RISC-V: sifive_l2_cache: Add L2 cache controller driver for SiFive SoCs

The driver currently supports only SiFive FU540-C000 platform.

The initial version of L2 cache controller driver includes:
- Initial configuration reporting at boot up.
- Support for ECC related functionality.

Signed-off-by: Yash Shah <yash.shah@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This commit is contained in:
Yash Shah 2019-05-06 16:18:40 +05:30 committed by Palmer Dabbelt
parent 5545b6d1ba
commit a967a289f1
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3 changed files with 192 additions and 0 deletions

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@ -0,0 +1,16 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* SiFive L2 Cache Controller header file
*
*/
#ifndef _ASM_RISCV_SIFIVE_L2_CACHE_H
#define _ASM_RISCV_SIFIVE_L2_CACHE_H
extern int register_sifive_l2_error_notifier(struct notifier_block *nb);
extern int unregister_sifive_l2_error_notifier(struct notifier_block *nb);
#define SIFIVE_L2_ERR_TYPE_CE 0
#define SIFIVE_L2_ERR_TYPE_UE 1
#endif /* _ASM_RISCV_SIFIVE_L2_CACHE_H */

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@ -10,3 +10,4 @@ obj-y += extable.o
obj-y += ioremap.o
obj-y += cacheflush.o
obj-y += context.o
obj-y += sifive_l2_cache.o

