FRV: permit the memory to be located elsewhere in NOMMU mode

Permit the memory to be located somewhere other than address 0xC0000000 in
NOMMU mode. The configuration options are already present, it just
requires wiring up in the linker script.

Note that only a limited set of locations of runtime addresses are available
because of the way the CPU protection registers work.

Signed-off-by: David Howells <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/frv/Kconfig

···
 
 endchoice
 
+config PAGE_OFFSET
+	hex
+	default 0x20000000 if UCPAGE_OFFSET_20000000
+	default 0x40000000 if UCPAGE_OFFSET_40000000
+	default 0x60000000 if UCPAGE_OFFSET_60000000
+	default 0x80000000 if UCPAGE_OFFSET_80000000
+	default 0xA0000000 if UCPAGE_OFFSET_A0000000
+	default 0xC0000000
+
 config PROTECT_KERNEL
 	bool "Protect core kernel against userspace"
 	depends on !MMU

arch/frv/kernel/vmlinux.lds.S

···
 
 jiffies = jiffies_64 + 4;
 
-__page_offset = 0xc0000000;		/* start of area covered by struct pages */
+__page_offset = CONFIG_PAGE_OFFSET;	/* start of area covered by struct pages */
 __kernel_image_start = __page_offset;	/* address at which kernel image resides */
 
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