ARC: [plat-arfpga] BVCI Latency Unit setup
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
diff --git a/arch/arc/plat-arcfpga/platform.c b/arch/arc/plat-arcfpga/platform.c
index 33bcac8..b7f63e3 100644
--- a/arch/arc/plat-arcfpga/platform.c
+++ b/arch/arc/plat-arcfpga/platform.c
@@ -12,6 +12,7 @@
#include <linux/init.h>
#include <linux/device.h>
#include <linux/platform_device.h>
+#include <linux/io.h>
#include <linux/console.h>
#include <linux/of_platform.h>
#include <asm/setup.h>
@@ -19,6 +20,59 @@
#include <asm/clk.h>
#include <plat/memmap.h>
+/*-----------------------BVCI Latency Unit -----------------------------*/
+
+#ifdef CONFIG_ARC_HAS_BVCI_LAT_UNIT
+
+int lat_cycles = CONFIG_BVCI_LAT_CYCLES;
+
+/* BVCI Bus Profiler: Latency Unit */
+static void __init setup_bvci_lat_unit(void)
+{
+#define MAX_BVCI_UNITS 12
+
+ unsigned int i;
+ unsigned int *base = (unsigned int *)BVCI_LAT_UNIT_BASE;
+ const unsigned long units_req = CONFIG_BVCI_LAT_UNITS;
+ const unsigned int REG_UNIT = 21;
+ const unsigned int REG_VAL = 22;
+
+ /*
+ * There are multiple Latency Units corresponding to the many
+ * interfaces of the system bus arbiter (both CPU side as well as
+ * the peripheral side).
+ *
+ * Unit 0 - System Arb and Mem Controller - adds latency to all
+ * memory trasactions
+ * Unit 1 - I$ and System Bus
+ * Unit 2 - D$ and System Bus
+ * ..
+ * Unit 12 - IDE Disk controller and System Bus
+ *
+ * The programmers model requires writing to lat_unit reg first
+ * and then the latency value (cycles) to lat_value reg
+ */
+
+ if (CONFIG_BVCI_LAT_UNITS == 0) {
+ writel(0, base + REG_UNIT);
+ writel(lat_cycles, base + REG_VAL);
+ pr_info("BVCI Latency for all Memory Transactions %d cycles\n",
+ lat_cycles);
+ } else {
+ for_each_set_bit(i, &units_req, MAX_BVCI_UNITS) {
+ writel(i + 1, base + REG_UNIT); /* loop is 0 based */
+ writel(lat_cycles, base + REG_VAL);
+ pr_info("BVCI Latency for Unit[%d] = %d cycles\n",
+ (i + 1), lat_cycles);
+ }
+ }
+}
+#else
+static void __init setup_bvci_lat_unit(void)
+{
+}
+#endif
+
/*----------------------- Platform Devices -----------------------------*/
static unsigned long arc_uart_info[] = {
@@ -106,6 +160,8 @@
{
pr_info("[plat-arcfpga]: registering early dev resources\n");
+ setup_bvci_lat_unit();
+
arc_fpga_serial_init();
}