diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-07 10:11:12 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-07 10:11:12 -0700 |
commit | dbf83817315d9ce93b3e5b1c83a167f537245bd8 (patch) | |
tree | 63bd286d192b0867f608935d1ee114d9eb157941 /arch/riscv/kernel/jump_label.c | |
parent | e1ec517e18acc0aa9795ff92c15f0adabcb12db9 (diff) | |
parent | 40284a072c42f6177184fb1f62ba94c69e0c0277 (diff) |
Merge tag 'riscv-for-linus-5.9-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V updates from Palmer Dabbelt:
"We have a lot of new kernel features for this merge window:
- ARCH_SUPPORTS_ATOMIC_RMW, to allow OSQ locks to be enabled
- The ability to enable NO_HZ_FULL
- Support for enabling kcov, kmemleak, stack protector, and VM
debugging
- JUMP_LABEL support
There are also a handful of cleanups"
* tag 'riscv-for-linus-5.9-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (24 commits)
riscv: disable stack-protector for vDSO
RISC-V: Fix build warning for smpboot.c
riscv: fix build warning of mm/pageattr
riscv: Fix build warning for mm/init
RISC-V: Setup exception vector early
riscv: Select ARCH_HAS_DEBUG_VM_PGTABLE
riscv: Use generic pgprot_* macros from <linux/pgtable.h>
mm: pgtable: Make generic pgprot_* macros available for no-MMU
riscv: Cleanup unnecessary define in asm-offset.c
riscv: Add jump-label implementation
riscv: Support R_RISCV_ADD64 and R_RISCV_SUB64 relocs
Replace HTTP links with HTTPS ones: RISC-V
riscv: Add STACKPROTECTOR supported
riscv: Fix typo in asm/hwcap.h uapi header
riscv: Add kmemleak support
riscv: Allow building with kcov coverage
riscv: Enable context tracking
riscv: Support irq_work via self IPIs
riscv: Enable LOCKDEP_SUPPORT & fixup TRACE_IRQFLAGS_SUPPORT
riscv: Fixup lockdep_assert_held with wrong param cpu_running
...
Diffstat (limited to 'arch/riscv/kernel/jump_label.c')
-rw-r--r-- | arch/riscv/kernel/jump_label.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/arch/riscv/kernel/jump_label.c b/arch/riscv/kernel/jump_label.c new file mode 100644 index 000000000000..20e09056d141 --- /dev/null +++ b/arch/riscv/kernel/jump_label.c @@ -0,0 +1,53 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2020 Emil Renner Berthing + * + * Based on arch/arm64/kernel/jump_label.c + */ +#include <linux/jump_label.h> +#include <linux/kernel.h> +#include <linux/memory.h> +#include <linux/mutex.h> +#include <asm/bug.h> +#include <asm/patch.h> + +#define RISCV_INSN_NOP 0x00000013U +#define RISCV_INSN_JAL 0x0000006fU + +void arch_jump_label_transform(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 = jump_entry_target(entry) - jump_entry_code(entry); + + if (WARN_ON(offset & 1 || offset < -524288 || offset >= 524288)) + return; + + insn = RISCV_INSN_JAL | + (((u32)offset & GENMASK(19, 12)) << (12 - 12)) | + (((u32)offset & GENMASK(11, 11)) << (20 - 11)) | + (((u32)offset & GENMASK(10, 1)) << (21 - 1)) | + (((u32)offset & GENMASK(20, 20)) << (31 - 20)); + } else { + insn = RISCV_INSN_NOP; + } + + mutex_lock(&text_mutex); + patch_text_nosync(addr, &insn, sizeof(insn)); + mutex_unlock(&text_mutex); +} + +void arch_jump_label_transform_static(struct jump_entry *entry, + enum jump_label_type type) +{ + /* + * We use the same instructions in the arch_static_branch and + * arch_static_branch_jump inline functions, so there's no + * need to patch them up here. + * The core will call arch_jump_label_transform when those + * instructions need to be replaced. + */ +} |