diff mbox series

[v3,3/5] riscv: Provide a mechanism to fix DT for reserved memory

Message ID 20200317211946.28062-4-atish.patra@wdc.com
State New
Headers show
Series DT related fixes for RISC-V UEFI | expand

Commit Message

Atish Patra March 17, 2020, 9:19 p.m. UTC
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>
---
 arch/riscv/cpu/start.S                |  1 +
 arch/riscv/include/asm/global_data.h  |  1 +
 arch/riscv/include/asm/u-boot-riscv.h |  1 +
 arch/riscv/lib/asm-offsets.c          |  1 +
 arch/riscv/lib/bootm.c                | 68 +++++++++++++++++++++++++++
 5 files changed, 72 insertions(+)

Comments

Bin Meng March 19, 2020, 2:31 p.m. UTC | #1
On Wed, Mar 18, 2020 at 5:19 AM Atish Patra <atish.patra at wdc.com> 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 at wdc.com>
> ---
>  arch/riscv/cpu/start.S                |  1 +
>  arch/riscv/include/asm/global_data.h  |  1 +
>  arch/riscv/include/asm/u-boot-riscv.h |  1 +
>  arch/riscv/lib/asm-offsets.c          |  1 +
>  arch/riscv/lib/bootm.c                | 68 +++++++++++++++++++++++++++
>  5 files changed, 72 insertions(+)
>
> 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..b7bea0ba184d 100644
> --- a/arch/riscv/include/asm/u-boot-riscv.h
> +++ b/arch/riscv/include/asm/u-boot-riscv.h
> @@ -17,5 +17,6 @@ int cleanup_before_linux(void);
>  /* board/.../... */
>  int board_init(void);
>  void board_quiesce_devices(void);
> +int riscv_board_reserved_mem_fixup(void *fdt);
>
>  #endif /* _U_BOOT_RISCV_H_ */
> 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/bootm.c b/arch/riscv/lib/bootm.c
> index f927694ae32f..5e907e96701c 100644
> --- a/arch/riscv/lib/bootm.c
> +++ b/arch/riscv/lib/bootm.c
> @@ -19,6 +19,7 @@
>  #include <dm/device.h>
>  #include <dm/root.h>
>  #include <u-boot/zlib.h>
> +#include <mapmem.h>
>
>  DECLARE_GLOBAL_DATA_PTR;
>
> @@ -26,6 +27,73 @@ __weak void board_quiesce_devices(void)
>  {
>  }
>
> +int riscv_fdt_copy_resv_mem_node(const void *src, void *dst)

We probably need find a better place for this routine, see below
comments for riscv_board_reserved_mem_fixup().

We need make this routine public in u-boot-riscv.h as well.

> +{
> +       uint32_t phandle;
> +       struct fdt_memory pmp_mem;
> +       fdt_addr_t addr;
> +       fdt_size_t size;
> +       int offset, node, err, rmem_offset;
> +       bool nomap = false;
> +       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,
> +                                                         true);
> +               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';

nits: need space around +

> +               }
> +               pmp_mem.start = addr;
> +               pmp_mem.end = addr + size;
> +               err = fdtdec_add_reserved_memory(dst, basename, &pmp_mem,
> +                                                &phandle);
> +               if (err < 0) {
> +                       printf("failed to add reserved memory: %d\n", err);
> +                       return err;
> +               }
> +               rmem_offset = fdt_node_offset_by_phandle(dst, phandle);

nits: this line can be put in the "if (nomap)" block below

> +               nomap = fdt_get_property(src, node, "no-map", NULL);
> +               if (nomap)
> +                       fdt_setprop_empty(dst, rmem_offset, "no-map");
> +       }
> +
> +       return 0;
> +}
> +
> +int riscv_board_reserved_mem_fixup(void *fdt)

This routine should not be put to boom.c as it's nothing related to
bootm. Maybe arch/riscv/lib/fdt.c ?



