#include "config.h"
#include "backend.h"
#include "frontend.h"
+#include "smp.h"
/**
* lib_ring_buffer_backend_allocate - allocate a channel buffer
int lib_ring_buffer_backend_allocate(const struct lib_ring_buffer_config *config,
struct lib_ring_buffer_backend *bufb,
size_t size, size_t num_subbuf,
- int extra_reader_sb)
+ int extra_reader_sb,
+ struct shm_header *shm_header)
{
- struct channel_backend *chanb = &bufb->chan->backend;
- unsigned long j, num_pages, num_pages_per_subbuf, page_idx = 0;
+ struct channel_backend *chanb = &shmp(bufb->chan)->backend;
unsigned long subbuf_size, mmap_offset = 0;
unsigned long num_subbuf_alloc;
- struct page **pages;
- void **virt;
unsigned long i;
- num_pages = size >> get_count_order(PAGE_SIZE);
- num_pages_per_subbuf = num_pages >> get_count_order(num_subbuf);
subbuf_size = chanb->subbuf_size;
num_subbuf_alloc = num_subbuf;
- if (extra_reader_sb) {
- num_pages += num_pages_per_subbuf; /* Add pages for reader */
+ if (extra_reader_sb)
num_subbuf_alloc++;
- }
-
- pages = malloc_align(sizeof(*pages) * num_pages);
- if (unlikely(!pages))
- goto pages_error;
- virt = malloc_align(sizeof(*virt) * num_pages);
- if (unlikely(!virt))
- goto virt_error;
-
- bufb->array = malloc_align(sizeof(*bufb->array) * num_subbuf_alloc);
- if (unlikely(!bufb->array))
+ set_shmp(bufb->array, zalloc_shm(shm_header,
+ sizeof(*bufb->array) * num_subbuf_alloc));
+ if (unlikely(!shmp(bufb->array)))
goto array_error;
- for (i = 0; i < num_pages; i++) {
- pages[i] = alloc_pages_node(cpu_to_node(max(bufb->cpu, 0)),
- GFP_KERNEL | __GFP_ZERO, 0);
- if (unlikely(!pages[i]))
- goto depopulate;
- virt[i] = page_address(pages[i]);
- }
- bufb->num_pages_per_subbuf = num_pages_per_subbuf;
+ set_shmp(bufb->memory_map, zalloc_shm(shm_header,
+ subbuf_size * num_subbuf_alloc));
+ if (unlikely(!shmp(bufb->memory_map)))
+ goto memory_map_error;
/* Allocate backend pages array elements */
for (i = 0; i < num_subbuf_alloc; i++) {
- bufb->array[i] =
- zmalloc_align(
+ set_shmp(bufb->array[i],
+ zalloc_shm(shm_header,
sizeof(struct lib_ring_buffer_backend_pages) +
- sizeof(struct lib_ring_buffer_backend_page)
- * num_pages_per_subbuf);
- if (!bufb->array[i])
+ subbuf_size));
+ if (!shmp(bufb->array[i]))
goto free_array;
}
/* Allocate write-side subbuffer table */
- bufb->buf_wsb = zmalloc_align(
+ bufb->buf_wsb = zalloc_shm(shm_header,
sizeof(struct lib_ring_buffer_backend_subbuffer)
* num_subbuf);
- if (unlikely(!bufb->buf_wsb))
+ if (unlikely(!shmp(bufb->buf_wsb)))
goto free_array;
for (i = 0; i < num_subbuf; i++)
- bufb->buf_wsb[i].id = subbuffer_id(config, 0, 1, i);
+ shmp(bufb->buf_wsb)[i].id = subbuffer_id(config, 0, 1, i);
/* Assign read-side subbuffer table */
if (extra_reader_sb)
/* Assign pages to page index */
for (i = 0; i < num_subbuf_alloc; i++) {
- for (j = 0; j < num_pages_per_subbuf; j++) {
- CHAN_WARN_ON(chanb, page_idx > num_pages);
- bufb->array[i]->p[j].virt = virt[page_idx];
- bufb->array[i]->p[j].page = pages[page_idx];
- page_idx++;
- }
+ set_shmp(shmp(bufb->array)[i]->p,
+ &shmp(bufb->memory_map)[i * subbuf_size]);
