From b6d92b4a6bdb880b39789c677b952c53a437028d Mon Sep 17 00:00:00 2001 From: "Steven J. Hill" Date: Mon, 25 Mar 2013 13:47:29 -0500 Subject: [PATCH] MIPS: Add option to disable software I/O coherency. Some MIPS controllers have hardware I/O coherency. This patch detects those and turns off software coherency. A new kernel command line option also allows the user to manually turn software coherency on or off. Signed-off-by: Steven J. Hill --- arch/mips/include/asm/dma-coherence.h | 15 +++++ arch/mips/include/asm/dma-mapping.h | 1 + .../include/asm/mach-generic/dma-coherence.h | 5 +- arch/mips/mm/c-r4k.c | 24 +++---- arch/mips/mm/dma-default.c | 25 +++++++- arch/mips/mti-malta/malta-setup.c | 63 +++++++++++++++++++ arch/mips/mti-sead3/sead3-setup.c | 3 - 7 files changed, 112 insertions(+), 24 deletions(-) create mode 100644 arch/mips/include/asm/dma-coherence.h diff --git a/arch/mips/include/asm/dma-coherence.h b/arch/mips/include/asm/dma-coherence.h new file mode 100644 index 000000000000..242cbb3ca582 --- /dev/null +++ b/arch/mips/include/asm/dma-coherence.h @@ -0,0 +1,15 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2006 Ralf Baechle + * + */ +#ifndef __ASM_DMA_COHERENCE_H +#define __ASM_DMA_COHERENCE_H + +extern int coherentio; +extern int hw_coherentio; + +#endif diff --git a/arch/mips/include/asm/dma-mapping.h b/arch/mips/include/asm/dma-mapping.h index f8fc74b6cb47..84238c574d5e 100644 --- a/arch/mips/include/asm/dma-mapping.h +++ b/arch/mips/include/asm/dma-mapping.h @@ -2,6 +2,7 @@ #define _ASM_DMA_MAPPING_H #include +#include #include #include diff --git a/arch/mips/include/asm/mach-generic/dma-coherence.h b/arch/mips/include/asm/mach-generic/dma-coherence.h index 9c95177f7a7e..fe23034aaf72 100644 --- a/arch/mips/include/asm/mach-generic/dma-coherence.h +++ b/arch/mips/include/asm/mach-generic/dma-coherence.h @@ -61,9 +61,8 @@ static inline int plat_device_is_coherent(struct device *dev) { #ifdef CONFIG_DMA_COHERENT return 1; -#endif -#ifdef CONFIG_DMA_NONCOHERENT - return 0; +#else + return coherentio; #endif } diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c index 2078915eacb9..f5943ab44987 100644 --- a/arch/mips/mm/c-r4k.c +++ b/arch/mips/mm/c-r4k.c @@ -33,6 +33,7 @@ #include #include /* for run_uncached() */ #include +#include /* * Special Variant of smp_call_function for use by cache functions: @@ -1377,20 +1378,6 @@ static void __cpuinit coherency_setup(void) } } -#if defined(CONFIG_DMA_NONCOHERENT) - -static int __cpuinitdata coherentio; - -static int __init setcoherentio(char *str) -{ - coherentio = 1; - - return 0; -} - -early_param("coherentio", setcoherentio); -#endif - static void __cpuinit r4k_cache_error_setup(void) { extern char __weak except_vec2_generic; @@ -1472,9 +1459,14 @@ void __cpuinit r4k_cache_init(void) build_clear_page(); build_copy_page(); -#if !defined(CONFIG_MIPS_CMP) + + /* + * We want to run CMP kernels on core with and without coherent + * caches. Therefore, do not use CONFIG_MIPS_CMP to decide whether + * or not to flush caches. + */ local_r4k___flush_cache_all(NULL); -#endif + coherency_setup(); board_cache_error_setup = r4k_cache_error_setup; } diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c index f9ef83829a52..caf92ecb37d6 100644 --- a/arch/mips/mm/dma-default.c +++ b/arch/mips/mm/dma-default.c @@ -22,6 +22,26 @@ #include +int coherentio = 0; /* User defined DMA coherency from command line. */ +EXPORT_SYMBOL_GPL(coherentio); +int hw_coherentio = 0; /* Actual hardware supported DMA coherency setting. */ + +static int __init setcoherentio(char *str) +{ + coherentio = 1; + pr_info("Hardware DMA cache coherency (command line)\n"); + return 0; +} +early_param("coherentio", setcoherentio); + +static int __init setnocoherentio(char *str) +{ + coherentio = 0; + pr_info("Software DMA cache coherency (command line)\n"); + return 0; +} +early_param("nocoherentio", setnocoherentio); + static inline struct page *dma_addr_to_page(struct device *dev, dma_addr_t dma_addr) { @@ -115,7 +135,8 @@ static void *mips_dma_alloc_coherent(struct device *dev, size_t size, if (!plat_device_is_coherent(dev)) { dma_cache_wback_inv((unsigned long) ret, size); - ret = UNCAC_ADDR(ret); + if (!hw_coherentio) + ret = UNCAC_ADDR(ret); } } @@ -142,7 +163,7 @@ static void mips_dma_free_coherent(struct device *dev, size_t size, void *vaddr, plat_unmap_dma_mem(dev, dma_handle, size, DMA_BIDIRECTIONAL); - if (!plat_device_is_coherent(dev)) + if (!plat_device_is_coherent(dev) && !hw_coherentio) addr = CAC_ADDR(addr); free_pages(addr, get_order(size)); diff --git a/arch/mips/mti-malta/malta-setup.c b/arch/mips/mti-malta/malta-setup.c index 200f64df2c9b..a85557171faa 100644 --- a/arch/mips/mti-malta/malta-setup.c +++ b/arch/mips/mti-malta/malta-setup.c @@ -32,6 +32,7 @@ #include #include #include +#include #ifdef CONFIG_VT #include #endif @@ -105,6 +106,66 @@ static void __init fd_activate(void) } #endif +static int __init plat_enable_iocoherency(void) +{ + int supported = 0; + if (mips_revision_sconid == MIPS_REVISION_SCON_BONITO) { + if (BONITO_PCICACHECTRL & BONITO_PCICACHECTRL_CPUCOH_PRES) { + BONITO_PCICACHECTRL |= BONITO_PCICACHECTRL_CPUCOH_EN; + pr_info("Enabled Bonito CPU coherency\n"); + supported = 1; + } + if (strstr(fw_getcmdline(), "iobcuncached")) { + BONITO_PCICACHECTRL &= ~BONITO_PCICACHECTRL_IOBCCOH_EN; + BONITO_PCIMEMBASECFG = BONITO_PCIMEMBASECFG & + ~(BONITO_PCIMEMBASECFG_MEMBASE0_CACHED | + BONITO_PCIMEMBASECFG_MEMBASE1_CACHED); + pr_info("Disabled Bonito IOBC coherency\n"); + } else { + BONITO_PCICACHECTRL |= BONITO_PCICACHECTRL_IOBCCOH_EN; + BONITO_PCIMEMBASECFG |= + (BONITO_PCIMEMBASECFG_MEMBASE0_CACHED | + BONITO_PCIMEMBASECFG_MEMBASE1_CACHED); + pr_info("Enabled Bonito IOBC coherency\n"); + } + } else if (gcmp_niocu() != 0) { + /* Nothing special needs to be done to enable coherency */ + pr_info("CMP IOCU detected\n"); + if ((*(unsigned int *)0xbf403000 & 0x81) != 0x81) { + pr_crit("IOCU OPERATION DISABLED BY SWITCH - DEFAULTING TO SW IO COHERENCY\n"); + return 0; + } + supported = 1; + } + hw_coherentio = supported; + return supported; +} + +static void __init plat_setup_iocoherency(void) +{ +#ifdef CONFIG_DMA_NONCOHERENT + /* + * Kernel has been configured with software coherency + * but we might choose to turn it off and use hardware + * coherency instead. + */ + if (plat_enable_iocoherency()) { + if (coherentio == 0) + pr_info("Hardware DMA cache coherency disabled\n"); + else + pr_info("Hardware DMA cache coherency enabled\n"); + } else { + if (coherentio == 1) + pr_info("Hardware DMA cache coherency unsupported, but enabled from command line!\n"); + else + pr_info("Software DMA cache coherency enabled\n"); + } +#else + if (!plat_enable_iocoherency()) + panic("Hardware DMA cache coherency not supported!"); +#endif +} + #ifdef CONFIG_BLK_DEV_IDE static void __init pci_clock_check(void) { @@ -207,6 +268,8 @@ void __init plat_mem_setup(void) if (mips_revision_sconid == MIPS_REVISION_SCON_BONITO) bonito_quirks_setup(); + plat_setup_iocoherency(); + #ifdef CONFIG_BLK_DEV_IDE pci_clock_check(); #endif diff --git a/arch/mips/mti-sead3/sead3-setup.c b/arch/mips/mti-sead3/sead3-setup.c index f012fd164cee..14633bc80049 100644 --- a/arch/mips/mti-sead3/sead3-setup.c +++ b/arch/mips/mti-sead3/sead3-setup.c @@ -13,9 +13,6 @@ #include #include -int coherentio; /* 0 => no DMA cache coherency (may be set by user) */ -int hw_coherentio; /* 0 => no HW DMA cache coherency (reflects real HW) */ - const char *get_system_type(void) { return "MIPS SEAD3"; -- 2.30.2