[PATCH 2/2] board: sifive: use ccache driver instead of helper function

Zong Li zong.li at sifive.com
Fri Jul 30 11:16:46 CEST 2021


On Thu, Jul 29, 2021 at 8:26 PM Zong Li <zong.li at sifive.com> wrote:
>
> On Wed, Jul 28, 2021 at 11:18 PM Sean Anderson <seanga2 at gmail.com> wrote:
> >
> > On 7/28/21 3:25 AM, Zong Li wrote:
> > > On Wed, Jul 28, 2021 at 12:29 PM Sean Anderson <seanga2 at gmail.com> wrote:
> > >>
> > >> On 7/27/21 4:54 AM, Zong Li wrote:
> > >>> Invokes the generic cache_enable interface to execute the relative
> > >>> implementation in SiFive ccache driver.
> > >>>
> > >>> Signed-off-by: Zong Li <zong.li at sifive.com>
> > >>> ---
> > >>>    arch/riscv/cpu/fu540/Kconfig              |  1 +
> > >>>    arch/riscv/cpu/fu540/cache.c              | 62 ++++++++---------------
> > >>>    arch/riscv/cpu/fu740/Kconfig              |  1 +
> > >>>    arch/riscv/cpu/fu740/cache.c              | 60 +++++++---------------
> > >>>    arch/riscv/include/asm/arch-fu540/cache.h |  2 +-
> > >>>    arch/riscv/include/asm/arch-fu740/cache.h |  2 +-
> > >>>    board/sifive/unleashed/unleashed.c        | 10 +---
> > >>>    board/sifive/unmatched/unmatched.c        |  9 +---
> > >>>    8 files changed, 45 insertions(+), 102 deletions(-)
> > >>>
> > >>> diff --git a/arch/riscv/cpu/fu540/Kconfig b/arch/riscv/cpu/fu540/Kconfig
> > >>> index 05463b2625..1f50b823ed 100644
> > >>> --- a/arch/riscv/cpu/fu540/Kconfig
> > >>> +++ b/arch/riscv/cpu/fu540/Kconfig
> > >>> @@ -19,6 +19,7 @@ config SIFIVE_FU540
> > >>>        imply SMP
> > >>>        imply CLK_SIFIVE
> > >>>        imply CLK_SIFIVE_PRCI
> > >>> +     imply SIFIVE_CACHE_CCACHE
> > >>>        imply SIFIVE_SERIAL
> > >>>        imply MACB
> > >>>        imply MII
> > >>> diff --git a/arch/riscv/cpu/fu540/cache.c b/arch/riscv/cpu/fu540/cache.c
> > >>> index 0fc4ef6c00..3c754c4614 100644
> > >>> --- a/arch/riscv/cpu/fu540/cache.c
> > >>> +++ b/arch/riscv/cpu/fu540/cache.c
> > >>> @@ -1,55 +1,33 @@
> > >>>    // SPDX-License-Identifier: GPL-2.0+
> > >>>    /*
> > >>> - * Copyright (C) 2020 SiFive, Inc
> > >>> + * Copyright (C) 2020 - 2021 SiFive, Inc
> > >>>     *
> > >>>     * Authors:
> > >>>     *   Pragnesh Patel <pragnesh.patel at sifive.com>
> > >>>     */
> > >>>
> > >>>    #include <common.h>
> > >>> -#include <asm/global_data.h>
> > >>> -#include <asm/io.h>
> > >>> -#include <linux/bitops.h>
> > >>> +#include <cache.h>
> > >>> +#include <dm.h>
> > >>>
> > >>> -/* Register offsets */
> > >>> -#define L2_CACHE_CONFIG      0x000
> > >>> -#define L2_CACHE_ENABLE      0x008
> > >>> -
> > >>> -#define MASK_NUM_WAYS        GENMASK(15, 8)
> > >>> -#define NUM_WAYS_SHIFT       8
> > >>> -
> > >>> -DECLARE_GLOBAL_DATA_PTR;
> > >>> -
> > >>> -int cache_enable_ways(void)
> > >>> +int sifive_ccache_enable_ways(void)
> > >>>    {
> > >>
> > >> Is there any reason this function is duplicated? See below for further comments.