if (config->output == RING_BUFFER_MMAP) {
- bufb->array[i]->mmap_offset = mmap_offset;
+ shmp(bufb->array)[i]->mmap_offset = mmap_offset;
mmap_offset += subbuf_size;
}
}
- kfree(virt);
- kfree(pages);
return 0;
free_array:
- for (i = 0; (i < num_subbuf_alloc && bufb->array[i]); i++)
- kfree(bufb->array[i]);
-depopulate:
- /* Free all allocated pages */
- for (i = 0; (i < num_pages && pages[i]); i++)
- __free_page(pages[i]);
- kfree(bufb->array);
+ /* bufb->array[i] will be freed by shm teardown */
+memory_map_error:
+ /* bufb->array will be freed by shm teardown */
array_error:
- kfree(virt);
-virt_error:
- kfree(pages);
-pages_error:
return -ENOMEM;
}
int lib_ring_buffer_backend_create(struct lib_ring_buffer_backend *bufb,
- struct channel_backend *chanb, int cpu)
+ struct channel_backend *chanb, int cpu,
+ struct shm_header *shm_header)
{
const struct lib_ring_buffer_config *config = chanb->config;
- bufb->chan = caa_container_of(chanb, struct channel, backend);
+ set_shmp(&bufb->chan, caa_container_of(chanb, struct channel, backend));
bufb->cpu = cpu;
return lib_ring_buffer_backend_allocate(config, bufb, chanb->buf_size,
chanb->num_subbuf,
- chanb->extra_reader_sb);
+ chanb->extra_reader_sb,
+ shm_header);
}
void lib_ring_buffer_backend_free(struct lib_ring_buffer_backend *bufb)
{
- struct channel_backend *chanb = &bufb->chan->backend;
- unsigned long i, j, num_subbuf_alloc;
-
- num_subbuf_alloc = chanb->num_subbuf;
- if (chanb->extra_reader_sb)
- num_subbuf_alloc++;
-
- kfree(bufb->buf_wsb);
- for (i = 0; i < num_subbuf_alloc; i++) {
- for (j = 0; j < bufb->num_pages_per_subbuf; j++)
- __free_page(bufb->array[i]->p[j].page);
- kfree(bufb->array[i]);
- }
- kfree(bufb->array);
+ /* bufb->buf_wsb will be freed by shm teardown */
+ /* bufb->array[i] will be freed by shm teardown */
+ /* bufb->array will be freed by shm teardown */
bufb->allocated = 0;
}
void lib_ring_buffer_backend_reset(struct lib_ring_buffer_backend *bufb)
{
- struct channel_backend *chanb = &bufb->chan->backend;
+ struct channel_backend *chanb = &shmp(bufb->chan)->backend;
const struct lib_ring_buffer_config *config = chanb->config;
unsigned long num_subbuf_alloc;
unsigned int i;
num_subbuf_alloc++;
for (i = 0; i < chanb->num_subbuf; i++)
- bufb->buf_wsb[i].id = subbuffer_id(config, 0, 1, i);
+ shmp(bufb->buf_wsb)[i].id = subbuffer_id(config, 0, 1, i);
if (chanb->extra_reader_sb)
bufb->buf_rsb.id = subbuffer_id(config, 0, 1,
num_subbuf_alloc - 1);
for (i = 0; i < num_subbuf_alloc; i++) {
/* Don't reset mmap_offset */
- v_set(config, &bufb->array[i]->records_commit, 0);
- v_set(config, &bufb->array[i]->records_unread, 0);
- bufb->array[i]->data_size = 0;
+ v_set(config, &shmp(bufb->array)[i]->records_commit, 0);
+ v_set(config, &shmp(bufb->array)[i]->records_unread, 0);
+ shmp(bufb->array)[i]->data_size = 0;
/* Don't reset backend page and virt addresses */
}
/* Don't reset num_pages_per_subbuf, cpu, allocated */
chanb->start_tsc = config->cb.ring_buffer_clock_read(chan);
}
-#ifdef CONFIG_HOTPLUG_CPU
-/**
- * lib_ring_buffer_cpu_hp_callback - CPU hotplug callback
- * @nb: notifier block
