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MIPS: bitops: Abstract LL/SC loops
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Introduce __bit_op() & __test_bit_op() macros which abstract away the
implementation of LL/SC loops. This cuts down on a lot of duplicate
boilerplate code, and also allows R10000_LLSC_WAR to be handled outside
of the individual bitop functions.

Signed-off-by: Paul Burton <[email protected]>
Cc: [email protected]
Cc: Huacai Chen <[email protected]>
Cc: Jiaxun Yang <[email protected]>
Cc: [email protected]
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@paulburton
paulburton committed Oct 7, 2019
1 parent aad028c commit cc99987
Showing 1 changed file with 63 additions and 204 deletions.
267 changes: 63 additions & 204 deletions arch/mips/include/asm/bitops.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -25,6 +25,41 @@
#include <asm/sgidefs.h>
#include <asm/war.h>

#define __bit_op(mem, insn, inputs...) do { \
unsigned long temp; \
\
asm volatile( \
" .set push \n" \
" .set " MIPS_ISA_LEVEL " \n" \
"1: " __LL "%0, %1 \n" \
" " insn " \n" \
" " __SC "%0, %1 \n" \
" " __SC_BEQZ "%0, 1b \n" \
" .set pop \n" \
: "=&r"(temp), "+" GCC_OFF_SMALL_ASM()(mem) \
: inputs \
: __LLSC_CLOBBER); \
} while (0)

#define __test_bit_op(mem, ll_dst, insn, inputs...) ({ \
unsigned long orig, temp; \
\
asm volatile( \
" .set push \n" \
" .set " MIPS_ISA_LEVEL " \n" \
"1: " __LL ll_dst ", %2 \n" \
" " insn " \n" \
" " __SC "%1, %2 \n" \
" " __SC_BEQZ "%1, 1b \n" \
" .set pop \n" \
: "=&r"(orig), "=&r"(temp), \
"+" GCC_OFF_SMALL_ASM()(mem) \
: inputs \
: __LLSC_CLOBBER); \
\
orig; \
})

/*
* These are the "slower" versions of the functions and are in bitops.c.
* These functions call raw_local_irq_{save,restore}().
Expand Down Expand Up @@ -54,55 +89,20 @@ static inline void set_bit(unsigned long nr, volatile unsigned long *addr)
{
unsigned long *m = ((unsigned long *)addr) + (nr >> SZLONG_LOG);
int bit = nr & SZLONG_MASK;
unsigned long temp;

if (!kernel_uses_llsc) {
__mips_set_bit(nr, addr);
return;
}

if (R10000_LLSC_WAR) {
__asm__ __volatile__(
" .set push \n"
" .set arch=r4000 \n"
"1: " __LL "%0, %1 # set_bit \n"
" or %0, %2 \n"
" " __SC "%0, %1 \n"
" beqzl %0, 1b \n"
" .set pop \n"
: "=&r" (temp), "=" GCC_OFF_SMALL_ASM() (*m)
: "ir" (BIT(bit)), GCC_OFF_SMALL_ASM() (*m)
: __LLSC_CLOBBER);
return;
}

if ((MIPS_ISA_REV >= 2) && __builtin_constant_p(bit) && (bit >= 16)) {
loongson_llsc_mb();
do {
__asm__ __volatile__(
" " __LL "%0, %1 # set_bit \n"
" " __INS "%0, %3, %2, 1 \n"
" " __SC "%0, %1 \n"
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (*m)
: "i" (bit), "r" (~0)
: __LLSC_CLOBBER);
} while (unlikely(!temp));
__bit_op(*m, __INS "%0, %3, %2, 1", "i"(bit), "r"(~0));
return;
}

loongson_llsc_mb();
do {
__asm__ __volatile__(
" .set push \n"
" .set "MIPS_ISA_ARCH_LEVEL" \n"
" " __LL "%0, %1 # set_bit \n"
" or %0, %2 \n"
" " __SC "%0, %1 \n"
" .set pop \n"
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (*m)
: "ir" (BIT(bit))
: __LLSC_CLOBBER);
} while (unlikely(!temp));
__bit_op(*m, "or\t%0, %2", "ir"(BIT(bit)));
}

