arch/cris/arch-v32/kernel/arbiter.c

   1 /*
   2  * Memory arbiter functions. Allocates bandwidth through the
   3  * arbiter and sets up arbiter breakpoints.
   4  *
   5  * The algorithm first assigns slots to the clients that has specified
   6  * bandwidth (e.g. ethernet) and then the remaining slots are divided
   7  * on all the active clients.
   8  *
   9  * Copyright (c) 2004, 2005 Axis Communications AB.
  10  */
  11
  12 #include <asm/arch/hwregs/reg_map.h>
  13 #include <asm/arch/hwregs/reg_rdwr.h>
  14 #include <asm/arch/hwregs/marb_defs.h>
  15 #include <asm/arch/arbiter.h>
  16 #include <asm/arch/hwregs/intr_vect.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/signal.h>
  19 #include <linux/errno.h>
  20 #include <linux/spinlock.h>
  21 #include <asm/io.h>
  22
  23 struct crisv32_watch_entry
  24 {
  25   unsigned long instance;
  26   watch_callback* cb;
  27   unsigned long start;
  28   unsigned long end;
  29   int used;
  30 };
  31
  32 #define NUMBER_OF_BP 4
  33 #define NBR_OF_CLIENTS 14
  34 #define NBR_OF_SLOTS 64
  35 #define SDRAM_BANDWIDTH 100000000 /* Some kind of expected value */
  36 #define INTMEM_BANDWIDTH 400000000
  37 #define NBR_OF_REGIONS 2
  38
  39 static struct crisv32_watch_entry watches[NUMBER_OF_BP] =
  40 {
  41   {regi_marb_bp0},
  42   {regi_marb_bp1},
  43   {regi_marb_bp2},
  44   {regi_marb_bp3}
  45 };
  46
  47 static int requested_slots[NBR_OF_REGIONS][NBR_OF_CLIENTS];
  48 static int active_clients[NBR_OF_REGIONS][NBR_OF_CLIENTS];
  49 static int max_bandwidth[NBR_OF_REGIONS] = {SDRAM_BANDWIDTH, INTMEM_BANDWIDTH};
  50
  51 DEFINE_SPINLOCK(arbiter_lock);
  52
  53 static irqreturn_t
  54 crisv32_arbiter_irq(int irq, void* dev_id, struct pt_regs* regs);
  55
  56 static void crisv32_arbiter_config(int region)
  57 {
  58         int slot;
  59         int client;
  60         int interval = 0;
  61         int val[NBR_OF_SLOTS];
  62
  63         for (slot = 0; slot < NBR_OF_SLOTS; slot++)
  64             val[slot] = NBR_OF_CLIENTS + 1;
  65
  66         for (client = 0; client < NBR_OF_CLIENTS; client++)
  67         {
  68             int pos;
  69             if (!requested_slots[region][client])
  70                continue;
  71             interval = NBR_OF_SLOTS / requested_slots[region][client];
  72             pos = 0;
  73             while (pos < NBR_OF_SLOTS)
  74             {
  75                 if (val[pos] != NBR_OF_CLIENTS + 1)
  76                    pos++;
  77                 else
  78                 {
  79                         val[pos] = client;
  80                         pos += interval;
  81                 }
  82             }
  83         }
  84
  85         client = 0;
  86         for (slot = 0; slot < NBR_OF_SLOTS; slot++)
  87         {
  88                 if (val[slot] == NBR_OF_CLIENTS + 1)
  89                 {
  90                         int first = client;
  91                         while(!active_clients[region][client]) {
  92                                 client = (client + 1) % NBR_OF_CLIENTS;
  93                                 if (client == first)
  94                                    break;
  95                         }
  96                         val[slot] = client;
  97                         client = (client + 1) % NBR_OF_CLIENTS;
  98                 }
  99                 if (region == EXT_REGION)
 100                    REG_WR_INT_VECT(marb, regi_marb, rw_ext_slots, slot, val[slot]);
 101                 else if (region == INT_REGION)
 102                    REG_WR_INT_VECT(marb, regi_marb, rw_int_slots, slot, val[slot]);
 103         }
 104 }
 105
 106 extern char _stext, _etext;