- * @action: hotplug action to take
- * @hcpu: CPU number
- *
- * Returns the success/failure of the operation. (%NOTIFY_OK, %NOTIFY_BAD)
- */
-static
-int __cpuinit lib_ring_buffer_cpu_hp_callback(struct notifier_block *nb,
- unsigned long action,
- void *hcpu)
-{
- unsigned int cpu = (unsigned long)hcpu;
- struct channel_backend *chanb = caa_container_of(nb, struct channel_backend,
- cpu_hp_notifier);
- const struct lib_ring_buffer_config *config = chanb->config;
- struct lib_ring_buffer *buf;
- int ret;
-
- CHAN_WARN_ON(chanb, config->alloc == RING_BUFFER_ALLOC_GLOBAL);
-
- switch (action) {
- case CPU_UP_PREPARE:
- case CPU_UP_PREPARE_FROZEN:
- buf = per_cpu_ptr(chanb->buf, cpu);
- ret = lib_ring_buffer_create(buf, chanb, cpu);
- if (ret) {
- printk(KERN_ERR
- "ring_buffer_cpu_hp_callback: cpu %d "
- "buffer creation failed\n", cpu);
- return NOTIFY_BAD;
- }
- break;
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
- /* No need to do a buffer switch here, because it will happen
- * when tracing is stopped, or will be done by switch timer CPU
- * DEAD callback. */
- break;
- }
- return NOTIFY_OK;
-}
-#endif
-
/**
* channel_backend_init - initialize a channel backend
* @chanb: channel backend
* @parent: dentry of parent directory, %NULL for root directory
* @subbuf_size: size of sub-buffers (> PAGE_SIZE, power of 2)
* @num_subbuf: number of sub-buffers (power of 2)
+ * @shm_header: shared memory header
*
* Returns channel pointer if successful, %NULL otherwise.
*
int channel_backend_init(struct channel_backend *chanb,
const char *name,
const struct lib_ring_buffer_config *config,
- void *priv, size_t subbuf_size, size_t num_subbuf)
+ void *priv, size_t subbuf_size, size_t num_subbuf,
+ struct shm_header *shm_header)
{
struct channel *chan = caa_container_of(chanb, struct channel, backend);
unsigned int i;
chanb->extra_reader_sb =
(config->mode == RING_BUFFER_OVERWRITE) ? 1 : 0;
chanb->num_subbuf = num_subbuf;
- strlcpy(chanb->name, name, NAME_MAX);
+ strncpy(chanb->name, name, NAME_MAX);
+ chanb->name[NAME_MAX - 1] = '\0';
chanb->config = config;
if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
- if (!zalloc_cpumask_var(&chanb->cpumask, GFP_KERNEL))
- return -ENOMEM;
- }
+ struct lib_ring_buffer *buf;
+ size_t alloc_size;
- if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
/* Allocating the buffer per-cpu structures */
- chanb->buf = alloc_percpu(struct lib_ring_buffer);
- if (!chanb->buf)
- goto free_cpumask;
+ alloc_size = sizeof(struct lib_ring_buffer);
+ buf = zalloc_shm(shm_header, alloc_size * num_possible_cpus());
+ if (!buf)
+ goto end;
+ set_shmp(chanb->buf, buf);
/*
- * In case of non-hotplug cpu, if the ring-buffer is allocated
- * in early initcall, it will not be notified of secondary cpus.
- * In that off case, we need to allocate for all possible cpus.
- */
-#ifdef CONFIG_HOTPLUG_CPU
- /*
- * buf->backend.allocated test takes care of concurrent CPU
- * hotplug.
- * Priority higher than frontend, so we create the ring buffer
- * before we start the timer.
+ * We need to allocate for all possible cpus.
