diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 6221a1d057dd58de265283de65e785c618ea6758..accc400b43f1d1b3ce912d70c24dd5ff88292b8a 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3576,7 +3576,10 @@
emulation library even if a 387 maths coprocessor
is present.
- no5lvl [X86-64] Disable 5-level paging mode. Forces
+ no4lvl [RISCV] Disable 4-level and 5-level paging modes. Forces
+ kernel to use 3-level paging instead.
+
+ no5lvl [X86-64,RISCV] Disable 5-level paging mode. Forces
kernel to use 4-level paging instead.
nofsgsbase [X86] Disables FSGSBASE instructions.
diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index e859e1721a8f2b6f98d20b2d035eefe5f12daeb1..d44d0fb981686fd7dc8f0d50bdebecfb8302f530 100644
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -7,8 +7,9 @@
#
OBJCOPYFLAGS := -O binary
+LDFLAGS_vmlinux := -z norelro
ifeq ($(CONFIG_RELOCATABLE),y)
- LDFLAGS_vmlinux += -shared -Bsymbolic -z notext -z norelro --emit-relocs
+ LDFLAGS_vmlinux += -shared -Bsymbolic -z notext --emit-relocs
KBUILD_CFLAGS += -fPIE
endif
ifeq ($(CONFIG_DYNAMIC_FTRACE),y)
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index 392fa6e35d4a7c39edacc327034b427d0da635cd..0fee73a20c87acc2e172f74aa1cf56e4f6277089 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -87,3 +87,5 @@ obj-$(CONFIG_EFI) += efi.o
obj-$(CONFIG_COMPAT) += compat_syscall_table.o
obj-$(CONFIG_COMPAT) += compat_signal.o
obj-$(CONFIG_COMPAT) += compat_vdso/
+
+obj-$(CONFIG_64BIT) += pi/
diff --git a/arch/riscv/kernel/pi/Makefile b/arch/riscv/kernel/pi/Makefile
new file mode 100644
index 0000000000000000000000000000000000000000..5d7cb991f2b86c8d7604ee21dd9f04eb1482f4ee
--- /dev/null
+++ b/arch/riscv/kernel/pi/Makefile
@@ -0,0 +1,39 @@
+# SPDX-License-Identifier: GPL-2.0
+# This file was copied from arm64/kernel/pi/Makefile.
+
+KBUILD_CFLAGS := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) -fpie \
+ -Os -DDISABLE_BRANCH_PROFILING $(DISABLE_STACKLEAK_PLUGIN) \
+ $(call cc-option,-mbranch-protection=none) \
+ -I$(srctree)/scripts/dtc/libfdt -fno-stack-protector \
+ -D__DISABLE_EXPORTS -ffreestanding \
+ -fno-asynchronous-unwind-tables -fno-unwind-tables \
+ $(call cc-option,-fno-addrsig)
+
+KBUILD_CFLAGS += -mcmodel=medany
+
+CFLAGS_cmdline_early.o += -D__NO_FORTIFY
+CFLAGS_lib-fdt_ro.o += -D__NO_FORTIFY
+
+GCOV_PROFILE := n
+KASAN_SANITIZE := n
+KCSAN_SANITIZE := n
+UBSAN_SANITIZE := n
+KCOV_INSTRUMENT := n
+
+$(obj)/%.pi.o: OBJCOPYFLAGS := --prefix-symbols=__pi_ \
+ --remove-section=.note.gnu.property \
+ --prefix-alloc-sections=.init
+$(obj)/%.pi.o: $(obj)/%.o FORCE
+ $(call if_changed,objcopy)
+
+$(obj)/lib-%.o: $(srctree)/lib/%.c FORCE
+ $(call if_changed_rule,cc_o_c)
+
+$(obj)/string.o: $(srctree)/lib/string.c FORCE
+ $(call if_changed_rule,cc_o_c)
+
+$(obj)/ctype.o: $(srctree)/lib/ctype.c FORCE
+ $(call if_changed_rule,cc_o_c)
+
+obj-y := cmdline_early.pi.o string.pi.o ctype.pi.o lib-fdt.pi.o lib-fdt_ro.pi.o
+extra-y := $(patsubst %.pi.o,%.o,$(obj-y))
diff --git a/arch/riscv/kernel/pi/cmdline_early.c b/arch/riscv/kernel/pi/cmdline_early.c
new file mode 100644
index 0000000000000000000000000000000000000000..05652d13c746232550803882de481278b56e7063
--- /dev/null
+++ b/arch/riscv/kernel/pi/cmdline_early.c
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/libfdt.h>
+#include <linux/string.h>
+#include <asm/pgtable.h>
+#include <asm/setup.h>
+
+static char early_cmdline[COMMAND_LINE_SIZE];
+
+/*
+ * Declare the functions that are exported (but prefixed) here so that LLVM
+ * does not complain it lacks the 'static' keyword (which, if added, makes
+ * LLVM complain because the function is actually unused in this file).
