Re: [PATCH v4 3/6] riscv: Provide a mechanism to fix DT for reserved memory

On 3/24/20 5:16 AM, Atish Patra wrote:

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

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 | 80 +++++++++++++++++++++++++++ 6 files changed, 86 insertions(+) create mode 100644 arch/riscv/lib/fdt_fixup.c

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..f3d1ec5c5d02 --- /dev/null +++ b/arch/riscv/lib/fdt_fixup.c @@ -0,0 +1,80 @@ +// 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;

Please, provide Sphinx style comments for new functions. Cf. https://www.kernel.org/doc/html/latest/doc-guide/kernel-doc.html.

+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;

+}

Same here.

Best regards

Heinrich

+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;

+}