*/
- chanb->cpu_hp_notifier.notifier_call =
- lib_ring_buffer_cpu_hp_callback;
- chanb->cpu_hp_notifier.priority = 5;
- register_hotcpu_notifier(&chanb->cpu_hp_notifier);
-
- get_online_cpus();
- for_each_online_cpu(i) {
- ret = lib_ring_buffer_create(per_cpu_ptr(chanb->buf, i),
- chanb, i);
- if (ret)
- goto free_bufs; /* cpu hotplug locked */
- }
- put_online_cpus();
-#else
for_each_possible_cpu(i) {
- ret = lib_ring_buffer_create(per_cpu_ptr(chanb->buf, i),
- chanb, i);
+ ret = lib_ring_buffer_create(&shmp(chanb->buf)[i],
+ chanb, i, shm_header);
if (ret)
goto free_bufs; /* cpu hotplug locked */
}
-#endif
} else {
- chanb->buf = kzalloc(sizeof(struct lib_ring_buffer), GFP_KERNEL);
- if (!chanb->buf)
- goto free_cpumask;
- ret = lib_ring_buffer_create(chanb->buf, chanb, -1);
+ struct lib_ring_buffer *buf;
+ size_t alloc_size;
+
+ alloc_size = sizeof(struct lib_ring_buffer);
+ chanb->buf = zmalloc(sizeof(struct lib_ring_buffer));
+ buf = zalloc_shm(shm_header, alloc_size);
+ if (!buf)
+ goto end;
+ set_shmp(chanb->buf, buf);
+ ret = lib_ring_buffer_create(shmp(chanb->buf), chanb, -1,
+ shm_header);
if (ret)
goto free_bufs;
}
free_bufs:
if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
for_each_possible_cpu(i) {
- struct lib_ring_buffer *buf = per_cpu_ptr(chanb->buf, i);
+ struct lib_ring_buffer *buf = &shmp(chanb->buf)[i];
if (!buf->backend.allocated)
continue;
lib_ring_buffer_free(buf);
}
-#ifdef CONFIG_HOTPLUG_CPU
- put_online_cpus();
-#endif
- free_percpu(chanb->buf);
- } else
- kfree(chanb->buf);
-free_cpumask:
- if (config->alloc == RING_BUFFER_ALLOC_PER_CPU)
- free_cpumask_var(chanb->cpumask);
+ }
+ /* We only free the buffer data upon shm teardown */
+end:
return -ENOMEM;
}
-/**
- * channel_backend_unregister_notifiers - unregister notifiers
- * @chan: the channel
- *
- * Holds CPU hotplug.
- */
-void channel_backend_unregister_notifiers(struct channel_backend *chanb)
-{
- const struct lib_ring_buffer_config *config = chanb->config;
-
- if (config->alloc == RING_BUFFER_ALLOC_PER_CPU)
- unregister_hotcpu_notifier(&chanb->cpu_hp_notifier);
-}
-
/**
* channel_backend_free - destroy the channel
* @chan: the channel
if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
for_each_possible_cpu(i) {
- struct lib_ring_buffer *buf = per_cpu_ptr(chanb->buf, i);
+ struct lib_ring_buffer *buf = &shmp(chanb->buf)[i];
if (!buf->backend.allocated)
continue;
lib_ring_buffer_free(buf);
}
- free_cpumask_var(chanb->cpumask);
- free_percpu(chanb->buf);
} else {
- struct lib_ring_buffer *buf = chanb->buf;
+ struct lib_ring_buffer *buf = shmp(chanb->buf);
CHAN_WARN_ON(chanb, !buf->backend.allocated);
lib_ring_buffer_free(buf);
- kfree(buf);
}
+ /* We only free the buffer data upon shm teardown */
}
-/**
- * lib_ring_buffer_write - write data to a ring_buffer buffer.
- * @bufb : buffer backend
- * @offset : offset within the buffer
- * @src : source address
- * @len : length to write
- * @pagecpy : page size copied so far
- */
-void _lib_ring_buffer_write(struct lib_ring_buffer_backend *bufb, size_t offset,
- const void *src, size_t len, ssize_t pagecpy)
-{
- struct channel_backend *chanb = &bufb->chan->backend;
- const struct lib_ring_buffer_config *config = chanb->config;
- size_t sbidx, index;
- struct lib_ring_buffer_backend_pages *rpages;
- unsigned long sb_bindex, id;
-
- do {
- len -= pagecpy;
- src += pagecpy;
- offset += pagecpy;
- sbidx = offset >> chanb->subbuf_size_order;
- index = (offset & (chanb->subbuf_size - 1)) >> get_count_order(PAGE_SIZE);
-
- /*
- * Underlying layer should never ask for writes across
- * subbuffers.
- */
- CHAN_WARN_ON(chanb, offset >= chanb->buf_size);
-
- pagecpy = min_t(size_t, len, PAGE_SIZE - (offset & ~PAGE_MASK));
- id = bufb->buf_wsb[sbidx].id;
- sb_bindex = subbuffer_id_get_index(config, id);
- rpages = bufb->array[sb_bindex];
- CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE
- && subbuffer_id_is_noref(config, id));
- lib_ring_buffer_do_copy(config,
- rpages->p[index].virt
- + (offset & ~PAGE_MASK),
- src, pagecpy);
- } while (unlikely(len != pagecpy));
-}
-EXPORT_SYMBOL_GPL(_lib_ring_buffer_write);
-
/**
* lib_ring_buffer_read - read data from ring_buffer_buffer.