> > >
> > > Sorry, I don't completely understand about duplication here. Do you
> > > mean why we need this function? or why is it present in both unleashed
> > > and unmatched?
> >
> > Why it is present in both. Shouldn't it be present in some shared file?
> >
>
> I considered that before, the places to put this ccache function might
> be either 'arch/riscv/lib/' or 'arch/riscv/cpu/generic', these two
> folders put some common stuff for all riscv platforms, but this ccache
> function is actually used in sifive platform only, I'm not sure if it
> is suitable to put the function into them, so I just followed the
> original tree. OTOH, the compiler will drop the unused code, so it
> might be OK to put it into the folders above, and not influence other
> platforms. Do you have any preference or any recommendation?
>

I'm going to add a cache_init() or a weak enable_caches() which is
declared in cpu_func.h into 'arch/riscv/lib/cache.c' for the next
version.

> > >
> > >>
> > >>> -     const void *blob = gd->fdt_blob;
> > >>> -     int node;
> > >>> -     fdt_addr_t base;
> > >>> -     u32 config;
> > >>> -     u32 ways;
> > >>> -
> > >>> -     volatile u32 *enable;
> > >>> -
> > >>> -     node = fdt_node_offset_by_compatible(blob, -1,
> > >>> -                                          "sifive,fu540-c000-ccache");
> > >>> -
> > >>> -     if (node < 0)
> > >>> -             return node;
> > >>> -
> > >>> -     base = fdtdec_get_addr_size_auto_parent(blob, 0, node, "reg", 0,
> > >>> -                                             NULL, false);
> > >>> -     if (base == FDT_ADDR_T_NONE)
> > >>> -             return FDT_ADDR_T_NONE;
> > >>> -
> > >>> -     config = readl((volatile u32 *)base + L2_CACHE_CONFIG);
> > >>> -     ways = (config & MASK_NUM_WAYS) >> NUM_WAYS_SHIFT;
> > >>> -
> > >>> -     enable = (volatile u32 *)(base + L2_CACHE_ENABLE);
> > >>> +     struct udevice *dev;
> > >>> +     int ret;
> > >>> +
> > >>> +     ret = uclass_get_device_by_driver(UCLASS_CACHE,
> > >>> +                                       DM_DRIVER_GET(sifive_ccache),
> > >>> +                                       &dev);
> > >>> +     if (ret) {
> > >>> +             pr_debug("%s: could not enable cache ways\n", __func__);
> > >>> +             return ret;
> > >>> +     }
> > >>> +
> > >>> +     ret = cache_enable(dev);
> > >>> +     if (ret) {
> > >>> +             pr_debug("%s: ccache enable filed\n", __func__);
> > >>> +             return ret;
> > >>> +     }
> > >>>
> > >>> -     /* memory barrier */
> > >>> -     mb();
> > >>> -     (*enable) = ways - 1;
> > >>> -     /* memory barrier */
> > >>> -     mb();
> > >>>        return 0;
> > >>>    }
> > >>> diff --git a/arch/riscv/cpu/fu740/Kconfig b/arch/riscv/cpu/fu740/Kconfig
> > >>> index 8e54310b9c..87d8016c88 100644
> > >>> --- a/arch/riscv/cpu/fu740/Kconfig
> > >>> +++ b/arch/riscv/cpu/fu740/Kconfig
> > >>> @@ -19,6 +19,7 @@ config SIFIVE_FU740
> > >>>        imply SMP
> > >>>        imply CLK_SIFIVE
