1 /* 2 * Copyright 2012 Cisco Systems, Inc. All rights reserved. 3 * 4 * This program is free software; you may redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; version 2 of the License. 7 * 8 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 9 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 10 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 11 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 12 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 13 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 14 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 15 * SOFTWARE. 16 */ 17 18 #include <linux/module.h> 19 #include <linux/mempool.h> 20 #include <linux/errno.h> 21 #include <linux/spinlock.h> 22 #include <linux/kallsyms.h> 23 #include "fnic_io.h" 24 #include "fnic.h" 25 26 unsigned int trace_max_pages; 27 static int fnic_max_trace_entries; 28 29 static unsigned long fnic_trace_buf_p; 30 static DEFINE_SPINLOCK(fnic_trace_lock); 31 32 static fnic_trace_dbg_t fnic_trace_entries; 33 int fnic_tracing_enabled = 1; 34 35 /* 36 * fnic_trace_get_buf - Give buffer pointer to user to fill up trace information 37 * 38 * Description: 39 * This routine gets next available trace buffer entry location @wr_idx 40 * from allocated trace buffer pages and give that memory location 41 * to user to store the trace information. 42 * 43 * Return Value: 44 * This routine returns pointer to next available trace entry 45 * @fnic_buf_head for user to fill trace information. 46 */ 47 fnic_trace_data_t *fnic_trace_get_buf(void) 48 { 49 unsigned long fnic_buf_head; 50 unsigned long flags; 51 52 spin_lock_irqsave(&fnic_trace_lock, flags); 53 54 /* 55 * Get next available memory location for writing trace information 56 * at @wr_idx and increment @wr_idx 57 */ 58 fnic_buf_head = 59 fnic_trace_entries.page_offset[fnic_trace_entries.wr_idx]; 60 fnic_trace_entries.wr_idx++; 61 62 /* 63 * Verify if trace buffer is full then change wd_idx to 64 * start from zero 65 */ 66 if (fnic_trace_entries.wr_idx >= fnic_max_trace_entries) 67 fnic_trace_entries.wr_idx = 0; 68 69 /* 70 * Verify if write index @wr_idx and read index @rd_idx are same then 71 * increment @rd_idx to move to next entry in trace buffer 72 */ 73 if (fnic_trace_entries.wr_idx == fnic_trace_entries.rd_idx) { 74 fnic_trace_entries.rd_idx++; 75 if (fnic_trace_entries.rd_idx >= fnic_max_trace_entries) 76 fnic_trace_entries.rd_idx = 0; 77 } 78 spin_unlock_irqrestore(&fnic_trace_lock, flags); 79 return (fnic_trace_data_t *)fnic_buf_head; 80 } 81 82 /* 83 * fnic_get_trace_data - Copy trace buffer to a memory file 84 * @fnic_dbgfs_t: pointer to debugfs trace buffer 85 * 86 * Description: 87 * This routine gathers the fnic trace debugfs data from the fnic_trace_data_t 88 * buffer and dumps it to fnic_dbgfs_t. It will start at the rd_idx entry in 89 * the log and process the log until the end of the buffer. Then it will gather 90 * from the beginning of the log and process until the current entry @wr_idx. 91 * 92 * Return Value: 93 * This routine returns the amount of bytes that were dumped into fnic_dbgfs_t 94 */ 95 int fnic_get_trace_data(fnic_dbgfs_t *fnic_dbgfs_prt) 96 { 97 int rd_idx; 98 int wr_idx; 99 int len = 0; 100 unsigned long flags; 101 char str[KSYM_SYMBOL_LEN]; 102 struct timespec val; 103 fnic_trace_data_t *tbp; 104 105 spin_lock_irqsave(&fnic_trace_lock, flags); 106 rd_idx = fnic_trace_entries.rd_idx; 107 wr_idx = fnic_trace_entries.wr_idx; 108 if (wr_idx < rd_idx) { 109 while (1) { 110 /* Start from read index @rd_idx */ 111 tbp = (fnic_trace_data_t *) 112 fnic_trace_entries.page_offset[rd_idx]; 113 if (!tbp) { 114 spin_unlock_irqrestore(&fnic_trace_lock, flags); 115 return 0; 116 } 117 /* Convert function pointer to function name */ 118 if (sizeof(unsigned long) < 8) { 119 sprint_symbol(str, tbp->fnaddr.low); 120 jiffies_to_timespec(tbp->timestamp.low, &val); 121 } else { 122 sprint_symbol(str, tbp->fnaddr.val); 123 jiffies_to_timespec(tbp->timestamp.val, &val); 124 } 125 /* 126 * Dump trace buffer entry to memory file 127 * and increment read index @rd_idx 128 */ 129 len += snprintf(fnic_dbgfs_prt->buffer + len, 130 (trace_max_pages * PAGE_SIZE * 3) - len, 131 "%16lu.