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linux/drivers/cache/starfive_starlink_cache.c
Joshua Yeong cabff60ca7 cache: Add StarFive StarLink cache management
Add StarFive Starlink cache management driver.
The driver enables RISC-V non-standard cache
operation on SoC that does not support Zicbom
extension instructions.

Signed-off-by: Joshua Yeong <joshua.yeong@starfivetech.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
2024-05-28 12:34:11 +01:00

131 lines
3.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Cache Management Operations for StarFive's Starlink cache controller
*
* Copyright (C) 2024 Shanghai StarFive Technology Co., Ltd.
*
* Author: Joshua Yeong <joshua.yeong@starfivetech.com>
*/
#include <linux/bitfield.h>
#include <linux/cacheflush.h>
#include <linux/iopoll.h>
#include <linux/of_address.h>
#include <asm/dma-noncoherent.h>
#define STARLINK_CACHE_FLUSH_START_ADDR 0x0
#define STARLINK_CACHE_FLUSH_END_ADDR 0x8
#define STARLINK_CACHE_FLUSH_CTL 0x10
#define STARLINK_CACHE_ALIGN 0x40
#define STARLINK_CACHE_ADDRESS_RANGE_MASK GENMASK(39, 0)
#define STARLINK_CACHE_FLUSH_CTL_MODE_MASK GENMASK(2, 1)
#define STARLINK_CACHE_FLUSH_CTL_ENABLE_MASK BIT(0)
#define STARLINK_CACHE_FLUSH_CTL_CLEAN_INVALIDATE 0
#define STARLINK_CACHE_FLUSH_CTL_MAKE_INVALIDATE 1
#define STARLINK_CACHE_FLUSH_CTL_CLEAN_SHARED 2
#define STARLINK_CACHE_FLUSH_POLL_DELAY_US 1
#define STARLINK_CACHE_FLUSH_TIMEOUT_US 5000000
static void __iomem *starlink_cache_base;
static void starlink_cache_flush_complete(void)
{
volatile void __iomem *ctl = starlink_cache_base + STARLINK_CACHE_FLUSH_CTL;
u64 v;
int ret;
ret = readq_poll_timeout_atomic(ctl, v, !(v & STARLINK_CACHE_FLUSH_CTL_ENABLE_MASK),
STARLINK_CACHE_FLUSH_POLL_DELAY_US,
STARLINK_CACHE_FLUSH_TIMEOUT_US);
if (ret)
WARN(1, "StarFive Starlink cache flush operation timeout\n");
}
static void starlink_cache_dma_cache_wback(phys_addr_t paddr, unsigned long size)
{
writeq(FIELD_PREP(STARLINK_CACHE_ADDRESS_RANGE_MASK, paddr),
starlink_cache_base + STARLINK_CACHE_FLUSH_START_ADDR);
writeq(FIELD_PREP(STARLINK_CACHE_ADDRESS_RANGE_MASK, paddr + size),
starlink_cache_base + STARLINK_CACHE_FLUSH_END_ADDR);
mb();
writeq(FIELD_PREP(STARLINK_CACHE_FLUSH_CTL_MODE_MASK,
STARLINK_CACHE_FLUSH_CTL_CLEAN_SHARED),
starlink_cache_base + STARLINK_CACHE_FLUSH_CTL);
starlink_cache_flush_complete();
}
static void starlink_cache_dma_cache_invalidate(phys_addr_t paddr, unsigned long size)
{
writeq(FIELD_PREP(STARLINK_CACHE_ADDRESS_RANGE_MASK, paddr),
starlink_cache_base + STARLINK_CACHE_FLUSH_START_ADDR);
writeq(FIELD_PREP(STARLINK_CACHE_ADDRESS_RANGE_MASK, paddr + size),
starlink_cache_base + STARLINK_CACHE_FLUSH_END_ADDR);
mb();
writeq(FIELD_PREP(STARLINK_CACHE_FLUSH_CTL_MODE_MASK,
STARLINK_CACHE_FLUSH_CTL_MAKE_INVALIDATE),
starlink_cache_base + STARLINK_CACHE_FLUSH_CTL);
starlink_cache_flush_complete();
}
static void starlink_cache_dma_cache_wback_inv(phys_addr_t paddr, unsigned long size)
{
writeq(FIELD_PREP(STARLINK_CACHE_ADDRESS_RANGE_MASK, paddr),
starlink_cache_base + STARLINK_CACHE_FLUSH_START_ADDR);
writeq(FIELD_PREP(STARLINK_CACHE_ADDRESS_RANGE_MASK, paddr + size),
starlink_cache_base + STARLINK_CACHE_FLUSH_END_ADDR);
mb();
writeq(FIELD_PREP(STARLINK_CACHE_FLUSH_CTL_MODE_MASK,
STARLINK_CACHE_FLUSH_CTL_CLEAN_INVALIDATE),
starlink_cache_base + STARLINK_CACHE_FLUSH_CTL);
starlink_cache_flush_complete();
}
static const struct riscv_nonstd_cache_ops starlink_cache_ops = {
.wback = &starlink_cache_dma_cache_wback,
.inv = &starlink_cache_dma_cache_invalidate,
.wback_inv = &starlink_cache_dma_cache_wback_inv,
};
static const struct of_device_id starlink_cache_ids[] = {
{ .compatible = "starfive,jh8100-starlink-cache" },
{ /* sentinel */ }
};
static int __init starlink_cache_init(void)
{
struct device_node *np;
u32 block_size;
int ret;
np = of_find_matching_node(NULL, starlink_cache_ids);
if (!of_device_is_available(np))
return -ENODEV;
ret = of_property_read_u32(np, "cache-block-size", &block_size);
if (ret)
return ret;
if (block_size % STARLINK_CACHE_ALIGN)
return -EINVAL;
starlink_cache_base = of_iomap(np, 0);
if (!starlink_cache_base)
return -ENOMEM;
riscv_cbom_block_size = block_size;
riscv_noncoherent_supported();
riscv_noncoherent_register_cache_ops(&starlink_cache_ops);
return 0;
}
arch_initcall(starlink_cache_init);