> > >>>        imply CLK_SIFIVE_PRCI
> > >>> +     imply SIFIVE_CACHE_CCACHE
> > >>>        imply SIFIVE_SERIAL
> > >>>        imply MACB
> > >>>        imply MII
> > >>> diff --git a/arch/riscv/cpu/fu740/cache.c b/arch/riscv/cpu/fu740/cache.c
> > >>> index 680955c9e3..1d6c295d98 100644
> > >>> --- a/arch/riscv/cpu/fu740/cache.c
> > >>> +++ b/arch/riscv/cpu/fu740/cache.c
> > >>> @@ -7,49 +7,27 @@
> > >>>     */
> > >>>
> > >>>    #include <common.h>
> > >>> -#include <asm/io.h>
> > >>> -#include <linux/bitops.h>
> > >>> -#include <asm/global_data.h>
> > >>> +#include <cache.h>
> > >>> +#include <dm.h>
> > >>>
> > >>> -/* Register offsets */
> > >>> -#define L2_CACHE_CONFIG      0x000
> > >>> -#define L2_CACHE_ENABLE      0x008
> > >>> -
> > >>> -#define MASK_NUM_WAYS        GENMASK(15, 8)
> > >>> -#define NUM_WAYS_SHIFT       8
> > >>> -
> > >>> -DECLARE_GLOBAL_DATA_PTR;
> > >>> -
> > >>> -int cache_enable_ways(void)
> > >>> +int sifive_ccache_enable_ways(void)
> > >>>    {
> > >>> -     const void *blob = gd->fdt_blob;
> > >>> -     int node;
> > >>> -     fdt_addr_t base;
> > >>> -     u32 config;
> > >>> -     u32 ways;
> > >>> -
> > >>> -     volatile u32 *enable;
> > >>> -
> > >>> -     node = fdt_node_offset_by_compatible(blob, -1,
> > >>> -                                          "sifive,fu740-c000-ccache");
> > >>> -
> > >>> -     if (node < 0)
> > >>> -             return node;
> > >>> -
> > >>> -     base = fdtdec_get_addr_size_auto_parent(blob, 0, node, "reg", 0,
> > >>> -                                             NULL, false);
> > >>> -     if (base == FDT_ADDR_T_NONE)
> > >>> -             return FDT_ADDR_T_NONE;
> > >>> -
> > >>> -     config = readl((volatile u32 *)base + L2_CACHE_CONFIG);
> > >>> -     ways = (config & MASK_NUM_WAYS) >> NUM_WAYS_SHIFT;
> > >>> -
> > >>> -     enable = (volatile u32 *)(base + L2_CACHE_ENABLE);
> > >>> +     struct udevice *dev;
> > >>> +     int ret;
> > >>> +
> > >>> +     ret = uclass_get_device_by_driver(UCLASS_CACHE,
> > >>> +                                       DM_DRIVER_GET(sifive_ccache),
> > >>> +                                       &dev);
> > >>> +     if (ret) {
> > >>> +             pr_debug("%s: could not enable cache ways\n", __func__);
> > >>> +             return ret;
> > >>
> > >> return log_msg_ret(...);
> > >>
> > >> (and you don't have to add a __func__ parameter if you use that function)
> > >
> > > Okay, let me change the function. Thanks.
> > >
> > >>
> > >>> +     }
> > >>> +
> > >>> +     ret = cache_enable(dev);
> > >>> +     if (ret) {
> > >>> +             pr_debug("%s: ccache enable filed\n", __func__);
> > >>
> > >> failed; ditto
> > >
> > > okay.
> > >
> > >>
> > >>> +             return ret;
> > >>> +     }
> > >>>
> > >>> -     /* memory barrier */
> > >>> -     mb();
> > >>> -     (*enable) = ways - 1;
> > >>> -     /* memory barrier */
> > >>> -     mb();
> > >>
> > >> Is this handled by the __iowmb/__iormb in writel/readl in the driver?
