desc_format, const char* name)
 153 #else
 154 int __qmgr_request_queue(unsigned int queue, unsigned int len /* dwords */,
 155                          unsigned int nearly_empty_watermark,
 156                          unsigned int nearly_full_watermark)
 157 #endif
 158 {
 159         u32 cfg, addr = 0, mask[4]; /* in 16-dwords */
 160         int err;
 161
 162         BUG_ON(queue >= QUEUES);
 163
 164         if ((nearly_empty_watermark | nearly_full_watermark) & ~7)
 165                 return -EINVAL;
 166
 167         switch (len) {
 168         case  16:
 169                 cfg = 0 << 24;
 170                 mask[0] = 0x1;
 171                 break;
 172         case  32:
 173                 cfg = 1 << 24;
 174                 mask[0] = 0x3;
 175                 break;
 176         case  64:
 177                 cfg = 2 << 24;
 178                 mask[0] = 0xF;
 179                 break;
 180         case 128:
 181                 cfg = 3 << 24;
 182                 mask[0] = 0xFF;
 183                 break;
 184         default:
 185                 return -EINVAL;
 186         }
 187
 188         cfg |= nearly_empty_watermark << 26;
 189         cfg |= nearly_full_watermark << 29;
 190         len /= 16;              /* in 16-dwords: 1, 2, 4 or 8 */
 191         mask[1] = mask[2] = mask[3] = 0;
 192
 193         if (!try_module_get(THIS_MODULE))
 194                 return -ENODEV;
 195
 196         spin_lock_irq(&qmgr_lock);
 197         if (__raw_readl(&qmgr_regs->sram[queue])) {
 198                 err = -EBUSY;
 199                 goto err;
 200         }
 201
 202         while (1) {
 203                 if (!(used_sram_bitmap[0] & mask[0]) &&
 204                     !(used_sram_bitmap[1] & mask[1]) &&
 205                     !(used_sram_bitmap[2] & mask[2]) &&
 206                     !(used_sram_bitmap[3] & mask[3]))
 207                         break; /* found free space */
 208
 209                 addr++;
 210                 shift_mask(mask);
 211                 if (addr + len > ARRAY_SIZE(qmgr_regs->sram)) {
 212                         printk(KERN_ERR "qmgr: no free SRAM space for"
 213                                " queue %i\n", queue);
 214                         err = -ENOMEM;
 215                         goto err;
 216                 }
 217         }
 218
 219         used_sram_bitmap[0] |= mask[0];
 220         used_sram_bitmap[1] |= mask[1];
 221         used_sram_bitmap[2] |= mask[2];
 222         used_sram_bitmap[3] |= mask[3];
 223         __raw_writel(cfg | (addr << 14), &qmgr_regs->sram[queue]);
 224 #if DEBUG_QMGR
 225         snprintf(qmgr_queue_descs[queue], sizeof(qmgr_queue_descs[0]),
 226                  desc_format, name);
 227         printk(KERN_DEBUG "qmgr: requested queue %s(%i) addr = 0x%02X\n",
 228                qmgr_queue_descs[queue], queue, addr);
 229 #endif
 230         spin_unlock_irq(&qmgr_lock);
 231         return 0;
 232
 233 err:
 234         spin_unlock_irq(&qmgr_lock);
 235         module_put(THIS_MODULE);
 236         return err;
 237 }
 238
 239 void qmgr_release_queue(unsigned int queue)
 240 {
 241         u32 cfg, addr, mask[4];
 242
 243         BUG_ON(queue >= QUEUES); /* not in valid range */
 244
 245         spin_lock_irq(&qmgr_lock);
 246         cfg = __raw_readl(&qmgr_regs->sram[queue]);
 247         addr = (cfg >> 14) & 0xFF;
 248
 249         BUG_ON(!addr);          /* not requested */
 250
 251         switch ((cfg >> 24) & 3) {
 252         case 0: mask[0] = 0x1; break;
 253         case 1: mask[0] = 0x3; break;
 254         case 2: mask[0] = 0xF; break;
 255         case 3: mask[0] = 0xFF; break;
 256         }
 257
 258         mask[1] = mask[2] = mask[3] = 0;
 259
 260         while (addr--)
 261                 shift_mask(mask);
 262
 263 #if DEBUG_QMGR
 264         printk(KERN_DEBUG "qmgr: releasing queue %s(%i)\n",
 265                qmgr_queue_descs[queue], queue);
 266         qmgr_queue_descs[queue][0] = '\x0';
 267 #endif
 268         __raw_writel(0, &qmgr_regs->sram[queue]);