> +{
> +       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;
> +}
> +
>  int arch_fixup_fdt(void *blob)
>  {
>         u32 size;
> --
> 2.25.1
>
Atish Patra March 19, 2020, 8:46 p.m. UTC | #2
On Thu, Mar 19, 2020 at 7:31 AM Bin Meng <bmeng.cn at gmail.com> wrote:
>
> On Wed, Mar 18, 2020 at 5:19 AM Atish Patra <atish.patra at wdc.com> 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 at wdc.com>
> > ---
> >  arch/riscv/cpu/start.S                |  1 +
> >  arch/riscv/include/asm/global_data.h  |  1 +
> >  arch/riscv/include/asm/u-boot-riscv.h |  1 +
> >  arch/riscv/lib/asm-offsets.c          |  1 +
> >  arch/riscv/lib/bootm.c                | 68 +++++++++++++++++++++++++++
> >  5 files changed, 72 insertions(+)
> >
> > 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..b7bea0ba184d 100644
> > --- a/arch/riscv/include/asm/u-boot-riscv.h
> > +++ b/arch/riscv/include/asm/u-boot-riscv.h
> > @@ -17,5 +17,6 @@ int cleanup_before_linux(void);
> >  /* board/.../... */
> >  int board_init(void);
> >  void board_quiesce_devices(void);
> > +int riscv_board_reserved_mem_fixup(void *fdt);
> >
> >  #endif /* _U_BOOT_RISCV_H_ */
> > 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/bootm.c b/arch/riscv/lib/bootm.c
> > index f927694ae32f..5e907e96701c 100644
> > --- a/arch/riscv/lib/bootm.c
> > +++ b/arch/riscv/lib/bootm.c
> > @@ -19,6 +19,7 @@
> >  #include <dm/device.h>
> >  #include <dm/root.h>
> >  #include <u-boot/zlib.h>
> > +#include <mapmem.h>
> >
> >  DECLARE_GLOBAL_DATA_PTR;
> >
> > @@ -26,6 +27,73 @@ __weak void board_quiesce_devices(void)
> >  {
> >  }
> >
> > +int riscv_fdt_copy_resv_mem_node(const void *src, void *dst)
>
> We probably need find a better place for this routine, see below
> comments for riscv_board_reserved_mem_fixup().
>
> We need make this routine public in u-boot-riscv.h as well.
>
> > +{
> > +       uint32_t phandle;
> > +       struct fdt_memory pmp_mem;
> > +       fdt_addr_t addr;
> > +       fdt_size_t size;
> > +       int offset, node, err, rmem_offset;
> > +       bool nomap = false;
> > +       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,
> > +                                                         true);
> > +               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';
>
> nits: need space around +
>
sure.

> > +               }
> > +               pmp_mem.start = addr;
> > +               pmp_mem.end = addr + size;
> > +               err = fdtdec_add_reserved_memory(dst, basename, &pmp_mem,
> > +                                                &phandle);
> > +               if (err < 0) {
> > +                       printf("failed to add reserved memory: %d\n", err);
> > +                       return err;
> > +               }
> > +               rmem_offset = fdt_node_offset_by_phandle(dst, phandle);
>
> nits: this line can be put in the "if (nomap)" block below
>

sure.

> > +               nomap = fdt_get_property(src, node, "no-map", NULL);
> > +               if (nomap)
> > +                       fdt_setprop_empty(dst, rmem_offset, "no-map");
> > +       }
> > +
> > +       return 0;
> > +}
> > +
> > +int riscv_board_reserved_mem_fixup(void *fdt)
>
> This routine should not be put to boom.c as it's nothing related to
> bootm. Maybe arch/riscv/lib/fdt.c ?
>

I wanted to keep all the fdt fixups together  as arch_fixup_fdt was
already defined in bootm.c
But I agree with your point that it is not related to bootm. I think
we can move all the fdt fixups
including arch_fixup_fdt to arch/riscv/lib/fdt_fixup.c. Thoughts ?