/*
Expand All @@ -119,55 +119,20 @@ static inline void clear_bit(unsigned long nr, volatile unsigned long *addr)
{
unsigned long *m = ((unsigned long *)addr) + (nr >> SZLONG_LOG);
int bit = nr & SZLONG_MASK;
unsigned long temp;

if (!kernel_uses_llsc) {
__mips_clear_bit(nr, addr);
return;
}

if (R10000_LLSC_WAR) {
__asm__ __volatile__(
" .set push \n"
" .set arch=r4000 \n"
"1: " __LL "%0, %1 # clear_bit \n"
" and %0, %2 \n"
" " __SC "%0, %1 \n"
" beqzl %0, 1b \n"
" .set pop \n"
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (*m)
: "ir" (~(BIT(bit)))
: __LLSC_CLOBBER);
return;
}

if ((MIPS_ISA_REV >= 2) && __builtin_constant_p(bit)) {
loongson_llsc_mb();
do {
__asm__ __volatile__(
" " __LL "%0, %1 # clear_bit \n"
" " __INS "%0, $0, %2, 1 \n"
" " __SC "%0, %1 \n"
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (*m)
: "i" (bit)
: __LLSC_CLOBBER);
} while (unlikely(!temp));
__bit_op(*m, __INS "%0, $0, %2, 1", "i"(bit));
return;
}

loongson_llsc_mb();
do {
__asm__ __volatile__(
" .set push \n"
" .set "MIPS_ISA_ARCH_LEVEL" \n"
" " __LL "%0, %1 # clear_bit \n"
" and %0, %2 \n"
" " __SC "%0, %1 \n"
" .set pop \n"
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (*m)
: "ir" (~(BIT(bit)))
: __LLSC_CLOBBER);
} while (unlikely(!temp));
__bit_op(*m, "and\t%0, %2", "ir"(~BIT(bit)));
}

/*
Expand Down Expand Up @@ -197,41 +162,14 @@ static inline void change_bit(unsigned long nr, volatile unsigned long *addr)
{
unsigned long *m = ((unsigned long *)addr) + (nr >> SZLONG_LOG);
int bit = nr & SZLONG_MASK;
unsigned long temp;

if (!kernel_uses_llsc) {
__mips_change_bit(nr, addr);
return;
}

if (R10000_LLSC_WAR) {
__asm__ __volatile__(
" .set push \n"
" .set arch=r4000 \n"
"1: " __LL "%0, %1 # change_bit \n"
" xor %0, %2 \n"
" " __SC "%0, %1 \n"
" beqzl %0, 1b \n"
" .set pop \n"
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (*m)
: "ir" (BIT(bit))
: __LLSC_CLOBBER);
return;
}

loongson_llsc_mb();
do {
__asm__ __volatile__(
" .set push \n"
" .set "MIPS_ISA_ARCH_LEVEL" \n"
" " __LL "%0, %1 # change_bit \n"
" xor %0, %2 \n"
" " __SC "%0, %1 \n"
" .set pop \n"
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (*m)
: "ir" (BIT(bit))
: __LLSC_CLOBBER);
} while (unlikely(!temp));
__bit_op(*m, "xor\t%0, %2", "ir"(BIT(bit)));
}

/*
Expand All @@ -247,41 +185,16 @@ static inline int test_and_set_bit_lock(unsigned long nr,
{
unsigned long *m = ((unsigned long *)addr) + (nr >> SZLONG_LOG);
int bit = nr & SZLONG_MASK;
unsigned long res, temp;
unsigned long res, orig;

if (!kernel_uses_llsc) {
res = __mips_test_and_set_bit_lock(nr, addr);
} else if (R10000_LLSC_WAR) {
__asm__ __volatile__(
" .set push \n"
" .set arch=r4000 \n"
"1: " __LL "%0, %1 # test_and_set_bit \n"
" or %2, %0, %3 \n"
" " __SC "%2, %1 \n"
" beqzl %2, 1b \n"
" and %2, %0, %3 \n"
" .set pop \n"
: "=&r" (temp), "+m" (*m), "=&r" (res)
: "ir" (BIT(bit))
: __LLSC_CLOBBER);

res = res != 0;
} else {
loongson_llsc_mb();
do {
__asm__ __volatile__(
" .set push \n"
" .set "MIPS_ISA_ARCH_LEVEL" \n"
" " __LL "%0, %1 # test_and_set_bit \n"
" or %2, %0, %3 \n"
" " __SC "%2, %1 \n"
" .set pop \n"
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (*m), "=&r" (res)
: "ir" (BIT(bit))
: __LLSC_CLOBBER);
} while (unlikely(!res));

