platform/mellanox: mlxbf-pmc: Add Mellanox BlueField PMC driver

The performance modules in BlueField are present in several hardware
blocks and each block provides access to these stats either through
counters that can be programmed to monitor supported events or
through memory-mapped registers that hold the relevant information.
The hardware blocks that include a performance module are:
 * Tile (block containing 2 cores and a shared L2 cache)
 * TRIO (PCIe root complex)
 * MSS (Memory Sub-system containing the Memory Controller and L3 cache)
 * GIC (Interrupt controller)
 * SMMU (System Memory Management Unit)
The mlx_pmc driver provides access to all of these performance modules
through a hwmon sysfs interface.

v2 --> v3
Update copyright info.

v1 --> v2
Remove unused headers.
Add comma to arrays where last line is not a termination.
Use kstrtoint in place of sscanf.
UUID manipulation follows drivers/platform/mellanox/mlxbf-bootctl.c

Signed-off-by: Shravan Kumar Ramani <shravankr@nvidia.com>
Reviewed-by: Vadim Pasternak <vadimp@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/4e19a1e5bf4197ad27fc57981fd280eaebd23577.1602160468.git.shravankr@nvidia.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

drivers/platform/mellanox/Kconfig

@@ -56,4 +56,14 @@ config MLXBF_BOOTCTL
 	  to the userspace tools, to be used in conjunction with the eMMC
 	  device driver to do necessary initial swap of the boot partition.
 
+config MLXBF_PMC
+	tristate "Mellanox BlueField Performance Monitoring Counters driver"
+	depends on ARM64
+	depends on HWMON
+	depends on ACPI
+	help
+	  Say y here to enable PMC support. The PMC driver provides access
+	  to performance monitoring counters within various blocks in the
+	  Mellanox BlueField SoC via a sysfs interface.
+
 endif # MELLANOX_PLATFORM

drivers/platform/mellanox/Makefile

@@ -4,6 +4,7 @@
 # Mellanox Platform-Specific Drivers
 #
 obj-$(CONFIG_MLXBF_BOOTCTL)	+= mlxbf-bootctl.o
+obj-$(CONFIG_MLXBF_PMC)		+= mlxbf-pmc.o
 obj-$(CONFIG_MLXBF_TMFIFO)	+= mlxbf-tmfifo.o
 obj-$(CONFIG_MLXREG_HOTPLUG)	+= mlxreg-hotplug.o
 obj-$(CONFIG_MLXREG_IO) += mlxreg-io.o