---

yaml
---
r: 281875
b: refs/heads/master
c: 137d105
h: refs/heads/master
i:
  281873: f3d55b8
  281871: 558bf99
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 49404dd09f5dc78c247c6044c60d7be7768a71bc
+refs/heads/master: 137d105d50f6e6c373c1aa759f59045e6239cf66

trunk/arch/arm/mach-omap2/Kconfig

@@ -353,6 +353,27 @@ config OMAP3_SDRC_AC_TIMING
 	  wish to say no.  Selecting yes without understanding what is
 	  going on could result in system crashes;
 
+config OMAP4_ERRATA_I688
+	bool "OMAP4 errata: Async Bridge Corruption"
+	depends on ARCH_OMAP4
+	select ARCH_HAS_BARRIERS
+	help
+	  If a data is stalled inside asynchronous bridge because of back
+	  pressure, it may be accepted multiple times, creating pointer
+	  misalignment that will corrupt next transfers on that data path
+	  until next reset of the system (No recovery procedure once the
+	  issue is hit, the path remains consistently broken). Async bridge
+	  can be found on path between MPU to EMIF and MPU to L3 interconnect.
+	  This situation can happen only when the idle is initiated by a
+	  Master Request Disconnection (which is trigged by software when
+	  executing WFI on CPU).
+	  The work-around for this errata needs all the initiators connected
+	  through async bridge must ensure that data path is properly drained
+	  before issuing WFI. This condition will be met if one Strongly ordered
+	  access is performed to the target right before executing the WFI.
+	  In MPU case, L3 T2ASYNC FIFO and DDR T2ASYNC FIFO needs to be drained.
+	  IO barrier ensure that there is no synchronisation loss on initiators
+	  operating on both interconnect port simultaneously.
 endmenu
 
 endif

trunk/arch/arm/mach-omap2/include/mach/barriers.h

@@ -0,0 +1,31 @@
+/*
+ * OMAP memory barrier header.
+ *
+ * Copyright (C) 2011 Texas Instruments, Inc.
+ *  Santosh Shilimkar <santosh.shilimkar@ti.com>
+ *  Richard Woodruff <r-woodruff2@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef __MACH_BARRIERS_H
+#define __MACH_BARRIERS_H
+
+extern void omap_bus_sync(void);
+
+#define rmb()		dsb()
+#define wmb()		do { dsb(); outer_sync(); omap_bus_sync(); } while (0)
+#define mb()		wmb()
+
+#endif	/* __MACH_BARRIERS_H */

trunk/arch/arm/mach-omap2/io.c

@@ -237,6 +237,15 @@ static struct map_desc omap44xx_io_desc[] __initdata = {
 		.length		= L4_EMU_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_SO,
+	},
+#endif
+
 };
 #endif
 

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

@@ -15,11 +15,14 @@
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/platform_device.h>
+#include <linux/memblock.h>
 
 #include <asm/hardware/gic.h>
 #include <asm/hardware/cache-l2x0.h>
+#include <asm/mach/map.h>
 
 #include <plat/irqs.h>
+#include <plat/sram.h>
 
 #include <mach/hardware.h>
 #include <mach/omap-wakeupgen.h>
@@ -33,6 +36,54 @@ static void __iomem *l2cache_base;
 
 static void __iomem *sar_ram_base;
 
+#ifdef CONFIG_OMAP4_ERRATA_I688
+/* Used to implement memory barrier on DRAM path */
+#define OMAP4_DRAM_BARRIER_VA			0xfe600000
+
+void __iomem *dram_sync, *sram_sync;
+
+void omap_bus_sync(void)
+{
+	if (dram_sync && sram_sync) {
+		writel_relaxed(readl_relaxed(dram_sync), dram_sync);
+		writel_relaxed(readl_relaxed(sram_sync), sram_sync);
+		isb();
+	}
+}
+
+static int __init omap_barriers_init(void)
+{
+	struct map_desc dram_io_desc[1];
+	phys_addr_t paddr;
+	u32 size;
+
+	if (!cpu_is_omap44xx())
+		return -ENODEV;
+
+	size = ALIGN(PAGE_SIZE, SZ_1M);
+	paddr = memblock_alloc(size, SZ_1M);
+	if (!paddr) {
+		pr_err("%s: failed to reserve 4 Kbytes\n", __func__);
+		return -ENOMEM;
+	}
+	memblock_free(paddr, size);
+	memblock_remove(paddr, size);
+	dram_io_desc[0].virtual = OMAP4_DRAM_BARRIER_VA;
+	dram_io_desc[0].pfn = __phys_to_pfn(paddr);
+	dram_io_desc[0].length = size;
+	dram_io_desc[0].type = MT_MEMORY_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);
+
+	return 0;
+}
+core_initcall(omap_barriers_init);
+#endif
+
 void __init gic_init_irq(void)
 {
 	void __iomem *omap_irq_base;

trunk/arch/arm/mach-omap2/sleep44xx.S

@@ -325,8 +325,16 @@ skip_l2en:
 ENDPROC(omap4_cpu_resume)
 #endif
 
+#ifndef CONFIG_OMAP4_ERRATA_I688
+ENTRY(omap_bus_sync)
+	mov	pc, lr
+ENDPROC(omap_bus_sync)
+#endif
+
 ENTRY(omap_do_wfi)
 	stmfd	sp!, {lr}
+	/* Drain interconnect write buffers. */
+	bl omap_bus_sync
 
 	/*
 	 * Execute an ISB instruction to ensure that all of the

trunk/arch/arm/plat-omap/include/plat/sram.h

@@ -95,6 +95,10 @@ 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
 #endif

trunk/arch/arm/plat-omap/sram.c

@@ -40,7 +40,11 @@
 #define OMAP1_SRAM_PA		0x20000000
 #define OMAP2_SRAM_PUB_PA	(OMAP2_SRAM_PA + 0xf800)
 #define OMAP3_SRAM_PUB_PA       (OMAP3_SRAM_PA + 0x8000)
+#ifdef CONFIG_OMAP4_ERRATA_I688
+#define OMAP4_SRAM_PUB_PA	OMAP4_SRAM_PA
+#else
 #define OMAP4_SRAM_PUB_PA	(OMAP4_SRAM_PA + 0x4000)
+#endif
 
 #if defined(CONFIG_ARCH_OMAP2PLUS)
 #define SRAM_BOOTLOADER_SZ	0x00
@@ -163,6 +167,10 @@ static void __init omap_map_sram(void)
 	if (omap_sram_size == 0)
 		return;
 
+#ifdef CONFIG_OMAP4_ERRATA_I688
+		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