-#ifndef _LINUX_RING_BUFFER_BACKEND_INTERNAL_H
-#define _LINUX_RING_BUFFER_BACKEND_INTERNAL_H
-
-/*
- * linux/ringbuffer/backend_internal.h
+/* SPDX-License-Identifier: (GPL-2.0-only OR LGPL-2.1-only)
*
- * Copyright (C) 2008-2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * lib/ringbuffer/backend_internal.h
*
* Ring buffer backend (internal helpers).
*
- * Dual LGPL v2.1/GPL v2 license.
+ * Copyright (C) 2008-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*/
-#include "../../wrapper/ringbuffer/config.h"
-#include "../../wrapper/ringbuffer/backend_types.h"
-#include "../../wrapper/ringbuffer/frontend_types.h"
+#ifndef _LIB_RING_BUFFER_BACKEND_INTERNAL_H
+#define _LIB_RING_BUFFER_BACKEND_INTERNAL_H
+
+#include <wrapper/compiler.h>
+#include <wrapper/ringbuffer/config.h>
+#include <wrapper/ringbuffer/backend_types.h>
+#include <wrapper/ringbuffer/frontend_types.h>
#include <linux/string.h>
#include <linux/uaccess.h>
extern void _lib_ring_buffer_write(struct lib_ring_buffer_backend *bufb,
size_t offset, const void *src, size_t len,
- ssize_t pagecpy);
+ size_t pagecpy);
extern void _lib_ring_buffer_memset(struct lib_ring_buffer_backend *bufb,
size_t offset, int c, size_t len,
- ssize_t pagecpy);
-extern void _lib_ring_buffer_copy_from_user(struct lib_ring_buffer_backend *bufb,
+ size_t pagecpy);
+extern void _lib_ring_buffer_strcpy(struct lib_ring_buffer_backend *bufb,
+ size_t offset, const char *src, size_t len,
+ size_t pagecpy, int pad);
+extern void _lib_ring_buffer_copy_from_user_inatomic(struct lib_ring_buffer_backend *bufb,
size_t offset, const void *src,
- size_t len, ssize_t pagecpy);
+ size_t len, size_t pagecpy);
+extern void _lib_ring_buffer_strcpy_from_user_inatomic(struct lib_ring_buffer_backend *bufb,
+ size_t offset, const char __user *src, size_t len,
+ size_t pagecpy, int pad);
/*
* Subbuffer ID bits for overwrite mode. Need to fit within a single word to be
tmp |= offset << SB_ID_OFFSET_SHIFT;
tmp |= SB_ID_NOREF_MASK;
/* Volatile store, read concurrently by readers. */
- ACCESS_ONCE(*id) = tmp;
+ WRITE_ONCE(*id, tmp);
}
}
return 0;
}
+static inline
+void lib_ring_buffer_backend_get_pages(const struct lib_ring_buffer_config *config,
+ struct lib_ring_buffer_ctx *ctx,
+ struct lib_ring_buffer_backend_pages **backend_pages)
+{
+ struct lib_ring_buffer_backend *bufb = &ctx->buf->backend;
+ struct channel_backend *chanb = &ctx->chan->backend;
+ size_t sbidx, offset = ctx->buf_offset;
+ unsigned long sb_bindex, id;
+ struct lib_ring_buffer_backend_pages *rpages;
+
+ offset &= chanb->buf_size - 1;
+ sbidx = offset >> chanb->subbuf_size_order;
+ id = bufb->buf_wsb[sbidx].id;
+ sb_bindex = subbuffer_id_get_index(config, id);
+ rpages = bufb->array[sb_bindex];
+ CHAN_WARN_ON(ctx->chan,
+ config->mode == RING_BUFFER_OVERWRITE
+ && subbuffer_id_is_noref(config, id));
+ *backend_pages = rpages;
+}
+
+/* Get backend pages from cache. */
+static inline
+struct lib_ring_buffer_backend_pages *
+ lib_ring_buffer_get_backend_pages_from_ctx(const struct lib_ring_buffer_config *config,
+ struct lib_ring_buffer_ctx *ctx)
+{
+ return ctx->backend_pages;
+}
+
+/*
+ * The ring buffer can count events recorded and overwritten per buffer,
+ * but it is disabled by default due to its performance overhead.
