linux_dsm_epyc7002/arch/sparc/kernel/jump_label.c
Masahiro Yamada e9666d10a5 jump_label: move 'asm goto' support test to Kconfig
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>
2019-01-06 09:46:51 +09:00

48 lines
1.0 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/cpu.h>
#include <linux/jump_label.h>
#include <linux/memory.h>
#include <asm/cacheflush.h>
void arch_jump_label_transform(struct jump_entry *entry,
enum jump_label_type type)
{
u32 *insn = (u32 *) (unsigned long) entry->code;
u32 val;
if (type == JUMP_LABEL_JMP) {
s32 off = (s32)entry->target - (s32)entry->code;
bool use_v9_branch = false;
BUG_ON(off & 3);
#ifdef CONFIG_SPARC64
if (off <= 0xfffff && off >= -0x100000)
use_v9_branch = true;
#endif
if (use_v9_branch) {
/* WDISP19 - target is . + immed << 2 */
/* ba,pt %xcc, . + off */
val = 0x10680000 | (((u32) off >> 2) & 0x7ffff);
} else {
/* WDISP22 - target is . + immed << 2 */
BUG_ON(off > 0x7fffff);
BUG_ON(off < -0x800000);
/* ba . + off */
val = 0x10800000 | (((u32) off >> 2) & 0x3fffff);
}
} else {
val = 0x01000000;
}
mutex_lock(&text_mutex);
*insn = val;
flushi(insn);
mutex_unlock(&text_mutex);
}