[PATCH v6 3/6] riscv: Provide a mechanism to fix DT for reserved memory

Atish Patra atishp at atishpatra.org
Tue Apr 21 05:34:51 CEST 2020


On Mon, Apr 20, 2020 at 1:41 AM Rick Chen <rickchen36 at gmail.com> wrote:
>
> Hi Atish
>
> > From: Atish Patra [mailto:atish.patra at wdc.com]
> > Sent: Sunday, April 19, 2020 3:32 AM
> > To: u-boot at lists.denx.de
> > Cc: Atish Patra; Bin Meng; Anup Patel; Lukas Auer; Heinrich Schuchardt; agraf at csgraf.de; ard.biesheuvel at linaro.org; Marcus Comstedt; Paul Walmsley; Rick Jian-Zhi Chen(陳建志); palmer at dabbelt.com
> > Subject: [PATCH v6 3/6] riscv: Provide a mechanism to fix DT for reserved memory
> >
> > In RISC-V, M-mode software can reserve physical memory regions by setting appropriate physical memory protection (PMP) csr. As the PMP csr are accessible only in M-mode, S-mode U-Boot can not read this configuration directly. However, M-mode software can pass this information via reserved-memory node in device tree so that S-mode software can access this information.
> >
> > This patch provides a framework to copy to the reserved-memory node from one DT to another. This will be used to update the DT used by U-Boot and the DT passed to the next stage OS.
> >
> > Signed-off-by: Atish Patra <atish.patra at wdc.com>
> > Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
> > ---
> >  arch/riscv/cpu/start.S                |   1 +
> >  arch/riscv/include/asm/global_data.h  |   1 +
> >  arch/riscv/include/asm/u-boot-riscv.h |   2 +
> >  arch/riscv/lib/Makefile               |   1 +
> >  arch/riscv/lib/asm-offsets.c          |   1 +
> >  arch/riscv/lib/fdt_fixup.c            | 102 ++++++++++++++++++++++++++
> >  6 files changed, 108 insertions(+)
> >  create mode 100644 arch/riscv/lib/fdt_fixup.c
> >
>
> I am trying to applied Bin and your patch.
> The sequence of apply is according to submit date.
> This patch seem conflict with [PATCH v2 2/6] riscv: Merge unnecessary
> SMP ifdefs in start.S of Bin
> Can you rebase it and send again ?
>

Ok. I will rebase on top of Bin's series and resend.

