ARM: OMAP4+: Remove static iotable mappings for SRAM

In order to handle errata I688, a page of sram was reserved by doing a
static iotable map. Now that we use gen_pool to manage sram, we can
completely remove all of these static mappings and use gen_pool_alloc()
to get the one page of sram space needed to implement errata I688.
omap_bus_sync will be NOP until SRAM initialization happens.

Suggested-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

Documentation/devicetree/bindings/arm/omap/mpu.txt

@@ -10,6 +10,9 @@ Required properties:
 	       Should be "ti,omap5-mpu" for OMAP5
 - ti,hwmods: "mpu"
 
+Optional properties:
+- sram:	Phandle to the ocmcram node
+
 Examples:
 
 - For an OMAP5 SMP system:

arch/arm/boot/dts/omap4.dtsi

@@ -81,6 +81,7 @@ soc {
 		mpu {
 			compatible = "ti,omap4-mpu";
 			ti,hwmods = "mpu";
+			sram = <&ocmcram>;
 		};
 
 		dsp {

arch/arm/boot/dts/omap5.dtsi

@@ -104,8 +104,9 @@ gic: interrupt-controller@48211000 {
 	soc {
 		compatible = "ti,omap-infra";
 		mpu {
-			compatible = "ti,omap5-mpu";
+			compatible = "ti,omap4-mpu";
 			ti,hwmods = "mpu";
+			sram = <&ocmcram>;
 		};
 	};
 

arch/arm/mach-omap2/io.c

@@ -231,15 +231,6 @@ static struct map_desc omap44xx_io_desc[] __initdata = {
 		.length		= L4_PER_44XX_SIZE,
 		.type		= MT_DEVICE,
 	},
-#ifdef CONFIG_OMAP4_ERRATA_I688
-	{
-		.virtual	= OMAP4_SRAM_VA,
-		.pfn		= __phys_to_pfn(OMAP4_SRAM_PA),
-		.length		= PAGE_SIZE,
-		.type		= MT_MEMORY_RW_SO,
-	},
-#endif
-
 };
 #endif
 
@@ -269,14 +260,6 @@ static struct map_desc omap54xx_io_desc[] __initdata = {
 		.length		= L4_PER_54XX_SIZE,
 		.type		= MT_DEVICE,
 	},
-#ifdef CONFIG_OMAP4_ERRATA_I688
-	{
-		.virtual	= OMAP4_SRAM_VA,
-		.pfn		= __phys_to_pfn(OMAP4_SRAM_PA),
-		.length		= PAGE_SIZE,
-		.type		= MT_MEMORY_RW_SO,
-	},
-#endif
 };
 #endif
 

arch/arm/mach-omap2/omap4-common.c

@@ -25,6 +25,7 @@
 #include <linux/irqchip/irq-crossbar.h>
 #include <linux/of_address.h>
 #include <linux/reboot.h>
+#include <linux/genalloc.h>
 
 #include <asm/hardware/cache-l2x0.h>
 #include <asm/mach/map.h>
@@ -71,6 +72,26 @@ void omap_bus_sync(void)
 }
 EXPORT_SYMBOL(omap_bus_sync);
 
+static int __init omap4_sram_init(void)
+{
+	struct device_node *np;
+	struct gen_pool *sram_pool;
+
+	np = of_find_compatible_node(NULL, NULL, "ti,omap4-mpu");
+	if (!np)
+		pr_warn("%s:Unable to allocate sram needed to handle errata I688\n",
+			__func__);
+	sram_pool = of_get_named_gen_pool(np, "sram", 0);
+	if (!sram_pool)
+		pr_warn("%s:Unable to get sram pool needed to handle errata I688\n",
+			__func__);
+	else
+		sram_sync = (void *)gen_pool_alloc(sram_pool, PAGE_SIZE);
+
+	return 0;
+}
+omap_arch_initcall(omap4_sram_init);
+
 /* Steal one page physical memory for barrier implementation */
 int __init omap_barrier_reserve_memblock(void)
 {
@@ -91,7 +112,6 @@ void __init omap_barriers_init(void)
 	dram_io_desc[0].type = MT_MEMORY_RW_SO;
 	iotable_init(dram_io_desc, ARRAY_SIZE(dram_io_desc));
 	dram_sync = (void __iomem *) dram_io_desc[0].virtual;
-	sram_sync = (void __iomem *) OMAP4_SRAM_VA;
 
 	pr_info("OMAP4: Map 0x%08llx to 0x%08lx for dram barrier\n",
 		(long long) paddr, dram_io_desc[0].virtual);

arch/arm/mach-omap2/sram.c

@@ -124,12 +124,6 @@ static void __init omap2_map_sram(void)
 {
 	int cached = 1;
 
-#ifdef CONFIG_OMAP4_ERRATA_I688
-	if (cpu_is_omap44xx()) {
-		omap_sram_start += PAGE_SIZE;
-		omap_sram_size -= SZ_16K;
-	}
-#endif
 	if (cpu_is_omap34xx()) {
 		/*
 		 * SRAM must be marked as non-cached on OMAP3 since the

arch/arm/mach-omap2/sram.h

@@ -74,9 +74,3 @@ static inline void omap_push_sram_idle(void) {}
  */
 #define OMAP2_SRAM_PA		0x40200000
 #define OMAP3_SRAM_PA           0x40200000
-#ifdef CONFIG_OMAP4_ERRATA_I688
-#define OMAP4_SRAM_PA		0x40304000
-#define OMAP4_SRAM_VA		0xfe404000
-#else
-#define OMAP4_SRAM_PA		0x40300000
-#endif