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-rw-r--r--arch/cris/arch-v32/kernel/arbiter.c297
1 files changed, 297 insertions, 0 deletions
diff --git a/arch/cris/arch-v32/kernel/arbiter.c b/arch/cris/arch-v32/kernel/arbiter.c
new file mode 100644
index 0000000..3870d2fd
--- /dev/null
+++ b/arch/cris/arch-v32/kernel/arbiter.c
@@ -0,0 +1,297 @@
+/*
+ * Memory arbiter functions. Allocates bandwith through the
+ * arbiter and sets up arbiter breakpoints.
+ *
+ * The algorithm first assigns slots to the clients that has specified
+ * bandwith (e.g. ethernet) and then the remaining slots are divided
+ * on all the active clients.
+ *
+ * Copyright (c) 2004, 2005 Axis Communications AB.
+ */
+
+#include <linux/config.h>
+#include <asm/arch/hwregs/reg_map.h>
+#include <asm/arch/hwregs/reg_rdwr.h>
+#include <asm/arch/hwregs/marb_defs.h>
+#include <asm/arch/arbiter.h>
+#include <asm/arch/hwregs/intr_vect.h>
+#include <linux/interrupt.h>
+#include <linux/signal.h>
+#include <linux/errno.h>
+#include <linux/spinlock.h>
+#include <asm/io.h>
+
+struct crisv32_watch_entry
+{
+ unsigned long instance;
+ watch_callback* cb;
+ unsigned long start;
+ unsigned long end;
+ int used;
+};
+
+#define NUMBER_OF_BP 4
+#define NBR_OF_CLIENTS 14
+#define NBR_OF_SLOTS 64
+#define SDRAM_BANDWIDTH 100000000 /* Some kind of expected value */
+#define INTMEM_BANDWIDTH 400000000
+#define NBR_OF_REGIONS 2
+
+static struct crisv32_watch_entry watches[NUMBER_OF_BP] =
+{
+ {regi_marb_bp0},
+ {regi_marb_bp1},
+ {regi_marb_bp2},
+ {regi_marb_bp3}
+};
+
+static int requested_slots[NBR_OF_REGIONS][NBR_OF_CLIENTS];
+static int active_clients[NBR_OF_REGIONS][NBR_OF_CLIENTS];
+static int max_bandwidth[NBR_OF_REGIONS] = {SDRAM_BANDWIDTH, INTMEM_BANDWIDTH};
+
+DEFINE_SPINLOCK(arbiter_lock);
+
+static irqreturn_t
+crisv32_arbiter_irq(int irq, void* dev_id, struct pt_regs* regs);
+
+static void crisv32_arbiter_config(int region)
+{
+ int slot;
+ int client;
+ int interval = 0;
+ int val[NBR_OF_SLOTS];
+
+ for (slot = 0; slot < NBR_OF_SLOTS; slot++)
+ val[slot] = NBR_OF_CLIENTS + 1;
+
+ for (client = 0; client < NBR_OF_CLIENTS; client++)
+ {
+ int pos;
+ if (!requested_slots[region][client])
+ continue;
+ interval = NBR_OF_SLOTS / requested_slots[region][client];
+ pos = 0;
+ while (pos < NBR_OF_SLOTS)
+ {
+ if (val[pos] != NBR_OF_CLIENTS + 1)
+ pos++;
+ else
+ {
+ val[pos] = client;
+ pos += interval;
+ }
+ }
+ }
+
+ client = 0;
+ for (slot = 0; slot < NBR_OF_SLOTS; slot++)
+ {
+ if (val[slot] == NBR_OF_CLIENTS + 1)
+ {
+ int first = client;
+ while(!active_clients[region][client]) {
+ client = (client + 1) % NBR_OF_CLIENTS;
+ if (client == first)
+ break;
+ }