> Thanks
> Rick
>
> > diff --git a/arch/riscv/cpu/start.S b/arch/riscv/cpu/start.S index 6b3ff99c3882..0282685c2906 100644
> > --- a/arch/riscv/cpu/start.S
> > +++ b/arch/riscv/cpu/start.S
> > @@ -121,6 +121,7 @@ call_board_init_f_0:
> >
> >         jal     board_init_f_init_reserve
> >
> > +       SREG    s1, GD_FIRMWARE_FDT_ADDR(gp)
> >         /* save the boot hart id to global_data */
> >         SREG    tp, GD_BOOT_HART(gp)
> >
> > diff --git a/arch/riscv/include/asm/global_data.h b/arch/riscv/include/asm/global_data.h
> > index b74bd7e738bb..51ac8d1c98e2 100644
> > --- a/arch/riscv/include/asm/global_data.h
> > +++ b/arch/riscv/include/asm/global_data.h
> > @@ -15,6 +15,7 @@
> >  /* Architecture-specific global data */  struct arch_global_data {
> >         long boot_hart;         /* boot hart id */
> > +       phys_addr_t firmware_fdt_addr;
> >  #ifdef CONFIG_SIFIVE_CLINT
> >         void __iomem *clint;    /* clint base address */
> >  #endif
> > diff --git a/arch/riscv/include/asm/u-boot-riscv.h b/arch/riscv/include/asm/u-boot-riscv.h
> > index 49febd588102..543a1688db8f 100644
> > --- a/arch/riscv/include/asm/u-boot-riscv.h
> > +++ b/arch/riscv/include/asm/u-boot-riscv.h
> > @@ -17,5 +17,7 @@ int cleanup_before_linux(void);
> >  /* board/.../... */
> >  int board_init(void);
> >  void board_quiesce_devices(void);
> > +int riscv_board_reserved_mem_fixup(void *fdt); int
> > +riscv_fdt_copy_resv_mem_node(const void *src_fdt, void *dest_fdt);
> >
> >  #endif /* _U_BOOT_RISCV_H_ */
> > diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile index adadbf4bcbef..d132b59ce32c 100644
> > --- a/arch/riscv/lib/Makefile
> > +++ b/arch/riscv/lib/Makefile
> > @@ -24,6 +24,7 @@ obj-y += reset.o
> >  obj-y   += setjmp.o
> >  obj-$(CONFIG_SMP) += smp.o
> >  obj-$(CONFIG_SPL_BUILD)        += spl.o
> > +obj-y   += fdt_fixup.o
> >
> >  # For building EFI apps
> >  CFLAGS_$(EFI_CRT0) := $(CFLAGS_EFI)
> > diff --git a/arch/riscv/lib/asm-offsets.c b/arch/riscv/lib/asm-offsets.c index 4fa4fd371473..7301c1b98e23 100644
> > --- a/arch/riscv/lib/asm-offsets.c
> > +++ b/arch/riscv/lib/asm-offsets.c
> > @@ -14,6 +14,7 @@
> >  int main(void)
> >  {
> >         DEFINE(GD_BOOT_HART, offsetof(gd_t, arch.boot_hart));
> > +       DEFINE(GD_FIRMWARE_FDT_ADDR, offsetof(gd_t, arch.firmware_fdt_addr));
> >  #ifndef CONFIG_XIP
> >         DEFINE(GD_AVAILABLE_HARTS, offsetof(gd_t, arch.available_harts));  #endif diff --git a/arch/riscv/lib/fdt_fixup.c b/arch/riscv/lib/fdt_fixup.c new file mode 100644 index 000000000000..1fce41490973
> > --- /dev/null
> > +++ b/arch/riscv/lib/fdt_fixup.c
> > @@ -0,0 +1,102 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/*
> > + * Copyright (c) 2020 Western Digital Corporation or its affiliates
> > + *
> > + */
> > +
> > +#include <common.h>
> > +#include <fdt_support.h>
> > +#include <mapmem.h>
> > +
> > +DECLARE_GLOBAL_DATA_PTR;
> > +
> > +/**
> > + * riscv_fdt_copy_resv_mem_node() - Copy reserve memory node entry
> > + * @src: Pointer to the source device tree from which reserved memory node
> > + *      needs to be copied.
> > + * @dst: Pointer to the destination device tree to which reserved memory node
> > + *      needs to be copied.
> > + *
> > + * Return: 0 on success or if source doesn't have reserved memory node.
> > + *        Error if copy process failed.
> > + */
> > +int riscv_fdt_copy_resv_mem_node(const void *src, void *dst) {
> > +       u32 phandle;
> > +       struct fdt_memory pmp_mem;
> > +       fdt_addr_t addr;
> > +       fdt_size_t size;
> > +       int offset, node, err, rmem_offset;
> > +       bool nomap = true;
> > +       char basename[32] = {0};
> > +       int bname_len;
> > +       int max_len = sizeof(basename);
> > +       const char *name;
> > +       char *temp;
> > +
> > +       offset = fdt_path_offset(src, "/reserved-memory");
> > +       if (offset < 0) {
> > +               printf("No reserved memory region found in source FDT\n");
> > +               return 0;
> > +       }
> > +
> > +       fdt_for_each_subnode(node, src, offset) {
> > +               name = fdt_get_name(src, node, NULL);
> > +
> > +               addr = fdtdec_get_addr_size_auto_noparent(src, node,
> > +                                                         "reg", 0, &size,
> > +                                                         false);
> > +               if (addr == FDT_ADDR_T_NONE) {
> > +                       debug("failed to read address/size for %s\n", name);
> > +                       continue;
> > +               }
> > +               strncpy(basename, name, max_len);
> > +               temp = strchr(basename, '@');
> > +               if (temp) {
> > +                       bname_len = strnlen(basename, max_len) - strnlen(temp,
> > +                                                                      max_len);
> > +                       *(basename + bname_len) = '\0';
> > +               }
> > +               pmp_mem.start = addr;
> > +               pmp_mem.end = addr + size - 1;
> > +               err = fdtdec_add_reserved_memory(dst, basename, &pmp_mem,
> > +                                                &phandle);
> > +               if (err < 0) {
> > +                       printf("failed to add reserved memory: %d\n", err);
> > +                       return err;
> > +               }
> > +               if (!fdt_getprop(src, node, "no-map", NULL))
> > +                       nomap = false;
> > +               if (nomap) {
> > +                       rmem_offset = fdt_node_offset_by_phandle(dst, phandle);
> > +                       fdt_setprop_empty(dst, rmem_offset, "no-map");
> > +               }
> > +       }
> > +
> > +       return 0;
> > +}
> > +
> > +/**
> > + * riscv_board_reserved_mem_fixup() - Fix up reserved memory node for a
> > +board
> > + * @fdt: Pointer to the device tree in which reserved memory node needs to be
> > + *      added.
> > + *
> > + * In RISC-V, any board compiled with OF_SEPARATE needs to copy the
> > +reserved
> > + * memory node from the device tree provided by the firmware to the
> > +device tree
> > + * used by U-Boot. This is a common function that individual board
> > +fixup
> > + * functions can invoke.
> > + *
> > + * Return: 0 on success or error otherwise.
> > + */
> > +int riscv_board_reserved_mem_fixup(void *fdt) {
> > +       int err;
> > +       void *src_fdt_addr;
> > +
> > +       src_fdt_addr = map_sysmem(gd->arch.firmware_fdt_addr, 0);
> > +       err = riscv_fdt_copy_resv_mem_node(src_fdt_addr, fdt);
> > +       if (err < 0)
> > +               return err;
> > +
> > +       return 0;
> > +}
> > --
> > 2.25.1
> >
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-- 
Regards,
Atish


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