microblaze: Allow PAGE_SIZE configuration
Allow developer to configure memory page size at compile time.
Larger pages can improve performance on some workloads.
Based on PowerPC code.
Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 505a085..a517421 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -223,6 +223,36 @@
hex "Size of user task space" if TASK_SIZE_BOOL
default "0x80000000"
+choice
+ prompt "Page size"
+ default MICROBLAZE_4K_PAGES
+ depends on ADVANCED_OPTIONS && !MMU
+ help
+ Select the kernel logical page size. Increasing the page size
+ will reduce software overhead at each page boundary, allow
+ hardware prefetch mechanisms to be more effective, and allow
+ larger dma transfers increasing IO efficiency and reducing
+ overhead. However the utilization of memory will increase.
+ For example, each cached file will using a multiple of the
+ page size to hold its contents and the difference between the
+ end of file and the end of page is wasted.
+
+ If unsure, choose 4K_PAGES.
+
+config MICROBLAZE_4K_PAGES
+ bool "4k page size"
+
+config MICROBLAZE_8K_PAGES
+ bool "8k page size"
+
+config MICROBLAZE_16K_PAGES
+ bool "16k page size"
+
+config MICROBLAZE_32K_PAGES
+ bool "32k page size"
+
+endchoice
+
endmenu
source "mm/Kconfig"