 269
 270         used_sram_bitmap[0] &= ~mask[0];
 271         used_sram_bitmap[1] &= ~mask[1];
 272         used_sram_bitmap[2] &= ~mask[2];
 273         used_sram_bitmap[3] &= ~mask[3];
 274         irq_handlers[queue] = NULL; /* catch IRQ bugs */
 275         spin_unlock_irq(&qmgr_lock);
 276
 277         module_put(THIS_MODULE);
 278
 279         while ((addr = qmgr_get_entry(queue)))
 280                 printk(KERN_ERR "qmgr: released queue %i not empty: 0x%08X\n",
 281                        queue, addr);
 282 }
 283
 284 static int qmgr_init(void)
 285 {
 286         int i, err;
 287         irq_handler_t handler1, handler2;
 288
 289         mem_res = request_mem_region(IXP4XX_QMGR_BASE_PHYS,
 290                                      IXP4XX_QMGR_REGION_SIZE,
 291                                      "IXP4xx Queue Manager");
 292         if (mem_res == NULL)
 293                 return -EBUSY;
 294
 295         qmgr_regs = ioremap(IXP4XX_QMGR_BASE_PHYS, IXP4XX_QMGR_REGION_SIZE);
 296         if (qmgr_regs == NULL) {
 297                 err = -ENOMEM;
 298                 goto error_map;
 299         }
 300
 301         /* reset qmgr registers */
 302         for (i = 0; i < 4; i++) {
 303                 __raw_writel(0x33333333, &qmgr_regs->stat1[i]);
 304                 __raw_writel(0, &qmgr_regs->irqsrc[i]);
 305         }
 306         for (i = 0; i < 2; i++) {
 307                 __raw_writel(0, &qmgr_regs->stat2[i]);
 308                 __raw_writel(0xFFFFFFFF, &qmgr_regs->irqstat[i]); /* clear */
 309                 __raw_writel(0, &qmgr_regs->irqen[i]);
 310         }
 311
 312         __raw_writel(0xFFFFFFFF, &qmgr_regs->statne_h);
 313         __raw_writel(0, &qmgr_regs->statf_h);
 314
 315         for (i = 0; i < QUEUES; i++)
 316                 __raw_writel(0, &qmgr_regs->sram[i]);
 317
 318         if (cpu_is_ixp42x_rev_a0()) {
 319                 handler1 = qmgr_irq1_a0;
 320                 handler2 = qmgr_irq2_a0;
 321         } else
 322                 handler1 = handler2 = qmgr_irq;
 323
 324         err = request_irq(IRQ_IXP4XX_QM1, handler1, 0, "IXP4xx Queue Manager",
 325                           NULL);
 326         if (err) {
 327                 printk(KERN_ERR "qmgr: failed to request IRQ%i (%i)\n",
 328                        IRQ_IXP4XX_QM1, err);
 329                 goto error_irq;
 330         }
 331
 332         err = request_irq(IRQ_IXP4XX_QM2, handler2, 0, "IXP4xx Queue Manager",
 333                           NULL);
 334         if (err) {
 335                 printk(KERN_ERR "qmgr: failed to request IRQ%i (%i)\n",
 336                        IRQ_IXP4XX_QM2, err);
 337                 goto error_irq2;
 338         }
 339
 340         used_sram_bitmap[0] = 0xF; /* 4 first pages reserved for config */
 341         spin_lock_init(&qmgr_lock);
 342
 343         printk(KERN_INFO "IXP4xx Queue Manager initialized.\n");
 344         return 0;
 345
 346 error_irq2:
 347         free_irq(IRQ_IXP4XX_QM1, NULL);
 348 error_irq:
 349         iounmap(qmgr_regs);
 350 error_map:
 351         release_mem_region(IXP4XX_QMGR_BASE_PHYS, IXP4XX_QMGR_REGION_SIZE);
 352         return err;
 353 }
 354
 355 static void qmgr_remove(void)
 356 {
 357         free_irq(IRQ_IXP4XX_QM1, NULL);
 358         free_irq(IRQ_IXP4XX_QM2, NULL);
 359         synchronize_irq(IRQ_IXP4XX_QM1);
 360         synchronize_irq(IRQ_IXP4XX_QM2);
 361         iounmap(qmgr_regs);
 362         release_mem_region(IXP4XX_QMGR_BASE_PHYS, IXP4XX_QMGR_REGION_SIZE);
 363 }
 364
 365 module_init(qmgr_init);
 366 module_exit(qmgr_remove);
 367
 368 MODULE_LICENSE("GPL v2");
 369 MODULE_AUTHOR("Krzysztof Halasa");
 370
 371 EXPORT_SYMBOL(qmgr_regs);
 372 EXPORT_SYMBOL(qmgr_set_irq);
 373 EXPORT_SYMBOL(qmgr_enable_irq);
 374 EXPORT_SYMBOL(qmgr_disable_irq);
 375 #if DEBUG_QMGR
 376 EXPORT_SYMBOL(qmgr_queue_descs);
 377 EXPORT_SYMBOL(qmgr_request_queue);
 378 #else
 379 EXPORT_SYMBOL(__qmgr_request_queue);
 380 #endif
 381 EXPORT_SYMBOL(qmgr_release_queue);