Merge tag 'for-linus' of https://github.com/openrisc/linux

Pull OpenRISC updates from Stafford Horne:
 "I picked up one series from Chen Miao, our Google Summer of Code
  contributor, which adds OpenRISC support for static keys"

* tag 'for-linus' of https://github.com/openrisc/linux:
  openrisc: Add jump label support
  openrisc: Regenerate defconfigs.
  openrisc: Add R_OR1K_32_PCREL relocation type module support
  openrisc: Add text patching API support

Documentation/features/core/jump-labels/arch-support.txt

@@ -17,7 +17,7 @@
     |  microblaze: | TODO |
     |        mips: |  ok  |
     |       nios2: | TODO |
-    |    openrisc: | TODO |
+    |    openrisc: |  ok  |
     |      parisc: |  ok  |
     |     powerpc: |  ok  |
     |       riscv: |  ok  |

arch/openrisc/Kconfig

@@ -24,6 +24,8 @@ config OPENRISC
 	select GENERIC_PCI_IOMAP
 	select GENERIC_IOREMAP
 	select GENERIC_CPU_DEVICES
+	select HAVE_ARCH_JUMP_LABEL
+	select HAVE_ARCH_JUMP_LABEL_RELATIVE
 	select HAVE_PCI
 	select HAVE_UID16
 	select HAVE_PAGE_SIZE_8KB

arch/openrisc/configs/or1ksim_defconfig

@@ -3,26 +3,23 @@ CONFIG_LOG_BUF_SHIFT=14
 CONFIG_BLK_DEV_INITRD=y
 # CONFIG_RD_GZIP is not set
 CONFIG_EXPERT=y
-# CONFIG_KALLSYMS is not set
 # CONFIG_EPOLL is not set
 # CONFIG_TIMERFD is not set
 # CONFIG_EVENTFD is not set
 # CONFIG_AIO is not set
-# CONFIG_VM_EVENT_COUNTERS is not set
+# CONFIG_KALLSYMS is not set
-# CONFIG_COMPAT_BRK is not set
-CONFIG_SLUB=y
-CONFIG_SLUB_TINY=y
-CONFIG_MODULES=y
-# CONFIG_BLOCK is not set
 CONFIG_BUILTIN_DTB_NAME="or1ksim"
 CONFIG_HZ_100=y
+CONFIG_JUMP_LABEL=y
+CONFIG_MODULES=y
+# CONFIG_BLOCK is not set
+CONFIG_SLUB_TINY=y
+# CONFIG_COMPAT_BRK is not set
+# CONFIG_VM_EVENT_COUNTERS is not set
 CONFIG_NET=y
 CONFIG_PACKET=y
 CONFIG_UNIX=y
 CONFIG_INET=y
-# CONFIG_INET_XFRM_MODE_TRANSPORT is not set
-# CONFIG_INET_XFRM_MODE_TUNNEL is not set
-# CONFIG_INET_XFRM_MODE_BEET is not set
 # CONFIG_INET_DIAG is not set
 CONFIG_TCP_CONG_ADVANCED=y
 # CONFIG_TCP_CONG_BIC is not set
@@ -35,7 +32,6 @@ CONFIG_DEVTMPFS=y
 CONFIG_DEVTMPFS_MOUNT=y
 # CONFIG_PREVENT_FIRMWARE_BUILD is not set
 # CONFIG_FW_LOADER is not set
-CONFIG_PROC_DEVICETREE=y
 CONFIG_NETDEVICES=y
 CONFIG_ETHOC=y
 CONFIG_MICREL_PHY=y
@@ -53,4 +49,3 @@ CONFIG_SERIAL_OF_PLATFORM=y
 # CONFIG_DNOTIFY is not set
 CONFIG_TMPFS=y
 CONFIG_NFS_FS=y
-# CONFIG_ENABLE_MUST_CHECK is not set

arch/openrisc/configs/virt_defconfig

@@ -12,6 +12,7 @@ CONFIG_NR_CPUS=8
 CONFIG_SMP=y
 CONFIG_HZ_100=y
 # CONFIG_OPENRISC_NO_SPR_SR_DSX is not set
+CONFIG_JUMP_LABEL=y
 # CONFIG_COMPAT_BRK is not set
 CONFIG_NET=y
 CONFIG_PACKET=y
@@ -55,7 +56,6 @@ CONFIG_DRM=y
 # CONFIG_DRM_FBDEV_EMULATION is not set
 CONFIG_DRM_VIRTIO_GPU=y
 CONFIG_FB=y
-CONFIG_FIRMWARE_EDID=y
 CONFIG_FRAMEBUFFER_CONSOLE=y
 CONFIG_FRAMEBUFFER_CONSOLE_DETECT_PRIMARY=y
 CONFIG_LOGO=y

arch/openrisc/include/asm/Kbuild

@@ -9,4 +9,3 @@ generic-y += spinlock.h
 generic-y += qrwlock_types.h
 generic-y += qrwlock.h
 generic-y += user.h
-generic-y += text-patching.h

