[PATCH v3 3/5] riscv: Provide a mechanism to fix DT for reserved memory
Atish Patra
atishp at atishpatra.org
Thu Mar 19 21:46:26 CET 2020
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
> >
--
Regards,
Atish
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