 107
 108 static void crisv32_arbiter_init(void)
 109 {
 110         static int initialized = 0;
 111
 112         if (initialized)
 113                 return;
 114
 115         initialized = 1;
 116
 117         /* CPU caches are active. */
 118         active_clients[EXT_REGION][10] = active_clients[EXT_REGION][11] = 1;
 119         crisv32_arbiter_config(EXT_REGION);
 120         crisv32_arbiter_config(INT_REGION);
 121
 122         if (request_irq(MEMARB_INTR_VECT, crisv32_arbiter_irq, SA_INTERRUPT,
 123                         "arbiter", NULL))
 124                 printk(KERN_ERR "Couldn't allocate arbiter IRQ\n");
 125
 126 #ifndef CONFIG_ETRAX_KGDB
 127         /* Global watch for writes to kernel text segment. */
 128         crisv32_arbiter_watch(virt_to_phys(&_stext), &_etext - &_stext,
 129                               arbiter_all_clients, arbiter_all_write, NULL);
 130 #endif
 131 }
 132
 133
 134
 135 int crisv32_arbiter_allocate_bandwidth(int client, int region,
 136                                        unsigned long bandwidth)
 137 {
 138         int i;
 139         int total_assigned = 0;
 140         int total_clients = 0;
 141         int req;
 142
 143         crisv32_arbiter_init();
 144
 145         for (i = 0; i < NBR_OF_CLIENTS; i++)
 146         {
 147                 total_assigned += requested_slots[region][i];
 148                 total_clients += active_clients[region][i];
 149         }
 150         req = NBR_OF_SLOTS / (max_bandwidth[region] / bandwidth);
 151
 152         if (total_assigned + total_clients + req + 1 > NBR_OF_SLOTS)
 153            return -ENOMEM;
 154
 155         active_clients[region][client] = 1;
 156         requested_slots[region][client] = req;
 157         crisv32_arbiter_config(region);
 158
 159         return 0;
 160 }
 161
 162 int crisv32_arbiter_watch(unsigned long start, unsigned long size,
 163                           unsigned long clients, unsigned long accesses,
 164                           watch_callback* cb)
 165 {
 166         int i;
 167
 168         crisv32_arbiter_init();
 169
 170         if (start > 0x80000000) {
 171                 printk("Arbiter: %lX doesn't look like a physical address", start);
 172                 return -EFAULT;
 173         }
 174
 175         spin_lock(&arbiter_lock);
 176
 177         for (i = 0; i < NUMBER_OF_BP; i++) {
 178                 if (!watches[i].used) {
 179                         reg_marb_rw_intr_mask intr_mask = REG_RD(marb, regi_marb, rw_intr_mask);
 180
 181                         watches[i].used = 1;
 182                         watches[i].start = start;
 183                         watches[i].end = start + size;
 184                         watches[i].cb = cb;
 185
 186                         REG_WR_INT(marb_bp, watches[i].instance, rw_first_addr, watches[i].start);
 187                         REG_WR_INT(marb_bp, watches[i].instance, rw_last_addr, watches[i].end);
 188                         REG_WR_INT(marb_bp, watches[i].instance, rw_op, accesses);
 189                         REG_WR_INT(marb_bp, watches[i].instance, rw_clients, clients);
 190
 191                         if (i == 0)
 192                                 intr_mask.bp0 = regk_marb_yes;
 193                         else if (i == 1)
 194                                 intr_mask.bp1 = regk_marb_yes;
 195                         else if (i == 2)
 196                                 intr_mask.bp2 = regk_marb_yes;
 197                         else if (i == 3)
 198                                 intr_mask.bp3 = regk_marb_yes;
 199
 200                         REG_WR(marb, regi_marb, rw_intr_mask, intr_mask);
