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Diffstat (limited to 'arch/cris/arch-v32/mach-a3/arbiter.c')
-rw-r--r--arch/cris/arch-v32/mach-a3/arbiter.c634
1 files changed, 634 insertions, 0 deletions
diff --git a/arch/cris/arch-v32/mach-a3/arbiter.c b/arch/cris/arch-v32/mach-a3/arbiter.c
new file mode 100644
index 000000000..ab5c421a4
--- /dev/null
+++ b/arch/cris/arch-v32/mach-a3/arbiter.c
@@ -0,0 +1,634 @@
+/*
+ * Memory arbiter functions. Allocates bandwidth through the
+ * arbiter and sets up arbiter breakpoints.
+ *
+ * The algorithm first assigns slots to the clients that has specified
+ * bandwidth (e.g. ethernet) and then the remaining slots are divided
+ * on all the active clients.
+ *
+ * Copyright (c) 2004-2007 Axis Communications AB.
+ *
+ * The artpec-3 has two arbiters. The memory hierarchy looks like this:
+ *
+ *
+ * CPU DMAs
+ * | |
+ * | |
+ * -------------- ------------------
+ * | foo arbiter|----| Internal memory|
+ * -------------- ------------------
+ * |
+ * --------------
+ * | L2 cache |
+ * --------------
+ * |
+ * h264 etc |
+ * | |
+ * | |
+ * --------------
+ * | bar arbiter|
+ * --------------
+ * |
+ * ---------
+ * | SDRAM |
+ * ---------
+ *
+ */
+
+#include <hwregs/reg_map.h>
+#include <hwregs/reg_rdwr.h>
+#include <hwregs/marb_foo_defs.h>
+#include <hwregs/marb_bar_defs.h>
+#include <arbiter.h>
+#include <hwregs/intr_vect.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/signal.h>
+#include <linux/errno.h>
+#include <linux/spinlock.h>
+#include <asm/io.h>
+#include <asm/irq_regs.h>
+
+#define D(x)
+
+struct crisv32_watch_entry {
+ unsigned long instance;
+ watch_callback *cb;
+ unsigned long start;
+ unsigned long end;
+ int used;
+};
+
+#define NUMBER_OF_BP 4
+#define SDRAM_BANDWIDTH 400000000
+#define INTMEM_BANDWIDTH 400000000
+#define NBR_OF_SLOTS 64
+#define NBR_OF_REGIONS 2
+#define NBR_OF_CLIENTS 15
+#define ARBITERS 2
+#define UNASSIGNED 100
+
+struct arbiter {
+ unsigned long instance;
+ int nbr_regions;
+ int nbr_clients;
+ int requested_slots[NBR_OF_REGIONS][NBR_OF_CLIENTS];
+ int active_clients[NBR_OF_REGIONS][NBR_OF_CLIENTS];
+};
+
+static struct crisv32_watch_entry watches[ARBITERS][NUMBER_OF_BP] =
+{
+ {
+ {regi_marb_foo_bp0},
+ {regi_marb_foo_bp1},
+ {regi_marb_foo_bp2},
+ {regi_marb_foo_bp3}
+ },
+ {
+ {regi_marb_bar_bp0},
+ {regi_marb_bar_bp1},
+ {regi_marb_bar_bp2},
+ {regi_marb_bar_bp3}
+ }
+};
+
+struct arbiter arbiters[ARBITERS] =
+{
+ { /* L2 cache arbiter */
+ .instance = regi_marb_foo,
+ .nbr_regions = 2,
+ .nbr_clients = 15
+ },
+ { /* DDR2 arbiter */
+ .instance = regi_marb_bar,
+ .nbr_regions = 1,
+ .nbr_clients = 9
+ }
+};
+
+static int max_bandwidth[NBR_OF_REGIONS] = {SDRAM_BANDWIDTH, INTMEM_BANDWIDTH};
+
+DEFINE_SPINLOCK(arbiter_lock);
+
+static irqreturn_t
+crisv32_foo_arbiter_irq(int irq, void *dev_id);
+static irqreturn_t
+crisv32_bar_arbiter_irq(int irq, void *dev_id);
+
+/*
+ * "I'm the arbiter, I know the score.
