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ARC: [plat-arfpga] BVCI Latency Unit setup

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Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This commit is contained in:
Vineet Gupta 2013-01-18 15:12:24 +05:30
parent af61742813
commit 7fadc1e8fe
2 changed files with 88 additions and 0 deletions
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32
arch/arc/plat-arcfpga/Kconfig
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@ -44,4 +44,36 @@ config ARC_SERIAL_BAUD
help
Baud rate for the ARC UART
menuconfig ARC_HAS_BVCI_LAT_UNIT
bool "BVCI Bus Latency Unit"
depends on ARC_BOARD_ML509 || ARC_BOARD_ANGEL4
help
IP to add artifical latency to BVCI Bus Based FPGA builds.
The default latency (even worst case) for FPGA is non-realistic
(~10 SDRAM, ~5 SSRAM).
config BVCI_LAT_UNITS
hex "Latency Unit(s) Bitmap"
default "0x0"
depends on ARC_HAS_BVCI_LAT_UNIT
help
There are multiple Latency Units corresponding to the many
interfaces of the system bus arbiter (both CPU side as well as
the peripheral side).
To add latency to ALL memory transaction, choose Unit 0, otherwise
for finer grainer - interface wise latency, specify a bitmap (1 bit
per unit) of all units. e.g. 1,2,12 will be 0x1003
Unit 0 - System Arb and Mem Controller
Unit 1 - I$ and System Bus
Unit 2 - D$ and System Bus
..
Unit 12 - IDE Disk controller and System Bus
config BVCI_LAT_CYCLES
int "Latency Value in cycles"
range 0 63
default "30"
depends on ARC_HAS_BVCI_LAT_UNIT
endif

56
arch/arc/plat-arcfpga/platform.c
View File

@ -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 @@ void __init arc_platform_early_init(void)
{
pr_info("[plat-arcfpga]: registering early dev resources\n");
setup_bvci_lat_unit();
arc_fpga_serial_init();
}