From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Chalamarla, Tirumalesh" Subject: Re: [PATCH] iommu/arm-smmu-v2: Workaround for ThunderX errata#27704 Date: Fri, 5 Feb 2016 20:32:00 +0000 Message-ID: <812E9BBE-CFA6-4B90-A38F-2CA27FE04752@caviumnetworks.com> References: <1454698027-20911-1-git-send-email-tchalamarla@caviumnetworks.com> <20160205200142.GA8647@leverpostej> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20160205200142.GA8647@leverpostej> Content-Language: en-US Content-ID: <43B93B8D8C13AC4383A938DCD8BD2EB5-Tk6F3M/euE6cE4WynfumptQqCkab/8FMAL8bYrjMMd8@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Mark Rutland Cc: "iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org" , "will.deacon-5wv7dgnIgG8@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "Akula, Geethasowjanya" List-Id: iommu@lists.linux-foundation.org On 2/5/16, 12:02 PM, "Mark Rutland" wrote: >On Fri, Feb 05, 2016 at 10:47:07AM -0800, tchalamarla-M3mlKVOIwJVv6pq1l3V1OdBPR1lH4CV8@public.gmane.org wrote: >> From: Tirumalesh Chalamarla >> >> An issue exists whereby the Linux kernel requires that ASIDs are a >> unique namespace per SMMU. > >The SMMU architecture requires this, and Linux relies on hardware >following the architecture. > >Please describe the problem correctly. i.e. that the hardware >erroneously shares TLBs between SMMU instances. > >> That ASID-local choice conflicts with the >> CN88xx SMMU, where only shared ASID namespaces are supported; >> specifically within a given node SMMU0 and SMMU1 share, as does SMMU2 >> and SMMU3. CN88xx SMMU also requires global VMIDs. >> >> This patch tries to address these issuee by supplying asid and vmid >> transformations from devicetree. >> >> Signed-off-by: Akula Geethasowjanya >> Signed-off-by: Tirumalesh Chalamarla >> --- >> .../devicetree/bindings/iommu/arm,smmu.txt | 16 ++++++ >> drivers/iommu/arm-smmu.c | 59 ++++++++++++++++++---- >> 2 files changed, 65 insertions(+), 10 deletions(-) >> >> diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt b/Documentation/devicetree/bindings/iommu/arm,smmu.txt >> index 7180745..eef06d0 100644 >> --- a/Documentation/devicetree/bindings/iommu/arm,smmu.txt >> +++ b/Documentation/devicetree/bindings/iommu/arm,smmu.txt >> @@ -55,6 +55,22 @@ conditions. >> aliases of secure registers have to be used during >> SMMU configuration. >> >> +- thunderx,smmu-asid-transform : Enable proper handling for buggy >> + implementations that require special transformations >> + for smmu asid. if this property exists asid-transform >> + property must be present. >> + >> +- thunderx,smmu-vmid-transform : Enable proper handling for buggy >> + implementations that require special transformations >> + for smmu vmid. if this property exists vmid-transform >> + property must be present. >> + >> +- asid-transform : Transform mask that needs to be applied to asid. >> + This property has to be specified as '/bits/ 8' value. >> + >> +- vmid-transform : Transform mask that needs to be applied to vmid. >> + This property has to be specified as '/bits/ 