1 | // |
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2 | // Cforall Version 1.0.0 Copyright (C) 2020 University of Waterloo |
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3 | // |
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4 | // The contents of this file are covered under the licence agreement in the |
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5 | // file "LICENCE" distributed with Cforall. |
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6 | // |
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7 | // io/setup.cfa -- |
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8 | // |
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9 | // Author : Thierry Delisle |
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10 | // Created On : Fri Jul 31 16:25:51 2020 |
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11 | // Last Modified By : |
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12 | // Last Modified On : |
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13 | // Update Count : |
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14 | // |
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15 | |
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16 | #define __cforall_thread__ |
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17 | #define _GNU_SOURCE /* See feature_test_macros(7) */ |
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18 | |
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19 | #if defined(__CFA_DEBUG__) |
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20 | // #define __CFA_DEBUG_PRINT_IO__ |
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21 | // #define __CFA_DEBUG_PRINT_IO_CORE__ |
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22 | #endif |
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23 | |
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24 | #include "io/types.hfa" |
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25 | #include "kernel.hfa" |
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26 | |
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27 | #if !defined(CFA_HAVE_LINUX_IO_URING_H) |
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28 | void ?{}(io_context_params & this) {} |
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29 | |
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30 | void ?{}($io_context & this, struct cluster & cl) {} |
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31 | void ^?{}($io_context & this) {} |
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32 | |
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33 | void __cfa_io_start( processor * proc ) {} |
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34 | void __cfa_io_flush( processor * proc ) {} |
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35 | void __cfa_io_stop ( processor * proc ) {} |
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36 | |
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37 | $io_arbiter * create(void) { return 0p; } |
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38 | void destroy($io_arbiter *) {} |
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39 | |
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40 | #else |
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41 | #include <errno.h> |
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42 | #include <stdint.h> |
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43 | #include <string.h> |
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44 | #include <signal.h> |
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45 | #include <unistd.h> |
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46 | |
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47 | extern "C" { |
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48 | #include <pthread.h> |
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49 | #include <sys/epoll.h> |
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50 | #include <sys/eventfd.h> |
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51 | #include <sys/mman.h> |
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52 | #include <sys/syscall.h> |
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53 | |
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54 | #include <linux/io_uring.h> |
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55 | } |
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56 | |
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57 | #include "bitmanip.hfa" |
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58 | #include "kernel_private.hfa" |
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59 | #include "thread.hfa" |
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60 | |
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61 | void ?{}(io_context_params & this) { |
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62 | this.num_entries = 256; |
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63 | } |
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64 | |
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65 | static void * __io_poller_slow( void * arg ); |
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66 | |
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67 | // Weirdly, some systems that do support io_uring don't actually define these |
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68 | #ifdef __alpha__ |
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69 | /* |
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70 | * alpha is the only exception, all other architectures |
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71 | * have common numbers for new system calls. |
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72 | */ |
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73 | #ifndef __NR_io_uring_setup |
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74 | #define __NR_io_uring_setup 535 |
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75 | #endif |
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76 | #ifndef __NR_io_uring_enter |
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77 | #define __NR_io_uring_enter 536 |
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78 | #endif |
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79 | #ifndef __NR_io_uring_register |
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80 | #define __NR_io_uring_register 537 |
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81 | #endif |
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82 | #else /* !__alpha__ */ |
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83 | #ifndef __NR_io_uring_setup |
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84 | #define __NR_io_uring_setup 425 |
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85 | #endif |
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86 | #ifndef __NR_io_uring_enter |
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87 | #define __NR_io_uring_enter 426 |
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88 | #endif |
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89 | #ifndef __NR_io_uring_register |
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90 | #define __NR_io_uring_register 427 |
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91 | #endif |
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92 | #endif |
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93 | |
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94 | //============================================================================================= |
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95 | // I/O Context Constrution/Destruction |
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96 | //============================================================================================= |
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97 | |
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98 | |
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99 | |