arch/openrisc/include/asm/fixmap.h

@@ -28,6 +28,7 @@
 
 enum fixed_addresses {
 	FIX_EARLYCON_MEM_BASE,
+	FIX_TEXT_POKE0,
 	__end_of_fixed_addresses
 };
 

arch/openrisc/include/asm/insn-def.h

@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2025 Chen Miao
+ */
+
+#ifndef __ASM_OPENRISC_INSN_DEF_H
+#define __ASM_OPENRISC_INSN_DEF_H
+
+/* or1k instructions are always 32 bits. */
+#define	OPENRISC_INSN_SIZE		4
+
+/* or1k nop instruction code */
+#define OPENRISC_INSN_NOP     0x15000000U
+
+#endif /* __ASM_OPENRISC_INSN_DEF_H */

arch/openrisc/include/asm/jump_label.h

@@ -0,0 +1,72 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2025 Chen Miao
+ *
+ * Based on arch/arm/include/asm/jump_label.h
+ */
+#ifndef __ASM_OPENRISC_JUMP_LABEL_H
+#define __ASM_OPENRISC_JUMP_LABEL_H
+
+#ifndef __ASSEMBLER__
+
+#include <linux/types.h>
+#include <asm/insn-def.h>
+
+#define HAVE_JUMP_LABEL_BATCH
+
+#define JUMP_LABEL_NOP_SIZE OPENRISC_INSN_SIZE
+
+/**
+ * JUMP_TABLE_ENTRY - Create a jump table entry
+ * @key: Jump key identifier (typically a symbol address)
+ * @label: Target label address
+ *
+ * This macro creates a jump table entry in the dedicated kernel section (__jump_table).
+ * Each entry contains the following information:
+ * 		Offset from current instruction to jump instruction (1b - .)
+ * 		Offset from current instruction to target label (label - .)
+ * 		Offset from current instruction to key identifier (key - .)
+ */
+#define JUMP_TABLE_ENTRY(key, label)			\
+	".pushsection	__jump_table, \"aw\"	\n\t"	\
+	".align 	4 			\n\t"	\
+	".long 		1b - ., " label " - .	\n\t"	\
+	".long 		" key " - . 		\n\t"	\
+	".popsection				\n\t"
+
+#define ARCH_STATIC_BRANCH_ASM(key, label)		\
+	".align		4			\n\t"	\
+	"1: l.nop				\n\t"	\
+	"    l.nop				\n\t"	\
+	JUMP_TABLE_ENTRY(key, label)
+
+static __always_inline bool arch_static_branch(struct static_key *const key,
+					       const bool branch)
+{
+	asm goto (ARCH_STATIC_BRANCH_ASM("%0", "%l[l_yes]")
+		  ::"i"(&((char *)key)[branch])::l_yes);
+
+	return false;
+l_yes:
+	return true;
+}
+
+#define ARCH_STATIC_BRANCH_JUMP_ASM(key, label)		\
+	".align		4			\n\t"	\
+	"1: l.j	" label "			\n\t"	\
+	"    l.nop				\n\t"	\
+	JUMP_TABLE_ENTRY(key, label)
+
+static __always_inline bool
+arch_static_branch_jump(struct static_key *const key, const bool branch)
+{
+	asm goto (ARCH_STATIC_BRANCH_JUMP_ASM("%0", "%l[l_yes]")
+		  ::"i"(&((char *)key)[branch])::l_yes);
+
+	return false;
+l_yes:
+	return true;
+}
+
+#endif /* __ASSEMBLER__ */
+#endif /* __ASM_OPENRISC_JUMP_LABEL_H */

arch/openrisc/include/asm/text-patching.h

@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2025 Chen Miao
+ */
+
+#ifndef _ASM_OPENRISC_PATCHING_H
+#define _ASM_OPENRISC_PATCHING_H
+
+#include <linux/types.h>
+
+int patch_insn_write(void *addr, u32 insn);
+
+#endif /* _ASM_OPENRISC_PATCHING_H */

arch/openrisc/kernel/Makefile

@@ -9,9 +9,11 @@ obj-y	:= head.o setup.o or32_ksyms.o process.o dma.o \
 	   traps.o time.o irq.o entry.o ptrace.o signal.o \
 	   sys_call_table.o unwinder.o cacheinfo.o
 
