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

Hi Atish

On Mon, Apr 20, 2020 at 1:41 AM Rick Chen rickchen36@gmail.com wrote:

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Hi Atish

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From: Atish Patra [mailto:atish.patra@wdc.com] Sent: Sunday, April 19, 2020 3:32 AM To: u-boot@lists.denx.de Cc: Atish Patra; Bin Meng; Anup Patel; Lukas Auer; Heinrich Schuchardt; agraf@csgraf.de; ard.biesheuvel@linaro.org; Marcus Comstedt; Paul Walmsley; Rick Jian-Zhi Chen(陳建志); palmer@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@wdc.com Reviewed-by: Bin Meng bmeng.cn@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.

Please rebase on u-boot-riscv/master. I also applied Sean's patch today.

Thanks, Rick

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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