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e9666d10a5
Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label". The jump label is controlled by HAVE_JUMP_LABEL, which is defined like this: #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) # define HAVE_JUMP_LABEL #endif We can improve this by testing 'asm goto' support in Kconfig, then make JUMP_LABEL depend on CC_HAS_ASM_GOTO. Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will match to the real kernel capability. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
48 lines
1.0 KiB
C
48 lines
1.0 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <linux/mutex.h>
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#include <linux/cpu.h>
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#include <linux/jump_label.h>
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#include <linux/memory.h>
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#include <asm/cacheflush.h>
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void arch_jump_label_transform(struct jump_entry *entry,
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enum jump_label_type type)
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{
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u32 *insn = (u32 *) (unsigned long) entry->code;
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u32 val;
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if (type == JUMP_LABEL_JMP) {
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s32 off = (s32)entry->target - (s32)entry->code;
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bool use_v9_branch = false;
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BUG_ON(off & 3);
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#ifdef CONFIG_SPARC64
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if (off <= 0xfffff && off >= -0x100000)
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use_v9_branch = true;
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#endif
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if (use_v9_branch) {
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/* WDISP19 - target is . + immed << 2 */
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/* ba,pt %xcc, . + off */
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val = 0x10680000 | (((u32) off >> 2) & 0x7ffff);
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} else {
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/* WDISP22 - target is . + immed << 2 */
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BUG_ON(off > 0x7fffff);
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BUG_ON(off < -0x800000);
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/* ba . + off */
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val = 0x10800000 | (((u32) off >> 2) & 0x3fffff);
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}
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} else {
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val = 0x01000000;
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}
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mutex_lock(&text_mutex);
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*insn = val;
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flushi(insn);
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mutex_unlock(&text_mutex);
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}
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