arch/sh/include/asm/bitops-grb.h

Source file repositories/reference/linux-study-clean/arch/sh/include/asm/bitops-grb.h

File Facts

System: Linux kernel
Corpus path: arch/sh/include/asm/bitops-grb.h
Extension: .h
Size: 6364 bytes
Lines: 174
Domain: Architecture Layer
Bucket: arch/sh
Inferred role: Architecture Layer: implementation source
Status: source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

asm-generic/bitops/non-atomic.h

Detected Declarations

function set_bit
function clear_bit
function change_bit
function test_and_set_bit
function test_and_clear_bit
function test_and_change_bit

Annotated Snippet

#ifndef __ASM_SH_BITOPS_GRB_H
#define __ASM_SH_BITOPS_GRB_H

static inline void set_bit(int nr, volatile void * addr)
{
	int	mask;
	volatile unsigned int *a = addr;
	unsigned long tmp;

	a += nr >> 5;
	mask = 1 << (nr & 0x1f);

        __asm__ __volatile__ (
                "   .align 2              \n\t"
                "   mova    1f,   r0      \n\t" /* r0 = end point */
                "   mov    r15,   r1      \n\t" /* r1 = saved sp */
                "   mov    #-6,   r15     \n\t" /* LOGIN: r15 = size */
                "   mov.l  @%1,   %0      \n\t" /* load  old value */
                "   or      %2,   %0      \n\t" /* or */
                "   mov.l   %0,   @%1     \n\t" /* store new value */
                "1: mov     r1,   r15     \n\t" /* LOGOUT */
                : "=&r" (tmp),
                  "+r"  (a)
                : "r"   (mask)
                : "memory" , "r0", "r1");
}

static inline void clear_bit(int nr, volatile void * addr)
{
	int	mask;
	volatile unsigned int *a = addr;
        unsigned long tmp;

	a += nr >> 5;
        mask = ~(1 << (nr & 0x1f));
        __asm__ __volatile__ (
                "   .align 2              \n\t"
                "   mova    1f,   r0      \n\t" /* r0 = end point */
                "   mov    r15,   r1      \n\t" /* r1 = saved sp */
                "   mov    #-6,   r15     \n\t" /* LOGIN: r15 = size */
                "   mov.l  @%1,   %0      \n\t" /* load  old value */
                "   and     %2,   %0      \n\t" /* and */
                "   mov.l   %0,   @%1     \n\t" /* store new value */
                "1: mov     r1,   r15     \n\t" /* LOGOUT */
                : "=&r" (tmp),
                  "+r"  (a)
                : "r"   (mask)
                : "memory" , "r0", "r1");
}

static inline void change_bit(int nr, volatile void * addr)
{
        int     mask;
        volatile unsigned int *a = addr;
        unsigned long tmp;

        a += nr >> 5;
        mask = 1 << (nr & 0x1f);
        __asm__ __volatile__ (
                "   .align 2              \n\t"
                "   mova    1f,   r0      \n\t" /* r0 = end point */
                "   mov    r15,   r1      \n\t" /* r1 = saved sp */
                "   mov    #-6,   r15     \n\t" /* LOGIN: r15 = size */
                "   mov.l  @%1,   %0      \n\t" /* load  old value */
                "   xor     %2,   %0      \n\t" /* xor */
                "   mov.l   %0,   @%1     \n\t" /* store new value */
                "1: mov     r1,   r15     \n\t" /* LOGOUT */
                : "=&r" (tmp),
                  "+r"  (a)
                : "r"   (mask)
                : "memory" , "r0", "r1");
}

static inline int test_and_set_bit(int nr, volatile void * addr)
{
        int     mask, retval;
	volatile unsigned int *a = addr;
        unsigned long tmp;

	a += nr >> 5;
	mask = 1 << (nr & 0x1f);

        __asm__ __volatile__ (
                "   .align 2              \n\t"
                "   mova    1f,   r0      \n\t" /* r0 = end point */
                "   mov    r15,   r1      \n\t" /* r1 = saved sp */
                "   mov   #-14,   r15     \n\t" /* LOGIN: r15 = size */
                "   mov.l  @%2,   %0      \n\t" /* load old value */
                "   mov     %0,   %1      \n\t"
                "   tst     %1,   %3      \n\t" /* T = ((*a & mask) == 0) */

Annotation

Immediate include surface: `asm-generic/bitops/non-atomic.h`.
Detected declarations: `function set_bit`, `function clear_bit`, `function change_bit`, `function test_and_set_bit`, `function test_and_clear_bit`, `function test_and_change_bit`.
Atlas domain: Architecture Layer / arch/sh.
Implementation status: source implementation candidate.

Implementation Notes

This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.