+ */
+u64 set_satp_mode_from_cmdline(uintptr_t dtb_pa);
+
+static char *get_early_cmdline(uintptr_t dtb_pa)
+{
+ const char *fdt_cmdline = NULL;
+ unsigned int fdt_cmdline_size = 0;
+ int chosen_node;
+
+ if (!IS_ENABLED(CONFIG_CMDLINE_FORCE)) {
+ chosen_node = fdt_path_offset((void *)dtb_pa, "/chosen");
+ if (chosen_node >= 0) {
+ fdt_cmdline = fdt_getprop((void *)dtb_pa, chosen_node,
+ "bootargs", NULL);
+ if (fdt_cmdline) {
+ fdt_cmdline_size = strlen(fdt_cmdline);
+ strscpy(early_cmdline, fdt_cmdline,
+ COMMAND_LINE_SIZE);
+ }
+ }
+ }
+
+ if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) ||
+ IS_ENABLED(CONFIG_CMDLINE_FORCE) ||
+ fdt_cmdline_size == 0 /* CONFIG_CMDLINE_FALLBACK */) {
+ strncat(early_cmdline, CONFIG_CMDLINE,
+ COMMAND_LINE_SIZE - fdt_cmdline_size);
+ }
+
+ return early_cmdline;
+}
+
+static u64 match_noXlvl(char *cmdline)
+{
+ if (strstr(cmdline, "no4lvl"))
+ return SATP_MODE_48;
+ else if (strstr(cmdline, "no5lvl"))
+ return SATP_MODE_57;
+
+ return 0;
+}
+
+u64 set_satp_mode_from_cmdline(uintptr_t dtb_pa)
+{
+ char *cmdline = get_early_cmdline(dtb_pa);
+
+ return match_noXlvl(cmdline);
+}
diff --git a/arch/riscv/kernel/vmlinux.lds.S b/arch/riscv/kernel/vmlinux.lds.S
index 615ff5842690b1e0cc963061088c3885ae87bd28..305877d85e96bb3eb2aa24caf6b0d6f23333a2c0 100644
--- a/arch/riscv/kernel/vmlinux.lds.S
+++ b/arch/riscv/kernel/vmlinux.lds.S
@@ -83,6 +83,14 @@ SECTIONS
/* Start of init data section */
__init_data_begin = .;
INIT_DATA_SECTION(16)
+
+ /* Those sections result from the compilation of kernel/pi/string.c */
+ .init.pidata : {
+ *(.init.srodata.cst8*)
+ *(.init__bug_table*)
+ *(.init.sdata*)
+ }
+
.init.bss : {
*(.init.bss) /* from the EFI stub */
}
@@ -128,9 +136,10 @@ SECTIONS
__rela_dyn_end = .;
}
+ .got : { *(.got*) }
+
#ifdef CONFIG_RELOCATABLE
.data.rel : { *(.data.rel*) }
- .got : { *(.got*) }
.plt : { *(.plt) }
.dynamic : { *(.dynamic) }
.dynsym : { *(.dynsym) }
diff --git a/arch/riscv/lib/memcpy.S b/arch/riscv/lib/memcpy.S
index 51ab716253fa3c9939a95b8721b7524099824e63..1a40d01a95439e1592b673ad76e5f5b964bbbed3 100644
--- a/arch/riscv/lib/memcpy.S
+++ b/arch/riscv/lib/memcpy.S
@@ -106,3 +106,5 @@ WEAK(memcpy)
6:
ret
END(__memcpy)
+SYM_FUNC_ALIAS(__pi_memcpy, __memcpy)
+SYM_FUNC_ALIAS(__pi___memcpy, __memcpy)
diff --git a/arch/riscv/lib/memmove.S b/arch/riscv/lib/memmove.S
index e0609e1f0864dedf88ae4e2e9983f0f928ff6c31..838ff2022fe32d8e16769ef0e5962d9c294b0ed3 100644
--- a/arch/riscv/lib/memmove.S
+++ b/arch/riscv/lib/memmove.S
@@ -314,3 +314,5 @@ return_from_memmove:
SYM_FUNC_END(memmove)
SYM_FUNC_END(__memmove)
+SYM_FUNC_ALIAS(__pi_memmove, __memmove)
+SYM_FUNC_ALIAS(__pi___memmove, __memmove)
diff --git a/arch/riscv/lib/strlen.S b/arch/riscv/lib/strlen.S