8' value. > >Don't bother with /bits/ 8. It saves no space in the DTB and only adds >to confusion. Use a full cell, and of_property_read_u32, and validate >that the value is in range. > >Having two properties for each seems redundant. The presence of a mask >should be sufficient to make it clear that the use of the mask is >required. Sure. > >These properties aren't sufficiently described. How is the mask >"applied", and what is it applied to? What constraints does it impose >on the OS's selection of ASIDs/VMIDs? > >>From the looks of the patch, it's ANDed into the value Linux has >selected, so it sounds like an OS must avoid using any bits set in any >mask on any SMMU instance. That sounds very difficult to ensure in >general, and very fragile. For now it is only specific to ThunderX errata, its not a general requirement. So ThunderX DTS will make sure it defined proper values. If all agree to make it a general requirement, I am happy to re write it with ASID and VMID coming from DTS. > >Mark. > >> + >> Example: >> >> smmu { >> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c >> index 59ee4b8..8047834 100644 >> --- a/drivers/iommu/arm-smmu.c >> +++ b/drivers/iommu/arm-smmu.c >> @@ -300,8 +300,12 @@ struct arm_smmu_device { >> u32 features; >> >> #define ARM_SMMU_OPT_SECURE_CFG_ACCESS (1 << 0) >> +#define ARM_SMMU_OPT_TRANSFORM_ASID (1 << 1) >> +#define ARM_SMMU_OPT_TRANSFORM_VMID (1 << 2) >> u32 options; >> enum arm_smmu_arch_version version; >> + u8 asid_transform; >> + u8 vmid_transform; >> >> u32 num_context_banks; >> u32 num_s2_context_banks; >> @@ -330,8 +334,25 @@ struct arm_smmu_cfg { >> }; >> #define INVALID_IRPTNDX 0xff >> >> -#define ARM_SMMU_CB_ASID(cfg) ((cfg)->cbndx) >> -#define ARM_SMMU_CB_VMID(cfg) ((cfg)->cbndx + 1) >> +/* >> + * ThunderX has a unique requirement because of ERRATA#27704 >> + * An issue exists whereby the Linux kernel requires that ASIDs are a >> + * unique namespace per SMMU. That ASID-local choice conflicts with the >> + * CN88xx SMMU, where only shared ASID namespaces are supported; >> + * specifically within a given node SMMU0 and SMMU1 share, as does SMMU2 >> + * and SMMU3. >> + * CN88xx SMMU also requires global VMIDs. >> + */ >> + >> +#define ARM_SMMU_CB_ASID(smmu, cfg) \ >> + (((smmu)->options & ARM_SMMU_OPT_TRANSFORM_ASID) \ >> + ? ((cfg)->cbndx | (smmu)->asid_transform) \ >> + : ((cfg)->cbndx)) >> + >> +#define ARM_SMMU_CB_VMID(smmu, cfg) \ >> + (((smmu)->options & ARM_SMMU_OPT_TRANSFORM_VMID) \ >> + ? (((cfg)->cbndx + 1) | (smmu)->vmid_transform) \ >> + : ((cfg)->cbndx + 1)) >> >> enum arm_smmu_domain_stage { >> ARM_SMMU_DOMAIN_S1 = 0, >> @@ -361,6 +382,8 @@ struct arm_smmu_option_prop { >> >> static struct arm_smmu_option_prop arm_smmu_options[] = { >> { ARM_SMMU_OPT_SECURE_CFG_ACCESS, "calxeda,smmu-secure-config-access" }, >> + { ARM_SMMU_OPT_TRANSFORM_ASID, "thunderx,smmu-asid-transform" }, >> + { ARM_SMMU_OPT_TRANSFORM_VMID, "thunderx,smmu-vmid-transform" }, >> { 0, NULL}, >> }; >> >> @@ -570,11 +593,11 @@ static void arm_smmu_tlb_inv_context(void *cookie) >> >> if (stage1) { >> base = ARM_SMMU_CB_BASE(smmu) + ARM_SMMU_CB(smmu, cfg->cbndx); >> - writel_relaxed(ARM_SMMU_CB_ASID(cfg), >> + writel_relaxed(ARM_SMMU_CB_ASID(smmu, cfg), >> base + ARM_SMMU_CB_S1_TLBIASID); >> } else { >> base = ARM_SMMU_GR0(smmu); >> - writel_relaxed(ARM_SMMU_CB_VMID(cfg), >> + writel_relaxed(ARM_SMMU_CB_VMID(smmu, cfg), >> base + ARM_SMMU_GR0_TLBIVMID); >> } >> >> @@ -596,7 +619,7 @@ static void arm_smmu_tlb_inv_range_nosync(unsigned long iova, size_t size, >> >> if (!IS_ENABLED(CONFIG_64BIT) || smmu->version == ARM_SMMU_V1) { >> iova &= ~12UL; >> - iova |= ARM_SMMU_CB_ASID(cfg); >> + iova |= ARM_SMMU_CB_ASID(smmu, cfg); >> do { >> writel_relaxed(iova, reg); >> iova += granule; >> @@ -604,7 +627,7 @@ static void arm_smmu_tlb_inv_range_nosync(unsigned long iova, size_t size, >> #ifdef CONFIG_64BIT >> } else { >> iova >>= 12; >> - iova |= (u64)ARM_SMMU_CB_ASID(cfg) << 48; >> + iova |= (u64)ARM_SMMU_CB_ASID(smmu, cfg) << 48; >> do { >> writeq_relaxed(iova, reg); >> iova += granule >> 12; >> @@ -624,7 +647,7 @@ static void arm_smmu_tlb_inv_range_nosync(unsigned long iova, size_t size, >> #endif >> } else { >> reg = ARM_SMMU_GR0(smmu) + ARM_SMMU_GR0_TLBIVMID; >> - writel_relaxed(ARM_SMMU_CB_VMID(cfg), reg); >> + writel_relaxed(ARM_SMMU_CB_VMID(smmu, cfg), reg); >> } >> } >> >> @@ -752,7 +775,7 @@ static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain, >> reg |= (CBAR_S1_BPSHCFG_NSH << CBAR_S1_BPSHCFG_SHIFT) | >> (CBAR_S1_MEMATTR_WB << CBAR_S1_MEMATTR_SHIFT); >> } else { >> - reg |= ARM_SMMU_CB_VMID(cfg) << CBAR_VMID_SHIFT; >> + reg |= ARM_SMMU_CB_VMID(smmu, cfg) << CBAR_VMID_SHIFT; >> } >> writel_relaxed(reg, gr1_base + ARM_SMMU_GR1_CBAR(cfg->cbndx)); >> >> @@ -760,11 +783,11 @@ static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain, >> if (stage1) { >> reg64 = pgtbl_cfg->arm_lpae_s1_cfg.ttbr[0]; >> >> - reg64 |= ((u64)ARM_SMMU_CB_ASID(cfg)) << TTBRn_ASID_SHIFT; >> + reg64 |= ((u64)ARM_SMMU_CB_ASID(smmu, cfg)) << TTBRn_ASID_SHIFT; >> smmu_writeq(reg64, cb_base + ARM_SMMU_CB_TTBR0); >> >> reg64 = pgtbl_cfg->arm_lpae_s1_cfg.ttbr[1]; >> - reg64 |= ((u64)ARM_SMMU_CB_ASID(cfg)) << TTBRn_ASID_SHIFT; >> + reg64 |= ((u64)ARM_SMMU_CB_ASID(smmu, cfg)) << TTBRn_ASID_SHIFT; >> smmu_writeq(reg64, cb_base + ARM_SMMU_CB_TTBR1); >> } else { >> reg64 = pgtbl_cfg->arm_lpae_s2_cfg.vttbr; >> @@ -1793,6 +1816,22 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev) >> >> parse_driver_options(smmu); >> >> + if (smmu->options & ARM_SMMU_OPT_TRANSFORM_ASID) { >> + if (of_property_read_u8(dev->of_node, "#asid-transform", >> + &smmu->asid_transform)) { >> + dev_err(dev, "missing #asid-transform property\n"); >> + return -ENODEV; >> + } >> + } >> + >> + if (smmu->options & ARM_SMMU_OPT_TRANSFORM_VMID) { >> + if (of_property_read_u8(dev->of_node, "#vmid-transform", >> + &smmu->vmid_transform)) { >> + dev_err(dev, "missing #vmid-transform property\n"); >> + return -ENODEV; >> + } >> + } >> + >` if (smmu->version > ARM_SMMU_V1 && >> smmu->num_context_banks != smmu->num_context_irqs) { >> dev_err(dev, >> -- >> 