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authorLinus Torvalds <torvalds@linux-foundation.org>2018-08-13 19:24:32 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-08-13 19:24:32 -0700
commite5a32b5b21a18d24e9d735891550c194b4c60bd2 (patch)
treea5c78286f8e6794a5760ab9f3f029c57ea624183 /arch/mips/include/asm/atomic.h
parent2280a5360e4ff9320bfb12f760a8e9916ff5e7bc (diff)
parent22f20a110321efb7cde3e87ae99862e1036ca285 (diff)
Merge tag 'mips_4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux
Pull MIPS updates from Paul Burton: "Here are the main MIPS changes for 4.19. An overview of the general architecture changes: - Massive DMA ops refactoring from Christoph Hellwig (huzzah for deleting crufty code!). - We introduce NT_MIPS_DSP & NT_MIPS_FP_MODE ELF notes & corresponding regsets to expose DSP ASE & floating point mode state respectively, both for live debugging & core dumps. - We better optimize our code by hard-coding cpu_has_* macros at compile time where their values are known due to the ISA revision that the kernel build is targeting. - The EJTAG exception handler now better handles SMP systems, where it was previously possible for CPUs to clobber a register value saved by another CPU. - Our implementation of memset() gained a couple of fixes for MIPSr6 systems to return correct values in some cases where stores fault. - We now implement ioremap_wc() using the uncached-accelerated cache coherency attribute where supported, which is detected during boot, and fall back to plain uncached access where necessary. The MIPS-specific (and unused in tree) ioremap_uncached_accelerated() & ioremap_cacheable_cow() are removed. - The prctl(PR_SET_FP_MODE, ...) syscall is better supported for SMP systems by reworking the way we ensure remote CPUs that may be running threads within the affected process switch mode. - Systems using the MIPS Coherence Manager will now set the MIPS_IC_SNOOPS_REMOTE flag to avoid some unnecessary cache maintenance overhead when flushing the icache. - A few fixes were made for building with clang/LLVM, which now sucessfully builds kernels for many of our platforms. - Miscellaneous cleanups all over. And some platform-specific changes: - ar7 gained stubs for a few clock API functions to fix build failures for some drivers. - ath79 gained support for a few new SoCs, a few fixes & better gpio-keys support. - Ci20 now exposes its SPI bus using the spi-gpio driver. - The generic platform can now auto-detect a suitable value for PHYS_OFFSET based upon the memory map described by the device tree, allowing us to avoid wasting memory on page book-keeping for systems where RAM starts at a non-zero physical address. - Ingenic systems using the jz4740 platform code now link their vmlinuz higher to allow for kernels of a realistic size. - Loongson32 now builds the kernel targeting MIPSr1 rather than MIPSr2 to avoid CPU errata. - Loongson64 gains a couple of fixes, a workaround for a write buffering issue & support for the Loongson 3A R3.1 CPU. - Malta now uses the piix4-poweroff driver to handle powering down. - Microsemi Ocelot gained support for its SPI bus & NOR flash, its second MDIO bus and can now be supported by a FIT/.itb image. - Octeon saw a bunch of header cleanups which remove a lot of duplicate or unused code" * tag 'mips_4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (123 commits) MIPS: Remove remnants of UASM_ISA MIPS: netlogic: xlr: Remove erroneous check in nlm_fmn_send() MIPS: VDSO: Force link endianness MIPS: Always specify -EB or -EL when using clang MIPS: Use dins to simplify __write_64bit_c0_split() MIPS: Use read-write output operand in __write_64bit_c0_split() MIPS: Avoid using array as parameter to write_c0_kpgd() MIPS: vdso: Allow clang's --target flag in VDSO cflags MIPS: genvdso: Remove GOT checks MIPS: Remove obsolete MIPS checks for DST node "chosen@0" MIPS: generic: Remove input symbols from defconfig MIPS: Delete unused code in linux32.c MIPS: Remove unused sys_32_mmap2 MIPS: Remove nabi_no_regargs mips: dts: mscc: enable spi and NOR flash support on ocelot PCB123 mips: dts: mscc: Add spi on Ocelot MIPS: Loongson: Merge load addresses MIPS: Loongson: Set Loongson32 to MIPS32R1 MIPS: mscc: ocelot: add interrupt controller properties to GPIO controller MIPS: generic: Select MIPS_AUTO_PFN_OFFSET ...
Diffstat (limited to 'arch/mips/include/asm/atomic.h')
-rw-r--r--arch/mips/include/asm/atomic.h195
1 files changed, 36 insertions, 159 deletions
diff --git a/arch/mips/include/asm/atomic.h b/arch/mips/include/asm/atomic.h
index 79be687de4ab..0269b3de8b51 100644
--- a/arch/mips/include/asm/atomic.h
+++ b/arch/mips/include/asm/atomic.h
@@ -22,6 +22,17 @@
#include <asm/cmpxchg.h>
#include <asm/war.h>
+/*
+ * Using a branch-likely instruction to check the result of an sc instruction
+ * works around a bug present in R10000 CPUs prior to revision 3.0 that could
+ * cause ll-sc sequences to execute non-atomically.
+ */
+#if R10000_LLSC_WAR
+# define __scbeqz "beqzl"
+#else
+# define __scbeqz "beqz"
+#endif
+
#define ATOMIC_INIT(i) { (i) }
/*
@@ -44,31 +55,18 @@
#define ATOMIC_OP(op, c_op, asm_op) \
static __inline__ void atomic_##op(int i, atomic_t * v) \
{ \
- if (kernel_uses_llsc && R10000_LLSC_WAR) { \
+ if (kernel_uses_llsc) { \
int temp; \
\
__asm__ __volatile__( \
- " .set arch=r4000 \n" \
+ " .set "MIPS_ISA_LEVEL" \n" \
"1: ll %0, %1 # atomic_" #op " \n" \
" " #asm_op " %0, %2 \n" \
" sc %0, %1 \n" \
- " beqzl %0, 1b \n" \
+ "\t" __scbeqz " %0, 1b \n" \
" .set mips0 \n" \
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
: "Ir" (i)); \
- } else if (kernel_uses_llsc) { \
- int temp; \
- \
- do { \
- __asm__ __volatile__( \
- " .set "MIPS_ISA_LEVEL" \n" \
- " ll %0, %1 # atomic_" #op "\n" \
- " " #asm_op " %0, %2 \n" \
- " sc %0, %1 \n" \
- " .set mips0 \n" \
- : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
- : "Ir" (i)); \
- } while (unlikely(!temp)); \
} else { \
unsigned long flags; \
\
@@ -83,36 +81,20 @@ static __inline__ int atomic_##op##_return_relaxed(int i, atomic_t * v) \
{ \
int result; \
\
- if (kernel_uses_llsc && R10000_LLSC_WAR) { \
+ if (kernel_uses_llsc) { \
int temp; \
\
__asm__ __volatile__( \
- " .set arch=r4000 \n" \
+ " .set "MIPS_ISA_LEVEL" \n" \
"1: ll %1, %2 # atomic_" #op "_return \n" \
" " #asm_op " %0, %1, %3 \n" \
" sc %0, %2 \n" \
- " beqzl %0, 1b \n" \
+ "\t" __scbeqz " %0, 1b \n" \
" " #asm_op " %0, %1, %3 \n" \
" .set mips0 \n" \
: "=&r" (result), "=&r" (temp), \
"+" GCC_OFF_SMALL_ASM() (v->counter) \
: "Ir" (i)); \
- } else if (kernel_uses_llsc) { \
- int temp; \
- \
- do { \
- __asm__ __volatile__( \
- " .set "MIPS_ISA_LEVEL" \n" \
- " ll %1, %2 # atomic_" #op "_return \n" \
- " " #asm_op " %0, %1, %3 \n" \
- " sc %0, %2 \n" \
- " .set mips0 \n" \
- : "=&r" (result), "=&r" (temp), \
- "+" GCC_OFF_SMALL_ASM() (v->counter) \
- : "Ir" (i)); \
- } while (unlikely(!result)); \
- \
- result = temp; result c_op i; \
} else { \
unsigned long flags; \
\
@@ -131,36 +113,20 @@ static __inline__ int atomic_fetch_##op##_relaxed(int i, atomic_t * v) \
{ \
int result; \
\
- if (kernel_uses_llsc && R10000_LLSC_WAR) { \
+ if (kernel_uses_llsc) { \
int temp; \
\
__asm__ __volatile__( \
- " .set arch=r4000 \n" \
+ " .set "MIPS_ISA_LEVEL" \n" \
"1: ll %1, %2 # atomic_fetch_" #op " \n" \
" " #asm_op " %0, %1, %3 \n" \
" sc %0, %2 \n" \
- " beqzl %0, 1b \n" \
+ "\t" __scbeqz " %0, 1b \n" \
" move %0, %1 \n" \
" .set mips0 \n" \
: "=&r" (result), "=&r" (temp), \
"+" GCC_OFF_SMALL_ASM() (v->counter) \
: "Ir" (i)); \
- } else if (kernel_uses_llsc) { \
- int temp; \
- \
- do { \
- __asm__ __volatile__( \
- " .set "MIPS_ISA_LEVEL" \n" \
- " ll %1, %2 # atomic_fetch_" #op " \n" \
- " " #asm_op " %0, %1, %3 \n" \
- " sc %0, %2 \n" \
- " .set mips0 \n" \
- : "=&r" (result), "=&r" (temp), \
- "+" GCC_OFF_SMALL_ASM() (v->counter) \
- : "Ir" (i)); \
- } while (unlikely(!result)); \
- \
- result = temp; \
} else { \
unsigned long flags; \
\
@@ -218,38 +184,17 @@ static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
smp_mb__before_llsc();
- if (kernel_uses_llsc && R10000_LLSC_WAR) {
- int temp;
-
- __asm__ __volatile__(
- " .set arch=r4000 \n"
- "1: ll %1, %2 # atomic_sub_if_positive\n"
- " subu %0, %1, %3 \n"
- " bltz %0, 1f \n"
- " sc %0, %2 \n"
- " .set noreorder \n"
- " beqzl %0, 1b \n"
- " subu %0, %1, %3 \n"
- " .set reorder \n"
- "1: \n"
- " .set mips0 \n"
- : "=&r" (result), "=&r" (temp),
- "+" GCC_OFF_SMALL_ASM() (v->counter)
- : "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter)
- : "memory");
- } else if (kernel_uses_llsc) {
+ if (kernel_uses_llsc) {
int temp;
__asm__ __volatile__(
" .set "MIPS_ISA_LEVEL" \n"
"1: ll %1, %2 # atomic_sub_if_positive\n"
" subu %0, %1, %3 \n"
+ " move %1, %0 \n"
" bltz %0, 1f \n"
- " sc %0, %2 \n"
- " .set noreorder \n"
- " beqz %0, 1b \n"
- " subu %0, %1, %3 \n"
- " .set reorder \n"
+ " sc %1, %2 \n"
+ "\t" __scbeqz " %1, 1b \n"
"1: \n"
" .set mips0 \n"
: "=&r" (result), "=&r" (temp),
@@ -301,31 +246,18 @@ static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
#define ATOMIC64_OP(op, c_op, asm_op) \
static __inline__ void atomic64_##op(long i, atomic64_t * v) \
{ \
- if (kernel_uses_llsc && R10000_LLSC_WAR) { \
+ if (kernel_uses_llsc) { \
long temp; \
\
__asm__ __volatile__( \
- " .set arch=r4000 \n" \
+ " .set "MIPS_ISA_LEVEL" \n" \
"1: lld %0, %1 # atomic64_" #op " \n" \
" " #asm_op " %0, %2 \n" \
" scd %0, %1 \n" \
- " beqzl %0, 1b \n" \
+ "\t" __scbeqz " %0, 1b \n" \
" .set mips0 \n" \
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
: "Ir" (i)); \
- } else if (kernel_uses_llsc) { \
- long temp; \
- \
- do { \
- __asm__ __volatile__( \
- " .set "MIPS_ISA_LEVEL" \n" \
- " lld %0, %1 # atomic64_" #op "\n" \
- " " #asm_op " %0, %2 \n" \
- " scd %0, %1 \n" \
- " .set mips0 \n" \
- : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
- : "Ir" (i)); \
- } while (unlikely(!temp)); \
} else { \
unsigned long flags; \
\
@@ -340,37 +272,20 @@ static __inline__ long atomic64_##op##_return_relaxed(long i, atomic64_t * v) \
{ \
long result; \
\
- if (kernel_uses_llsc && R10000_LLSC_WAR) { \
+ if (kernel_uses_llsc) { \
long temp; \
\
__asm__ __volatile__( \
- " .set arch=r4000 \n" \
+ " .set "MIPS_ISA_LEVEL" \n" \
"1: lld %1, %2 # atomic64_" #op "_return\n" \
" " #asm_op " %0, %1, %3 \n" \
" scd %0, %2 \n" \
- " beqzl %0, 1b \n" \
+ "\t" __scbeqz " %0, 1b \n" \
" " #asm_op " %0, %1, %3 \n" \
" .set mips0 \n" \
: "=&r" (result), "=&r" (temp), \
"+" GCC_OFF_SMALL_ASM() (v->counter) \
: "Ir" (i)); \
- } else if (kernel_uses_llsc) { \
- long temp; \
- \
- do { \
- __asm__ __volatile__( \
- " .set "MIPS_ISA_LEVEL" \n" \
- " lld %1, %2 # atomic64_" #op "_return\n" \
- " " #asm_op " %0, %1, %3 \n" \
- " scd %0, %2 \n" \
- " .set mips0 \n" \
- : "=&r" (result), "=&r" (temp), \
- "=" GCC_OFF_SMALL_ASM() (v->counter) \
- : "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter) \
- : "memory"); \
- } while (unlikely(!result)); \
- \
- result = temp; result c_op i; \
} else { \
unsigned long flags; \
\
@@ -393,33 +308,16 @@ static __inline__ long atomic64_fetch_##op##_relaxed(long i, atomic64_t * v) \
long temp; \
\
__asm__ __volatile__( \
- " .set arch=r4000 \n" \
+ " .set "MIPS_ISA_LEVEL" \n" \
"1: lld %1, %2 # atomic64_fetch_" #op "\n" \
" " #asm_op " %0, %1, %3 \n" \
" scd %0, %2 \n" \
- " beqzl %0, 1b \n" \
+ "\t" __scbeqz " %0, 1b \n" \
" move %0, %1 \n" \
" .set mips0 \n" \
: "=&r" (result), "=&r" (temp), \
"+" GCC_OFF_SMALL_ASM() (v->counter) \
: "Ir" (i)); \
- } else if (kernel_uses_llsc) { \
- long temp; \
- \
- do { \
- __asm__ __volatile__( \
- " .set "MIPS_ISA_LEVEL" \n" \
- " lld %1, %2 # atomic64_fetch_" #op "\n" \
- " " #asm_op " %0, %1, %3 \n" \
- " scd %0, %2 \n" \
- " .set mips0 \n" \
- : "=&r" (result), "=&r" (temp), \
- "=" GCC_OFF_SMALL_ASM() (v->counter) \
- : "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter) \
- : "memory"); \
- } while (unlikely(!result)); \
- \
- result = temp; \
} else { \
unsigned long flags; \
\
@@ -478,38 +376,17 @@ static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
smp_mb__before_llsc();
- if (kernel_uses_llsc && R10000_LLSC_WAR) {
- long temp;
-
- __asm__ __volatile__(
- " .set arch=r4000 \n"
- "1: lld %1, %2 # atomic64_sub_if_positive\n"
- " dsubu %0, %1, %3 \n"
- " bltz %0, 1f \n"
- " scd %0, %2 \n"
- " .set noreorder \n"
- " beqzl %0, 1b \n"
- " dsubu %0, %1, %3 \n"
- " .set reorder \n"
- "1: \n"
- " .set mips0 \n"
- : "=&r" (result), "=&r" (temp),
- "=" GCC_OFF_SMALL_ASM() (v->counter)
- : "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter)
- : "memory");
- } else if (kernel_uses_llsc) {
+ if (kernel_uses_llsc) {
long temp;
__asm__ __volatile__(
" .set "MIPS_ISA_LEVEL" \n"
"1: lld %1, %2 # atomic64_sub_if_positive\n"
" dsubu %0, %1, %3 \n"
+ " move %1, %0 \n"
" bltz %0, 1f \n"
- " scd %0, %2 \n"
- " .set noreorder \n"
- " beqz %0, 1b \n"
- " dsubu %0, %1, %3 \n"
- " .set reorder \n"
+ " scd %1, %2 \n"
+ "\t" __scbeqz " %1, 1b \n"
"1: \n"
" .set mips0 \n"
: "=&r" (result), "=&r" (temp),