index db3d42d99b78a475f5a49cc1d8b6db1077f7df11..8ae3064e45ff00592d2b927ee8cc6e4216642867 100644
--- a/arch/riscv/lib/strlen.S
+++ b/arch/riscv/lib/strlen.S
@@ -130,3 +130,4 @@ strlen_zbb:
.option pop
#endif
SYM_FUNC_END(strlen)
+SYM_FUNC_ALIAS(__pi_strlen, strlen)
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index bce899b180cd2b3f68740a3b96c761c19d1b5b51..3ad771571c2d049939c0ec3ccf2eb14fa4aa77e0 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -746,6 +746,8 @@ static __init pgprot_t pgprot_from_va(uintptr_t va)
#endif /* CONFIG_STRICT_KERNEL_RWX */
#if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL)
+u64 __pi_set_satp_mode_from_cmdline(uintptr_t dtb_pa);
+
static void __init disable_pgtable_l5(void)
{
pgtable_l5_enabled = false;
@@ -760,17 +762,39 @@ static void __init disable_pgtable_l4(void)
satp_mode = SATP_MODE_39;
}
+static int __init print_no4lvl(char *p)
+{
+ pr_info("Disabled 4-level and 5-level paging");
+ return 0;
+}
+early_param("no4lvl", print_no4lvl);
+
+static int __init print_no5lvl(char *p)
+{
+ pr_info("Disabled 5-level paging");
+ return 0;
+}
+early_param("no5lvl", print_no5lvl);
+
/*
* There is a simple way to determine if 4-level is supported by the
* underlying hardware: establish 1:1 mapping in 4-level page table mode
* then read SATP to see if the configuration was taken into account
* meaning sv48 is supported.
*/
-static __init void set_satp_mode(void)
+static __init void set_satp_mode(uintptr_t dtb_pa)
{
u64 identity_satp, hw_satp;
uintptr_t set_satp_mode_pmd = ((unsigned long)set_satp_mode) & PMD_MASK;
- bool check_l4 = false;
+ u64 satp_mode_cmdline = __pi_set_satp_mode_from_cmdline(dtb_pa);
+
+ if (satp_mode_cmdline == SATP_MODE_57) {
+ disable_pgtable_l5();
+ } else if (satp_mode_cmdline == SATP_MODE_48) {
+ disable_pgtable_l5();
+ disable_pgtable_l4();
+ return;
+ }
create_p4d_mapping(early_p4d,
set_satp_mode_pmd, (uintptr_t)early_pud,
@@ -789,7 +813,8 @@ static __init void set_satp_mode(void)
retry:
create_pgd_mapping(early_pg_dir,
set_satp_mode_pmd,
- check_l4 ? (uintptr_t)early_pud : (uintptr_t)early_p4d,
+ pgtable_l5_enabled ?
+ (uintptr_t)early_p4d : (uintptr_t)early_pud,
PGDIR_SIZE, PAGE_TABLE);
identity_satp = PFN_DOWN((uintptr_t)&early_pg_dir) | satp_mode;
@@ -800,9 +825,8 @@ static __init void set_satp_mode(void)
local_flush_tlb_all();
if (hw_satp != identity_satp) {
- if (!check_l4) {
+ if (pgtable_l5_enabled) {
disable_pgtable_l5();
- check_l4 = true;
memset(early_pg_dir, 0, PAGE_SIZE);
goto retry;
}
@@ -1031,7 +1055,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
#endif
#if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL)
- set_satp_mode();
+ set_satp_mode(dtb_pa);
#endif
/*