+ * From square one I'll be watching all 64."
+ * (memory arbiter slots, that is)
+ *
+ * Or in other words:
+ * Program the memory arbiter slots for "region" according to what's
+ * in requested_slots[] and active_clients[], while minimizing
+ * latency. A caller may pass a non-zero positive amount for
+ * "unused_slots", which must then be the unallocated, remaining
+ * number of slots, free to hand out to any client.
+ */
+
+static void crisv32_arbiter_config(int arbiter, int region, int unused_slots)
+{
+ int slot;
+ int client;
+ int interval = 0;
+
+ /*
+ * This vector corresponds to the hardware arbiter slots (see
+ * the hardware documentation for semantics). We initialize
+ * each slot with a suitable sentinel value outside the valid
+ * range {0 .. NBR_OF_CLIENTS - 1} and replace them with
+ * client indexes. Then it's fed to the hardware.
+ */
+ s8 val[NBR_OF_SLOTS];
+
+ for (slot = 0; slot < NBR_OF_SLOTS; slot++)
+ val[slot] = -1;
+
+ for (client = 0; client < arbiters[arbiter].nbr_clients; client++) {
+ int pos;
+ /* Allocate the requested non-zero number of slots, but
+ * also give clients with zero-requests one slot each
+ * while stocks last. We do the latter here, in client
+ * order. This makes sure zero-request clients are the
+ * first to get to any spare slots, else those slots
+ * could, when bandwidth is allocated close to the limit,
+ * all be allocated to low-index non-zero-request clients
+ * in the default-fill loop below. Another positive but
+ * secondary effect is a somewhat better spread of the
+ * zero-bandwidth clients in the vector, avoiding some of
+ * the latency that could otherwise be caused by the
+ * partitioning of non-zero-bandwidth clients at low
+ * indexes and zero-bandwidth clients at high
+ * indexes. (Note that this spreading can only affect the
+ * unallocated bandwidth.) All the above only matters for
+ * memory-intensive situations, of course.
+ */
+ if (!arbiters[arbiter].requested_slots[region][client]) {
+ /*
+ * Skip inactive clients. Also skip zero-slot
+ * allocations in this pass when there are no known
+ * free slots.
+ */
+ if (!arbiters[arbiter].active_clients[region][client] ||
+ unused_slots <= 0)
+ continue;
+
+ unused_slots--;
+
+ /* Only allocate one slot for this client. */
+ interval = NBR_OF_SLOTS;
+ } else
+ interval = NBR_OF_SLOTS /
+ arbiters[arbiter].requested_slots[region][client];
+
+ pos = 0;
+ while (pos < NBR_OF_SLOTS) {
+ if (val[pos] >= 0)
+ pos++;
+ else {
+ val[pos] = client;
+ pos += interval;
+ }
+ }
+ }
+
+ client = 0;
+ for (slot = 0; slot < NBR_OF_SLOTS; slot++) {
+ /*
+ * Allocate remaining slots in round-robin
+ * client-number order for active clients. For this
+ * pass, we ignore requested bandwidth and previous
+ * allocations.
+ */
+ if (val[slot] < 0) {
+ int first = client;
+ while (!arbiters[arbiter].active_clients[region][client]) {
+ client = (client + 1) %
+ arbiters[arbiter].nbr_clients;
+ if (client == first)
+ break;
+ }
+ val[slot] = client;
+ client = (client + 1) % arbiters[arbiter].nbr_clients;
+ }
+ if (arbiter == 0) {
+ if (region == EXT_REGION)
+ REG_WR_INT_VECT(marb_foo, regi_marb_foo,
+ rw_l2_slots, slot, val[slot]);
+ else if (region == INT_REGION)
+ REG_WR_INT_VECT(marb_foo, regi_marb_foo,
+ rw_intm_slots, slot, val[slot]);
+ } else {
+ REG_WR_INT_VECT(marb_bar, regi_marb_bar,
+ rw_ddr2_slots, slot, val[slot]);
+ }
+ }
+}
+
+extern char _stext, _etext;
+
+static void crisv32_arbiter_init(void)
+{
+ static int initialized;
+
+ if (initialized)
+ return;
+
+ initialized = 1;
+
+ /*
+ * CPU caches are always set to active, but with zero
+ * bandwidth allocated. It should be ok to allocate zero
+ * bandwidth for the caches, because DMA for other channels
+ * will supposedly finish, once their programmed amount is
+ * done, and then the caches will get access according to the
+ * "fixed scheme" for unclaimed slots. Though, if for some
+ * use-case somewhere, there's a maximum CPU latency for
+ * e.g. some interrupt, we have to start allocating specific
+ * bandwidth for the CPU caches too.