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100 | static void __io_uring_setup ( $io_context & this, const io_context_params & params_in, int procfd ); |
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101 | static void __io_uring_teardown( $io_context & this ); |
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102 | static void __epoll_register($io_context & ctx); |
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103 | static void __epoll_unregister($io_context & ctx); |
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104 | void __ioarbiter_register( $io_arbiter & mutex, $io_context & ctx ); |
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105 | void __ioarbiter_unregister( $io_arbiter & mutex, $io_context & ctx ); |
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106 | |
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107 | void ?{}($io_context & this, processor * proc, struct cluster & cl) { |
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108 | /* paranoid */ verify( cl.io.arbiter ); |
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109 | this.proc = proc; |
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110 | this.arbiter = cl.io.arbiter; |
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111 | this.ext_sq.empty = true; |
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112 | (this.ext_sq.queue){}; |
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113 | __io_uring_setup( this, cl.io.params, proc->idle ); |
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114 | __cfadbg_print_safe(io_core, "Kernel I/O : Created ring for io_context %u (%p)\n", this.fd, &this); |
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115 | } |
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116 | |
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117 | void ^?{}($io_context & this) { |
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118 | __cfadbg_print_safe(io_core, "Kernel I/O : tearing down io_context %u\n", this.fd); |
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119 | |
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120 | __io_uring_teardown( this ); |
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121 | __cfadbg_print_safe(io_core, "Kernel I/O : Destroyed ring for io_context %u\n", this.fd); |
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122 | } |
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123 | |
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124 | extern void __disable_interrupts_hard(); |
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125 | extern void __enable_interrupts_hard(); |
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126 | |
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127 | static void __io_uring_setup( $io_context & this, const io_context_params & params_in, int procfd ) { |
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128 | // Step 1 : call to setup |
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129 | struct io_uring_params params; |
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130 | memset(¶ms, 0, sizeof(params)); |
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131 | // if( params_in.poll_submit ) params.flags |= IORING_SETUP_SQPOLL; |
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132 | // if( params_in.poll_complete ) params.flags |= IORING_SETUP_IOPOLL; |
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133 | |
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134 | __u32 nentries = params_in.num_entries != 0 ? params_in.num_entries : 256; |
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135 | if( !is_pow2(nentries) ) { |
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136 | abort("ERROR: I/O setup 'num_entries' must be a power of 2\n"); |
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137 | } |
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138 | |
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139 | int fd = syscall(__NR_io_uring_setup, nentries, ¶ms ); |
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140 | if(fd < 0) { |
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141 | abort("KERNEL ERROR: IO_URING SETUP - %s\n", strerror(errno)); |
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142 | } |
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143 | |
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144 | // Step 2 : mmap result |
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145 | struct __sub_ring_t & sq = this.sq; |
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146 | struct __cmp_ring_t & cq = this.cq; |
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147 | |
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148 | // calculate the right ring size |
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149 | sq.ring_sz = params.sq_off.array + (params.sq_entries * sizeof(unsigned) ); |
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150 | cq.ring_sz = params.cq_off.cqes + (params.cq_entries * sizeof(struct io_uring_cqe)); |
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151 | |
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152 | // Requires features |
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153 | #if defined(IORING_FEAT_SINGLE_MMAP) |
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154 | // adjust the size according to the parameters |
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155 | if ((params.features & IORING_FEAT_SINGLE_MMAP) != 0) { |
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156 | cq.ring_sz = sq.ring_sz = max(cq.ring_sz, sq.ring_sz); |
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157 | } |
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158 | #endif |
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159 | |
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160 | // mmap the Submit Queue into existence |
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161 | sq.ring_ptr = mmap(0, sq.ring_sz, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, fd, IORING_OFF_SQ_RING); |
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162 | if (sq.ring_ptr == (void*)MAP_FAILED) { |
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163 | abort("KERNEL ERROR: IO_URING MMAP1 - %s\n", strerror(errno)); |
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164 | } |
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165 | |
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166 | // Requires features |
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167 | #if defined(IORING_FEAT_SINGLE_MMAP) |
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168 | // mmap the Completion Queue into existence (may or may not be needed) |
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169 | if ((params.features & IORING_FEAT_SINGLE_MMAP) != 0) { |
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170 | cq.ring_ptr = sq.ring_ptr; |
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171 | } |
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172 | else |
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173 | #endif |
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174 | { |
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175 | // We need multiple call to MMAP |
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176 | cq.ring_ptr = mmap(0, cq.ring_sz, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, fd, IORING_OFF_CQ_RING); |
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177 | if (cq.ring_ptr == (void*)MAP_FAILED) { |
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178 | munmap(sq.ring_ptr, sq.ring_sz); |
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179 | abort("KERNEL ERROR: IO_URING MMAP2 - %s\n", strerror(errno)); |
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180 | } |
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181 | } |
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182 | |
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183 | // mmap the submit queue entries |