res = (temp & BIT(bit)) != 0;
orig = __test_bit_op(*m, "%0",
"or\t%1, %0, %3",
"ir"(BIT(bit)));
res = (orig & BIT(bit)) != 0;
}

smp_llsc_mb();
Expand Down Expand Up @@ -317,57 +230,25 @@ static inline int test_and_clear_bit(unsigned long nr,
{
unsigned long *m = ((unsigned long *)addr) + (nr >> SZLONG_LOG);
int bit = nr & SZLONG_MASK;
unsigned long res, temp;
unsigned long res, orig;

smp_mb__before_llsc();

if (!kernel_uses_llsc) {
res = __mips_test_and_clear_bit(nr, addr);
} else if (R10000_LLSC_WAR) {
__asm__ __volatile__(
" .set push \n"
" .set arch=r4000 \n"
"1: " __LL "%0, %1 # test_and_clear_bit \n"
" or %2, %0, %3 \n"
" xor %2, %3 \n"
" " __SC "%2, %1 \n"
" beqzl %2, 1b \n"
" and %2, %0, %3 \n"
" .set pop \n"
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (*m), "=&r" (res)
: "ir" (BIT(bit))
: __LLSC_CLOBBER);

res = res != 0;
} else if ((MIPS_ISA_REV >= 2) && __builtin_constant_p(nr)) {
loongson_llsc_mb();
do {
__asm__ __volatile__(
" " __LL "%0, %1 # test_and_clear_bit \n"
" " __EXT "%2, %0, %3, 1 \n"
" " __INS "%0, $0, %3, 1 \n"
" " __SC "%0, %1 \n"
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (*m), "=&r" (res)
: "i" (bit)
: __LLSC_CLOBBER);
} while (unlikely(!temp));
res = __test_bit_op(*m, "%1",
__EXT "%0, %1, %3, 1;"
__INS "%1, $0, %3, 1",
"i"(bit));
} else {
loongson_llsc_mb();
do {
__asm__ __volatile__(
" .set push \n"
" .set "MIPS_ISA_ARCH_LEVEL" \n"
" " __LL "%0, %1 # test_and_clear_bit \n"
" or %2, %0, %3 \n"
" xor %2, %3 \n"
" " __SC "%2, %1 \n"
" .set pop \n"
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (*m), "=&r" (res)
: "ir" (BIT(bit))
: __LLSC_CLOBBER);
} while (unlikely(!res));

res = (temp & BIT(bit)) != 0;
orig = __test_bit_op(*m, "%0",
"or\t%1, %0, %3;"
"xor\t%1, %1, %3",
"ir"(BIT(bit)));
res = (orig & BIT(bit)) != 0;
}

smp_llsc_mb();
Expand All @@ -388,50 +269,28 @@ static inline int test_and_change_bit(unsigned long nr,
{
unsigned long *m = ((unsigned long *)addr) + (nr >> SZLONG_LOG);
int bit = nr & SZLONG_MASK;
unsigned long res, temp;
unsigned long res, orig;

smp_mb__before_llsc();

if (!kernel_uses_llsc) {
res = __mips_test_and_change_bit(nr, addr);
} else if (R10000_LLSC_WAR) {
__asm__ __volatile__(
" .set push \n"
" .set arch=r4000 \n"
"1: " __LL "%0, %1 # test_and_change_bit \n"
" xor %2, %0, %3 \n"
" " __SC "%2, %1 \n"
" beqzl %2, 1b \n"
" and %2, %0, %3 \n"
" .set pop \n"
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (*m), "=&r" (res)
: "ir" (BIT(bit))
: __LLSC_CLOBBER);

res = res != 0;
} else {
loongson_llsc_mb();
do {
__asm__ __volatile__(
" .set push \n"
" .set "MIPS_ISA_ARCH_LEVEL" \n"
" " __LL "%0, %1 # test_and_change_bit \n"
" xor %2, %0, %3 \n"
" " __SC "\t%2, %1 \n"
" .set pop \n"
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (*m), "=&r" (res)
: "ir" (BIT(bit))
: __LLSC_CLOBBER);
} while (unlikely(!res));

res = (temp & BIT(bit)) != 0;
orig = __test_bit_op(*m, "%0",
"xor\t%1, %0, %3",
"ir"(BIT(bit)));
res = (orig & BIT(bit)) != 0;
}

smp_llsc_mb();

return res;
}

#undef __bit_op
#undef __test_bit_op

#include <asm-generic/bitops/non-atomic.h>

/*
Expand Down

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