+ */
+ arbiters[0].active_clients[EXT_REGION][11] = 1;
+ arbiters[0].active_clients[EXT_REGION][12] = 1;
+ crisv32_arbiter_config(0, EXT_REGION, 0);
+ crisv32_arbiter_config(0, INT_REGION, 0);
+ crisv32_arbiter_config(1, EXT_REGION, 0);
+
+ if (request_irq(MEMARB_FOO_INTR_VECT, crisv32_foo_arbiter_irq,
+ 0, "arbiter", NULL))
+ printk(KERN_ERR "Couldn't allocate arbiter IRQ\n");
+
+ if (request_irq(MEMARB_BAR_INTR_VECT, crisv32_bar_arbiter_irq,
+ 0, "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,
+ MARB_CLIENTS(arbiter_all_clients, arbiter_bar_all_clients),
+ arbiter_all_write, NULL);
+#endif
+
+ /* Set up max burst sizes by default */
+ REG_WR_INT(marb_bar, regi_marb_bar, rw_h264_rd_burst, 3);
+ REG_WR_INT(marb_bar, regi_marb_bar, rw_h264_wr_burst, 3);
+ REG_WR_INT(marb_bar, regi_marb_bar, rw_ccd_burst, 3);
+ REG_WR_INT(marb_bar, regi_marb_bar, rw_vin_wr_burst, 3);
+ REG_WR_INT(marb_bar, regi_marb_bar, rw_vin_rd_burst, 3);
+ REG_WR_INT(marb_bar, regi_marb_bar, rw_sclr_rd_burst, 3);
+ REG_WR_INT(marb_bar, regi_marb_bar, rw_vout_burst, 3);
+ REG_WR_INT(marb_bar, regi_marb_bar, rw_sclr_fifo_burst, 3);
+ REG_WR_INT(marb_bar, regi_marb_bar, rw_l2cache_burst, 3);
+}
+
+int crisv32_arbiter_allocate_bandwidth(int client, int region,
+ unsigned long bandwidth)
+{
+ int i;
+ int total_assigned = 0;
+ int total_clients = 0;
+ int req;
+ int arbiter = 0;
+
+ crisv32_arbiter_init();
+
+ if (client & 0xffff0000) {
+ arbiter = 1;
+ client >>= 16;
+ }
+
+ for (i = 0; i < arbiters[arbiter].nbr_clients; i++) {
+ total_assigned += arbiters[arbiter].requested_slots[region][i];
+ total_clients += arbiters[arbiter].active_clients[region][i];
+ }
+
+ /* Avoid division by 0 for 0-bandwidth requests. */
+ req = bandwidth == 0
+ ? 0 : NBR_OF_SLOTS / (max_bandwidth[region] / bandwidth);
+
+ /*
+ * We make sure that there are enough slots only for non-zero
+ * requests. Requesting 0 bandwidth *may* allocate slots,
+ * though if all bandwidth is allocated, such a client won't
+ * get any and will have to rely on getting memory access
+ * according to the fixed scheme that's the default when one
+ * of the slot-allocated clients doesn't claim their slot.
+ */
+ if (total_assigned + req > NBR_OF_SLOTS)
+ return -ENOMEM;
+
+ arbiters[arbiter].active_clients[region][client] = 1;
+ arbiters[arbiter].requested_slots[region][client] = req;
+ crisv32_arbiter_config(arbiter, region, NBR_OF_SLOTS - total_assigned);
+
+ /* Propagate allocation from foo to bar */
+ if (arbiter == 0)
+ crisv32_arbiter_allocate_bandwidth(8 << 16,
+ EXT_REGION, bandwidth);
+ return 0;
+}
+
+/*
+ * Main entry for bandwidth deallocation.