%16lu %-50s %8x %8x %16llx %16llx " 132 "%16llx %16llx %16llx\n", val.tv_sec, 133 val.tv_nsec, str, tbp->host_no, tbp->tag, 134 tbp->data[0], tbp->data[1], tbp->data[2], 135 tbp->data[3], tbp->data[4]); 136 rd_idx++; 137 /* 138 * If rd_idx is reached to maximum trace entries 139 * then move rd_idx to zero 140 */ 141 if (rd_idx > (fnic_max_trace_entries-1)) 142 rd_idx = 0; 143 /* 144 * Continure dumpping trace buffer entries into 145 * memory file till rd_idx reaches write index 146 */ 147 if (rd_idx == wr_idx) 148 break; 149 } 150 } else if (wr_idx > rd_idx) { 151 while (1) { 152 /* Start from read index @rd_idx */ 153 tbp = (fnic_trace_data_t *) 154 fnic_trace_entries.page_offset[rd_idx]; 155 if (!tbp) { 156 spin_unlock_irqrestore(&fnic_trace_lock, flags); 157 return 0; 158 } 159 /* Convert function pointer to function name */ 160 if (sizeof(unsigned long) < 8) { 161 sprint_symbol(str, tbp->fnaddr.low); 162 jiffies_to_timespec(tbp->timestamp.low, &val); 163 } else { 164 sprint_symbol(str, tbp->fnaddr.val); 165 jiffies_to_timespec(tbp->timestamp.val, &val); 166 } 167 /* 168 * Dump trace buffer entry to memory file 169 * and increment read index @rd_idx 170 */ 171 len += snprintf(fnic_dbgfs_prt->buffer + len, 172 (trace_max_pages * PAGE_SIZE * 3) - len, 173 "%16lu.%16lu %-50s %8x %8x %16llx %16llx " 174 "%16llx %16llx %16llx\n", val.tv_sec, 175 val.tv_nsec, str, tbp->host_no, tbp->tag, 176 tbp->data[0], tbp->data[1], tbp->data[2], 177 tbp->data[3], tbp->data[4]); 178 rd_idx++; 179 /* 180 * Continue dumpping trace buffer entries into 181 * memory file till rd_idx reaches write index 182 */ 183 if (rd_idx == wr_idx) 184 break; 185 } 186 } 187 spin_unlock_irqrestore(&fnic_trace_lock, flags); 188 return len; 189 } 190 191 /* 192 * fnic_trace_buf_init - Initialize fnic trace buffer logging facility 193 * 194 * Description: 195 * Initialize trace buffer data structure by allocating required memory and 196 * setting page_offset information for every trace entry by adding trace entry 197 * length to previous page_offset value. 198 */ 199 int fnic_trace_buf_init(void) 200 { 201 unsigned long fnic_buf_head; 202 int i; 203 int err = 0; 204 205 trace_max_pages = fnic_trace_max_pages; 206 fnic_max_trace_entries = (trace_max_pages * PAGE_SIZE)/ 207 FNIC_ENTRY_SIZE_BYTES; 208 209 fnic_trace_buf_p = (unsigned long)vmalloc((trace_max_pages * PAGE_SIZE)); 210 if (!fnic_trace_buf_p) { 211 printk(KERN_ERR PFX "Failed to allocate memory " 212 "for fnic_trace_buf_p\n"); 213 err = -ENOMEM; 214 goto err_fnic_trace_buf_init; 215 } 216 memset((void *)fnic_trace_buf_p, 0, (trace_max_pages * PAGE_SIZE)); 217 218 fnic_trace_entries.page_offset = vmalloc(fnic_max_trace_entries * 219 sizeof(unsigned long)); 220 if (!fnic_trace_entries.page_offset) { 221 printk(KERN_ERR PFX "Failed to allocate memory for" 222 " page_offset\n"); 223 if (fnic_trace_buf_p) { 224 vfree((void *)fnic_trace_buf_p); 225 fnic_trace_buf_p = 0; 226 } 227 err = -ENOMEM; 228 goto err_fnic_trace_buf_init; 229 } 230 memset((void *)fnic_trace_entries.page_offset, 0, 231 (fnic_max_trace_entries * sizeof(unsigned long))); 232 fnic_trace_entries.wr_idx = fnic_trace_entries.rd_idx = 0; 233 fnic_buf_head = fnic_trace_buf_p; 234 235 /* 236 * Set page_offset field of fnic_trace_entries struct by 237 * calculating memory location for every trace entry using 238 * length of each trace entry 239 */ 240 for (i = 0; i < fnic_max_trace_entries; i++) { 241 fnic_trace_entries.page_offset[i] = fnic_buf_head; 242 fnic_buf_head += FNIC_ENTRY_SIZE_BYTES; 243 } 244 err = fnic_trace_debugfs_init(); 245 if (err < 0) { 246 printk(KERN_ERR PFX "Failed to initialize debugfs for tracing\n"); 247 goto err_fnic_trace_debugfs_init; 248 } 249 printk(KERN_INFO PFX "Successfully Initialized Trace Buffer\n"); 250 return err; 251 err_fnic_trace_debugfs_init: 252 fnic_trace_free(); 253 err_fnic_trace_buf_init: 254 return err; 255 } 256 257 /* 258 * fnic_trace_free - Free memory of fnic trace data structures. 259 */ 260 void fnic_trace_free(void) 261 { 262 fnic_tracing_enabled = 0; 263 fnic_trace_debugfs_terminate(); 264 if (fnic_trace_entries.page_offset) { 265 vfree((void *)fnic_trace_entries.page_offset); 266 fnic_trace_entries.page_offset = NULL; 267 } 268 if (fnic_trace_buf_p) { 269 vfree((void *)fnic_trace_buf_p); 270 fnic_trace_buf_p = 0; 271 } 272 printk(KERN_INFO PFX "Successfully Freed Trace Buffer\n"); 273 } 274