+ */
+#ifdef LTTNG_RING_BUFFER_COUNT_EVENTS
static inline
void subbuffer_count_record(const struct lib_ring_buffer_config *config,
struct lib_ring_buffer_backend *bufb,
sb_bindex = subbuffer_id_get_index(config, bufb->buf_wsb[idx].id);
v_inc(config, &bufb->array[sb_bindex]->records_commit);
}
+#else /* LTTNG_RING_BUFFER_COUNT_EVENTS */
+static inline
+void subbuffer_count_record(const struct lib_ring_buffer_config *config,
+ struct lib_ring_buffer_backend *bufb,
+ unsigned long idx)
+{
+}
+#endif /* #else LTTNG_RING_BUFFER_COUNT_EVENTS */
/*
* Reader has exclusive subbuffer access for record consumption. No need to
/*
* Must be executed at subbuffer delivery when the writer has _exclusive_
- * subbuffer access. See ring_buffer_check_deliver() for details.
- * ring_buffer_get_records_count() must be called to get the records count
- * before this function, because it resets the records_commit count.
+ * subbuffer access. See lib_ring_buffer_check_deliver() for details.
+ * lib_ring_buffer_get_records_count() must be called to get the records
+ * count before this function, because it resets the records_commit
+ * count.
*/
static inline
unsigned long subbuffer_count_records_overrun(
return pages->data_size;
}
+static inline
+void subbuffer_inc_packet_count(const struct lib_ring_buffer_config *config,
+ struct lib_ring_buffer_backend *bufb,
+ unsigned long idx)
+{
+ bufb->buf_cnt[idx].seq_cnt++;
+}
+
/**
* lib_ring_buffer_clear_noref - Clear the noref subbuffer flag, called by
* writer.
* Performing a volatile access to read the sb_pages, because we want to
* read a coherent version of the pointer and the associated noref flag.
*/
- id = ACCESS_ONCE(bufb->buf_wsb[idx].id);
+ id = READ_ONCE(bufb->buf_wsb[idx].id);
for (;;) {
/* This check is called on the fast path for each record. */
if (likely(!subbuffer_id_is_noref(config, id))) {
if (config->mode == RING_BUFFER_OVERWRITE) {
/*
* Exchange the target writer subbuffer with our own unused
- * subbuffer. No need to use ACCESS_ONCE() here to read the
+ * subbuffer. No need to use READ_ONCE() here to read the
* old_wpage, because the value read will be confirmed by the
* following cmpxchg().
*/
return 0;
}
+static inline __attribute__((always_inline))
+void lttng_inline_memcpy(void *dest, const void *src,
+ unsigned long len)
+{
+ switch (len) {
+ case 1:
+ *(uint8_t *) dest = *(const uint8_t *) src;
+ break;
+ case 2:
+ *(uint16_t *) dest = *(const uint16_t *) src;
+ break;
+ case 4:
+ *(uint32_t *) dest = *(const uint32_t *) src;
+ break;
+ case 8:
+ *(uint64_t *) dest = *(const uint64_t *) src;
+ break;
+ default:
+ inline_memcpy(dest, src, len);
+ }
+}
+
/*
* Use the architecture-specific memcpy implementation for constant-sized
* inputs, but rely on an inline memcpy for length statically unknown.
if (__builtin_constant_p(len)) \
memcpy(dest, src, __len); \
else \
- inline_memcpy(dest, src, __len); \
+ lttng_inline_memcpy(dest, src, __len); \
} while (0)
/*
- * We use __copy_from_user to copy userspace data since we already
+ * We use __copy_from_user_inatomic to copy userspace data since we already
* did the access_ok for the whole range.
+ *
+ * Return 0 if OK, nonzero on error.
*/
static inline
-unsigned long lib_ring_buffer_do_copy_from_user(void *dest,
+unsigned long lib_ring_buffer_do_copy_from_user_inatomic(void *dest,
const void __user *src,
unsigned long len)
{
- return __copy_from_user(dest, src, len);
+ return __copy_from_user_inatomic(dest, src, len);
}
/*
dest[i] = c;
}
-#endif /* _LINUX_RING_BUFFER_BACKEND_INTERNAL_H */
+#endif /* _LIB_RING_BUFFER_BACKEND_INTERNAL_H */
projects / lttng-modules.git / blobdiff