+ *
+ * Strictly speaking, for a somewhat constant set of clients where
+ * each client gets a constant bandwidth and is just enabled or
+ * disabled (somewhat dynamically), no action is necessary here to
+ * avoid starvation for non-zero-allocation clients, as the allocated
+ * slots will just be unused. However, handing out those unused slots
+ * to active clients avoids needless latency if the "fixed scheme"
+ * would give unclaimed slots to an eager low-index client.
+ */
+
+void crisv32_arbiter_deallocate_bandwidth(int client, int region)
+{
+ int i;
+ int total_assigned = 0;
+ int arbiter = 0;
+
+ if (client & 0xffff0000)
+ arbiter = 1;
+
+ arbiters[arbiter].requested_slots[region][client] = 0;
+ arbiters[arbiter].active_clients[region][client] = 0;
+
+ for (i = 0; i < arbiters[arbiter].nbr_clients; i++)
+ total_assigned += arbiters[arbiter].requested_slots[region][i];
+
+ crisv32_arbiter_config(arbiter, region, NBR_OF_SLOTS - total_assigned);
+}
+
+int crisv32_arbiter_watch(unsigned long start, unsigned long size,
+ unsigned long clients, unsigned long accesses,
+ watch_callback *cb)
+{
+ int i;
+ int arbiter;
+ int used[2];
+ int ret = 0;
+
+ crisv32_arbiter_init();
+
+ if (start > 0x80000000) {
+ printk(KERN_ERR "Arbiter: %lX doesn't look like a "
+ "physical address", start);
+ return -EFAULT;
+ }
+
+ spin_lock(&arbiter_lock);
+
+ if (clients & 0xffff)
+ used[0] = 1;
+ if (clients & 0xffff0000)
+ used[1] = 1;
+
+ for (arbiter = 0; arbiter < ARBITERS; arbiter++) {
+ if (!used[arbiter])
+ continue;
+
+ for (i = 0; i < NUMBER_OF_BP; i++) {
+ if (!watches[arbiter][i].used) {
+ unsigned intr_mask;
+ if (arbiter)
+ intr_mask = REG_RD_INT(marb_bar,
+ regi_marb_bar, rw_intr_mask);
+ else
+ intr_mask = REG_RD_INT(marb_foo,
+ regi_marb_foo, rw_intr_mask);
+
+ watches[arbiter][i].used = 1;
+ watches[arbiter][i].start = start;
+ watches[arbiter][i].end = start + size;
+ watches[arbiter][i].cb = cb;
+
+ ret |= (i + 1) << (arbiter + 8);
+ if (arbiter) {
+ REG_WR_INT(marb_bar_bp,
+ watches[arbiter][i].instance,
+ rw_first_addr,
+ watches[arbiter][i].start);
+ REG_WR_INT(marb_bar_bp,
+ watches[arbiter][i].instance,
+ rw_last_addr,
+ watches[arbiter][i].end);
+ REG_WR_INT(marb_bar_bp,
+ watches[arbiter][i].instance,
+ rw_op, accesses);
+ REG_WR_INT(marb_bar_bp,
+ watches[arbiter][i].instance,
+ rw_clients,
+ clients & 0xffff);
+ } else {
+ REG_WR_INT(marb_foo_bp,
+ watches[arbiter][i].instance,
+ rw_first_addr,
+ watches[arbiter][i].start);
+ REG_WR_INT(marb_foo_bp,
+ watches[arbiter][i].instance,
+ rw_last_addr,
+ watches[arbiter][i].end);
+ REG_WR_INT(marb_foo_bp,
+ watches[arbiter][i].instance,
+ rw_op, accesses);
+ REG_WR_INT(marb_foo_bp,
+ watches[arbiter][i].instance,
