[PATCH v3 3/5] riscv: Provide a mechanism to fix DT for reserved memory
Bin Meng
bmeng.cn at gmail.com
Fri Mar 20 03:26:35 CET 2020
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
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