ARM: 9356/2: Move asm statements accessing TTBCR into C functions

This patch implements cpu_get_ttbcr() and cpu_set_ttbcr() and replaces
the corresponding asm statements.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

Author: Linus Walleij

arch/arm/include/asm/proc-fns.h

@@ -178,6 +178,18 @@ extern void cpu_resume(void);
 	})
 #endif
 
+static inline unsigned int cpu_get_ttbcr(void)
+{
+	unsigned int ttbcr;
+	asm("mrc p15, 0, %0, c2, c0, 2" : "=r" (ttbcr));
+	return ttbcr;
+}
+
+static inline void cpu_set_ttbcr(unsigned int ttbcr)
+{
+	asm("mcr p15, 0, %0, c2, c0, 2" : : "r" (ttbcr));
+}
+
 #else	/*!CONFIG_MMU */
 
 #define cpu_switch_mm(pgd,mm)	{ }

arch/arm/mm/mmu.c

@@ -1687,9 +1687,8 @@ static void __init early_paging_init(const struct machine_desc *mdesc)
 	 */
 	cr = get_cr();
 	set_cr(cr & ~(CR_I | CR_C));
-	asm("mrc p15, 0, %0, c2, c0, 2" : "=r" (ttbcr));
-	asm volatile("mcr p15, 0, %0, c2, c0, 2"
-		: : "r" (ttbcr & ~(3 << 8 | 3 << 10)));
+	ttbcr = cpu_get_ttbcr();
+	cpu_set_ttbcr(ttbcr & ~(3 << 8 | 3 << 10));
 	flush_cache_all();
 
 	/*
@@ -1701,7 +1700,7 @@ static void __init early_paging_init(const struct machine_desc *mdesc)
 	lpae_pgtables_remap(offset, pa_pgd);
 
 	/* Re-enable the caches and cacheable TLB walks */
-	asm volatile("mcr p15, 0, %0, c2, c0, 2" : : "r" (ttbcr));
+	cpu_set_ttbcr(ttbcr);
 	set_cr(cr);
 }