+ rw_clients, clients >> 16);
+ }
+
+ if (i == 0)
+ intr_mask |= 1;
+ else if (i == 1)
+ intr_mask |= 2;
+ else if (i == 2)
+ intr_mask |= 4;
+ else if (i == 3)
+ intr_mask |= 8;
+
+ if (arbiter)
+ REG_WR_INT(marb_bar, regi_marb_bar,
+ rw_intr_mask, intr_mask);
+ else
+ REG_WR_INT(marb_foo, regi_marb_foo,
+ rw_intr_mask, intr_mask);
+
+ spin_unlock(&arbiter_lock);
+
+ break;
+ }
+ }
+ }
+ spin_unlock(&arbiter_lock);
+ if (ret)
+ return ret;
+ else
+ return -ENOMEM;
+}
+
+int crisv32_arbiter_unwatch(int id)
+{
+ int arbiter;
+ int intr_mask;
+
+ crisv32_arbiter_init();
+
+ spin_lock(&arbiter_lock);
+
+ for (arbiter = 0; arbiter < ARBITERS; arbiter++) {
+ int id2;
+
+ if (arbiter)
+ intr_mask = REG_RD_INT(marb_bar, regi_marb_bar,
+ rw_intr_mask);
+ else
+ intr_mask = REG_RD_INT(marb_foo, regi_marb_foo,
+ rw_intr_mask);
+
+ id2 = (id & (0xff << (arbiter + 8))) >> (arbiter + 8);
+ if (id2 == 0)
+ continue;
+ id2--;
+ if ((id2 >= NUMBER_OF_BP) || (!watches[arbiter][id2].used)) {
+ spin_unlock(&arbiter_lock);
+ return -EINVAL;
+ }
+
+ memset(&watches[arbiter][id2], 0,
+ sizeof(struct crisv32_watch_entry));
+
+ if (id2 == 0)
+ intr_mask &= ~1;
+ else if (id2 == 1)
+ intr_mask &= ~2;
+ else if (id2 == 2)
+ intr_mask &= ~4;
+ else if (id2 == 3)
+ intr_mask &= ~8;
+
+ if (arbiter)
+ REG_WR_INT(marb_bar, regi_marb_bar, rw_intr_mask,
+ intr_mask);
+ else
+ REG_WR_INT(marb_foo, regi_marb_foo, rw_intr_mask,
+ intr_mask);
+ }
+
+ spin_unlock(&arbiter_lock);
+ return 0;
+}
+
+extern void show_registers(struct pt_regs *regs);
+
+
+static irqreturn_t
+crisv32_foo_arbiter_irq(int irq, void *dev_id)
+{
+ reg_marb_foo_r_masked_intr masked_intr =
+ REG_RD(marb_foo, regi_marb_foo, r_masked_intr);
+ reg_marb_foo_bp_r_brk_clients r_clients;
+ reg_marb_foo_bp_r_brk_addr r_addr;
+ reg_marb_foo_bp_r_brk_op r_op;
+ reg_marb_foo_bp_r_brk_first_client r_first;
+ reg_marb_foo_bp_r_brk_size r_size;
+ reg_marb_foo_bp_rw_ack ack = {0};
+ reg_marb_foo_rw_ack_intr ack_intr = {
+ .bp0 = 1, .bp1 = 1, .bp2 = 1, .bp3 = 1
+ };
+ struct crisv32_watch_entry *watch;
+ unsigned arbiter = (unsigned)dev_id;
+
+ masked_intr = REG_RD(marb_foo, regi_marb_foo, r_masked_intr);
+
+ if (masked_intr.bp0)
+ watch = &watches[arbiter][0];
+ else if (masked_intr.bp1)
+ watch = &watches[arbiter][1];
+ else if (masked_intr.bp2)
+ watch = &watches[arbiter][2];
+ else if (masked_intr.bp3)
+ watch = &watches[arbiter][3];
+ else
+ return IRQ_NONE;
+
+ /* Retrieve all useful information and print it. */
+ r_clients = REG_RD(marb_foo_bp, watch->instance, r_brk_clients);
+ r_addr = REG_RD(marb_foo_bp, watch->instance, r_brk_addr);
+ r_op = REG_RD(marb_foo_bp, watch->instance, r_brk_op);
+ r_first = REG_RD(marb_foo_bp, watch->instance, r_brk_first_client);
