RISC-V: Support HI20/LO12_I/LO12_S relocation type in kernel module

HI20 and LO12_I/LO12_S relocate the absolute address, the range of
offset must in 32-bit.

Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c
index 3f27308..f1bd6b1 100644 (file)
--- a/arch/riscv/kernel/module.c
+++ b/arch/riscv/kernel/module.c
@@ -92,6 +92,45 @@ static int apply_r_riscv_pcrel_lo12_s_rela(struct module *me, u32 *location,
        return 0;
 }
 
+static int apply_r_riscv_hi20_rela(struct module *me, u32 *location,
+                                  Elf_Addr v)
+{
+       s32 hi20;
+
+       if (IS_ENABLED(CMODEL_MEDLOW)) {
+               pr_err(
+                 "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n",
+                 me->name, v, location);
+               return -EINVAL;
+       }
+
+       hi20 = ((s32)v + 0x800) & 0xfffff000;
+       *location = (*location & 0xfff) | hi20;
+       return 0;
+}
+
+static int apply_r_riscv_lo12_i_rela(struct module *me, u32 *location,
+                                    Elf_Addr v)
+{
+       /* Skip medlow checking because of filtering by HI20 already */
+       s32 hi20 = ((s32)v + 0x800) & 0xfffff000;
+       s32 lo12 = ((s32)v - hi20);
+       *location = (*location & 0xfffff) | ((lo12 & 0xfff) << 20);
+       return 0;
+}
+
+static int apply_r_riscv_lo12_s_rela(struct module *me, u32 *location,
+                                    Elf_Addr v)
+{
+       /* Skip medlow checking because of filtering by HI20 already */
+       s32 hi20 = ((s32)v + 0x800) & 0xfffff000;
+       s32 lo12 = ((s32)v - hi20);
+       u32 imm11_5 = (lo12 & 0xfe0) << (31 - 11);
+       u32 imm4_0 = (lo12 & 0x1f) << (11 - 4);
+       *location = (*location & 0x1fff07f) | imm11_5 | imm4_0;
+       return 0;
+}
+
 static int apply_r_riscv_got_hi20_rela(struct module *me, u32 *location,
                                       Elf_Addr v)
 {
@@ -176,6 +215,9 @@ static int (*reloc_handlers_rela[]) (struct module *me, u32 *location,
        [R_RISCV_PCREL_HI20]            = apply_r_riscv_pcrel_hi20_rela,
        [R_RISCV_PCREL_LO12_I]          = apply_r_riscv_pcrel_lo12_i_rela,
        [R_RISCV_PCREL_LO12_S]          = apply_r_riscv_pcrel_lo12_s_rela,
+       [R_RISCV_HI20]                  = apply_r_riscv_hi20_rela,
+       [R_RISCV_LO12_I]                = apply_r_riscv_lo12_i_rela,
+       [R_RISCV_LO12_S]                = apply_r_riscv_lo12_s_rela,
        [R_RISCV_GOT_HI20]              = apply_r_riscv_got_hi20_rela,
        [R_RISCV_CALL_PLT]              = apply_r_riscv_call_plt_rela,
        [R_RISCV_CALL]                  = apply_r_riscv_call_rela,