2.1.0 >> >> >> _______________________________________________ >> linux-arm-kernel mailing list >> linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >> From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tirumalesh.Chalamarla@caviumnetworks.com (Chalamarla, Tirumalesh) Date: Fri, 5 Feb 2016 20:32:00 +0000 Subject: [PATCH] iommu/arm-smmu-v2: Workaround for ThunderX errata#27704 In-Reply-To: <20160205200142.GA8647@leverpostej> References: <1454698027-20911-1-git-send-email-tchalamarla@caviumnetworks.com> <20160205200142.GA8647@leverpostej> Message-ID: <812E9BBE-CFA6-4B90-A38F-2CA27FE04752@caviumnetworks.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 2/5/16, 12:02 PM, "Mark Rutland" wrote: >On Fri, Feb 05, 2016 at 10:47:07AM -0800, tchalamarla at caviumnetworks.com wrote: >> From: Tirumalesh Chalamarla >> >> An issue exists whereby the Linux kernel requires that ASIDs are a >> unique namespace per SMMU. > >The SMMU architecture requires this, and Linux relies on hardware >following the architecture. > >Please describe the problem correctly. i.e. that the hardware >erroneously shares TLBs between SMMU instances. > >> That ASID-local choice conflicts with the >> CN88xx SMMU, where only shared ASID namespaces are supported; >> specifically within a given node SMMU0 and SMMU1 share, as does SMMU2 >> and SMMU3. CN88xx SMMU also requires global VMIDs. >> >> This patch tries to address these issuee by supplying asid and vmid >> transformations from devicetree. >> >> Signed-off-by: Akula Geethasowjanya >> Signed-off-by: Tirumalesh Chalamarla >> --- >> .../devicetree/bindings/iommu/arm,smmu.txt | 16 ++++++ >> drivers/iommu/arm-smmu.c | 59 ++++++++++++++++++---- >> 2 files changed, 65 insertions(+), 10 deletions(-) >> >> diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt b/Documentation/devicetree/bindings/iommu/arm,smmu.txt >> index 7180745..eef06d0 100644 >> --- a/Documentation/devicetree/bindings/iommu/arm,smmu.txt >> +++ b/Documentation/devicetree/bindings/iommu/arm,smmu.txt >> @@ -55,6 +55,22 @@ conditions. >> aliases of secure registers have to be used during >> SMMU configuration. >> >> +- thunderx,smmu-asid-transform : Enable proper handling for buggy >> + implementations that require special transformations >> + for smmu asid. if this property exists asid-transform >> + property must be present. >> + >> +- thunderx,smmu-vmid-transform : Enable proper handling for buggy >> + implementations that require special transformations >> + for smmu vmid. if this property exists vmid-transform >> + property must be present. >> + >> +- asid-transform : Transform mask that needs to be applied to asid. >> + This property has to be specified as '/bits/ 8' value. >> + >> +- vmid-transform : Transform mask that needs to be applied to vmid. >> + This property has to be specified as '/bits/ 8' value. > >Don't bother with /bits/ 8. It saves no space in the DTB and only adds >to confusion. Use a full cell, and of_property_read_u32, and validate >that the value is in range. > >Having