[U-Boot] [PATCH 1/6] dm: cache: add v5l2 cache controller driver

Rick Chen rickchen36 at gmail.com
Mon Jun 10 02:26:10 UTC 2019


Hi Lukas

>
> Hi Rick,
>
> On Wed, 2019-06-05 at 16:58 +0800, Rick Chen wrote:
> > Hi Bin
> >
> > Bin Meng <bmeng.cn at gmail.com> 於 2019年6月4日 週二 上午10:48寫道:
> > > Hi Rick,
> > >
> > > On Tue, May 28, 2019 at 5:44 PM Andes <uboot at andestech.com> wrote:
> > > > From: Rick Chen <rick at andestech.com>
> > > >
> > > > Add a v5l2 cache controller driver that is usually found on
> > > > Andes RISC-V ae350 platform. It will parse the cache settings
> > > > from the dtb.
> > > >
> > > > In this version tag and data ram control timing can be adjusted
> > > > by the requirement from the dtb.
> > > >
> > > > Signed-off-by: Rick Chen <rick at andestech.com>
> > > > Cc: Greentime Hu <greentime at andestech.com>
> > > > ---
> > > >  arch/riscv/include/asm/global_data.h |   3 ++
> > > >  arch/riscv/include/asm/v5l2cache.h   |  61 +++++++++++++++++++++
> > > >  drivers/cache/Kconfig                |   9 ++++
> > > >  drivers/cache/Makefile               |   1 +
> > > >  drivers/cache/cache-v5l2.c           | 102 +++++++++++++++++++++++++++++++++++
> > > >  5 files changed, 176 insertions(+)
> > > >  create mode 100644 arch/riscv/include/asm/v5l2cache.h
> > > >  create mode 100644 drivers/cache/cache-v5l2.c
> > > >
> > > > diff --git a/arch/riscv/include/asm/global_data.h b/arch/riscv/include/asm/global_data.h
> > > > index b74bd7e..6e52d5d 100644
> > > > --- a/arch/riscv/include/asm/global_data.h
> > > > +++ b/arch/riscv/include/asm/global_data.h
> > > > @@ -24,6 +24,9 @@ struct arch_global_data {
> > > >  #ifdef CONFIG_ANDES_PLMT
> > > >         void __iomem *plmt;     /* plmt base address */
> > > >  #endif
> > > > +#ifdef CONFIG_V5L2_CACHE
> > > > +       void __iomem *v5l2;     /* v5l2 base address */
> > > > +#endif
> > >
> > > Please do not expose this to global data if it is only used inside a
> > > driver. Anything that is here is for "global" usage.
> >
> > OK.
> > I will remove it.
> >
> > > >  #ifdef CONFIG_SMP
> > > >         struct ipi_data ipi[CONFIG_NR_CPUS];
> > > >  #endif
> > > > diff --git a/arch/riscv/include/asm/v5l2cache.h b/arch/riscv/include/asm/v5l2cache.h
> > > > new file mode 100644
> > > > index 0000000..8ed1c6c
> > > > --- /dev/null
> > > > +++ b/arch/riscv/include/asm/v5l2cache.h
> > >
> > > Please create arch/riscv/include/asm/arch-ax25/v5l2cache.h. Speaking
> > > of the name, would it be more readable to name it as v5_l2cache.h? Or
> > > even add more information to v5, for me, I don't know what v5 stands
> > > for :)
> >
> > OK
> > I will create arch/riscv/include/asm/arch-ax25/v5_l2cache.h
> >
> > > > @@ -0,0 +1,61 @@
> > > > +/* SPDX-License-Identifier: GPL-2.0+ */
> > > > +/*
> > > > + * Copyright (C) 2019 Andes Technology Corporation
> > > > + * Rick Chen, Andes Technology Corporation <rick at andestech.com>
> > > > + */
> > > > +
> > > > +#ifndef _ASM_V5_L2CACHE_H
> > > > +#define _ASM_V5_L2CACHE_H
> > > > +
> > > > +struct l2cache {
> > > > +       volatile u64    configure;
> > >
> > > checkpatch.pl will report warnings against volatile usage. I think we
> > > should drop these.
> >
> > I know that checkpatch.pl will report this warning.
> > But I still need to add volatile. It help to fix some unpredictable problem.
> > Without this some driver code flows will be optimized and go wrong somehow.
> >
> > > > +       volatile u64    control;
> > > > +       volatile u64    hpm0;
> > > > +       volatile u64    hpm1;
> > > > +       volatile u64    hpm2;
> > > > +       volatile u64    hpm3;
> > > > +       volatile u64    error_status;
> > > > +       volatile u64    ecc_error;
> > > > +       volatile u64    cctl_command0;
> > > > +       volatile u64    cctl_access_line0;
> > > > +       volatile u64    cctl_command1;
> > > > +       volatile u64    cctl_access_line1;
> > > > +       volatile u64    cctl_command2;
> > > > +       volatile u64    cctl_access_line2;
> > > > +       volatile u64    cctl_command3;
