diff options
Diffstat (limited to 'arch/arm/mach-omap2')
| -rw-r--r-- | arch/arm/mach-omap2/Kconfig | 21 | ||||
| -rw-r--r-- | arch/arm/mach-omap2/include/mach/barriers.h | 31 | ||||
| -rw-r--r-- | arch/arm/mach-omap2/io.c | 9 | ||||
| -rw-r--r-- | arch/arm/mach-omap2/omap4-common.c | 51 | ||||
| -rw-r--r-- | arch/arm/mach-omap2/sleep44xx.S | 8 |
5 files changed, 120 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/Kconfig b/arch/arm/mach-omap2/Kconfig index b6625130831..50f43942c1a 100644 --- a/arch/arm/mach-omap2/Kconfig +++ b/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 diff --git a/arch/arm/mach-omap2/include/mach/barriers.h b/arch/arm/mach-omap2/include/mach/barriers.h new file mode 100644 index 00000000000..4fa72c7cc7c --- /dev/null +++ b/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 */ diff --git a/arch/arm/mach-omap2/io.c b/arch/arm/mach-omap2/io.c index 3f565dd2ea8..65843390e7f 100644 --- a/arch/arm/mach-omap2/io.c +++ b/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 diff --git a/arch/arm/mach-omap2/omap4-common.c b/arch/arm/mach-omap2/omap4-common.c index 1b93d31fe8e..bc16c818c6b 100644 --- a/arch/arm/mach-omap2/omap4-common.c +++ b/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; diff --git a/arch/arm/mach-omap2/sleep44xx.S b/arch/arm/mach-omap2/sleep44xx.S index 3154b63def3..abd28340049 100644 --- a/arch/arm/mach-omap2/sleep44xx.S +++ b/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 |