Merge tag 'char-misc-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver fixes from Greg KH:
 "Here are some small char and misc driver fixes for 5.2-rc4 to resolve
  a number of reported issues.

  The most "notable" one here is the kernel headers in proc^Wsysfs
  fixes. Those changes move the header file info into sysfs and fixes
  the build issues that you reported.

  Other than that, a bunch of small habanalabs driver fixes, some fpga
  driver fixes, and a few other tiny driver fixes.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  habanalabs: Read upper bits of trace buffer from RWPHI
  habanalabs: Fix virtual address access via debugfs for 2MB pages
  fpga: zynqmp-fpga: Correctly handle error pointer
  habanalabs: fix bug in checking huge page optimization
  habanalabs: Avoid using a non-initialized MMU cache mutex
  habanalabs: fix debugfs code
  uapi/habanalabs: add opcode for enable/disable device debug mode
  habanalabs: halt debug engines on user process close
  test_firmware: Use correct snprintf() limit
  genwqe: Prevent an integer overflow in the ioctl
  parport: Fix mem leak in parport_register_dev_model
  fpga: dfl: expand minor range when registering chrdev region
  fpga: dfl: Add lockdep classes for pdata->lock
  fpga: dfl: afu: Pass the correct device to dma_mapping_error()
  fpga: stratix10-soc: fix use-after-free on s10_init()
  w1: ds2408: Fix typo after 49695ac46861 (reset on output_write retry with readback)
  kheaders: Do not regenerate archive if config is not changed
  kheaders: Move from proc to sysfs
  lkdtm/bugs: Adjust recursion test to avoid elision
  lkdtm/usercopy: Moves the KERNEL_DS test to non-canonical

1 files changed, 20 insertions, 2 deletions

diff --git a/include/uapi/misc/habanalabs.h b/include/uapi/misc/habanalabs.h
index 8ac292cf4d00..204ab9b4ae67 100644
--- a/include/uapi/misc/habanalabs.h
+++ b/include/uapi/misc/habanalabs.h
@@ -413,6 +413,10 @@ struct hl_debug_params_spmu {
 #define HL_DEBUG_OP_SPMU	5
 /* Opcode for timestamp */
 #define HL_DEBUG_OP_TIMESTAMP	6
+/* Opcode for setting the device into or out of debug mode. The enable
+ * variable should be 1 for enabling debug mode and 0 for disabling it
+ */
+#define HL_DEBUG_OP_SET_MODE	7
 
 struct hl_debug_args {
 	/*
@@ -574,8 +578,22 @@ struct hl_debug_args {
  *
  * This IOCTL allows the user to get debug traces from the chip.
  *
- * The user needs to provide the register index and essential data such as
- * buffer address and size.
+ * Before the user can send configuration requests of the various
+ * debug/profile engines, it needs to set the device into debug mode.
+ * This is because the debug/profile infrastructure is shared component in the
+ * device and we can't allow multiple users to access it at the same time.
+ *
+ * Once a user set the device into debug mode, the driver won't allow other
+ * users to "work" with the device, i.e. open a FD. If there are multiple users
+ * opened on the device, the driver won't allow any user to debug the device.
+ *
+ * For each configuration request, the user needs to provide the register index
+ * and essential data such as buffer address and size.
+ *
+ * Once the user has finished using the debug/profile engines, he should
+ * set the device into non-debug mode, i.e. disable debug mode.
+ *
+ * The driver can decide to "kick out" the user if he abuses this interface.
  *
  */
 #define HL_IOCTL_DEBUG		\