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184 | size_t size = params.sq_entries * sizeof(struct io_uring_sqe); |
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185 | sq.sqes = (struct io_uring_sqe *)mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, fd, IORING_OFF_SQES); |
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186 | if (sq.sqes == (struct io_uring_sqe *)MAP_FAILED) { |
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187 | munmap(sq.ring_ptr, sq.ring_sz); |
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188 | if (cq.ring_ptr != sq.ring_ptr) munmap(cq.ring_ptr, cq.ring_sz); |
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189 | abort("KERNEL ERROR: IO_URING MMAP3 - %s\n", strerror(errno)); |
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190 | } |
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191 | |
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192 | // Step 3 : Initialize the data structure |
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193 | // Get the pointers from the kernel to fill the structure |
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194 | // submit queue |
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195 | sq.kring.head = (volatile __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.head); |
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196 | sq.kring.tail = (volatile __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.tail); |
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197 | sq.kring.array = ( __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.array); |
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198 | sq.mask = ( const __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.ring_mask); |
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199 | sq.num = ( const __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.ring_entries); |
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200 | sq.flags = ( __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.flags); |
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201 | sq.dropped = ( __u32 *)(((intptr_t)sq.ring_ptr) + params.sq_off.dropped); |
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202 | |
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203 | sq.kring.released = 0; |
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204 | |
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205 | sq.free_ring.head = 0; |
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206 | sq.free_ring.tail = *sq.num; |
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207 | sq.free_ring.array = alloc( *sq.num, 128`align ); |
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208 | for(i; (__u32)*sq.num) { |
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209 | sq.free_ring.array[i] = i; |
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210 | } |
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211 | |
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212 | sq.to_submit = 0; |
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213 | |
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214 | // completion queue |
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215 | cq.head = (volatile __u32 *)(((intptr_t)cq.ring_ptr) + params.cq_off.head); |
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216 | cq.tail = (volatile __u32 *)(((intptr_t)cq.ring_ptr) + params.cq_off.tail); |
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217 | cq.mask = ( const __u32 *)(((intptr_t)cq.ring_ptr) + params.cq_off.ring_mask); |
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218 | cq.num = ( const __u32 *)(((intptr_t)cq.ring_ptr) + params.cq_off.ring_entries); |
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219 | cq.overflow = ( __u32 *)(((intptr_t)cq.ring_ptr) + params.cq_off.overflow); |
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220 | cq.cqes = (struct io_uring_cqe *)(((intptr_t)cq.ring_ptr) + params.cq_off.cqes); |
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221 | |
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222 | // Step 4 : eventfd |
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223 | // io_uring_register is so f*cking slow on some machine that it |
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224 | // will never succeed if preemption isn't hard blocked |
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225 | __cfadbg_print_safe(io_core, "Kernel I/O : registering %d for completion with ring %d\n", procfd, fd); |
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226 | |
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227 | __disable_interrupts_hard(); |
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228 | |
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229 | int ret = syscall( __NR_io_uring_register, fd, IORING_REGISTER_EVENTFD, &procfd, 1); |
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230 | if (ret < 0) { |
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231 | abort("KERNEL ERROR: IO_URING EVENTFD REGISTER - %s\n", strerror(errno)); |
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232 | } |
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233 | |
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234 | __enable_interrupts_hard(); |
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235 | |
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236 | __cfadbg_print_safe(io_core, "Kernel I/O : registered %d for completion with ring %d\n", procfd, fd); |
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237 | |
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238 | // some paranoid checks |
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239 | /* paranoid */ verifyf( (*cq.mask) == ((*cq.num) - 1ul32), "IO_URING Expected mask to be %u (%u entries), was %u", (*cq.num) - 1ul32, *cq.num, *cq.mask ); |
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240 | /* paranoid */ verifyf( (*cq.num) >= nentries, "IO_URING Expected %u entries, got %u", nentries, *cq.num ); |
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241 | /* paranoid */ verifyf( (*cq.head) == 0, "IO_URING Expected head to be 0, got %u", *cq.head ); |
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242 | /* paranoid */ verifyf( (*cq.tail) == 0, "IO_URING Expected tail to be 0, got %u", *cq.tail ); |
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243 | |
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244 | /* paranoid */ verifyf( (*sq.mask) == ((*sq.num) - 1ul32), "IO_URING Expected mask to be %u (%u entries), was %u", (*sq.num) - 1ul32, *sq.num, *sq.mask ); |
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245 | /* paranoid */ verifyf( (*sq.num) >= nentries, "IO_URING Expected %u entries, got %u", nentries, *sq.num ); |
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246 | /* paranoid */ verifyf( (*sq.kring.head) == 0, "IO_URING Expected head to be 0, got %u", *sq.kring.head ); |
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247 | /* paranoid */ verifyf( (*sq.kring.tail) == 0, "IO_URING Expected tail to be 0, got %u", *sq.kring.tail ); |
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248 | |
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249 | // Update the global ring info |
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250 | this.ring_flags = 0; |
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251 | this.fd = fd; |
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252 | } |
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253 | |
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254 | static void __io_uring_teardown( $io_context & this ) { |
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255 | // Shutdown the io rings |
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256 | struct __sub_ring_t & sq = this.sq; |
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257 | struct __cmp_ring_t & cq = this.cq; |
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258 | |