* @bufb : buffer backend
size_t lib_ring_buffer_read(struct lib_ring_buffer_backend *bufb, size_t offset,
void *dest, size_t len)
{
- struct channel_backend *chanb = &bufb->chan->backend;
+ struct channel_backend *chanb = &shmp(bufb->chan)->backend;
const struct lib_ring_buffer_config *config = chanb->config;
- size_t index;
- ssize_t pagecpy, orig_len;
+ ssize_t orig_len;
struct lib_ring_buffer_backend_pages *rpages;
unsigned long sb_bindex, id;
orig_len = len;
offset &= chanb->buf_size - 1;
- index = (offset & (chanb->subbuf_size - 1)) >> get_count_order(PAGE_SIZE);
+
if (unlikely(!len))
return 0;
- for (;;) {
- pagecpy = min_t(size_t, len, PAGE_SIZE - (offset & ~PAGE_MASK));
- id = bufb->buf_rsb.id;
- sb_bindex = subbuffer_id_get_index(config, id);
- rpages = bufb->array[sb_bindex];
- CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE
- && subbuffer_id_is_noref(config, id));
- memcpy(dest, rpages->p[index].virt + (offset & ~PAGE_MASK),
- pagecpy);
- len -= pagecpy;
- if (likely(!len))
- break;
- dest += pagecpy;
- offset += pagecpy;
- index = (offset & (chanb->subbuf_size - 1)) >> get_count_order(PAGE_SIZE);
- /*
- * Underlying layer should never ask for reads across
- * subbuffers.
- */
- CHAN_WARN_ON(chanb, offset >= chanb->buf_size);
- }
+ id = bufb->buf_rsb.id;
+ sb_bindex = subbuffer_id_get_index(config, id);
+ rpages = shmp(bufb->array)[sb_bindex];
+ /*
+ * Underlying layer should never ask for reads across
+ * subbuffers.
+ */
+ CHAN_WARN_ON(chanb, offset >= chanb->buf_size);
+ CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE
+ && subbuffer_id_is_noref(config, id));
+ memcpy(dest, shmp(rpages->p) + (offset & ~(chanb->subbuf_size - 1)), len);
return orig_len;
}
-EXPORT_SYMBOL_GPL(lib_ring_buffer_read);
/**
* lib_ring_buffer_read_cstr - read a C-style string from ring_buffer.
int lib_ring_buffer_read_cstr(struct lib_ring_buffer_backend *bufb, size_t offset,
void *dest, size_t len)
{
- struct channel_backend *chanb = &bufb->chan->backend;
+ struct channel_backend *chanb = &shmp(bufb->chan)->backend;
const struct lib_ring_buffer_config *config = chanb->config;
- size_t index;
- ssize_t pagecpy, pagelen, strpagelen, orig_offset;
+ ssize_t string_len, orig_offset;
char *str;
struct lib_ring_buffer_backend_pages *rpages;
unsigned long sb_bindex, id;
offset &= chanb->buf_size - 1;
- index = (offset & (chanb->subbuf_size - 1)) >> get_count_order(PAGE_SIZE);
orig_offset = offset;
- for (;;) {
- id = bufb->buf_rsb.id;
- sb_bindex = subbuffer_id_get_index(config, id);
- rpages = bufb->array[sb_bindex];
- CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE
- && subbuffer_id_is_noref(config, id));
- str = (char *)rpages->p[index].virt + (offset & ~PAGE_MASK);
- pagelen = PAGE_SIZE - (offset & ~PAGE_MASK);
- strpagelen = strnlen(str, pagelen);
- if (len) {
- pagecpy = min_t(size_t, len, strpagelen);
- if (dest) {
- memcpy(dest, str, pagecpy);
- dest += pagecpy;
- }
- len -= pagecpy;
- }
- offset += strpagelen;
- index = (offset & (chanb->subbuf_size - 1)) >> get_count_order(PAGE_SIZE);
- if (strpagelen < pagelen)
- break;
- /*
- * Underlying layer should never ask for reads across
- * subbuffers.
- */
- CHAN_WARN_ON(chanb, offset >= chanb->buf_size);
- }
- if (dest && len)
- ((char *)dest)[0] = 0;
- return offset - orig_offset;
-}
-EXPORT_SYMBOL_GPL(lib_ring_buffer_read_cstr);
-
-/**
- * lib_ring_buffer_read_get_page - Get a whole page to read from
- * @bufb : buffer backend
- * @offset : offset within the buffer
- * @virt : pointer to page address (output)
- *
- * Should be protected by get_subbuf/put_subbuf.