> > > > +       volatile u64    cctl_access_line4;
> > > > +       volatile u64    cctl_status;
> > > > +};
> > > > +
> > > > +/* Control Register */
> > > > +#define L2_ENABLE      0x1
> > > > +/* prefetch */
> > > > +#define IPREPETCH_OFF  3
> > > > +#define DPREPETCH_OFF  5
> > > > +#define IPREPETCH_MSK  (3 << IPREPETCH_OFF)
> > > > +#define DPREPETCH_MSK  (3 << DPREPETCH_OFF)
> > > > +/* tag ram */
> > > > +#define TRAMOCTL_OFF   8
> > > > +#define TRAMICTL_OFF   10
> > > > +#define TRAMOCTL_MSK   (3 << TRAMOCTL_OFF)
> > > > +#define TRAMICTL_MSK   BIT(TRAMICTL_OFF)
> > > > +/* data ram */
> > > > +#define DRAMOCTL_OFF   11
> > > > +#define DRAMICTL_OFF   13
> > > > +#define DRAMOCTL_MSK   (3 << DRAMOCTL_OFF)
> > > > +#define DRAMICTL_MSK   BIT(DRAMICTL_OFF)
> > > > +
> > > > +/* CCTL Command Register */
> > > > +#define CCTL_CMD_REG(base, hart)       ((ulong)(base) + 0x40 + (hart) * 0x10)
> > > > +#define L2_WBINVAL_ALL 0x12
> > > > +
> > > > +/* CCTL Status Register */
> > > > +#define CCTL_STATUS_MSK(hart)          (0xf << ((hart) * 4))
> > > > +#define CCTL_STATUS_IDLE(hart)         (0 << ((hart) * 4))
> > > > +#define CCTL_STATUS_PROCESS(hart)      (1 << ((hart) * 4))
> > > > +#define CCTL_STATUS_ILLEGAL(hart)      (2 << ((hart) * 4))
> > > > +
> > > > +void v5l2_enable(void);
> > > > +void v5l2_disable(void);
> > > > +
> > > > +#endif /* _ASM_V5_L2CACHE_H */
> > > > diff --git a/drivers/cache/Kconfig b/drivers/cache/Kconfig
> > > > index 24def7a..665689a 100644
> > > > --- a/drivers/cache/Kconfig
> > > > +++ b/drivers/cache/Kconfig
> > > > @@ -22,4 +22,13 @@ config L2X0_CACHE
> > > >           ARMv7(32-bit) devices. The driver configures the cache settings
> > > >           found in the device tree.
> > > >
> > > > +config V5L2_CACHE
> > > > +       tristate "Andes V5L2 cache driver"
> > >
> > > This should be bool. U-Boot does not support "tristate"
> >
> > I will modify it as bool.
> >
> > > > +       select CACHE
> > > > +       depends on RISCV_NDS_CACHE
> > > > +       help
> > > > +         Support Andes V5L2 cache controller in AE350 platform.
> > > > +         It will configure tag and data ram timing control from the
> > > > +         device tree and enable L2 cache.
> > > > +
> > > >  endmenu
> > > > diff --git a/drivers/cache/Makefile b/drivers/cache/Makefile
> > > > index 9deb961..4a6458c 100644
> > > > --- a/drivers/cache/Makefile
> > > > +++ b/drivers/cache/Makefile
> > > > @@ -2,3 +2,4 @@
> > > >  obj-$(CONFIG_CACHE) += cache-uclass.o
> > > >  obj-$(CONFIG_SANDBOX) += sandbox_cache.o
> > > >  obj-$(CONFIG_L2X0_CACHE) += cache-l2x0.o
> > > > +obj-$(CONFIG_V5L2_CACHE) += cache-v5l2.o
> > > > diff --git a/drivers/cache/cache-v5l2.c b/drivers/cache/cache-v5l2.c
> > > > new file mode 100644
> > > > index 0000000..7022feb
> > > > --- /dev/null
> > > > +++ b/drivers/cache/cache-v5l2.c
> > > > @@ -0,0 +1,102 @@
> > > > +// SPDX-License-Identifier: GPL-2.0
> > > > +/*
> > > > + * Copyright (C) 2019 Andes Technology Corporation
> > > > + * Rick Chen, Andes Technology Corporation <rick at andestech.com>
> > > > + */
> > > > +
> > > > +#include <common.h>
> > > > +#include <command.h>
> > > > +#include <dm.h>
> > > > +#include <asm/io.h>
> > > > +#include <dm/ofnode.h>
> > > > +#include <asm/v5l2cache.h>
> > > > +
> > > > +DECLARE_GLOBAL_DATA_PTR;
> > > > +
> > > > +void v5l2_enable(void)
> > >
> > > This should really be avoided. It looks current DM cache uclass driver
> > > is lacking of ops to do cache enable/disable. Please improve the DM
> > > cache uclass driver first.
> >
> > OK
> > I will improve the DM cache uclass driver.
> >
> > > > +{
> > > > +       struct l2cache *regs = gd->arch.v5l2;
> > > > +
> > > > +       if (regs)
> > > > +               setbits_le32(&regs->control, L2_ENABLE);
> > > > +}
> > > > +
> > > > +void v5l2_disable(void)
> > > > +{
> > > > +       volatile struct l2cache *regs = gd->arch.v5l2;
> > > > +       u8 hart = gd->arch.boot_hart;
> > > > +       void __iomem *cctlcmd = (void __iomem *)CCTL_CMD_REG(gd->arch.v5l2, hart);
> > > > +
