[PATCH] MIPS: Make sure ebase address is in KSEG0

[Huacai Chen <chenhc@lemote.com>]

Dynamically allocated ebase address above 0x20000000 can be triggered
by some special physical memory layout, or just by a "big kernel + big
initrd + big swiotlb" configuration.

For MIPS32, ebase address above 0x20000000 is unusable, for MIPS64 it
is usable but this case is warned. However, this warning is useless
because it is unfixable in a specific system configuration. So we just
use CKSEG0 as a fallback.

Signed-off-by: Huacai Chen <chenhc@lemote.com>
---
 arch/mips/kernel/traps.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 9d9b2a4..7393f33 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -2306,10 +2306,15 @@ void __init trap_init(void)
 		 * EVA is special though as it allows segments to be rearranged
 		 * and to become uncached during cache error handling.
 		 */
-		if (!IS_ENABLED(CONFIG_EVA) && !WARN_ON(ebase_pa >= 0x20000000))
+		if (ebase_pa < 0x20000000)
 			ebase = CKSEG0ADDR(ebase_pa);
-		else
+		else if (IS_ENABLED(CONFIG_EVA))
 			ebase = (unsigned long)phys_to_virt(ebase_pa);
+		else {
+			memblock_free(ebase_pa, vec_size);
+			ebase = CKSEG0;
+			memblock_reserve(virt_to_phys((void *)ebase), vec_size);
+		}
 	}
 
 	if (cpu_has_mmips) {
-- 
2.7.0