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259 | // unmap the submit queue entries |
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260 | munmap(sq.sqes, (*sq.num) * sizeof(struct io_uring_sqe)); |
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261 | |
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262 | // unmap the Submit Queue ring |
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263 | munmap(sq.ring_ptr, sq.ring_sz); |
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264 | |
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265 | // unmap the Completion Queue ring, if it is different |
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266 | if (cq.ring_ptr != sq.ring_ptr) { |
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267 | munmap(cq.ring_ptr, cq.ring_sz); |
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268 | } |
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269 | |
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270 | // close the file descriptor |
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271 | close(this.fd); |
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272 | |
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273 | free( this.sq.free_ring.array ); // Maybe null, doesn't matter |
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274 | } |
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275 | |
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276 | void __cfa_io_start( processor * proc ) { |
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277 | proc->io.ctx = alloc(); |
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278 | (*proc->io.ctx){proc, *proc->cltr}; |
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279 | } |
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280 | void __cfa_io_stop ( processor * proc ) { |
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281 | ^(*proc->io.ctx){}; |
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282 | free(proc->io.ctx); |
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283 | } |
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284 | |
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285 | //============================================================================================= |
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286 | // I/O Context Sleep |
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287 | //============================================================================================= |
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288 | // static inline void __epoll_ctl($io_context & ctx, int op, const char * error) { |
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289 | // struct epoll_event ev; |
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290 | // ev.events = EPOLLIN | EPOLLONESHOT; |
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291 | // ev.data.u64 = (__u64)&ctx; |
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292 | // int ret = epoll_ctl(iopoll.epollfd, op, ctx.efd, &ev); |
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293 | // if (ret < 0) { |
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294 | // abort( "KERNEL ERROR: EPOLL %s - (%d) %s\n", error, (int)errno, strerror(errno) ); |
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295 | // } |
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296 | // } |
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297 | |
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298 | // static void __epoll_register($io_context & ctx) { |
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299 | // __epoll_ctl(ctx, EPOLL_CTL_ADD, "ADD"); |
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300 | // } |
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301 | |
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302 | // static void __epoll_unregister($io_context & ctx) { |
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303 | // // Read the current epoch so we know when to stop |
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304 | // size_t curr = __atomic_load_n(&iopoll.epoch, __ATOMIC_SEQ_CST); |
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305 | |
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306 | // // Remove the fd from the iopoller |
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307 | // __epoll_ctl(ctx, EPOLL_CTL_DEL, "REMOVE"); |
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308 | |
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309 | // // Notify the io poller thread of the shutdown |
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310 | // iopoll.run = false; |
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311 | // sigval val = { 1 }; |
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312 | // pthread_sigqueue( iopoll.thrd, SIGUSR1, val ); |
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313 | |
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314 | // // Make sure all this is done |
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315 | // __atomic_thread_fence(__ATOMIC_SEQ_CST); |
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316 | |
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317 | // // Wait for the next epoch |
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318 | // while(curr == iopoll.epoch && !iopoll.stopped) Pause(); |
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319 | // } |
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320 | |
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321 | // void __ioctx_prepare_block($io_context & ctx) { |
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322 | // __cfadbg_print_safe(io_core, "Kernel I/O - epoll : Re-arming io poller %d (%p)\n", ctx.fd, &ctx); |
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323 | // __epoll_ctl(ctx, EPOLL_CTL_MOD, "REARM"); |
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324 | // } |
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325 | |
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326 | |
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327 | //============================================================================================= |
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328 | // I/O Context Misc Setup |
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329 | //============================================================================================= |
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330 | void ?{}( $io_arbiter & this ) { |
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331 | this.pending.empty = true; |
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332 | } |
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333 | |
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334 | void ^?{}( $io_arbiter & this ) {} |
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335 | |
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336 | $io_arbiter * create(void) { |
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337 | return new(); |
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338 | } |
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339 | void destroy($io_arbiter * arbiter) { |
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340 | delete(arbiter); |
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341 | } |
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342 | |
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343 | //============================================================================================= |
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344 | // I/O Context Misc Setup |
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345 | //============================================================================================= |
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346 | |
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347 | #endif |
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