+obj-$(CONFIG_JUMP_LABEL)	+= jump_label.o
 obj-$(CONFIG_SMP)		+= smp.o sync-timer.o
 obj-$(CONFIG_STACKTRACE)	+= stacktrace.o
 obj-$(CONFIG_MODULES)		+= module.o
 obj-$(CONFIG_OF)		+= prom.o
+obj-y	+= patching.o
 
 clean:

arch/openrisc/kernel/jump_label.c

@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2025 Chen Miao
+ *
+ * Based on arch/arm/kernel/jump_label.c
+ */
+#include <linux/jump_label.h>
+#include <linux/kernel.h>
+#include <linux/memory.h>
+#include <asm/bug.h>
+#include <asm/cacheflush.h>
+#include <asm/text-patching.h>
+
+bool arch_jump_label_transform_queue(struct jump_entry *entry,
+				     enum jump_label_type type)
+{
+	void *addr = (void *)jump_entry_code(entry);
+	u32 insn;
+
+	if (type == JUMP_LABEL_JMP) {
+		long offset;
+
+		offset = jump_entry_target(entry) - jump_entry_code(entry);
+		/*
+		 * The actual maximum range of the l.j instruction's offset is -134,217,728
+		 * ~ 134,217,724 (sign 26-bit imm).
+		 * For the original jump range, we need to right-shift N by 2 to obtain the
+		 * instruction's offset.
+		 */
+		WARN_ON_ONCE(offset < -134217728 || offset > 134217724);
+
+		/* 26bit imm mask */
+		offset = (offset >> 2) & 0x03ffffff;
+
+		insn = offset;
+	} else {
+		insn = OPENRISC_INSN_NOP;
+	}
+
+	if (early_boot_irqs_disabled)
+		copy_to_kernel_nofault(addr, &insn, sizeof(insn));
+	else
+		patch_insn_write(addr, insn);
+
+	return true;
+}
+
+void arch_jump_label_transform_apply(void)
+{
+	kick_all_cpus_sync();
+}

arch/openrisc/kernel/module.c

@@ -55,6 +55,10 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,
 			value |= *location & 0xfc000000;
 			*location = value;
 			break;
+		case R_OR1K_32_PCREL:
+			value -= (uint32_t)location;
+			*location = value;
+			break;
 		case R_OR1K_AHI16:
 			/* Adjust the operand to match with a signed LO16.  */
 			value += 0x8000;

arch/openrisc/kernel/patching.c

@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2020 SiFive
+ * Copyright (C) 2025 Chen Miao
+ */
+
+#include <linux/mm.h>
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/uaccess.h>
+
+#include <asm/insn-def.h>
+#include <asm/cacheflush.h>
+#include <asm/page.h>
+#include <asm/fixmap.h>
+#include <asm/text-patching.h>
+#include <asm/sections.h>
+
+static DEFINE_RAW_SPINLOCK(patch_lock);
+
+static __always_inline void *patch_map(void *addr, int fixmap)
+{
+	uintptr_t uaddr = (uintptr_t) addr;
+	phys_addr_t phys;
+
+	if (core_kernel_text(uaddr)) {
+		phys = __pa_symbol(addr);
+	} else {
+		struct page *page = vmalloc_to_page(addr);
+		BUG_ON(!page);
+		phys = page_to_phys(page) + offset_in_page(addr);
+	}
+
+	return (void *)set_fixmap_offset(fixmap, phys);
+}
+
+static void patch_unmap(int fixmap)
+{
+	clear_fixmap(fixmap);
+}
+
+static int __patch_insn_write(void *addr, u32 insn)
+{
+	void *waddr = addr;
+	unsigned long flags = 0;
+	int ret;
+
+	raw_spin_lock_irqsave(&patch_lock, flags);
+
+	waddr = patch_map(addr, FIX_TEXT_POKE0);
+
+	ret = copy_to_kernel_nofault(waddr, &insn, OPENRISC_INSN_SIZE);
+	local_icache_range_inv((unsigned long)waddr,
+			       (unsigned long)waddr + OPENRISC_INSN_SIZE);
+
+	patch_unmap(FIX_TEXT_POKE0);
+
+	raw_spin_unlock_irqrestore(&patch_lock, flags);
+
+	return ret;
+}
+
+/*
+ * patch_insn_write - Write a single instruction to a specified memory location
+ * This API provides a single-instruction patching, primarily used for runtime
+ * code modification.
+ * By the way, the insn size must be 4 bytes.
+ */
+int patch_insn_write(void *addr, u32 insn)
+{
+	u32 *tp = addr;
+	int ret;
+
+	if ((uintptr_t) tp & 0x3)
+		return -EINVAL;
+
+	ret = __patch_insn_write(tp, insn);
+
+	return ret;
+}

arch/openrisc/kernel/setup.c

@@ -249,6 +249,8 @@ void __init setup_arch(char **cmdline_p)
 		initrd_below_start_ok = 1;
 	}
 #endif
+	/* perform jump_table sorting before paging_init locks down read only memory */
+	jump_label_init();
 
 	/* paging_init() sets up the MMU and marks all pages as reserved */
 	paging_init();

arch/openrisc/mm/init.c

@@ -226,7 +226,11 @@ static int __init map_page(unsigned long va, phys_addr_t pa, pgprot_t prot)
 	return 0;
 }
 
-void __init __set_fixmap(enum fixed_addresses idx,
+/*
+ * __set_fix must now support both EARLYCON and TEXT_POKE mappings,
+ * which are used at different stages of kernel execution.
+ */
+void __set_fixmap(enum fixed_addresses idx,
 			 phys_addr_t phys, pgprot_t prot)
 {
 	unsigned long address = __fix_to_virt(idx);