On 2024-03-14 1:12 AM, Joshua Yeong wrote:
> Add software workaround for StarFive StarLink-500
> on JH8100 SoC for CMO extension instructions.
>
> Signed-off-by: Joshua Yeong <joshua.yeong@xxxxxxxxxxxxxxxx>
> ---
> drivers/cache/Kconfig | 9 ++
> drivers/cache/Makefile | 1 +
> drivers/cache/starlink500_cache.c | 137 ++++++++++++++++++++++++++++++
> 3 files changed, 147 insertions(+)
> create mode 100644 drivers/cache/starlink500_cache.c
>
> diff --git a/drivers/cache/Kconfig b/drivers/cache/Kconfig
> index 9345ce4976d7..e215379f6a73 100644
> --- a/drivers/cache/Kconfig
> +++ b/drivers/cache/Kconfig
> @@ -14,4 +14,13 @@ config SIFIVE_CCACHE
> help
> Support for the composable cache controller on SiFive platforms.
>
> +config STARLINK_500_CACHE
> + bool "StarLink-500 Cache controller"
> + depends on RISCV_DMA_NONCOHERENT
> + depends on ERRATA_STARFIVE
> + select RISCV_NONSTANDARD_CACHE_OPS
> + default y
> + help
> + Support for the StarLink-500 cache controller on StarFive platforms.
> +
> endmenu
> diff --git a/drivers/cache/Makefile b/drivers/cache/Makefile
> index 7657cff3bd6c..c515eb5714ea 100644
> --- a/drivers/cache/Makefile
> +++ b/drivers/cache/Makefile
> @@ -2,3 +2,4 @@
>
> obj-$(CONFIG_AX45MP_L2_CACHE) += ax45mp_cache.o
> obj-$(CONFIG_SIFIVE_CCACHE) += sifive_ccache.o
> +obj-$(CONFIG_STARLINK_500_CACHE) += starlink500_cache.o
> diff --git a/drivers/cache/starlink500_cache.c b/drivers/cache/starlink500_cache.c
> new file mode 100644
> index 000000000000..eaf8303cb086
> --- /dev/null
> +++ b/drivers/cache/starlink500_cache.c
> @@ -0,0 +1,137 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Non-coherent cache functions for StarFive's StarLink-500 cache controller
> + *
> + * Copyright (C) 2024 Shanghai StarFive Technology Co., Ltd.
> + *
> + * Author: Joshua Yeong <joshua.yeong@xxxxxxxxxxxxxxxx>
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/cacheflush.h>
> +#include <linux/cacheinfo.h>
> +#include <linux/delay.h>
> +#include <linux/dma-direction.h>
> +#include <linux/io.h>
> +#include <linux/of_address.h>
> +#include <linux/of_platform.h>
> +#include <linux/processor.h>
> +
> +#include <asm/dma-noncoherent.h>
> +
> +#define STARFIVE_SL500_CMO_FLUSH_START_ADDR 0x0
> +#define STARFIVE_SL500_CMO_FLUSH_END_ADDR 0x8
> +#define STARFIVE_SL500_CMO_FLUSH_CTL 0x10
> +#define STARFIVE_SL500_CMO_CACHE_ALIGN 0x40
> +
> +#define STARFIVE_SL500_ADDRESS_RANGE_MASK GENMASK(39, 0)
> +#define STARFIVE_SL500_FLUSH_CTL_MODE_MASK GENMASK(2, 1)
> +#define STARFIVE_SL500_FLUSH_CTL_ENABLE_MASK BIT(0)
> +
> +#define STARFIVE_SL500_FLUSH_CTL_CLEAN_INVALIDATE 0
> +#define STARFIVE_SL500_FLUSH_CTL_MAKE_INVALIDATE 1
> +#define STARFIVE_SL500_FLUSH_CTL_CLEAN_SHARED 2
> +
> +struct starfive_sl500_cache_priv {
> + void __iomem *base_addr;
> +};
> +
> +static struct starfive_sl500_cache_priv starfive_sl500_cache_priv;
> +
> +static void starfive_sl500_cmo_flush_complete(void)
> +{
> + ktime_t timeout;
> +
> + volatile void __iomem *_ctl = starfive_sl500_cache_priv.base_addr +
> + STARFIVE_SL500_CMO_FLUSH_CTL;
> + timeout = ktime_add_ms(ktime_get(), 5000);
> +
> + do {
> + if(!(ioread64(_ctl) & STARFIVE_SL500_FLUSH_CTL_ENABLE_MASK))
> + return;
> + msleep(50);
These callbacks can be called from an atomic context, so you cannot use msleep()
here.
> + } while (ktime_before(ktime_get(), timeout));
I suggest using one of the helpers from linux/iopoll.h, e.g. readq_poll_timeout().
