Merge tag 'drm-xe-next-2024-08-28' of https://gitlab.freedesktop.org/drm/xe/kernel into drm-next

UAPI Changes:
- Fix OA format masks which were breaking build with gcc-5

Cross-subsystem Changes:

Driver Changes:
- Use dma_fence_chain_free in chain fence unused as a sync (Matthew Brost)
- Refactor hw engine lookup and mmio access to be used in more places
  (Dominik, Matt Auld, Mika Kuoppala)
- Enable priority mem read for Xe2 and later (Pallavi Mishra)
- Fix PL1 disable flow in xe_hwmon_power_max_write (Karthik)
- Fix refcount and speedup devcoredump (Matthew Brost)
- Add performance tuning changes to Xe2 (Akshata, Shekhar)
- Fix OA sysfs entry (Ashutosh)
- Add first GuC firmware support for BMG (Julia)
- Bump minimum GuC firmware for platforms under force_probe to match LNL
  and BMG (Julia)
- Fix access check on user fence creation (Nirmoy)
- Add/document workarounds for Xe2 (Julia, Daniele, John, Tejas)
- Document workaround and use proper WA infra (Matt Roper)
- Fix VF configuration on media GT (Michal Wajdeczko)
- Fix VM dma-resv lock (Matthew Brost)
- Allow suspend/resume exec queue backend op to be called multiple times
  (Matthew Brost)
- Add GT stats to debugfs (Nirmoy)
- Add hwconfig to debugfs (Matt Roper)
- Compile out all debugfs code with ONFIG_DEUBG_FS=n (Lucas)
- Remove dead kunit code (Jani Nikula)
- Refactor drvdata storing to help display (Jani Nikula)
- Cleanup unsused xe parameter in pte handling (Himal)
- Rename s/enable_display/probe_display/ for clarity (Lucas)
- Fix missing MCR annotation in couple of registers (Tejas)
- Fix DGFX display suspend/resume (Maarten)
- Prepare exec_queue_kill for PXP handling (Daniele)
- Fix devm/drmm issues (Daniele, Matthew Brost)
- Fix tile and ggtt fini sequences (Matthew Brost)
- Fix crashes when probing without firmware in place (Daniele, Matthew Brost)
- Use xe_managed for kernel BOs (Daniele, Matthew Brost)
- Future-proof dss_per_group calculation by using hwconfig (Matt Roper)
- Use reserved copy engine for user binds on faulting devices
  (Matthew Brost)
- Allow mixing dma-fence jobs and long-running faulting jobs (Francois)
- Cleanup redundant arg when creating use BO (Nirmoy)
- Prevent UAF around preempt fence (Auld)
- Fix display suspend/resume (Maarten)
- Use vma_pages() helper (Thorsten)
- Calculate pagefault queue size (Stuart, Matthew Auld)
- Fix missing pagefault wq destroy (Stuart)
- Fix lifetime handling of HW fence ctx (Matthew Brost)
- Fix order destroy order for jobs (Matthew Brost)
- Fix TLB invalidation for media GT (Matthew Brost)
- Document GGTT (Rodrigo Vivi)
- Refactor GGTT layering and fix runtime outer protection (Rodrigo Vivi)
- Handle HPD polling on display pm runtime suspend/resume (Imre, Vinod)
- Drop unrequired NULL checks (Apoorva, Himal)
- Use separate rpm lockdep map for non-d3cold-capable devices (Thomas Hellström)
- Support "nomodeset" kernel command-line option (Thomas Zimmermann)
- Drop force_probe requirement for LNL and BMG (Lucas, Balasubramani)

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/wd42jsh4i3q5zlrmi2cljejohdsrqc6hvtxf76lbxsp3ibrgmz@y54fa7wwxgsd

1 files changed, 53 insertions, 1 deletions

diff --git a/include/drm/drm_print.h b/include/drm/drm_print.h
index 5d9dff5149c9..d2676831d765 100644
--- a/include/drm/drm_print.h
+++ b/include/drm/drm_print.h
@@ -221,7 +221,8 @@ drm_vprintf(struct drm_printer *p, const char *fmt, va_list *va)
 
 /**
  * struct drm_print_iterator - local struct used with drm_printer_coredump
- * @data: Pointer to the devcoredump output buffer
+ * @data: Pointer to the devcoredump output buffer, can be NULL if using
+ * drm_printer_coredump to determine size of devcoredump
  * @start: The offset within the buffer to start writing
  * @remain: The number of bytes to write for this iteration
  */
@@ -266,6 +267,57 @@ struct drm_print_iterator {
  *			coredump_read, ...)
  *	}
  *
+ * The above example has a time complexity of O(N^2), where N is the size of the
+ * devcoredump. This is acceptable for small devcoredumps but scales poorly for
+ * larger ones.
+ *
+ * Another use case for drm_coredump_printer is to capture the devcoredump into
+ * a saved buffer before the dev_coredump() callback. This involves two passes:
+ * one to determine the size of the devcoredump and another to print it to a
+ * buffer. Then, in dev_coredump(), copy from the saved buffer into the
+ * devcoredump read buffer.
+ *
+ * For example::
+ *
+ *	char *devcoredump_saved_buffer;
+ *
+ *	ssize_t __coredump_print(char *buffer, ssize_t count, ...)
+ *	{
+ *		struct drm_print_iterator iter;
+ *		struct drm_printer p;
+ *
+ *		iter.data = buffer;
+ *		iter.start = 0;
+ *		iter.remain = count;
+ *
+ *		p = drm_coredump_printer(&iter);
+ *
+ *		drm_printf(p, "foo=%d\n", foo);
+ *		...
+ *		return count - iter.remain;
+ *	}
+ *
+ *	void coredump_print(...)
+ *	{
+ *		ssize_t count;
+ *
+ *		count = __coredump_print(NULL, INT_MAX, ...);
+ *		devcoredump_saved_buffer = kvmalloc(count, GFP_KERNEL);
+ *		__coredump_print(devcoredump_saved_buffer, count, ...);
+ *	}
+ *
+ *	void coredump_read(char *buffer, loff_t offset, size_t count,
+ *			   void *data, size_t datalen)
+ *	{
+ *		...
+ *		memcpy(buffer, devcoredump_saved_buffer + offset, count);
+ *		...
+ *	}
+ *
+ * The above example has a time complexity of O(N*2), where N is the size of the
+ * devcoredump. This scales better than the previous example for larger
+ * devcoredumps.
+ *
  * RETURNS:
  * The &drm_printer object
  */