sh: Use uncached I/O helpers in PMB setup.

The PMB code is an example of something that spends an absurd amount of
time running uncached when only a couple of operations really need to be.
This switches over to the shiny new uncached helpers, permitting us to
spend far more time running cached.

Additionally, MMUCR twiddling is perfectly safe from cached space given
that it's paired with a control register barrier, so fix that up, too.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/mm/pmb.c

@@ -161,32 +161,28 @@ static __always_inline unsigned long pmb_cache_flags(void)
  */
 static void __set_pmb_entry(struct pmb_entry *pmbe)
 {
-	jump_to_uncached();
-
 	pmbe->flags &= ~PMB_CACHE_MASK;
 	pmbe->flags |= pmb_cache_flags();
 
-	__raw_writel(pmbe->vpn | PMB_V, mk_pmb_addr(pmbe->entry));
-	__raw_writel(pmbe->ppn | pmbe->flags | PMB_V, mk_pmb_data(pmbe->entry));
-
-	back_to_cached();
+	writel_uncached(pmbe->vpn | PMB_V, mk_pmb_addr(pmbe->entry));
+	writel_uncached(pmbe->ppn | pmbe->flags | PMB_V,
+			mk_pmb_data(pmbe->entry));
 }
 
 static void __clear_pmb_entry(struct pmb_entry *pmbe)
 {
-	unsigned int entry = pmbe->entry;
-	unsigned long addr;
-
-	jump_to_uncached();
+	unsigned long addr, data;
+	unsigned long addr_val, data_val;
 
-	/* Clear V-bit */
-	addr = mk_pmb_addr(entry);
-	__raw_writel(__raw_readl(addr) & ~PMB_V, addr);
+	addr = mk_pmb_addr(pmbe->entry);
+	data = mk_pmb_data(pmbe->entry);
 
-	addr = mk_pmb_data(entry);
-	__raw_writel(__raw_readl(addr) & ~PMB_V, addr);
+	addr_val = __raw_readl(addr);
+	data_val = __raw_readl(data);
 
-	back_to_cached();
+	/* Clear V-bit */
+	writel_uncached(addr_val & ~PMB_V, addr);
+	writel_uncached(data_val & ~PMB_V, data);
 }
 
 static void set_pmb_entry(struct pmb_entry *pmbe)
@@ -400,8 +396,8 @@ static int pmb_synchronize_mappings(void)
 			/*
 			 * Invalidate anything out of bounds.
 			 */
-			__raw_writel(addr_val & ~PMB_V, addr);
-			__raw_writel(data_val & ~PMB_V, data);
+			writel_uncached(addr_val & ~PMB_V, addr);
+			writel_uncached(data_val & ~PMB_V, data);
 			continue;
 		}
 
@@ -411,7 +407,8 @@ static int pmb_synchronize_mappings(void)
 		if (data_val & PMB_C) {
 			data_val &= ~PMB_CACHE_MASK;
 			data_val |= pmb_cache_flags();
-			__raw_writel(data_val, data);
+
+			writel_uncached(data_val, data);
 		}
 
 		size = data_val & PMB_SZ_MASK;
@@ -462,25 +459,20 @@ int pmb_init(void)
 {
 	int ret;
 
-	jump_to_uncached();
-
 	/*
 	 * Sync our software copy of the PMB mappings with those in
 	 * hardware. The mappings in the hardware PMB were either set up
 	 * by the bootloader or very early on by the kernel.
 	 */
 	ret = pmb_synchronize_mappings();
-	if (unlikely(ret == 0)) {
-		back_to_cached();
+	if (unlikely(ret == 0))
 		return 0;
-	}
 
-	__raw_writel(0, PMB_IRMCR);
+	writel_uncached(0, PMB_IRMCR);
 
 	/* Flush out the TLB */
 	__raw_writel(__raw_readl(MMUCR) | MMUCR_TI, MMUCR);
-
-	back_to_cached();
+	ctrl_barrier();
 
 	return 0;
 }