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
--- /dev/null
+/*
+ * 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 */
.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
#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>
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;
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
*/
#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
#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
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
projects / linux-platform-drivers-x86.git / commitdiff