 201                         spin_unlock(&arbiter_lock);
 202
 203                         return i;
 204                 }
 205         }
 206         spin_unlock(&arbiter_lock);
 207         return -ENOMEM;
 208 }
 209
 210 int crisv32_arbiter_unwatch(int id)
 211 {
 212         reg_marb_rw_intr_mask intr_mask = REG_RD(marb, regi_marb, rw_intr_mask);
 213
 214         crisv32_arbiter_init();
 215
 216         spin_lock(&arbiter_lock);
 217
 218         if ((id < 0) || (id >= NUMBER_OF_BP) || (!watches[id].used)) {
 219                 spin_unlock(&arbiter_lock);
 220                 return -EINVAL;
 221         }
 222
 223         memset(&watches[id], 0, sizeof(struct crisv32_watch_entry));
 224
 225         if (id == 0)
 226                 intr_mask.bp0 = regk_marb_no;
 227         else if (id == 1)
 228                 intr_mask.bp2 = regk_marb_no;
 229         else if (id == 2)
 230                 intr_mask.bp2 = regk_marb_no;
 231         else if (id == 3)
 232                 intr_mask.bp3 = regk_marb_no;
 233
 234         REG_WR(marb, regi_marb, rw_intr_mask, intr_mask);
 235
 236         spin_unlock(&arbiter_lock);
 237         return 0;
 238 }
 239
 240 extern void show_registers(struct pt_regs *regs);
 241
 242 static irqreturn_t
 243 crisv32_arbiter_irq(int irq, void* dev_id, struct pt_regs* regs)
 244 {
 245         reg_marb_r_masked_intr masked_intr = REG_RD(marb, regi_marb, r_masked_intr);
 246         reg_marb_bp_r_brk_clients r_clients;
 247         reg_marb_bp_r_brk_addr r_addr;
 248         reg_marb_bp_r_brk_op r_op;
 249         reg_marb_bp_r_brk_first_client r_first;
 250         reg_marb_bp_r_brk_size r_size;
 251         reg_marb_bp_rw_ack ack = {0};
 252         reg_marb_rw_ack_intr ack_intr = {.bp0=1,.bp1=1,.bp2=1,.bp3=1};
 253         struct crisv32_watch_entry* watch;
 254
 255         if (masked_intr.bp0) {
 256                 watch = &watches[0];
 257                 ack_intr.bp0 = regk_marb_yes;
 258         } else if (masked_intr.bp1) {
 259                 watch = &watches[1];
 260                 ack_intr.bp1 = regk_marb_yes;
 261         } else if (masked_intr.bp2) {
 262                 watch = &watches[2];
 263                 ack_intr.bp2 = regk_marb_yes;
 264         } else if (masked_intr.bp3) {
 265                 watch = &watches[3];
 266                 ack_intr.bp3 = regk_marb_yes;
 267         } else {
 268                 return IRQ_NONE;
 269         }
 270
 271         /* Retrieve all useful information and print it. */
 272         r_clients = REG_RD(marb_bp, watch->instance, r_brk_clients);
 273         r_addr = REG_RD(marb_bp, watch->instance, r_brk_addr);
 274         r_op = REG_RD(marb_bp, watch->instance, r_brk_op);
 275         r_first = REG_RD(marb_bp, watch->instance, r_brk_first_client);
 276         r_size = REG_RD(marb_bp, watch->instance, r_brk_size);
 277
 278         printk("Arbiter IRQ\n");
 279         printk("Clients %X addr %X op %X first %X size %X\n",
 280                REG_TYPE_CONV(int, reg_marb_bp_r_brk_clients, r_clients),
 281                REG_TYPE_CONV(int, reg_marb_bp_r_brk_addr, r_addr),
 282                REG_TYPE_CONV(int, reg_marb_bp_r_brk_op, r_op),
 283                REG_TYPE_CONV(int, reg_marb_bp_r_brk_first_client, r_first),
 284                REG_TYPE_CONV(int, reg_marb_bp_r_brk_size, r_size));
 285
 286         REG_WR(marb_bp, watch->instance, rw_ack, ack);
 287         REG_WR(marb, regi_marb, rw_ack_intr, ack_intr);
 288
 289         printk("IRQ occured at %lX\n", regs->erp);
 290
 291         if (watch->cb)
 292                 watch->cb();
 293
 294
 295         return IRQ_HANDLED;
 296 }