arm64: Introduce raw_{d,i}cache_line_size

On systems with mismatched i/d cache min line sizes, we need to use
the smallest size possible across all CPUs. This will be done by fetching
the system wide safe value from CPU feature infrastructure.
However the some special users(e.g kexec, hibernate) would need the line
size on the CPU (rather than the system wide), when either the system
wide feature may not be accessible or it is guranteed that the caller
executes with a gurantee of no migration.
Provide another helper which will fetch cache line size on the current CPU.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: James Morse <james.morse@arm.com>
Reviewed-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

arch/arm64/kernel/hibernate-asm.S

@@ -96,7 +96,7 @@ ENTRY(swsusp_arch_suspend_exit)
 
 	add	x1, x10, #PAGE_SIZE
 	/* Clean the copied page to PoU - based on flush_icache_range() */
-	dcache_line_size x2, x3
+	raw_dcache_line_size x2, x3
 	sub	x3, x2, #1
 	bic	x4, x10, x3
 2:	dc	cvau, x4	/* clean D line / unified line */

arch/arm64/kernel/relocate_kernel.S

@@ -34,7 +34,7 @@ ENTRY(arm64_relocate_new_kernel)
 	/* Setup the list loop variables. */
 	mov	x17, x1				/* x17 = kimage_start */
 	mov	x16, x0				/* x16 = kimage_head */
-	dcache_line_size x15, x0		/* x15 = dcache line size */
+	raw_dcache_line_size x15, x0		/* x15 = dcache line size */
 	mov	x14, xzr			/* x14 = entry ptr */
 	mov	x13, xzr			/* x13 = copy dest */