qualcommax: Add new menu item for IPQ settings

Rather mess with target 'config-*' files, introduce a custom menu item
that consolidates all IPQ related kernel settings in one menu.

Most of these can be left as default since the options are derived from the
initial NSS fork for 'config-6.6'.

Options include:
1) enable or disable building `skbuff_recycle`
2) enable or disable preemption
3) select IPQ memory profile

Signed-off-by: Sean Khan <datapronix@protonmail.com>

Config.in

@@ -38,3 +38,5 @@ source "target/sdk/Config.in"
 source "target/toolchain/Config.in"
 
 source "tmp/.config-package.in"
+
+source "config/Config-ipq.in"

config/Config-ipq.in

@@ -0,0 +1,140 @@
+# vim: set ft=kconfig
+menu "Qualcomm IPQ Options"
+
+comment "Kernel build options"
+
+choice KERNEL_IPQ_MEM_PROFILE
+	prompt "IPQ memory profile"
+	default IPQ_MEM_PROFILE_512 if TARGET_qualcommax_ipq807x_DEVICE_edimax_cax1800
+	default IPQ_MEM_PROFILE_512 if TARGET_qualcommax_ipq807x_DEVICE_compex_wpq87
+	default IPQ_MEM_PROFILE_512 if TARGET_qualcommax_ipq807x_DEVICE_linksys_mx4200v1
+	default IPQ_MEM_PROFILE_512 if TARGET_qualcommax_ipq807x_DEVICE_redmi_ax6
+	default IPQ_MEM_PROFILE_512 if TARGET_qualcommax_ipq807x_DEVICE_xiaomi_ax3600
+	default IPQ_MEM_PROFILE_512 if TARGET_qualcommax_ipq807x_DEVICE_zte_mf269
+
+	config IPQ_MEM_PROFILE_1024
+			bool "1024"
+	config IPQ_MEM_PROFILE_512
+			bool "512"
+	config IPQ_MEM_PROFILE_256
+			bool "256"
+endchoice
+
+config KERNEL_IPQ_MEM_PROFILE
+	int
+	default 1024 if IPQ_MEM_PROFILE_1024
+	default 512 if IPQ_MEM_PROFILE_512
+	default 256 if IPQ_MEM_PROFILE_256
+
+	help
+	  This option select memory profile to used, which defines
+	  the reserved memory configuration used in device tree
+
+config KERNEL_SKB_RECYCLER
+	bool "Generic SKB recycling"
+	default y if KERNEL_IPQ_MEM_PROFILE < 1024
+
+choice KERNEL_SKB_RECYCLE_SIZE
+	prompt "SKB recycler size"
+	default SKB_RECYCLE_SIZE_2304
+	default SKB_RECYCLE_SIZE_1856 if KERNEL_IPQ_MEM_PROFILE < 1024
+
+	depends on KERNEL_SKB_RECYCLER
+	config SKB_RECYCLE_SIZE_1856
+			bool "1856"
+	config SKB_RECYCLE_SIZE_2304
+			bool "2304"
+endchoice
+
+config KERNEL_SKB_RECYCLE_SIZE
+	int
+	depends on KERNEL_SKB_RECYCLER
+	default 2304 if SKB_RECYCLE_SIZE_2304
+	default 1856 if SKB_RECYCLE_SIZE_1856
+
+	help
+	SKB recycler default size
+
+config KERNEL_SKB_RECYCLER_MULTI_CPU
+	bool "Cross-CPU recycling for CPU-locked workloads"
+	depends on KERNEL_SKB_RECYCLER
+	default y
+
+config KERNEL_SKB_RECYCLER_PREALLOC
+	bool "Enable preallocation of SKBs"
+	depends on KERNEL_SKB_RECYCLER
+	default n
+
+config KERNEL_SKB_RECYCLE_MAX_PREALLOC_SKBS
+	int "Number of SKBs to be preallocated"
+	depends on KERNEL_SKB_RECYCLER_PREALLOC
+	default 16384
+
+config KERNEL_SKB_FIXED_SIZE_2K
+	bool "SKB size fixed at 2K"
+	default n
+	help
+	   SKB size fixed at 2K.
+
+config KERNEL_ALLOC_SKB_PAGE_FRAG_DISABLE
+	depends on KERNEL_SKB_RECYCLER
+	bool "Disable alloc skb page frag"
+	default n
+
+choice KERNEL_PREEMPTION
+	prompt "Kernel preemption level"
+	default KERNEL_PREEMPT
+
+config KERNEL_PREEMPT_NONE
+	bool "No Forced Preemption (Server)"
+	help
+	  This is the traditional Linux preemption model, geared towards
+	  throughput. It will still provide good latencies most of the time,
+	  but there are no guarantees and occasional longer delays are
+	  possible.
+
+	  Select this option if you are building a kernel for a server or
+	  scientific/computation system, or if you want to maximize the
+	  raw processing power of the kernel, irrespective of scheduling
+	  latencies.
+
+config KERNEL_PREEMPT_NONE_BUILD
+	depends on KERNEL_PREEMPT_NONE
+	bool
+	default y
+
+config KERNEL_PREEMPT
+	bool "Preemptible Kernel (Low-Latency)"
+	help
+	  This option reduces the latency of the kernel by making
+	  all kernel code (that is not executing in a critical section)
+	  preemptible.  This allows reaction to interactive events by
+	  permitting a low priority process to be preempted involuntarily
+	  even if it is in kernel mode executing a system call and would
+	  otherwise not be about to reach a natural preemption point.
+	  This allows applications to run more 'smoothly' even when the
+	  system is under load, at the cost of slightly lower throughput
+	  and a slight runtime overhead to kernel code.
+
+	  Select this if you are building a kernel for a desktop or
+	  embedded system with latency requirements in the milliseconds
+	  range.
+
+if KERNEL_PREEMPT
+	config KERNEL_PREEMPT_RCU
+	bool "Preemptible RCU"
+	default y
+	select KERNEL_PREEMPT_COUNT
+	help
+	  This option selects the RCU implementation that is
+	  designed for very large SMP systems with hundreds or
+	  thousands of CPUs, but for which real-time response
+	  is also required.  It also scales down nicely to
+	  smaller systems.
+
+	  Select this option if you are unsure.
+
+endif
+endchoice
+
+endmenu