+ val[slot] = client;
+ client = (client + 1) % NBR_OF_CLIENTS;
+ }
+ if (region == EXT_REGION)
+ REG_WR_INT_VECT(marb, regi_marb, rw_ext_slots, slot, val[slot]);
+ else if (region == INT_REGION)
+ REG_WR_INT_VECT(marb, regi_marb, rw_int_slots, slot, val[slot]);
+ }
+}
+
+extern char _stext, _etext;
+
+static void crisv32_arbiter_init(void)
+{
+ static int initialized = 0;
+
+ if (initialized)
+ return;
+
+ initialized = 1;
+
+ /* CPU caches are active. */
+ active_clients[EXT_REGION][10] = active_clients[EXT_REGION][11] = 1;
+ crisv32_arbiter_config(EXT_REGION);
+ crisv32_arbiter_config(INT_REGION);
+
+ if (request_irq(MEMARB_INTR_VECT, crisv32_arbiter_irq, SA_INTERRUPT,
+ "arbiter", NULL))
+ printk(KERN_ERR "Couldn't allocate arbiter IRQ\n");
+
+#ifndef CONFIG_ETRAX_KGDB
+ /* Global watch for writes to kernel text segment. */
+ crisv32_arbiter_watch(virt_to_phys(&_stext), &_etext - &_stext,
+ arbiter_all_clients, arbiter_all_write, NULL);
+#endif
+}
+
+
+
+int crisv32_arbiter_allocate_bandwith(int client, int region,
+ unsigned long bandwidth)
+{
+ int i;
+ int total_assigned = 0;
+ int total_clients = 0;
+ int req;
+
+ crisv32_arbiter_init();
+
+ for (i = 0; i < NBR_OF_CLIENTS; i++)
+ {
+ total_assigned += requested_slots[region][i];
+ total_clients += active_clients[region][i];
+ }
+ req = NBR_OF_SLOTS / (max_bandwidth[region] / bandwidth);
+
+ if (total_assigned + total_clients + req + 1 > NBR_OF_SLOTS)
+ return -ENOMEM;
+
+ active_clients[region][client] = 1;
+ requested_slots[region][client] = req;
+ crisv32_arbiter_config(region);
+
+ return 0;
+}
+
+int crisv32_arbiter_watch(unsigned long start, unsigned long size,
+ unsigned long clients, unsigned long accesses,
+ watch_callback* cb)
+{
+ int i;
+
+ crisv32_arbiter_init();
+
+ if (start > 0x80000000) {
+ printk("Arbiter: %lX doesn't look like a physical address", start);
+ return -EFAULT;
+ }
+
+ spin_lock(&arbiter_lock);
+
+ for (i = 0; i < NUMBER_OF_BP; i++) {
+ if (!watches[i].used) {
+ reg_marb_rw_intr_mask intr_mask = REG_RD(marb, regi_marb, rw_intr_mask);
+
+ watches[i].used = 1;
+ watches[i].start = start;
+ watches[i].end = start + size;
+ watches[i].cb = cb;
+
+ REG_WR_INT(marb_bp, watches[i].instance, rw_first_addr, watches[i].start);
+ REG_WR_INT(marb_bp, watches[i].instance, rw_last_addr, watches[i].end);
+ REG_WR_INT(marb_bp, watches[i].instance, rw_op, accesses);
+ REG_WR_INT(marb_bp, watches[i].instance, rw_clients, clients);
+
+ if (i == 0)
+ intr_mask.bp0 = regk_marb_yes;
+ else if (i == 1)
+ intr_mask.bp1 = regk_marb_yes;
+ else if (i == 2)
+ intr_mask.bp2 = regk_marb_yes;
+ else if (i == 3)
+ intr_mask.bp3 = regk_marb_yes;
+
+ REG_WR(marb, regi_marb, rw_intr_mask, intr_mask);