two properties for each seems redundant. The presence of a mask >should be sufficient to make it clear that the use of the mask is >required. Sure. > >These properties aren't sufficiently described. How is the mask >"applied", and what is it applied to? What constraints does it impose >on the OS's selection of ASIDs/VMIDs? > >>From the looks of the patch, it's ANDed into the value Linux has >selected, so it sounds like an OS must avoid using any bits set in any >mask on any SMMU instance. That sounds very difficult to ensure in >general, and very fragile. For now it is only specific to ThunderX errata, its not a general requirement. So ThunderX DTS will make sure it defined proper values. If all agree to make it a general requirement, I am happy to re write it with ASID and VMID coming from DTS. > >Mark. > >> + >> Example: >> >> smmu { >> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c >> index 59ee4b8..8047834 100644 >> --- a/drivers/iommu/arm-smmu.c >> +++ b/drivers/iommu/arm-smmu.c >> @@ -300,8 +300,12 @@ struct arm_smmu_device { >> u32 features; >> >> #define ARM_SMMU_OPT_SECURE_CFG_ACCESS (1 << 0) >> +#define ARM_SMMU_OPT_TRANSFORM_ASID (1 << 1) >> +#define ARM_SMMU_OPT_TRANSFORM_VMID (1 << 2) >> u32 options; >> enum arm_smmu_arch_version version; >> + u8 asid_transform; >> + u8 vmid_transform; >> >> u32 num_context_banks; >> u32 num_s2_context_banks; >> @@ -330,8 +334,25 @@ struct arm_smmu_cfg { >> }; >> #define INVALID_IRPTNDX 0xff >> >> -#define ARM_SMMU_CB_ASID(cfg) ((cfg)->cbndx) >> -#define ARM_SMMU_CB_VMID(cfg) ((cfg)->cbndx + 1) >> +/* >> + * ThunderX has a unique requirement because of ERRATA#27704 >> + * An issue exists whereby the Linux kernel requires that ASIDs are a >> + * unique namespace per SMMU. That ASID-local choice conflicts with the >> + * CN88xx SMMU, where only shared ASID namespaces are supported; >> + * specifically within a given node SMMU0 and SMMU1 share, as does SMMU2 >> + * and SMMU3. >> + * CN88xx SMMU also requires global VMIDs. >> + */ >> + >> +#define ARM_SMMU_CB_ASID(smmu, cfg) \ >> + (((smmu)->options & ARM_SMMU_OPT_TRANSFORM_ASID) \ >> + ? ((cfg)->cbndx | (smmu)->asid_transform) \ >> + : ((cfg)->cbndx)) >> + >> +#define ARM_SMMU_CB_VMID(smmu, cfg) \ >> + (((smmu)->options & ARM_SMMU_OPT_TRANSFORM_VMID) \ >> + ? (((cfg)->cbndx + 1) | (smmu)->vmid_transform) \ >> + : ((cfg)->cbndx + 1)) >> >> enum arm_smmu_domain_stage { >> ARM_SMMU_DOMAIN_S1 = 0, >> @@ -361,6 +382,8 @@ struct arm_smmu_option_prop { >> >> static struct arm_smmu_option_prop arm_smmu_options[] = { >> { ARM_SMMU_OPT_SECURE_CFG_ACCESS, "calxeda,smmu-secure-config-access" }, >> + { ARM_SMMU_OPT_TRANSFORM_ASID, "thunderx,smmu-asid-transform" }, >> + { ARM_SMMU_OPT_TRANSFORM_VMID, "thunderx,smmu-vmid-transform" }, >> { 0, NULL}, >> }; >> >> @@ -570,11 +593,11 @@ static void arm_smmu_tlb_inv_context(void *cookie) >> >> if (stage1) { >> base = ARM_SMMU_CB_BASE(smmu) + ARM_SMMU_CB(smmu, cfg->cbndx); >> - writel_relaxed(ARM_SMMU_CB_ASID(cfg), >> + writel_relaxed(ARM_SMMU_CB_ASID(smmu, cfg), >> base + ARM_SMMU_CB_S1_TLBIASID); >> } else { >> base = ARM_SMMU_GR0(smmu); >> - writel_relaxed(ARM_SMMU_CB_VMID(cfg), >> + writel_relaxed(ARM_SMMU_CB_VMID(smmu, cfg), >> base + ARM_SMMU_GR0_TLBIVMID); >> } >> >> @@ -596,7 +619,7 @@ static void arm_smmu_tlb_inv_range_nosync(unsigned long iova, size_t size, >> >> if (!IS_ENABLED(CONFIG_64BIT) || smmu->version == ARM_SMMU_V1) { >> iova &= ~12UL; >> - iova |= ARM_SMMU_CB_ASID(cfg); >> + iova |= ARM_SMMU_CB_ASID(smmu, cfg); >> do { >> writel_relaxed(iova, reg); >> iova += granule; >> @@ -604,7 +627,7 @@ static void arm_smmu_tlb_inv_range_nosync(unsigned long iova, size_t size, >> #ifdef CONFIG_64BIT >> } else { >> iova >>= 12; >> - iova |= (u64)ARM_SMMU_CB_ASID(cfg) << 48; >> + iova |= (u64)ARM_SMMU_CB_ASID(smmu, cfg) << 48; >> do { >> writeq_relaxed(iova, reg); >> iova += granule >> 12; >> @@ -624,7 +647,7 @@ static void arm_smmu_tlb_inv_range_nosync(unsigned long iova, size_t size, >> #endif >> } else { >> reg = ARM_SMMU_GR0(smmu) + ARM_SMMU_GR0_TLBIVMID; >> - writel_relaxed(ARM_SMMU_CB_VMID(cfg), reg); >> + writel_relaxed(ARM_SMMU_CB_VMID(smmu, cfg), reg); >> } >> } >> >> @@ -752,7 +775,7 @@ static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain, >> reg |= (CBAR_S1_BPSHCFG_NSH << CBAR_S1_BPSHCFG_SHIFT) | >> (CBAR_S1_MEMATTR_WB << CBAR_S1_MEMATTR_SHIFT); >> } else { >> - reg |= ARM_SMMU_CB_VMID(cfg) << CBAR_VMID_SHIFT; >> + reg |= ARM_SMMU_CB_VMID(smmu, cfg) << CBAR_VMID_SHIFT; >> } >> writel_relaxed(reg, gr1_base + ARM_SMMU_GR1_CBAR(cfg->cbndx)); >> >> @@ -760,11 +783,11 @@ static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain, >> if (stage1) { >> reg64 = pgtbl_cfg->arm_lpae_s1_cfg.ttbr[0]; >> >> - reg64 |= ((u64)ARM_SMMU_CB_ASID(cfg)) << TTBRn_ASID_SHIFT; >> + reg64 |= ((u64)ARM_SMMU_CB_ASID(smmu, cfg)) << TTBRn_ASID_SHIFT; >> smmu_writeq(reg64, cb_base + ARM_SMMU_CB_TTBR0); >> >> reg64 = pgtbl_cfg->arm_lpae_s1_cfg.ttbr[1]; >> - reg64 |= ((u64)ARM_SMMU_CB_ASID(cfg)) << TTBRn_ASID_SHIFT; >> + reg64 |= ((u64)ARM_SMMU_CB_ASID(smmu, cfg)) << TTBRn_ASID_SHIFT; >> smmu_writeq(reg64, cb_base + ARM_SMMU_CB_TTBR1); >> } else { >> reg64 = pgtbl_cfg->arm_lpae_s2_cfg.vttbr; >> @@ -1793,6 +1816,22 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev) >> >> parse_driver_options(smmu); >> >> + if (smmu->options & ARM_SMMU_OPT_TRANSFORM_ASID) { >> + if (of_property_read_u8(dev->of_node, "#asid-transform", >> + &smmu->asid_transform)) { >> + dev_err(dev, "missing #asid-transform property\n"); >> + return -ENODEV; >> + } >> + } >> + >> + if (smmu->options & ARM_SMMU_OPT_TRANSFORM_VMID) { >> + if (of_property_read_u8(dev->of_node, "#vmid-transform", >> + &smmu->vmid_transform)) { >> + dev_err(dev, "missing #vmid-transform property\n"); >> + return -ENODEV; >> + } >> + } >> + >` if (smmu->version > ARM_SMMU_V1 && >> smmu->num_context_banks != smmu->num_context_irqs) { >> dev_err(dev, >> -- >> 2.1.0 >> >> >> _______________________________________________ >> linux-arm-kernel mailing list >> linux-arm-kernel at lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >>