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The previous commit, roughly one and a half years ago removed the
branch prediction optimization for LINT, because the kernel was too large. This commit now removes it altogether since it causes build failures for GENERIC kernels and the various applicable trends are such that one can expect that it these failure will cause more problems than they're worth in the future. These trends include: 1. Alpha was demoted from tier 1 to tier 2 due to lack of active support. The number of people willing to fix build breakages is not likely to increase and those developers that do have the gumption to test MI changes on alpha are not likely to spend time fixing unexpected build failures first. 2. The kernel will only increase in size. Even though stripped-down kernels do link without problems now, compiler optimizations (like inlining) and new (non-optional) functionality will likely cause stripped-down kernels to break in the future as well. So, with my asbestos suit on, get rid of potential problems before they happen. MT5 candidate.
This commit is contained in:
Marcel Moolenaar
parent
ca95b2de43
commit
7dafab2e78
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=135023
@ -31,18 +31,6 @@
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#include <machine/alpha_cpu.h>
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/*
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* Quick and dirty workaround for compiling LINT. The kernel is too
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* large to jump between sections without linker stubs/trampolines.
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*/
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#ifdef COMPILING_LINT
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#define __COLD_SECTION "br 3f\n"
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#define __HOT_SECTION "3:\n"
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#else
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#define __COLD_SECTION ".section .text3,\"ax\"\n"
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#define __HOT_SECTION ".previous\n"
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#endif
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/*
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* Various simple arithmetic on memory which is atomic in the presence
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* of interrupts and SMP safe.
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@ -67,10 +55,7 @@ static __inline void atomic_set_32(volatile u_int32_t *p, u_int32_t v)
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"1:\tldl_l %0, %2\n\t" /* load old value */
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"bis %0, %3, %0\n\t" /* calculate new value */
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"stl_c %0, %1\n\t" /* attempt to store */
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"beq %0, 2f\n\t" /* spin if failed */
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__COLD_SECTION /* improve branch prediction */
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"2:\tbr 1b\n" /* try again */
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__HOT_SECTION
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"beq %0, 1b\n" /* spin if failed */
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: "=&r" (temp), "=m" (*p)
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: "m" (*p), "r" (v)
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: "memory");
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@ -86,10 +71,7 @@ static __inline void atomic_clear_32(volatile u_int32_t *p, u_int32_t v)
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"1:\tldl_l %0, %1\n\t" /* load old value */
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"bic %0, %2, %0\n\t" /* calculate new value */
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"stl_c %0, %1\n\t" /* attempt to store */
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"beq %0, 2f\n\t" /* spin if failed */
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__COLD_SECTION /* improve branch prediction */
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"2:\tbr 1b\n" /* try again */
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__HOT_SECTION
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"beq %0, 1b\n" /* spin if failed */
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: "=&r" (temp), "+m" (*p)
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: "r" (v)
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: "memory");
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@ -105,10 +87,7 @@ static __inline void atomic_add_32(volatile u_int32_t *p, u_int32_t v)
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"1:\tldl_l %0, %1\n\t" /* load old value */
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"addl %0, %2, %0\n\t" /* calculate new value */
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"stl_c %0, %1\n\t" /* attempt to store */
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"beq %0, 2f\n\t" /* spin if failed */
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__COLD_SECTION /* improve branch prediction */
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"2:\tbr 1b\n" /* try again */
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__HOT_SECTION
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"beq %0, 1b\n" /* spin if failed */
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: "=&r" (temp), "+m" (*p)
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: "r" (v)
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: "memory");
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@ -124,10 +103,7 @@ static __inline void atomic_subtract_32(volatile u_int32_t *p, u_int32_t v)
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"1:\tldl_l %0, %1\n\t" /* load old value */
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"subl %0, %2, %0\n\t" /* calculate new value */
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"stl_c %0, %1\n\t" /* attempt to store */
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"beq %0, 2f\n\t" /* spin if failed */
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__COLD_SECTION /* improve branch prediction */
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"2:\tbr 1b\n" /* try again */
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__HOT_SECTION
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"beq %0, 1b\n" /* spin if failed */
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: "=&r" (temp), "+m" (*p)
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: "r" (v)
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: "memory");
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@ -144,10 +120,7 @@ static __inline u_int32_t atomic_readandclear_32(volatile u_int32_t *addr)
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"1:\tldl_l %0,%2\n\t" /* load current value, asserting lock */
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"ldiq %1,0\n\t" /* value to store */
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"stl_c %1,%2\n\t" /* attempt to store */
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"beq %1,2f\n\t" /* if the store failed, spin */
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"br 3f\n" /* it worked, exit */
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"2:\tbr 1b\n" /* *addr not updated, loop */
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"3:\n" /* it worked */
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"beq %1,1b\n" /* if the store failed, spin */
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: "=&r"(result), "=&r"(temp), "+m" (*addr)
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:
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: "memory");
