From: guoren@kernel.org
To: guoren@kernel.org
Cc: andy.chiu@sifive.com, aou@eecs.berkeley.edu, ardb@kernel.org,
greentime.hu@sifive.com, jbaron@akamai.com, jpoimboe@kernel.org,
kernel@esmil.dk, linux-riscv@lists.infradead.org,
mingo@redhat.com, palmer@dabbelt.com, paul.walmsley@sifive.com,
peterz@infradead.org, rostedt@goodmis.org, zong.li@sifive.com,
Guo Ren <guoren@linux.alibaba.com>
Subject: [PATCH] riscv: jump_label: Optimize size with RISCV_ISA_C
Date: Sat, 17 Sep 2022 14:17:42 -0400 [thread overview]
Message-ID: <20220917181743.585512-1-guoren@kernel.org> (raw)
In-Reply-To: <CAJF2gTRCkNHdE+JoLV=T7_D0eTaxDdjzoJ5fCJnUB_-ED+CrfA@mail.gmail.com>
From: Guo Ren <guoren@linux.alibaba.com>
Reduce size of static branch.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
---
arch/riscv/include/asm/jump_label.h | 17 ++++++++++-----
arch/riscv/kernel/jump_label.c | 32 +++++++++++++++++++++++++++++
2 files changed, 44 insertions(+), 5 deletions(-)
diff --git a/arch/riscv/include/asm/jump_label.h b/arch/riscv/include/asm/jump_label.h
index 38af2ec7b9bf..78f747dfa8a2 100644
--- a/arch/riscv/include/asm/jump_label.h
+++ b/arch/riscv/include/asm/jump_label.h
@@ -12,17 +12,21 @@
#include <linux/types.h>
#include <asm/asm.h>
+#ifdef CONFIG_RISCV_ISA_C
+#define JUMP_LABEL_NOP_SIZE 2
+#else
#define JUMP_LABEL_NOP_SIZE 4
+#endif
static __always_inline bool arch_static_branch(struct static_key *key,
bool branch)
{
asm_volatile_goto(
- " .option push \n\t"
- " .option norelax \n\t"
- " .option norvc \n\t"
+#ifdef CONFIG_RISCV_ISA_C
+ "1: c.nop \n\t"
+#else
"1: nop \n\t"
- " .option pop \n\t"
+#endif
" .pushsection __jump_table, \"aw\" \n\t"
" .align " RISCV_LGPTR " \n\t"
" .long 1b - ., %l[label] - . \n\t"
@@ -39,11 +43,14 @@ static __always_inline bool arch_static_branch_jump(struct static_key *key,
bool branch)
{
asm_volatile_goto(
+#ifdef CONFIG_RISCV_ISA_C
+ "1: c.j %l[label] \n\t"
+#else
" .option push \n\t"
" .option norelax \n\t"
- " .option norvc \n\t"
"1: jal zero, %l[label] \n\t"
" .option pop \n\t"
+#endif
" .pushsection __jump_table, \"aw\" \n\t"
" .align " RISCV_LGPTR " \n\t"
" .long 1b - ., %l[label] - . \n\t"
diff --git a/arch/riscv/kernel/jump_label.c b/arch/riscv/kernel/jump_label.c
index e6694759dbd0..64a4e5df093d 100644
--- a/arch/riscv/kernel/jump_label.c
+++ b/arch/riscv/kernel/jump_label.c
@@ -11,21 +11,52 @@
#include <asm/bug.h>
#include <asm/patch.h>
+#ifdef CONFIG_RISCV_ISA_C
+#define RISCV_INSN_C_NOP 0x0001U
+#define RISCV_INSN_C_JAL 0xa001U
+#else
#define RISCV_INSN_NOP 0x00000013U
#define RISCV_INSN_JAL 0x0000006fU
+#endif
void arch_jump_label_transform(struct jump_entry *entry,
enum jump_label_type type)
{
void *addr = (void *)jump_entry_code(entry);
+#ifdef CONFIG_RISCV_ISA_C
+ u16 insn;
+#else
u32 insn;
+#endif
if (type == JUMP_LABEL_JMP) {
long offset = jump_entry_target(entry) - jump_entry_code(entry);
+#ifdef CONFIG_RISCV_ISA_C
+ if (WARN_ON(offset & 1 || offset < -2048 || offset >= 2048))
+ return;
+ /*
+ * 001 | imm[11|4|9:8|10|6|7|3:1|5] 01 - C.JAL
+ */
+ insn = RISCV_INSN_C_JAL |
+ (((u16)offset & GENMASK(5, 5)) >> (5 - 2)) |
+ (((u16)offset & GENMASK(3, 1)) << (3 - 1)) |
+ (((u16)offset & GENMASK(7, 7)) >> (7 - 6)) |
+ (((u16)offset & GENMASK(6, 6)) << (7 - 6)) |
+ (((u16)offset & GENMASK(10, 10)) >> (10 - 8)) |
