[RFC] 64bit LWS CAS

Message ID	20140717220000.555b2bec@dellete.lux.tuxicoman.be (mailing list archive)
State	Superseded
Headers	show Return-Path: <linux-parisc-owner@kernel.org> Date: Thu, 17 Jul 2014 22:00:00 +0200 From: Guy Martin <gmsoft@tuxicoman.be> To: linux-parisc <linux-parisc@vger.kernel.org> Subject: [RFC PATCH] 64bit LWS CAS Message-ID: <20140717220000.555b2bec@dellete.lux.tuxicoman.be> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="MP_/km4FDq+E+/5RFV+s67pDqBM" Sender: linux-parisc-owner@vger.kernel.org Precedence: bulk

--- libgcc/config/pa/linux-atomic.c.orig 2014-07-16 19:29:28.670595484 +0000 +++ libgcc/config/pa/linux-atomic.c 2014-07-16 19:31:32.754003341 +0000 @@ -24,6 +24,8 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see <http://www.gnu.org/licenses/>. */ +#include <stdint.h> + #define EFAULT 14 #define EBUSY 16 #define ENOSYS 251 @@ -75,6 +77,39 @@ return lws_errno; } +/* Kernel helper for compare-and-exchange a 64-bit value from ELF32. */ +static inline long +__kernel_cmpxchg_dword32 (int64_t oldval, int64_t newval, int64_t *mem) +{ + register unsigned long lws_mem asm("r26") = (unsigned long) (mem); + register long lws_ret_h asm("r28"); + register long lws_ret_l asm("r29"); + register long lws_errno asm("r21"); + register int lws_old_h asm("r25") = oldval >> 32; + register int lws_old_l asm("r24") = oldval & 0xffffffff; + register int lws_new_h asm("r23") = newval >> 32; + register int lws_new_l asm("r22") = newval & 0xffffffff; + asm volatile ( "ble 0xb0(%%sr2, %%r0) \n\t" + "ldi %8, %%r20 \n\t" + : "=r" (lws_ret_h), "=r" (lws_ret_l), "=r" (lws_errno), "=r" (lws_mem), + "=r" (lws_old_h), "=r" (lws_old_l), "=r" (lws_new_h), "=r" (lws_new_l) + : "i" (2), "3" (lws_mem), "4" (lws_old_h), "5" (lws_old_l), "6" (lws_new_h), "7" (lws_new_l) + : "r1", "r20", "r31", "memory" + ); + if (__builtin_expect (lws_errno == -EFAULT || lws_errno == -ENOSYS, 0)) + ABORT_INSTRUCTION; + + int64_t lws_ret = ((int64_t)lws_ret_h << 32) | (int64_t)lws_ret_l; + + /* If the kernel LWS call succeeded (lws_errno == 0), lws_ret contains + the old value from memory. If this value is equal to OLDVAL, the + new value was written to memory. If not, return -EBUSY. */ + if (!lws_errno && lws_ret != oldval) + lws_errno = -EBUSY; + + return lws_errno; +} + #define HIDDEN __attribute__ ((visibility ("hidden"))) /* Big endian masks */ @@ -84,6 +119,28 @@ #define MASK_1 0xffu #define MASK_2 0xffffu +#define FETCH_AND_OP_DWORD(OP, PFX_OP, INF_OP) \ + int64_t HIDDEN \ + __sync_fetch_and_##OP##_8 (int64_t *ptr, int64_t val) \ + { \ + int64_t tmp; \ + int failure; \ + \ + do { \ + tmp = *ptr; \ + failure = __kernel_cmpxchg_dword32 (tmp, PFX_OP (tmp INF_OP val), ptr); \ + } while (failure != 0); \ + \ + return tmp; \ + } + +FETCH_AND_OP_DWORD (add, , +) +FETCH_AND_OP_DWORD (sub, , -) +FETCH_AND_OP_DWORD (or, , |) +FETCH_AND_OP_DWORD (and, , &) +FETCH_AND_OP_DWORD (xor, , ^) +FETCH_AND_OP_DWORD (nand, ~, &) + #define FETCH_AND_OP_WORD(OP, PFX_OP, INF_OP) \ int HIDDEN \ __sync_fetch_and_##OP##_4 (int *ptr, int val) \ @@ -147,6 +204,28 @@ SUBWORD_SYNC_OP (xor, , ^, unsigned char, 1, oldval) SUBWORD_SYNC_OP (nand, ~, &, unsigned char, 1, oldval) +#define OP_AND_FETCH_DWORD(OP, PFX_OP, INF_OP) \ + int64_t HIDDEN \ + __sync_##OP##_and_fetch_8 (int64_t *ptr, int64_t val) \ + { \ + int64_t tmp; \ + int failure; \ + \ + do { \ + tmp = *ptr; \ + failure = __kernel_cmpxchg_dword32 (tmp, PFX_OP (tmp INF_OP val), ptr); \ + } while (failure != 0); \ + \ + return PFX_OP (tmp INF_OP val); \ + } + +OP_AND_FETCH_DWORD (add, , +) +OP_AND_FETCH_DWORD (sub, , -) +OP_AND_FETCH_DWORD (or, , |) +OP_AND_FETCH_DWORD (and, , &) +OP_AND_FETCH_DWORD (xor, , ^) +OP_AND_FETCH_DWORD (nand, ~, &) + #define OP_AND_FETCH_WORD(OP, PFX_OP, INF_OP) \ int HIDDEN \ __sync_##OP##_and_fetch_4 (int *ptr, int val) \ @@ -182,6 +261,26 @@ SUBWORD_SYNC_OP (xor, , ^, unsigned char, 1, newval) SUBWORD_SYNC_OP (nand, ~, &, unsigned char, 1, newval) +int64_t HIDDEN +__sync_val_compare_and_swap_8 (int64_t *ptr, int64_t oldval, int64_t newval) +{ + int64_t actual_oldval; + int fail; + + while (1) + { + actual_oldval = *ptr; + + if (__builtin_expect (oldval != actual_oldval, 0)) + return actual_oldval; + + fail = __kernel_cmpxchg_dword32 (actual_oldval, newval, ptr); + + if (__builtin_expect (!fail, 1)) + return actual_oldval; + } +} + int HIDDEN __sync_val_compare_and_swap_4 (int *ptr, int oldval, int newval) { @@ -256,6 +355,20 @@ SUBWORD_BOOL_CAS (unsigned short, 2) SUBWORD_BOOL_CAS (unsigned char, 1) +int64_t HIDDEN +__sync_lock_test_and_set_8 (int64_t *ptr, int64_t val) +{ + int64_t oldval; + int failure; + + do { + oldval = *ptr; + failure = __kernel_cmpxchg_dword32 (oldval, val, ptr); + } while (failure != 0); + + return oldval; +} + int HIDDEN __sync_lock_test_and_set_4 (int *ptr, int val) { @@ -300,6 +413,7 @@ *ptr = 0; \ } -SYNC_LOCK_RELEASE (int, 4) -SYNC_LOCK_RELEASE (short, 2) -SYNC_LOCK_RELEASE (char, 1) +SYNC_LOCK_RELEASE (int64_t, 8) +SYNC_LOCK_RELEASE (int, 4) +SYNC_LOCK_RELEASE (short, 2) +SYNC_LOCK_RELEASE (char, 1)

[RFC] 64bit LWS CAS

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