2 * Ringbuffer implementation
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7 #include <linux/errno.h>
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8 #include <linux/percpu.h>
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9 #include <linux/sched.h>
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11 #include "palacios.h"
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12 #include "util-ringbuffer.h"
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14 void init_ringbuf(struct ringbuf * ring, unsigned int size) {
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15 ring->buf = palacios_alloc(size);
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17 if (!(ring->buf)) {
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18 ERROR("Cannot allocate ring buffer data\n");
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26 ring->current_len = 0;
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29 struct ringbuf * create_ringbuf(unsigned int size) {
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30 struct ringbuf * ring = (struct ringbuf *)palacios_alloc(sizeof(struct ringbuf));
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33 ERROR("Cannot allocate ring buffer\n");
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37 init_ringbuf(ring, size);
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42 void free_ringbuf(struct ringbuf * ring) {
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43 palacios_free(ring->buf);
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44 palacios_free(ring);
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47 static inline unsigned char * get_read_ptr(struct ringbuf * ring) {
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48 return (unsigned char *)(ring->buf + ring->start);
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52 static inline unsigned char * get_write_ptr(struct ringbuf * ring) {
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53 return (unsigned char *)(ring->buf + ring->end);
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56 static inline int get_read_section_size(struct ringbuf * ring) {
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57 return ring->size - ring->start;
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61 static inline int get_write_section_size(struct ringbuf * ring) {
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62 return ring->size - ring->end;
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66 static inline int is_read_loop(struct ringbuf * ring, unsigned int len) {
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67 if ((ring->start >= ring->end) && (ring->current_len > 0)) {
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68 // end is past the end of the buffer
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69 if (get_read_section_size(ring) < len) {
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77 static inline int is_write_loop(struct ringbuf * ring, unsigned int len) {
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78 if ((ring->end >= ring->start) && (ring->current_len < ring->size)) {
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79 // end is past the end of the buffer
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80 if (get_write_section_size(ring) < len) {
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88 static inline int ringbuf_avail_space(struct ringbuf * ring) {
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89 return ring->size - ring->current_len;
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93 int ringbuf_data_len(struct ringbuf * ring) {
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94 return ring->current_len;
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98 static inline int ringbuf_capacity(struct ringbuf * ring) {
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103 int ringbuf_read(struct ringbuf * ring, unsigned char * dst, unsigned int len) {
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105 int ring_data_len = ring->current_len;
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107 read_len = (len > ring_data_len) ? ring_data_len : len;
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109 if (is_read_loop(ring, read_len)) {
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110 int section_len = get_read_section_size(ring);
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112 memcpy(dst, get_read_ptr(ring), section_len);
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113 memcpy(dst + section_len, ring->buf, read_len - section_len);
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115 ring->start = read_len - section_len;
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117 memcpy(dst, get_read_ptr(ring), read_len);
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119 ring->start += read_len;
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122 ring->current_len -= read_len;
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130 static int ringbuf_peek(struct ringbuf * ring, unsigned char * dst, unsigned int len) {
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132 int ring_data_len = ring->current_len;
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134 read_len = (len > ring_data_len) ? ring_data_len : len;
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136 if (is_read_loop(ring, read_len)) {
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137 int section_len = get_read_section_size(ring);
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139 memcpy(dst, get_read_ptr(ring), section_len);
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140 memcpy(dst + section_len, ring->buf, read_len - section_len);
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142 memcpy(dst, get_read_ptr(ring), read_len);
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149 static int ringbuf_delete(struct ringbuf * ring, unsigned int len) {
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151 int ring_data_len = ring->current_len;
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153 del_len = (len > ring_data_len) ? ring_data_len : len;
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155 if (is_read_loop(ring, del_len)) {
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156 int section_len = get_read_section_size(ring);
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157 ring->start = del_len - section_len;
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159 ring->start += del_len;
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162 ring->current_len -= del_len;
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167 int ringbuf_write(struct ringbuf * ring, unsigned char * src, unsigned int len) {
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169 int ring_avail_space = ring->size - ring->current_len;
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171 write_len = (len > ring_avail_space) ? ring_avail_space : len;
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173 if (is_write_loop(ring, write_len)) {
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174 int section_len = get_write_section_size(ring);
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176 memcpy(get_write_ptr(ring), src, section_len);
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179 memcpy(get_write_ptr(ring), src + section_len, write_len - section_len);
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181 ring->end += write_len - section_len;
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183 memcpy(get_write_ptr(ring), src, write_len);
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185 ring->end += write_len;
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188 ring->current_len += write_len;
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