+ (((u16)offset & GENMASK(9, 8)) << (9 - 8)) |
+ (((u16)offset & GENMASK(4, 4)) << (11 - 4)) |
+ (((u16)offset & GENMASK(11, 11)) << (12 - 11));
+ } else {
+ insn = RISCV_INSN_C_NOP;
+ }
+#else
if (WARN_ON(offset & 1 || offset < -524288 || offset >= 524288))
return;
+ /*
+ * imm[20|10:1|11|19:12] | rd | 1101111 - JAL
+ */
insn = RISCV_INSN_JAL |
(((u32)offset & GENMASK(19, 12)) << (12 - 12)) |
(((u32)offset & GENMASK(11, 11)) << (20 - 11)) |
@@ -34,6 +65,7 @@ void arch_jump_label_transform(struct jump_entry *entry,
} else {
insn = RISCV_INSN_NOP;
}
+#endif
mutex_lock(&text_mutex);
patch_text_nosync(addr, &insn, sizeof(insn));
--
2.36.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
next prev parent reply other threads:[~2022-09-17 18:18 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-13 9:42 [PATCH RFC v2 riscv/for-next 0/5] Enable ftrace with kernel preemption for RISC-V Andy Chiu
2022-09-13 9:42 ` [PATCH RFC v2 riscv/for-next 1/5] riscv: align ftrace to 4 Byte boundary and increase ftrace prologue size Andy Chiu
2022-09-15 13:53 ` Guo Ren
2022-09-17 1:15 ` Andy Chiu
2022-09-13 9:42 ` [PATCH RFC v2 riscv/for-next 2/5] riscv: export patch_insn_write Andy Chiu
2022-09-13 9:42 ` [PATCH RFC v2 riscv/for-next 3/5] riscv: ftrace: use indirect jump to work with kernel preemption Andy Chiu
2022-09-14 13:45 ` Guo Ren
2022-09-15 13:30 ` Guo Ren
2022-09-17 1:04 ` Andy Chiu
2022-09-17 10:56 ` Guo Ren
2024-02-20 14:17 ` Evgenii Shatokhin
2022-09-13 9:42 ` [PATCH RFC v2 riscv/for-next 4/5] riscv: ftrace: do not use stop_machine to update code Andy Chiu
2022-09-13 9:42 ` [PATCH RFC v2 riscv/for-next 5/5] riscv: align arch_static_branch function Andy Chiu
2022-09-14 14:06 ` Guo Ren
2022-09-16 23:54 ` Andy Chiu
2022-09-17 0:22 ` Guo Ren
2022-09-17 18:17 ` guoren [this message]
2022-09-17 18:38 ` guoren
2022-09-17 23:49 ` Guo Ren
2022-09-17 23:59 ` Guo Ren
2022-09-18 0:12 ` Jessica Clarke
2022-09-18 0:46 ` Guo Ren
2022-09-14 14:24 ` Jessica Clarke
2022-09-15 1:47 ` Guo Ren
2022-09-15 2:34 ` Jessica Clarke
2024-02-13 19:42 ` [PATCH RFC v2 riscv/for-next 0/5] Enable ftrace with kernel preemption for RISC-V Evgenii Shatokhin
2024-02-21 5:27 ` Andy Chiu
2024-02-21 16:55 ` Evgenii Shatokhin
2024-03-06 20:57 ` Alexandre Ghiti
2024-03-07 8:35 ` Evgenii Shatokhin
2024-03-07 12:27 ` Andy Chiu
2024-03-07 13:21 ` Alexandre Ghiti
2024-03-07 15:57 ` Samuel Holland
2024-03-11 14:24 ` Andy Chiu
2024-03-19 14:50 ` Alexandre Ghiti
2024-03-19 14:58 ` Conor Dooley
2024-03-20 16:37 ` Andy Chiu
2024-03-18 15:31 ` Andy Chiu
2024-03-19 15:32 ` Evgenii Shatokhin
2024-03-20 16:38 ` Andy Chiu
2024-03-19 17:37 ` Alexandre Ghiti
2024-03-20 16:36 ` Andy Chiu
2024-03-21 11:02 ` Alexandre Ghiti
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220917181743.585512-1-guoren@kernel.org \
--to=guoren@kernel.org \
--cc=andy.chiu@sifive.com \
--cc=aou@eecs.berkeley.edu \
--cc=ardb@kernel.org \
--cc=greentime.hu@sifive.com \
--cc=guoren@linux.alibaba.com \
--cc=jbaron@akamai.com \
--cc=jpoimboe@kernel.org \
--cc=kernel@esmil.dk \
--cc=linux-riscv@lists.infradead.org \
--cc=mingo@redhat.com \
--cc=palmer@dabbelt.com \
--cc=paul.walmsley@sifive.com \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=zong.li@sifive.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).