- * Returns the pointer to the page struct pointer.
- */
-struct page **lib_ring_buffer_read_get_page(struct lib_ring_buffer_backend *bufb,
- size_t offset, void ***virt)
-{
- size_t index;
- struct lib_ring_buffer_backend_pages *rpages;
- struct channel_backend *chanb = &bufb->chan->backend;
- const struct lib_ring_buffer_config *config = chanb->config;
- unsigned long sb_bindex, id;
-
- offset &= chanb->buf_size - 1;
- index = (offset & (chanb->subbuf_size - 1)) >> get_count_order(PAGE_SIZE);
id = bufb->buf_rsb.id;
sb_bindex = subbuffer_id_get_index(config, id);
- rpages = bufb->array[sb_bindex];
+ rpages = shmp(bufb->array)[sb_bindex];
+ /*
+ * Underlying layer should never ask for reads across
+ * subbuffers.
+ */
+ CHAN_WARN_ON(chanb, offset >= chanb->buf_size);
CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE
&& subbuffer_id_is_noref(config, id));
- *virt = &rpages->p[index].virt;
- return &rpages->p[index].page;
+ str = (char *)shmp(rpages->p) + (offset & ~(chanb->subbuf_size - 1));
+ string_len = strnlen(str, len);
+ if (dest && len) {
+ memcpy(dest, str, string_len);
+ ((char *)dest)[0] = 0;
+ }
+ return offset - orig_offset;
}
-EXPORT_SYMBOL_GPL(lib_ring_buffer_read_get_page);
/**
* lib_ring_buffer_read_offset_address - get address of a buffer location
void *lib_ring_buffer_read_offset_address(struct lib_ring_buffer_backend *bufb,
size_t offset)
{
- size_t index;
struct lib_ring_buffer_backend_pages *rpages;
- struct channel_backend *chanb = &bufb->chan->backend;
+ struct channel_backend *chanb = &shmp(bufb->chan)->backend;
const struct lib_ring_buffer_config *config = chanb->config;
unsigned long sb_bindex, id;
offset &= chanb->buf_size - 1;
- index = (offset & (chanb->subbuf_size - 1)) >> get_count_order(PAGE_SIZE);
id = bufb->buf_rsb.id;
sb_bindex = subbuffer_id_get_index(config, id);
- rpages = bufb->array[sb_bindex];
+ rpages = shmp(bufb->array)[sb_bindex];
CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE
&& subbuffer_id_is_noref(config, id));
- return rpages->p[index].virt + (offset & ~PAGE_MASK);
+ return shmp(rpages->p) + (offset & ~(chanb->subbuf_size - 1));
}
-EXPORT_SYMBOL_GPL(lib_ring_buffer_read_offset_address);
/**
* lib_ring_buffer_offset_address - get address of a location within the buffer
void *lib_ring_buffer_offset_address(struct lib_ring_buffer_backend *bufb,
size_t offset)
{
- size_t sbidx, index;
+ size_t sbidx;
struct lib_ring_buffer_backend_pages *rpages;
- struct channel_backend *chanb = &bufb->chan->backend;
+ struct channel_backend *chanb = &shmp(bufb->chan)->backend;
const struct lib_ring_buffer_config *config = chanb->config;
unsigned long sb_bindex, id;
offset &= chanb->buf_size - 1;
sbidx = offset >> chanb->subbuf_size_order;
- index = (offset & (chanb->subbuf_size - 1)) >> get_count_order(PAGE_SIZE);
- id = bufb->buf_wsb[sbidx].id;
+ id = shmp(bufb->buf_wsb)[sbidx].id;
sb_bindex = subbuffer_id_get_index(config, id);
- rpages = bufb->array[sb_bindex];
+ rpages = shmp(bufb->array)[sb_bindex];
CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE
&& subbuffer_id_is_noref(config, id));
- return rpages->p[index].virt + (offset & ~PAGE_MASK);
+ return shmp(rpages->p) + (offset & ~(chanb->subbuf_size - 1));
}
-EXPORT_SYMBOL_GPL(lib_ring_buffer_offset_address);
projects / lttng-ust.git / blobdiff