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// SPDX-License-Identifier: GPL-2.0
/*
* SiFive L2 cache controller Driver
*
* Copyright (C) 2018-2019 SiFive, Inc.
*
*/
#include <linux/debugfs.h>
#include <linux/interrupt.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <asm/sifive_l2_cache.h>
#define SIFIVE_L2_DIRECCFIX_LOW 0x100
#define SIFIVE_L2_DIRECCFIX_HIGH 0x104
#define SIFIVE_L2_DIRECCFIX_COUNT 0x108
#define SIFIVE_L2_DATECCFIX_LOW 0x140
#define SIFIVE_L2_DATECCFIX_HIGH 0x144
#define SIFIVE_L2_DATECCFIX_COUNT 0x148
#define SIFIVE_L2_DATECCFAIL_LOW 0x160
#define SIFIVE_L2_DATECCFAIL_HIGH 0x164
#define SIFIVE_L2_DATECCFAIL_COUNT 0x168
#define SIFIVE_L2_CONFIG 0x00
#define SIFIVE_L2_WAYENABLE 0x08
#define SIFIVE_L2_ECCINJECTERR 0x40
#define SIFIVE_L2_MAX_ECCINTR 3
static void __iomem *l2_base;
static int g_irq[SIFIVE_L2_MAX_ECCINTR];
enum {
DIR_CORR = 0,
DATA_CORR,
DATA_UNCORR,
};
#ifdef CONFIG_DEBUG_FS
static struct dentry *sifive_test;
static ssize_t l2_write(struct file *file, const char __user *data,
size_t count, loff_t *ppos)
{
unsigned int val;
if (kstrtouint_from_user(data, count, 0, &val))
return -EINVAL;
if ((val >= 0 && val < 0xFF) || (val >= 0x10000 && val < 0x100FF))
writel(val, l2_base + SIFIVE_L2_ECCINJECTERR);
else
return -EINVAL;
return count;
}
static const struct file_operations l2_fops = {
.owner = THIS_MODULE,
.open = simple_open,
.write = l2_write
};
static void setup_sifive_debug(void)
{
sifive_test = debugfs_create_dir("sifive_l2_cache", NULL);
debugfs_create_file("sifive_debug_inject_error", 0200,
sifive_test, NULL, &l2_fops);
}
#endif
static void l2_config_read(void)
{
u32 regval, val;
regval = readl(l2_base + SIFIVE_L2_CONFIG);
val = regval & 0xFF;
pr_info("L2CACHE: No. of Banks in the cache: %d\n", val);
val = (regval & 0xFF00) >> 8;
pr_info("L2CACHE: No. of ways per bank: %d\n", val);
val = (regval & 0xFF0000) >> 16;
pr_info("L2CACHE: Sets per bank: %llu\n", (uint64_t)1 << val);
val = (regval & 0xFF000000) >> 24;
pr_info("L2CACHE: Bytes per cache block: %llu\n", (uint64_t)1 << val);
regval = readl(l2_base + SIFIVE_L2_WAYENABLE);
pr_info("L2CACHE: Index of the largest way enabled: %d\n", regval);
}
static const struct of_device_id sifive_l2_ids[] = {
{ .compatible = "sifive,fu540-c000-ccache" },
{ /* end of table */ },
};
static ATOMIC_NOTIFIER_HEAD(l2_err_chain);
int register_sifive_l2_error_notifier(struct notifier_block *nb)
{
return atomic_notifier_chain_register(&l2_err_chain, nb);
}
EXPORT_SYMBOL_GPL(register_sifive_l2_error_notifier);
int unregister_sifive_l2_error_notifier(struct notifier_block *nb)
{
return atomic_notifier_chain_unregister(&l2_err_chain, nb);
}
EXPORT_SYMBOL_GPL(unregister_sifive_l2_error_notifier);
static irqreturn_t l2_int_handler(int irq, void *device)
{
unsigned int regval, add_h, add_l;
if (irq == g_irq[DIR_CORR]) {
add_h = readl(l2_base + SIFIVE_L2_DIRECCFIX_HIGH);
add_l = readl(l2_base + SIFIVE_L2_DIRECCFIX_LOW);
pr_err("L2CACHE: DirError @ 0x%08X.%08X\n", add_h, add_l);
regval = readl(l2_base + SIFIVE_L2_DIRECCFIX_COUNT);
atomic_notifier_call_chain(&l2_err_chain, SIFIVE_L2_ERR_TYPE_CE,
"DirECCFix");
}
if (irq == g_irq[DATA_CORR]) {
add_h = readl(l2_base + SIFIVE_L2_DATECCFIX_HIGH);
add_l = readl(l2_base + SIFIVE_L2_DATECCFIX_LOW);
pr_err("L2CACHE: DataError @ 0x%08X.%08X\n", add_h, add_l);
regval = readl(l2_base + SIFIVE_L2_DATECCFIX_COUNT);
atomic_notifier_call_chain(&l2_err_chain, SIFIVE_L2_ERR_TYPE_CE,
"DatECCFix");
}
if (irq == g_irq[DATA_UNCORR]) {
add_h = readl(l2_base + SIFIVE_L2_DATECCFAIL_HIGH);
add_l = readl(l2_base + SIFIVE_L2_DATECCFAIL_LOW);
pr_err("L2CACHE: DataFail @ 0x%08X.%08X\n", add_h, add_l);
regval = readl(l2_base + SIFIVE_L2_DATECCFAIL_COUNT);
atomic_notifier_call_chain(&l2_err_chain, SIFIVE_L2_ERR_TYPE_UE,
"DatECCFail");
}
return IRQ_HANDLED;
}
int __init sifive_l2_init(void)
{
struct device_node *np;
struct resource res;
int i, rc;
np = of_find_matching_node(NULL, sifive_l2_ids);
if (!np)
return -ENODEV;
if (of_address_to_resource(np, 0, &res))
return -ENODEV;
l2_base = ioremap(res.start, resource_size(&res));
if (!l2_base)
return -ENOMEM;
for (i = 0; i < SIFIVE_L2_MAX_ECCINTR; i++) {
g_irq[i] = irq_of_parse_and_map(np, i);
rc = request_irq(g_irq[i], l2_int_handler, 0, "l2_ecc", NULL);
if (rc) {
pr_err("L2CACHE: Could not request IRQ %d\n", g_irq[i]);
return rc;
}
}
l2_config_read();
#ifdef CONFIG_DEBUG_FS
setup_sifive_debug();
#endif
return 0;
}
device_initcall(sifive_l2_init);