> +
> + pr_err("StarFive CMO operation timeout\n");
> + dump_stack();
WARN or WARN_ON would be idiomatic here.
> +}
> +
> +void starfive_sl500_dma_cache_wback(phys_addr_t paddr, unsigned long size)
> +{
> + writeq(FIELD_PREP(STARFIVE_SL500_ADDRESS_RANGE_MASK, paddr),
> + starfive_sl500_cache_priv.base_addr + STARFIVE_SL500_CMO_FLUSH_START_ADDR);
> + writeq(FIELD_PREP(STARFIVE_SL500_ADDRESS_RANGE_MASK, paddr + size),
> + starfive_sl500_cache_priv.base_addr + STARFIVE_SL500_CMO_FLUSH_END_ADDR);
> +
> + mb();
> + writeq(FIELD_PREP(STARFIVE_SL500_FLUSH_CTL_MODE_MASK,
> + STARFIVE_SL500_FLUSH_CTL_CLEAN_SHARED),
> + starfive_sl500_cache_priv.base_addr + STARFIVE_SL500_CMO_FLUSH_CTL);
> +
> + starfive_sl500_cmo_flush_complete();
> +}
> +
> +void starfive_sl500_dma_cache_invalidate(phys_addr_t paddr, unsigned long size)
> +{
> + writeq(FIELD_PREP(STARFIVE_SL500_ADDRESS_RANGE_MASK, paddr),
> + starfive_sl500_cache_priv.base_addr + STARFIVE_SL500_CMO_FLUSH_START_ADDR);
> + writeq(FIELD_PREP(STARFIVE_SL500_ADDRESS_RANGE_MASK, paddr + size),
> + starfive_sl500_cache_priv.base_addr + STARFIVE_SL500_CMO_FLUSH_END_ADDR);
> +
> + mb();
> + writeq(FIELD_PREP(STARFIVE_SL500_FLUSH_CTL_MODE_MASK,
> + STARFIVE_SL500_FLUSH_CTL_MAKE_INVALIDATE),
> + starfive_sl500_cache_priv.base_addr + STARFIVE_SL500_CMO_FLUSH_CTL);
> +
> + starfive_sl500_cmo_flush_complete();
> +}
> +
> +void starfive_sl500_dma_cache_wback_inv(phys_addr_t paddr, unsigned long size)
> +{
> + writeq(FIELD_PREP(STARFIVE_SL500_ADDRESS_RANGE_MASK, paddr),
> + starfive_sl500_cache_priv.base_addr + STARFIVE_SL500_CMO_FLUSH_START_ADDR);
> + writeq(FIELD_PREP(STARFIVE_SL500_ADDRESS_RANGE_MASK, paddr + size),
> + starfive_sl500_cache_priv.base_addr + STARFIVE_SL500_CMO_FLUSH_END_ADDR);
> +
> + mb();
> + writeq(FIELD_PREP(STARFIVE_SL500_FLUSH_CTL_MODE_MASK,
> + STARFIVE_SL500_FLUSH_CTL_CLEAN_INVALIDATE),
> + starfive_sl500_cache_priv.base_addr + STARFIVE_SL500_CMO_FLUSH_CTL);
> +
> + starfive_sl500_cmo_flush_complete();
> +}
> +
> +static const struct riscv_nonstd_cache_ops starfive_sl500_cmo_ops = {
> + .wback = &starfive_sl500_dma_cache_wback,
> + .inv = &starfive_sl500_dma_cache_invalidate,
> + .wback_inv = &starfive_sl500_dma_cache_wback_inv,
> +};
> +
> +static const struct of_device_id starfive_sl500_cache_ids[] = {
> + { .compatible = "starfive,starlink-500-cache" },
> + { /* sentinel */ }
> +};
> +
> +static int __init starfive_sl500_cache_init(void)
> +{
> + struct device_node *np;
> + struct resource res;
> + int ret;
> +
> + np = of_find_matching_node(NULL, starfive_sl500_cache_ids);
> + if (!of_device_is_available(np))
> + return -ENODEV;
> +
> + ret = of_address_to_resource(np, 0, &res);
> + if (ret)
> + return ret;
> +
> + starfive_sl500_cache_priv.base_addr = ioremap(res.start, resource_size(&res));
> + if (!starfive_sl500_cache_priv.base_addr)
> + return -ENOMEM;
of_address_to_resource() + ioremap() simplifies to of_iomap().
Regards,
Samuel
> +
> + riscv_noncoherent_register_cache_ops(&starfive_sl500_cmo_ops);
> +
> + return 0;
> +}
> +early_initcall(starfive_sl500_cache_init);