>
>
> > +{
> > +       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;
> > +}
> > +
> >  int arch_fixup_fdt(void *blob)
> >  {
> >         u32 size;
> > --
> > 2.25.1
> >
Bin Meng March 20, 2020, 2:26 a.m. UTC | #3
On Fri, Mar 20, 2020 at 4:46 AM Atish Patra <atishp at atishpatra.org> wrote:
>
> On Thu, Mar 19, 2020 at 7:31 AM Bin Meng <bmeng.cn at gmail.com> wrote:
> >
> > On Wed, Mar 18, 2020 at 5:19 AM Atish Patra <atish.patra at wdc.com> 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 at wdc.com>
> > > ---
> > >  arch/riscv/cpu/start.S                |  1 +
> > >  arch/riscv/include/asm/global_data.h  |  1 +
> > >  arch/riscv/include/asm/u-boot-riscv.h |  1 +
> > >  arch/riscv/lib/asm-offsets.c          |  1 +
> > >  arch/riscv/lib/bootm.c                | 68 +++++++++++++++++++++++++++
> > >  5 files changed, 72 insertions(+)
> > >
> > > 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..b7bea0ba184d 100644
> > > --- a/arch/riscv/include/asm/u-boot-riscv.h
> > > +++ b/arch/riscv/include/asm/u-boot-riscv.h
> > > @@ -17,5 +17,6 @@ int cleanup_before_linux(void);
> > >  /* board/.../... */
> > >  int board_init(void);
> > >  void board_quiesce_devices(void);
> > > +int riscv_board_reserved_mem_fixup(void *fdt);
> > >
> > >  #endif /* _U_BOOT_RISCV_H_ */
> > > 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/bootm.c b/arch/riscv/lib/bootm.c
> > > index f927694ae32f..5e907e96701c 100644
> > > --- a/arch/riscv/lib/bootm.c
> > > +++ b/arch/riscv/lib/bootm.c
> > > @@ -19,6 +19,7 @@
> > >  #include <dm/device.h>
> > >  #include <dm/root.h>
> > >  #include <u-boot/zlib.h>
> > > +#include <mapmem.h>
> > >
> > >  DECLARE_GLOBAL_DATA_PTR;
> > >
> > > @@ -26,6 +27,73 @@ __weak void board_quiesce_devices(void)
> > >  {
> > >  }
> > >
> > > +int riscv_fdt_copy_resv_mem_node(const void *src, void *dst)
> >
> > We probably need find a better place for this routine, see below
> > comments for riscv_board_reserved_mem_fixup().
> >
> > We need make this routine public in u-boot-riscv.h as well.
> >
> > > +{
> > > +       uint32_t phandle;
> > > +       struct fdt_memory pmp_mem;
> > > +       fdt_addr_t addr;
> > > +       fdt_size_t size;
> > > +       int offset, node, err, rmem_offset;
> > > +       bool nomap = false;
> > > +       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,
> > > +                                                         true);
> > > +               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';
> >
> > nits: need space around +
> >
> sure.
>
> > > +               }
> > > +               pmp_mem.start = addr;
> > > +               pmp_mem.end = addr + size;
> > > +               err = fdtdec_add_reserved_memory(dst, basename, &pmp_mem,
> > > +                                                &phandle);
> > > +               if (err < 0) {
> > > +                       printf("failed to add reserved memory: %d\n", err);
> > > +                       return err;
> > > +               }
> > > +               rmem_offset = fdt_node_offset_by_phandle(dst, phandle);
> >
> > nits: this line can be put in the "if (nomap)" block below
> >
>
> sure.
>
> > > +               nomap = fdt_get_property(src, node, "no-map", NULL);
> > > +               if (nomap)
> > > +                       fdt_setprop_empty(dst, rmem_offset, "no-map");
> > > +       }
> > > +
> > > +       return 0;
> > > +}
> > > +
> > > +int riscv_board_reserved_mem_fixup(void *fdt)
> >
> > This routine should not be put to boom.c as it's nothing related to
> > bootm. Maybe arch/riscv/lib/fdt.c ?
> >
>
> I wanted to keep all the fdt fixups together  as arch_fixup_fdt was
> already defined in bootm.c
> But I agree with your point that it is not related to bootm. I think
> we can move all the fdt fixups
> including arch_fixup_fdt to arch/riscv/lib/fdt_fixup.c. Thoughts ?
>

Sounds good to me.

Regards,
Bin
diff mbox series

Patch

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..b7bea0ba184d 100644
--- a/arch/riscv/include/asm/u-boot-riscv.h
+++ b/arch/riscv/include/asm/u-boot-riscv.h
@@ -17,5 +17,6 @@  int cleanup_before_linux(void);
 /* board/.../... */
 int board_init(void);
 void board_quiesce_devices(void);
+int riscv_board_reserved_mem_fixup(void *fdt);
 
 #endif	/* _U_BOOT_RISCV_H_ */
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/bootm.c b/arch/riscv/lib/bootm.c
index f927694ae32f..5e907e96701c 100644
--- a/arch/riscv/lib/bootm.c
+++ b/arch/riscv/lib/bootm.c
@@ -19,6 +19,7 @@ 
 #include <dm/device.h>
 #include <dm/root.h>
 #include <u-boot/zlib.h>
+#include <mapmem.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -26,6 +27,73 @@  __weak void board_quiesce_devices(void)
 {
 }
 
+int riscv_fdt_copy_resv_mem_node(const void *src, void *dst)
+{
+	uint32_t phandle;
+	struct fdt_memory pmp_mem;
+	fdt_addr_t addr;
+	fdt_size_t size;
+	int offset, node, err, rmem_offset;
+	bool nomap = false;
+	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,
+							  true);
+		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;
+		err = fdtdec_add_reserved_memory(dst, basename, &pmp_mem,
+						 &phandle);
+		if (err < 0) {
+			printf("failed to add reserved memory: %d\n", err);
+			return err;
+		}
+		rmem_offset = fdt_node_offset_by_phandle(dst, phandle);
+		nomap = fdt_get_property(src, node, "no-map", NULL);
+		if (nomap)
+			fdt_setprop_empty(dst, rmem_offset, "no-map");
+	}
+
+	return 0;
+}
+
+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;
+}
+
 int arch_fixup_fdt(void *blob)
 {
 	u32 size;