+ r_size = REG_RD(marb_foo_bp, watch->instance, r_brk_size);
+
+ printk(KERN_DEBUG "Arbiter IRQ\n");
+ printk(KERN_DEBUG "Clients %X addr %X op %X first %X size %X\n",
+ REG_TYPE_CONV(int, reg_marb_foo_bp_r_brk_clients, r_clients),
+ REG_TYPE_CONV(int, reg_marb_foo_bp_r_brk_addr, r_addr),
+ REG_TYPE_CONV(int, reg_marb_foo_bp_r_brk_op, r_op),
+ REG_TYPE_CONV(int, reg_marb_foo_bp_r_brk_first_client, r_first),
+ REG_TYPE_CONV(int, reg_marb_foo_bp_r_brk_size, r_size));
+
+ REG_WR(marb_foo_bp, watch->instance, rw_ack, ack);
+ REG_WR(marb_foo, regi_marb_foo, rw_ack_intr, ack_intr);
+
+ printk(KERN_DEBUG "IRQ occurred at %X\n", (unsigned)get_irq_regs());
+
+ if (watch->cb)
+ watch->cb();
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t
+crisv32_bar_arbiter_irq(int irq, void *dev_id)
+{
+ reg_marb_bar_r_masked_intr masked_intr =
+ REG_RD(marb_bar, regi_marb_bar, r_masked_intr);
+ reg_marb_bar_bp_r_brk_clients r_clients;
+ reg_marb_bar_bp_r_brk_addr r_addr;
+ reg_marb_bar_bp_r_brk_op r_op;
+ reg_marb_bar_bp_r_brk_first_client r_first;
+ reg_marb_bar_bp_r_brk_size r_size;
+ reg_marb_bar_bp_rw_ack ack = {0};
+ reg_marb_bar_rw_ack_intr ack_intr = {
+ .bp0 = 1, .bp1 = 1, .bp2 = 1, .bp3 = 1
+ };
+ struct crisv32_watch_entry *watch;
+ unsigned arbiter = (unsigned)dev_id;
+
+ masked_intr = REG_RD(marb_bar, regi_marb_bar, r_masked_intr);
+
+ if (masked_intr.bp0)
+ watch = &watches[arbiter][0];
+ else if (masked_intr.bp1)
+ watch = &watches[arbiter][1];
+ else if (masked_intr.bp2)
+ watch = &watches[arbiter][2];
+ else if (masked_intr.bp3)
+ watch = &watches[arbiter][3];
+ else
+ return IRQ_NONE;
+
+ /* Retrieve all useful information and print it. */
+ r_clients = REG_RD(marb_bar_bp, watch->instance, r_brk_clients);
+ r_addr = REG_RD(marb_bar_bp, watch->instance, r_brk_addr);
+ r_op = REG_RD(marb_bar_bp, watch->instance, r_brk_op);
+ r_first = REG_RD(marb_bar_bp, watch->instance, r_brk_first_client);
+ r_size = REG_RD(marb_bar_bp, watch->instance, r_brk_size);
+
+ printk(KERN_DEBUG "Arbiter IRQ\n");
+ printk(KERN_DEBUG "Clients %X addr %X op %X first %X size %X\n",
+ REG_TYPE_CONV(int, reg_marb_bar_bp_r_brk_clients, r_clients),
+ REG_TYPE_CONV(int, reg_marb_bar_bp_r_brk_addr, r_addr),
+ REG_TYPE_CONV(int, reg_marb_bar_bp_r_brk_op, r_op),
+ REG_TYPE_CONV(int, reg_marb_bar_bp_r_brk_first_client, r_first),
+ REG_TYPE_CONV(int, reg_marb_bar_bp_r_brk_size, r_size));
+
+ REG_WR(marb_bar_bp, watch->instance, rw_ack, ack);
+ REG_WR(marb_bar, regi_marb_bar, rw_ack_intr, ack_intr);
+
+ printk(KERN_DEBUG "IRQ occurred at %X\n", (unsigned)get_irq_regs()->erp);
+
+ if (watch->cb)
+ watch->cb();
+
+ return IRQ_HANDLED;
+}
+
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-05 17:42:36 +0000