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@ -165,10 +138,7 @@ static __inline void atomic_set_64(volatile u_int64_t *p, u_int64_t v)
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"1:\tldq_l %0, %1\n\t" /* load old value */
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"bis %0, %2, %0\n\t" /* calculate new value */
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"stq_c %0, %1\n\t" /* attempt to store */
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"beq %0, 2f\n\t" /* spin if failed */
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__COLD_SECTION /* improve branch prediction */
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"2:\tbr 1b\n" /* try again */
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__HOT_SECTION
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"beq %0, 1b\n" /* spin if failed */
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: "=&r" (temp), "+m" (*p)
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: "r" (v)
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: "memory");
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@ -184,10 +154,7 @@ static __inline void atomic_clear_64(volatile u_int64_t *p, u_int64_t v)
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"1:\tldq_l %0, %1\n\t" /* load old value */
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"bic %0, %2, %0\n\t" /* calculate new value */
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"stq_c %0, %1\n\t" /* attempt to store */
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"beq %0, 2f\n\t" /* spin if failed */
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__COLD_SECTION /* improve branch prediction */
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"2:\tbr 1b\n" /* try again */
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__HOT_SECTION
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"beq %0, 1b\n" /* spin if failed */
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: "=&r" (temp), "+m" (*p)
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: "r" (v)
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: "memory");
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@ -203,10 +170,7 @@ static __inline void atomic_add_64(volatile u_int64_t *p, u_int64_t v)
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"1:\tldq_l %0, %1\n\t" /* load old value */
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"addq %0, %2, %0\n\t" /* calculate new value */
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"stq_c %0, %1\n\t" /* attempt to store */
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"beq %0, 2f\n\t" /* spin if failed */
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__COLD_SECTION /* improve branch prediction */
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"2:\tbr 1b\n" /* try again */
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__HOT_SECTION
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"beq %0, 1b\n" /* spin if failed */
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: "=&r" (temp), "+m" (*p)
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: "r" (v)
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: "memory");
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@ -222,10 +186,7 @@ static __inline void atomic_subtract_64(volatile u_int64_t *p, u_int64_t v)
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"1:\tldq_l %0, %1\n\t" /* load old value */
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"subq %0, %2, %0\n\t" /* calculate new value */
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"stq_c %0, %1\n\t" /* attempt to store */
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"beq %0, 2f\n\t" /* spin if failed */
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__COLD_SECTION /* improve branch prediction */
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"2:\tbr 1b\n" /* try again */
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__HOT_SECTION
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"beq %0, 1b\n" /* spin if failed */
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: "=&r" (temp), "+m" (*p)
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: "r" (v)
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: "memory");
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@ -242,10 +203,7 @@ static __inline u_int64_t atomic_readandclear_64(volatile u_int64_t *addr)
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"1:\tldq_l %0,%2\n\t" /* load current value, asserting lock */
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"ldiq %1,0\n\t" /* value to store */
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"stq_c %1,%2\n\t" /* attempt to store */
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"beq %1,2f\n\t" /* if the store failed, spin */
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"br 3f\n" /* it worked, exit */
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"2:\tbr 1b\n" /* *addr not updated, loop */
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"3:\n" /* it worked */
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"beq %1,1b\n" /* if the store failed, spin */
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: "=&r"(result), "=&r"(temp), "+m" (*addr)
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:
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: "memory");
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@ -385,11 +343,8 @@ atomic_cmpset_32(volatile u_int32_t* p, u_int32_t cmpval, u_int32_t newval)
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"beq %0, 2f\n\t" /* exit if not equal */
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"mov %3, %0\n\t" /* value to store */
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"stl_c %0, %1\n\t" /* attempt to store */
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"beq %0, 3f\n\t" /* if it failed, spin */
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"2:\n" /* done */
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__COLD_SECTION /* improve branch prediction */
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"3:\tbr 1b\n" /* try again */
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__HOT_SECTION
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"beq %0, 1b\n\t" /* if it failed, spin */
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"2:\n"
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: "=&r" (ret), "+m" (*p)
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: "r" ((long)(int)cmpval), "r" (newval)
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: "memory");
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@ -415,11 +370,8 @@ atomic_cmpset_64(volatile u_int64_t* p, u_int64_t cmpval, u_int64_t newval)
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"beq %0, 2f\n\t" /* exit if not equal */
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"mov %3, %0\n\t" /* value to store */
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"stq_c %0, %1\n\t" /* attempt to store */
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"beq %0, 3f\n\t" /* if it failed, spin */
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"2:\n" /* done */
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__COLD_SECTION /* improve branch prediction */
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"3:\tbr 1b\n" /* try again */
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__HOT_SECTION
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"beq %0, 1b\n\t" /* if it failed, spin */
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"2:\n"
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: "=&r" (ret), "+m" (*p)
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: "r" (cmpval), "r" (newval)
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: "memory");
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