+ spin_unlock(&arbiter_lock);
+
+ return i;
+ }
+ }
+ spin_unlock(&arbiter_lock);
+ return -ENOMEM;
+}
+
+int crisv32_arbiter_unwatch(int id)
+{
+ reg_marb_rw_intr_mask intr_mask = REG_RD(marb, regi_marb, rw_intr_mask);
+
+ crisv32_arbiter_init();
+
+ spin_lock(&arbiter_lock);
+
+ if ((id < 0) || (id >= NUMBER_OF_BP) || (!watches[id].used)) {
+ spin_unlock(&arbiter_lock);
+ return -EINVAL;
+ }
+
+ memset(&watches[id], 0, sizeof(struct crisv32_watch_entry));
+
+ if (id == 0)
+ intr_mask.bp0 = regk_marb_no;
+ else if (id == 1)
+ intr_mask.bp2 = regk_marb_no;
+ else if (id == 2)
+ intr_mask.bp2 = regk_marb_no;
+ else if (id == 3)
+ intr_mask.bp3 = regk_marb_no;
+
+ REG_WR(marb, regi_marb, rw_intr_mask, intr_mask);
+
+ spin_unlock(&arbiter_lock);
+ return 0;
+}
+
+extern void show_registers(struct pt_regs *regs);
+
+static irqreturn_t
+crisv32_arbiter_irq(int irq, void* dev_id, struct pt_regs* regs)
+{
+ reg_marb_r_masked_intr masked_intr = REG_RD(marb, regi_marb, r_masked_intr);
+ reg_marb_bp_r_brk_clients r_clients;
+ reg_marb_bp_r_brk_addr r_addr;
+ reg_marb_bp_r_brk_op r_op;
+ reg_marb_bp_r_brk_first_client r_first;
+ reg_marb_bp_r_brk_size r_size;
+ reg_marb_bp_rw_ack ack = {0};
+ reg_marb_rw_ack_intr ack_intr = {.bp0=1,.bp1=1,.bp2=1,.bp3=1};
+ struct crisv32_watch_entry* watch;
+
+ if (masked_intr.bp0) {
+ watch = &watches[0];
+ ack_intr.bp0 = regk_marb_yes;
+ } else if (masked_intr.bp1) {
+ watch = &watches[1];
+ ack_intr.bp1 = regk_marb_yes;
+ } else if (masked_intr.bp2) {
+ watch = &watches[2];
+ ack_intr.bp2 = regk_marb_yes;
+ } else if (masked_intr.bp3) {
+ watch = &watches[3];
+ ack_intr.bp3 = regk_marb_yes;
+ } else {
+ return IRQ_NONE;
+ }
+
+ /* Retrieve all useful information and print it. */
+ r_clients = REG_RD(marb_bp, watch->instance, r_brk_clients);
+ r_addr = REG_RD(marb_bp, watch->instance, r_brk_addr);
+ r_op = REG_RD(marb_bp, watch->instance, r_brk_op);
+ r_first = REG_RD(marb_bp, watch->instance, r_brk_first_client);
+ r_size = REG_RD(marb_bp, watch->instance, r_brk_size);
+
+ printk("Arbiter IRQ\n");
+ printk("Clients %X addr %X op %X first %X size %X\n",
+ REG_TYPE_CONV(int, reg_marb_bp_r_brk_clients, r_clients),
+ REG_TYPE_CONV(int, reg_marb_bp_r_brk_addr, r_addr),
+ REG_TYPE_CONV(int, reg_marb_bp_r_brk_op, r_op),
+ REG_TYPE_CONV(int, reg_marb_bp_r_brk_first_client, r_first),
+ REG_TYPE_CONV(int, reg_marb_bp_r_brk_size, r_size));
+
+ REG_WR(marb_bp, watch->instance, rw_ack, ack);
+ REG_WR(marb, regi_marb, rw_ack_intr, ack_intr);
+
+ printk("IRQ occured at %lX\n", regs->erp);
+
+ if (watch->cb)
+ watch->cb();
+
+
+ return IRQ_HANDLED;
+}
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