[PATCH v3 2/4] riscv: lib: introduce a cache_init interface

[Sean Anderson]

On 8/17/21 5:08 AM, Zong Li wrote:
> Add an interface for cache initialization. Each platform can overwrite
> this weak function by their own implementation, such as sifive_cache in
> this patch.
> 
> In sifive_cache, it invokes the generic cache_enable interface of cache
> uclass to execute the relative implementation in SiFive ccache driver.
> 
> Signed-off-by: Zong Li <zong.li at sifive.com>
> ---
>   arch/riscv/Kconfig             |  5 +++++
>   arch/riscv/include/asm/cache.h |  1 +
>   arch/riscv/lib/Makefile        |  1 +
>   arch/riscv/lib/cache.c         |  5 +++++
>   arch/riscv/lib/sifive_cache.c  | 27 +++++++++++++++++++++++++++
>   5 files changed, 39 insertions(+)
>   create mode 100644 arch/riscv/lib/sifive_cache.c
> 
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 4b0c3dffa6..ec651fe0a4 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -179,6 +179,11 @@ config SPL_SIFIVE_CLINT
>   	  The SiFive CLINT block holds memory-mapped control and status registers
>   	  associated with software and timer interrupts.
>   
> +config SIFIVE_CACHE
> +	bool
> +	help
> +	  This enables the operations to configure SiFive cache
> +
>   config ANDES_PLIC
>   	bool
>   	depends on RISCV_MMODE || SPL_RISCV_MMODE
> diff --git a/arch/riscv/include/asm/cache.h b/arch/riscv/include/asm/cache.h
> index ec8fe201d3..6ebb2b4329 100644
> --- a/arch/riscv/include/asm/cache.h
> +++ b/arch/riscv/include/asm/cache.h
> @@ -9,6 +9,7 @@
>   
>   /* cache */
>   void	cache_flush(void);
> +int cache_init(void);
>   
>   /*
>    * The current upper bound for RISCV L1 data cache line sizes is 32 bytes.
> diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile
> index c4cc41434b..06020fcc2a 100644
> --- a/arch/riscv/lib/Makefile
> +++ b/arch/riscv/lib/Makefile
> @@ -10,6 +10,7 @@ obj-$(CONFIG_CMD_BOOTM) += bootm.o
>   obj-$(CONFIG_CMD_BOOTI) += bootm.o image.o
>   obj-$(CONFIG_CMD_GO) += boot.o
>   obj-y	+= cache.o
> +obj-$(CONFIG_SIFIVE_CACHE) += sifive_cache.o
>   ifeq ($(CONFIG_$(SPL_)RISCV_MMODE),y)
>   obj-$(CONFIG_$(SPL_)SIFIVE_CLINT) += sifive_clint.o
>   obj-$(CONFIG_ANDES_PLIC) += andes_plic.o
> diff --git a/arch/riscv/lib/cache.c b/arch/riscv/lib/cache.c
> index b1d42bcc2b..2cd66504c6 100644
> --- a/arch/riscv/lib/cache.c
> +++ b/arch/riscv/lib/cache.c
> @@ -70,3 +70,8 @@ __weak int dcache_status(void)
>   {
>   	return 0;
>   }
> +
> +__weak int cache_init(void)
> +{
> +	return 0;
> +}

Don't make this generic. Just call a `sifive_cache_init` or whatever.

IMO this pattern shouldn't be duplicated by other platforms, but it is OK to do for now until we have a more generic method.

--Sean

> diff --git a/arch/riscv/lib/sifive_cache.c b/arch/riscv/lib/sifive_cache.c
> new file mode 100644
> index 0000000000..94e84e024e
> --- /dev/null
> +++ b/arch/riscv/lib/sifive_cache.c
> @@ -0,0 +1,27 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2021 SiFive, Inc
> + */
> +
> +#include <common.h>
> +#include <cache.h>
> +#include <dm.h>
> +
> +int cache_init(void)
> +{
> +	struct udevice *dev;
> +	int ret;
> +
> +	/* Enable ways of ccache */
> +	ret = uclass_get_device_by_driver(UCLASS_CACHE,
> +					  DM_DRIVER_GET(sifive_ccache),
> +					  &dev);
> +	if (ret)
> +		return log_msg_ret("Cannot enable cache ways", ret);
> +
> +	ret = cache_enable(dev);
> +	if (ret)
> +		return log_msg_ret("ccache enable failed", ret);
> +
> +	return 0;
> +}
>