Re: [U-Boot] [PATCHv2 4/6] dm: cache: add the pl310 cache controller driver

[Simon Glass]

On Tue, 12 Mar 2019 at 22:41, Dinh Nguyen <dingu...@kernel.org> wrote:
>
> Add a PL310 cache controller driver that is usually found on
> ARMv7(32-bit) devices. The driver configures the cache settings that can
> be found in the device tree files.
>
> This initial revision only configures basic settings(data & instruction
> prefetch, shared-override, data & tag latency). I believe these are the
> settings that affect performance the most. Comprehensive settings can be
> done by the OS.
>
> Signed-off-by: Dinh Nguyen <dingu...@kernel.org>
> ---
> v2: split out patch and address comments from Simon Glass
> ---
>  drivers/cache/Kconfig      |  9 +++++
>  drivers/cache/Makefile     |  1 +
>  drivers/cache/cache-l2x0.c | 75 ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 85 insertions(+)
>  create mode 100644 drivers/cache/cache-l2x0.c

Reviewed-by: Simon Glass <s...@chromium.org>

nits below

>
> diff --git a/drivers/cache/Kconfig b/drivers/cache/Kconfig
> index 8b7c9c7f9f..24def7ac0f 100644
> --- a/drivers/cache/Kconfig
> +++ b/drivers/cache/Kconfig
> @@ -13,4 +13,13 @@ config CACHE
>           is usually located on the same chip. This uclass can be used for
>           configuring settings that be found from a device tree file.
>
> +config L2X0_CACHE
> +       tristate "PL310 cache driver"
> +       select CACHE
> +       depends on ARM
> +       help
> +         This driver is for the PL310 cache controller commonly found on
> +         ARMv7(32-bit) devices. The driver configures the cache settings
> +         found in the device tree.
> +
>  endmenu
> diff --git a/drivers/cache/Makefile b/drivers/cache/Makefile
> index 2ba68060c1..9deb961d91 100644
> --- a/drivers/cache/Makefile
> +++ b/drivers/cache/Makefile
> @@ -1,3 +1,4 @@
>
>  obj-$(CONFIG_CACHE) += cache-uclass.o
>  obj-$(CONFIG_SANDBOX) += sandbox_cache.o
> +obj-$(CONFIG_L2X0_CACHE) += cache-l2x0.o
> diff --git a/drivers/cache/cache-l2x0.c b/drivers/cache/cache-l2x0.c
> new file mode 100644
> index 0000000000..a23a66c4a8
> --- /dev/null
> +++ b/drivers/cache/cache-l2x0.c
> @@ -0,0 +1,75 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2019 Intel Corporation <www.intel.com>
> + */
> +#include <common.h>
> +#include <command.h>
> +#include <dm.h>
> +
> +#include <asm/io.h>
> +#include <asm/pl310.h>
> +
> +static void l2c310_of_parse(struct udevice *dev)

l2c310_of_parse_and_init()

(to be more descriptive)

> +{
> +       u32 tag[3] = { 0, 0, 0 };
> +       u32 saved_reg, prefetch;
> +       struct pl310_regs *regs = (struct pl310_regs *)dev_read_addr(dev);
> +
> +       /* Disable the L2 Cache */
> +       clrbits_le32(&regs->pl310_ctrl, L2X0_CTRL_EN);
> +
> +       saved_reg = readl(&regs->pl310_aux_ctrl);
> +       if (!dev_read_u32(dev, "prefetch-data", &prefetch)) {
> +               if (prefetch)
> +                       saved_reg |= L310_AUX_CTRL_DATA_PREFETCH_MASK;
> +               else
> +                       saved_reg &= ~L310_AUX_CTRL_DATA_PREFETCH_MASK;
> +       }
> +
> +       if (!dev_read_u32(dev, "prefetch-instr", &prefetch)) {
> +               if (prefetch)
> +                       saved_reg |= L310_AUX_CTRL_INST_PREFETCH_MASK;
> +               else
> +                       saved_reg &= ~L310_AUX_CTRL_INST_PREFETCH_MASK;
> +       }
> +
> +       saved_reg |= dev_read_bool(dev, "arm,shared-override");
> +       writel(saved_reg, &regs->pl310_aux_ctrl);
> +
> +       saved_reg = readl(&regs->pl310_tag_latency_ctrl);
> +       if (!dev_read_u32_array(dev, "arm,tag-latency", tag, 3))
> +               saved_reg |= L310_LATENCY_CTRL_RD(tag[0] - 1) |
> +                            L310_LATENCY_CTRL_WR(tag[1] - 1) |
> +                            L310_LATENCY_CTRL_SETUP(tag[2] - 1);
> +       writel(saved_reg, &regs->pl310_tag_latency_ctrl);
> +
> +       saved_reg = readl(&regs->pl310_data_latency_ctrl);
> +       if (!dev_read_u32_array(dev, "arm,data-latency", tag, 3))
> +               saved_reg |= L310_LATENCY_CTRL_RD(tag[0] - 1) |
> +                            L310_LATENCY_CTRL_WR(tag[1] - 1) |
> +                            L310_LATENCY_CTRL_SETUP(tag[2] - 1);
> +       writel(saved_reg, &regs->pl310_data_latency_ctrl);
> +
> +       /* Enable the L2 cache */
> +       setbits_le32(&regs->pl310_ctrl, L2X0_CTRL_EN);
> +}
> +
> +static int l2x0_probe(struct udevice *dev)
> +{
> +       l2c310_of_parse(dev);

blank line

> +       return 0;
> +}
> +
> +
> +static const struct udevice_id l2x0_ids[] = {
> +       { .compatible = "arm,pl310-cache" },
> +       {}
> +};
> +
> +U_BOOT_DRIVER(pl310_cache) = {
> +       .name   = "pl310_cache",
> +       .id     = UCLASS_CACHE,
> +       .of_match = l2x0_ids,
> +       .probe  = l2x0_probe,
> +       .flags  = DM_FLAG_PRE_RELOC,
> +};
> --
> 2.20.0
>

Regards,
Simon
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