From: Russell King Date: Fri, 5 Jun 2015 23:13:40 +0000 (+0100) Subject: Revert "ARM: OMAP4: remove dead kconfig option OMAP4_ERRATA_I688" X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=f746929ffdc8;p=linux-beck.git Revert "ARM: OMAP4: remove dead kconfig option OMAP4_ERRATA_I688" This reverts commit 606da4826b89b044b51e3a84958b802204cfe4c7. We actually need this code for proper behaviour of OMAP4, and it needs fixing a different way other than just removing the code. Disabling code which is necessary in the hopes of persuing multiplatform kernels is a stupid approach. Acked-by: Tony Lindgren Acked-by: Richard Woodruff Signed-off-by: Russell King --- diff --git a/arch/arm/mach-omap2/Kconfig b/arch/arm/mach-omap2/Kconfig index ecc04ff13e95..2128441430ad 100644 --- a/arch/arm/mach-omap2/Kconfig +++ b/arch/arm/mach-omap2/Kconfig @@ -240,6 +240,27 @@ 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 || SOC_OMAP5) && !ARCH_MULTIPLATFORM + 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/common.c b/arch/arm/mach-omap2/common.c index eae6a0e87c90..484cdadfb187 100644 --- a/arch/arm/mach-omap2/common.c +++ b/arch/arm/mach-omap2/common.c @@ -30,4 +30,5 @@ int __weak omap_secure_ram_reserve_memblock(void) void __init omap_reserve(void) { omap_secure_ram_reserve_memblock(); + omap_barrier_reserve_memblock(); } diff --git a/arch/arm/mach-omap2/common.h b/arch/arm/mach-omap2/common.h index cf3cf22ecd42..46e24581d624 100644 --- a/arch/arm/mach-omap2/common.h +++ b/arch/arm/mach-omap2/common.h @@ -200,6 +200,9 @@ void __init omap4_map_io(void); void __init omap5_map_io(void); void __init ti81xx_map_io(void); +/* omap_barriers_init() is OMAP4 only */ +void omap_barriers_init(void); + /** * omap_test_timeout - busy-loop, testing a condition * @cond: condition to test until it evaluates to true diff --git a/arch/arm/mach-omap2/io.c b/arch/arm/mach-omap2/io.c index 820dde8b5b04..7743e3672f98 100644 --- a/arch/arm/mach-omap2/io.c +++ b/arch/arm/mach-omap2/io.c @@ -306,6 +306,7 @@ void __init am33xx_map_io(void) void __init omap4_map_io(void) { iotable_init(omap44xx_io_desc, ARRAY_SIZE(omap44xx_io_desc)); + omap_barriers_init(); } #endif @@ -313,6 +314,7 @@ void __init omap4_map_io(void) void __init omap5_map_io(void) { iotable_init(omap54xx_io_desc, ARRAY_SIZE(omap54xx_io_desc)); + omap_barriers_init(); } #endif /* diff --git a/arch/arm/mach-omap2/omap-secure.h b/arch/arm/mach-omap2/omap-secure.h index af2851fbcdf0..dec2b05d184b 100644 --- a/arch/arm/mach-omap2/omap-secure.h +++ b/arch/arm/mach-omap2/omap-secure.h @@ -70,6 +70,13 @@ extern u32 rx51_secure_dispatcher(u32 idx, u32 process, u32 flag, u32 nargs, extern u32 rx51_secure_update_aux_cr(u32 set_bits, u32 clear_bits); extern u32 rx51_secure_rng_call(u32 ptr, u32 count, u32 flag); +#ifdef CONFIG_OMAP4_ERRATA_I688 +extern int omap_barrier_reserve_memblock(void); +#else +static inline void omap_barrier_reserve_memblock(void) +{ } +#endif + #ifdef CONFIG_SOC_HAS_REALTIME_COUNTER void set_cntfreq(void); #else diff --git a/arch/arm/mach-omap2/omap4-common.c b/arch/arm/mach-omap2/omap4-common.c index 16350eefa66c..7bb116a6f86f 100644 --- a/arch/arm/mach-omap2/omap4-common.c +++ b/arch/arm/mach-omap2/omap4-common.c @@ -51,6 +51,75 @@ static void __iomem *twd_base; #define IRQ_LOCALTIMER 29 +#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; + +static phys_addr_t paddr; +static u32 size; + +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(); + } +} +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) +{ + + size = ALIGN(PAGE_SIZE, SZ_1M); + paddr = arm_memblock_steal(size, SZ_1M); + + return 0; +} + +void __init omap_barriers_init(void) +{ + struct map_desc dram_io_desc[1]; + + 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_RW_SO; + iotable_init(dram_io_desc, ARRAY_SIZE(dram_io_desc)); + dram_sync = (void __iomem *) dram_io_desc[0].virtual; + + pr_info("OMAP4: Map 0x%08llx to 0x%08lx for dram barrier\n", + (long long) paddr, dram_io_desc[0].virtual); + +} +#else +void __init omap_barriers_init(void) +{} +#endif + void gic_dist_disable(void) { if (gic_dist_base_addr) diff --git a/arch/arm/mach-omap2/sleep44xx.S b/arch/arm/mach-omap2/sleep44xx.S index ad1bb9431e94..b84a0122d823 100644 --- a/arch/arm/mach-omap2/sleep44xx.S +++ b/arch/arm/mach-omap2/sleep44xx.S @@ -333,9 +333,11 @@ ENDPROC(omap4_cpu_resume) #endif /* defined(CONFIG_SMP) && defined(CONFIG_PM) */ +#ifndef CONFIG_OMAP4_ERRATA_I688 ENTRY(omap_bus_sync) ret lr ENDPROC(omap_bus_sync) +#endif ENTRY(omap_do_wfi) stmfd sp!, {lr}