svn commit: r361587 - in head/sys/riscv: include riscv

[Mitchell Horne]

On Thu, May 28, 2020 at 11:56 AM Mitchell Horne <mhorne at freebsd.org> wrote:
>
> Author: mhorne
> Date: Thu May 28 14:56:11 2020
> New Revision: 361587
> URL: https://svnweb.freebsd.org/changeset/base/361587
>
> Log:
>   Add macros simplifying the fake preload setup
>
>   This is in preparation for booting via loader(8). Lift these macros from arm64
>   so we don't need to worry about the size when inserting new elements. This
>   could have been done in r359673, but I didn't think I would be returning to
>   this function so soon.
>
>   Reviewed by:  markj
>   Differential Revision:        https://reviews.freebsd.org/D24910
>
> Modified:
>   head/sys/riscv/include/vmparam.h
>   head/sys/riscv/riscv/machdep.c
>
> Modified: head/sys/riscv/include/vmparam.h
> ==============================================================================
> --- head/sys/riscv/include/vmparam.h    Thu May 28 13:48:33 2020        (r361586)
> +++ head/sys/riscv/include/vmparam.h    Thu May 28 14:56:11 2020        (r361587)
> @@ -190,8 +190,6 @@
>  #define        SHAREDPAGE              (VM_MAXUSER_ADDRESS - PAGE_SIZE)
>  #define        USRSTACK                SHAREDPAGE
>
> -#define        KERNENTRY               (0)
> -
>  #define        VM_EARLY_DTB_ADDRESS    (VM_MAX_KERNEL_ADDRESS - (2 * L2_SIZE))
>
>  /*
>
> Modified: head/sys/riscv/riscv/machdep.c
> ==============================================================================
> --- head/sys/riscv/riscv/machdep.c      Thu May 28 13:48:33 2020        (r361586)
> +++ head/sys/riscv/riscv/machdep.c      Thu May 28 14:56:11 2020        (r361587)
> @@ -733,29 +733,36 @@ fake_preload_metadata(struct riscv_bootparams *rvbp)
>         vm_offset_t zstart = 0, zend = 0;
>  #endif
>         vm_offset_t lastaddr;
> -       size_t dtb_size;
> -       int i;
> +       size_t fake_size, dtb_size;
>
> -       i = 0;
> +#define PRELOAD_PUSH_VALUE(type, value) do {                   \
> +       *(type *)((char *)fake_preload + fake_size) = (value);  \
> +       fake_size += sizeof(type);                              \
> +} while (0)
>
> -       fake_preload[i++] = MODINFO_NAME;
> -       fake_preload[i++] = strlen("kernel") + 1;
> -       strcpy((char*)&fake_preload[i++], "kernel");
> -       i += 1;
> -       fake_preload[i++] = MODINFO_TYPE;
> -       fake_preload[i++] = strlen("elf64 kernel") + 1;
> -       strcpy((char*)&fake_preload[i++], "elf64 kernel");
> -       i += 3;
> -       fake_preload[i++] = MODINFO_ADDR;
> -       fake_preload[i++] = sizeof(vm_offset_t);
> -       *(vm_offset_t *)&fake_preload[i++] =
> -           (vm_offset_t)(KERNBASE + KERNENTRY);
> -       i += 1;
> -       fake_preload[i++] = MODINFO_SIZE;
> -       fake_preload[i++] = sizeof(vm_offset_t);
> -       fake_preload[i++] = (vm_offset_t)&end -
> -           (vm_offset_t)(KERNBASE + KERNENTRY);
> -       i += 1;
> +#define PRELOAD_PUSH_STRING(str) do {                          \
> +       uint32_t ssize;                                         \
> +       ssize = strlen(str) + 1;                                \
> +       PRELOAD_PUSH_VALUE(uint32_t, ssize);                    \
> +       strcpy(((char *)fake_preload + fake_size), str);        \
> +       fake_size += ssize;                                     \
> +       fake_size = roundup(fake_size, sizeof(u_long));         \
> +} while (0)
> +
> +       fake_size = 0;
> +
> +       PRELOAD_PUSH_VALUE(uint32_t, MODINFO_NAME);
> +       PRELOAD_PUSH_STRING("kernel");
> +       PRELOAD_PUSH_VALUE(uint32_t, MODINFO_TYPE);
> +       PRELOAD_PUSH_STRING("elf kernel");

Note that the type here was unintentionally changed from "elf64
kernel" to "elf kernel". Fortunately, this ends up being more
consistent with both loader(8) and the other fake_preload_metadata
routines, which set the type as "elf kernel".

Thanks to rpokala@ for pointing this out.

> +
> +       PRELOAD_PUSH_VALUE(uint32_t, MODINFO_ADDR);
> +       PRELOAD_PUSH_VALUE(uint32_t, sizeof(vm_offset_t));
> +       PRELOAD_PUSH_VALUE(uint64_t, KERNBASE);
> +
> +       PRELOAD_PUSH_VALUE(uint32_t, MODINFO_SIZE);
> +       PRELOAD_PUSH_VALUE(uint32_t, sizeof(size_t));
> +       PRELOAD_PUSH_VALUE(uint64_t, (size_t)((vm_offset_t)&end - KERNBASE));
>  #ifdef DDB
>  #if 0
>         /* RISCVTODO */
> @@ -777,19 +784,20 @@ fake_preload_metadata(struct riscv_bootparams *rvbp)
>
>         /* Copy the DTB to KVA space. */
>         lastaddr = roundup(lastaddr, sizeof(int));
> -       fake_preload[i++] = MODINFO_METADATA | MODINFOMD_DTBP;
> -       fake_preload[i++] = sizeof(vm_offset_t);
> -       *(vm_offset_t *)&fake_preload[i] = (vm_offset_t)lastaddr;
> -       i += sizeof(vm_offset_t) / sizeof(uint32_t);
> +       PRELOAD_PUSH_VALUE(uint32_t, MODINFO_METADATA | MODINFOMD_DTBP);
> +       PRELOAD_PUSH_VALUE(uint32_t, sizeof(vm_offset_t));
> +       PRELOAD_PUSH_VALUE(vm_offset_t, lastaddr);
>         dtb_size = fdt_totalsize(rvbp->dtbp_virt);
>         memmove((void *)lastaddr, (const void *)rvbp->dtbp_virt, dtb_size);
>         lastaddr = roundup(lastaddr + dtb_size, sizeof(int));
>
> -       fake_preload[i++] = 0;
> -       fake_preload[i] = 0;
> -       preload_metadata = (void *)fake_preload;
> +       /* End marker */
> +       PRELOAD_PUSH_VALUE(uint32_t, 0);
> +       PRELOAD_PUSH_VALUE(uint32_t, 0);
> +       preload_metadata = (caddr_t)fake_preload;
>
> -       KASSERT(i < nitems(fake_preload), ("Too many fake_preload items"));
> +       KASSERT(fake_size < sizeof(fake_preload),
> +           ("Too many fake_preload items"));
>
>         return (lastaddr);
>  }