Merge tag 'irqchip-5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core

Pull irqchip/genirq updates from Marc Zyngier:

 * Core code update:

  - Non-SMP IRQ affinity fixes, allowing UP kernel to behave similarly
    to SMP ones for the purpose of interrupt affinity

  - Let irq_set_chip_handler_name_locked() take a const struct irq_chip *

  - Tidy-up the NOMAP irqdomain API variant

  - Teach action_show() to use for_each_action_of_desc()

  - Make irq_chip_request_resources_parent() allow the parent callback
    to be optional

  - Remove dynamic allocations from populate_parent_alloc_arg()

 * New drivers:

  - Merge the long awaited IRQ support for the LoongArch architecture,
    with the provisional ACPICA update (to be reverted once the official
    support lands)

  - New Renesas RZ/G2L IRQC driver, equipped with its companion GPIO
    driver

 * Driver updates

  - Optimise the hot path operations for the SiFive PLIC, trading the
    locking for per-CPU priority masking masking operations which are
    apparently faster

  - Work around broken PLIC implementations that deal pretty badly with
    edge-triggered interrupts. Flag two implementations as affected.

  - Simplify the irq-stm32-exti driver, particularly the table that
    remaps the interrupts from exti to the GIC, reducing the memory usage

  - Convert the ocelot irq_chip to being immutable

  - Check ioremap() return value in the MIPS GIC driver

  - Move MMP driver init function declarations into the common .h

  - The obligatory typo fixes

Link: https://lore.kernel.org/all/20220727192356.1860546-1-maz@kernel.org

1 files changed, 31 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.h b/drivers/net/ethernet/intel/ice/ice_ptp.h
index afd048d69959..10e396abf130 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.h
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.h
@@ -49,6 +49,37 @@ struct ice_perout_channel {
  * To allow multiple ports to access the shared register block independently,
  * the blocks are split up so that indexes are assigned to each port based on
  * hardware logical port number.
+ *
+ * The timestamp blocks are handled differently for E810- and E822-based
+ * devices. In E810 devices, each port has its own block of timestamps, while in
+ * E822 there is a need to logically break the block of registers into smaller
+ * chunks based on the port number to avoid collisions.
+ *
+ * Example for port 5 in E810:
+ *  +--------+--------+--------+--------+--------+--------+--------+--------+
+ *  |register|register|register|register|register|register|register|register|
+ *  | block  | block  | block  | block  | block  | block  | block  | block  |
+ *  |  for   |  for   |  for   |  for   |  for   |  for   |  for   |  for   |
+ *  | port 0 | port 1 | port 2 | port 3 | port 4 | port 5 | port 6 | port 7 |
+ *  +--------+--------+--------+--------+--------+--------+--------+--------+
+ *                                               ^^
+ *                                               ||
+ *                                               |---  quad offset is always 0
+ *                                               ---- quad number
+ *
+ * Example for port 5 in E822:
+ * +-----------------------------+-----------------------------+
+ * |  register block for quad 0  |  register block for quad 1  |
+ * |+------+------+------+------+|+------+------+------+------+|
+ * ||port 0|port 1|port 2|port 3|||port 0|port 1|port 2|port 3||
+ * |+------+------+------+------+|+------+------+------+------+|
+ * +-----------------------------+-------^---------------------+
+ *                                ^      |
+ *                                |      --- quad offset*
+ *                                ---- quad number
+ *
+ *   * PHY port 5 is port 1 in quad 1
+ *
  */
 
 /**