/*
* 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;
}
