/************************************************************************** * * Copyright 2010 Pauli Nieminen. * All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sub license, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice (including the * next paragraph) shall be included in all copies or substantial portions * of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE * USE OR OTHER DEALINGS IN THE SOFTWARE. * * **************************************************************************/ /* * Multipart buffer for coping data which is larger than the page size. * * Authors: * Pauli Nieminen */ #include #include /** * Allocate the drm buffer object. * * buf: Pointer to a pointer where the object is stored. * size: The number of bytes to allocate. */ int drm_buffer_alloc(struct drm_buffer **buf, int size) { int nr_pages = size / PAGE_SIZE + 1; int idx; /* Allocating pointer table to end of structure makes drm_buffer * variable sized */ *buf = kzalloc(sizeof(struct drm_buffer) + nr_pages*sizeof(char *), GFP_KERNEL); if (*buf == NULL) { DRM_ERROR("Failed to allocate drm buffer object to hold" " %d bytes in %d pages.\n", size, nr_pages); return -ENOMEM; } (*buf)->size = size; for (idx = 0; idx < nr_pages; ++idx) { (*buf)->data[idx] = kmalloc(min(PAGE_SIZE, size - idx * PAGE_SIZE), GFP_KERNEL); if ((*buf)->data[idx] == NULL) { DRM_ERROR("Failed to allocate %dth page for drm" " buffer with %d bytes and %d pages.\n", idx + 1, size, nr_pages); goto error_out; } } return 0; error_out: /* Only last element can be null pointer so check for it first. */ if ((*buf)->data[idx]) kfree((*buf)->data[idx]); for (--idx; idx >= 0; --idx) kfree((*buf)->data[idx]); kfree(*buf); return -ENOMEM; } EXPORT_SYMBOL(drm_buffer_alloc); /** * Copy the user data to the begin of the buffer and reset the processing * iterator. * * user_data: A pointer the data that is copied to the buffer. * size: The Number of bytes to copy. */ int drm_buffer_copy_from_user(struct drm_buffer *buf, void __user *user_data, int size) { int nr_pages = size / PAGE_SIZE + 1; int idx; if (size > buf->size) { DRM_ERROR("Requesting to copy %d bytes to a drm buffer with" " %d bytes space\n", size, buf->size); return -EFAULT; } for (idx = 0; idx < nr_pages; ++idx) { if (DRM_COPY_FROM_USER(buf->data[idx], user_data + idx * PAGE_SIZE, min(PAGE_SIZE, size - idx * PAGE_SIZE))) { DRM_ERROR("Failed to copy user data (%p) to drm buffer" " (%p) %dth page.\n", user_data, buf, idx); return -EFAULT; } } buf->iterator = 0; return 0; } EXPORT_SYMBOL(drm_buffer_copy_from_user); /** * Free the drm buffer object */ void drm_buffer_free(struct drm_buffer *buf) { if (buf != NULL) { int nr_pages = buf->size / PAGE_SIZE + 1; int idx; for (idx = 0; idx < nr_pages; ++idx) kfree(buf->data[idx]); kfree(buf); } } EXPORT_SYMBOL(drm_buffer_free); /** * Read an object from buffer that may be split to multiple parts. If object * is not split function just returns the pointer to object in buffer. But in * case of split object data is copied to given stack object that is suplied * by caller. * * The processing location of the buffer is also advanced to the next byte * after the object. * * objsize: The size of the objet in bytes. * stack_obj: A pointer to a memory location where object can be copied. */ void *drm_buffer_read_object(struct drm_buffer *buf, int objsize, void *stack_obj) { int idx = drm_buffer_index(buf); int page = drm_buffer_page(buf); void *obj = NULL; if (idx + objsize <= PAGE_SIZE) { obj = &buf->data[page][idx]; } else { /* The object is split which forces copy to temporary object.*/ int beginsz = PAGE_SIZE - idx; memcpy(stack_obj, &buf->data[page][idx], beginsz); memcpy(stack_obj + beginsz, &buf->data[page + 1][0], objsize - beginsz); obj = stack_obj; } drm_buffer_advance(buf, objsize); return obj; } EXPORT_SYMBOL(drm_buffer_read_object); ux-5.14.y Hosts the 0x221E linux distro kernel.Ubuntu
summaryrefslogtreecommitdiff
path: root/Documentation/trace/ftrace.txt
AgeCommit message (Expand)Author
2016-05-18Merge tag 'trace-v4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/roste...Linus Torvalds
2016-04-23sched/fair: Gather CPU load functions under a more conventional namespaceFrederic Weisbecker
2016-04-19tracing: Update the documentation to describe "event-fork" optionSteven Rostedt (Red Hat)
2015-11-03tracing: Add some documentation about set_event_pidSteven Rostedt (Red Hat)
2015-10-20Documentation: ftrace: Module globbing usageDmitry Safonov
2015-09-08Merge tag 'trace-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/roste...Linus Torvalds
2015-08-06powerpc/ftrace: add powerpc timebase as a trace clock sourceNaveen N. Rao
2015-07-20tracing: Introduce two additional marks for delayJungseok Lee
2015-05-13Documentation: tracing: fix grammarRabin Vincent
2015-02-09Documentation: Fix the wrong command `echo -1 > set_ftrace_pid` for cleaning ...Wang Long
2014-12-03tracing: Add additional marks to signal very large time deltasByungchul Park
2014-11-21ftrace, kprobes: Support IPMODIFY flag to find IP modify conflictMasami Hiramatsu
2014-07-16sched: Transform resched_task() into resched_curr()Kirill Tkhai
2014-05-20tracing: Add funcgraph_tail option to print function name after closing bracesRobert Elliott
2013-11-11ftrace, sched: Add TRACE_FLAG_PREEMPT_RESCHEDPeter Zijlstra
2013-08-20Documentation: replace strict_strtoul() with kstrtoul()Jingoo Han
2013-06-11tracing: Add function probe to trigger a ftrace dump of current CPU traceSteven Rostedt (Red Hat)
2013-06-11tracing: Add function probe to trigger a ftrace dump to consoleSteven Rostedt (Red Hat)
2013-03-15tracing: Bring Documentation/trace/ftrace.txt up to dateSteven Rostedt (Red Hat)
2013-03-08tracing: update documentation of snapshot utilityHiraku Toyooka
2013-01-30tracing: Add documentation of snapshot utilityHiraku Toyooka