> > > > +       if ((regs) && (readl(&regs->control) & L2_ENABLE)) {
> > > > +               writel(L2_WBINVAL_ALL, cctlcmd);
> > > > +
> > > > +               while ((readl(&regs->cctl_status) & CCTL_STATUS_MSK(hart))) {
> > > > +                       if ((readl(&regs->cctl_status) & CCTL_STATUS_ILLEGAL(hart))) {
> > > > +                               printf("L2 flush illegal! hanging...");
> > > > +                               hang();
> > > > +                       }
> > > > +               }
> > > > +               clrbits_le32(&regs->control, L2_ENABLE);
> > > > +       }
> > > > +}
> > > > +
> > > > +static void v5l2_of_parse_and_init(struct udevice *dev)
> > >
> > > The entire function below should really be created as the driver's
> > > ofdata_to_platdata() function, inside which all DT properties are
> > > parsed and saved to driver's platdata. After that, there is no need to
> > > get register base from global data.
> >
> > I will use ofdata_to_platdata() to parse dtb information and save it
> > into platdata instead of saving in global data.
> >
> > > > +{
> > > > +       struct l2cache *regs;
> > > > +       u32 ctl_val, prefetch;
> > > > +       u32 tram_ctl[2];
> > > > +       u32 dram_ctl[2];
> > > > +
> > > > +       regs = (struct l2cache *)dev_read_addr(dev);
> > > > +       gd->arch.v5l2 = regs;
> > > > +       ctl_val = readl(&regs->control);
> > > > +
> > > > +       if (!(ctl_val & L2_ENABLE))
> > > > +               ctl_val |= L2_ENABLE;
> > > > +
> > > > +       /* Instruction and data fetch prefetch depth */
> > > > +       if (!dev_read_u32(dev, "andes,inst-prefetch", &prefetch)) {
> > > > +               ctl_val &= ~(IPREPETCH_MSK);
> > > > +               ctl_val |= (prefetch << IPREPETCH_OFF);
> > > > +       }
> > > > +
> > > > +       if (!dev_read_u32(dev, "andes,data-prefetch", &prefetch)) {
> > > > +               ctl_val &= ~(DPREPETCH_MSK);
> > > > +               ctl_val |= (prefetch << DPREPETCH_OFF);
> > > > +       }
> > > > +
> > > > +       /* Set tag RAM and data RAM setup and output cycle */
> > > > +       if (!dev_read_u32_array(dev, "andes,tag-ram-ctl", tram_ctl, 2)) {
> > > > +               ctl_val &= ~(TRAMOCTL_MSK | TRAMICTL_MSK);
> > > > +               ctl_val |= tram_ctl[0] << TRAMOCTL_OFF;
> > > > +               ctl_val |= tram_ctl[1] << TRAMICTL_OFF;
> > > > +       }
> > > > +
> > > > +       if (!dev_read_u32_array(dev, "andes,data-ram-ctl", dram_ctl, 2)) {
> > > > +               ctl_val &= ~(DRAMOCTL_MSK | DRAMICTL_MSK);
> > > > +               ctl_val |= dram_ctl[0] << DRAMOCTL_OFF;
> > > > +               ctl_val |= dram_ctl[1] << DRAMICTL_OFF;
> > > > +       }
> > > > +
> > > > +       writel(ctl_val, &regs->control);
> > > > +}
> > > > +
> > > > +static int v5l2_probe(struct udevice *dev)
> > > > +{
> > > > +       v5l2_of_parse_and_init(dev);
> > > > +
> > > > +       return 0;
> > > > +}
> > > > +
> > > > +static const struct udevice_id v5l2_cache_ids[] = {
> > > > +       { .compatible = "cache" },
> > >
> > > I suspect this compatible string is too generic. Has this been
> > > reviewed by DT community upstream?
> > >
> >
> > It refer to many dts examples from arm,
> > For example :
> > arch/arm/dts/fsl-imx8-ca35.dtsi
> >      A35_L2: l2-cache0 {
> >        compatible = "cache";
> >      };
> >
>
> None of these have a driver for the cache controller, which is why it
> is sufficient to just use a generic compatible string.
>
> I agree with Bin that you should choose a more specific compatible
> string. This is likely to cause problems in the future otherwise. For
> example, if Andes develops a new L2 cache controller, it must be
> differentiated from this one using the compatible string. The new
> controller would therefore have to use a different compatible string.
> It is good practice to already use a more specific one now to avoid the
> headache later. :)

You are right.
I will modify it as compatible = "v5l2cache"

Thanks
Rick

>
> Thanks,
> Lukas


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