> > >>
> > >
> > > Yes, the ccache driver uses writel to write the register, and writel
> > > will invoke __iowmb.
> > >
> > >>>        return 0;
> > >>>    }
> > >>> diff --git a/arch/riscv/include/asm/arch-fu540/cache.h b/arch/riscv/include/asm/arch-fu540/cache.h
> > >>> index 135a17c679..c252eb64d1 100644
> > >>> --- a/arch/riscv/include/asm/arch-fu540/cache.h
> > >>> +++ b/arch/riscv/include/asm/arch-fu540/cache.h
> > >>> @@ -9,6 +9,6 @@
> > >>>    #ifndef _CACHE_SIFIVE_H
> > >>>    #define _CACHE_SIFIVE_H
> > >>>
> > >>> -int cache_enable_ways(void);
> > >>> +int sifive_ccache_enable_ways(void);
> > >>>
> > >>>    #endif /* _CACHE_SIFIVE_H */
> > >>> diff --git a/arch/riscv/include/asm/arch-fu740/cache.h b/arch/riscv/include/asm/arch-fu740/cache.h
> > >>> index 7d4fe9942b..8c456e3658 100644
> > >>> --- a/arch/riscv/include/asm/arch-fu740/cache.h
> > >>> +++ b/arch/riscv/include/asm/arch-fu740/cache.h
> > >>> @@ -9,6 +9,6 @@
> > >>>    #ifndef _CACHE_SIFIVE_H
> > >>>    #define _CACHE_SIFIVE_H
> > >>>
> > >>> -int cache_enable_ways(void);
> > >>> +int sifive_ccache_enable_ways(void);
> > >>>
> > >>>    #endif /* _CACHE_SIFIVE_H */
> > >>> diff --git a/board/sifive/unleashed/unleashed.c b/board/sifive/unleashed/unleashed.c
> > >>> index 43027f0b54..12e61ec85f 100644
> > >>> --- a/board/sifive/unleashed/unleashed.c
> > >>> +++ b/board/sifive/unleashed/unleashed.c
> > >>> @@ -126,14 +126,6 @@ void *board_fdt_blob_setup(void)
> > >>>
> > >>>    int board_init(void)
> > >>>    {
> > >>> -     int ret;
> > >>> -
> > >>>        /* enable all cache ways */
> > >>> -     ret = cache_enable_ways();
> > >>> -     if (ret) {
> > >>> -             debug("%s: could not enable cache ways\n", __func__);
> > >>> -             return ret;
> > >>
> > >> ditto, though here I would just skip the error message since you reported it above already
> > >>
> > >
> > > It seems to me that this part was dropped in this patch.
> >
> > Ah, whoops. Ignore this comment, then.
> >
> > >
> > >
> > >>> -     }
> > >>> -
> > >>> -     return 0;
> > >>> +     return sifive_ccache_enable_ways();
> > >>>    }
> > >>> diff --git a/board/sifive/unmatched/unmatched.c b/board/sifive/unmatched/unmatched.c
> > >>> index 2f5629b578..d27c4d3e88 100644
> > >>> --- a/board/sifive/unmatched/unmatched.c
> > >>> +++ b/board/sifive/unmatched/unmatched.c
> > >>> @@ -23,13 +23,6 @@ void *board_fdt_blob_setup(void)
> > >>>
> > >>>    int board_init(void)
> > >>>    {
> > >>> -     int ret;
> > >>> -
> > >>>        /* enable all cache ways */
> > >>> -     ret = cache_enable_ways();
> > >>> -     if (ret) {
> > >>> -             debug("%s: could not enable cache ways\n", __func__);
> > >>
> > >> ditto
> > >
> > > Okay.
> > >
> > >>
> > >>> -             return ret;
> > >>> -     }
> > >>> -     return 0;
> > >>> +     return sifive_ccache_enable_ways();
> > >>>    }
> > >>>
> > >>
> > >> --Sean
> >


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