| Message ID | 62860b753f304beef7b4b6f1e13d7094252f2f37.1455294748.git.robin.murphy@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Robin, Thank you for the patch. On Friday 12 February 2016 17:09:46 Robin Murphy wrote: > As the number of io-pgtable implementations grows beyond 1, it's time > to rationalise the quirks mechanism before things have a chance to > start getting really ugly and out-of-hand. > > To that end: > - Indicate exactly which quirks each format can/does support. > - Fail creating a table if a caller wants unsupported quirks. > - Properly document where each quirk applies and why. > > Signed-off-by: Robin Murphy <robin.murphy@arm.com> > --- > > Just to allay any confusion, I intend this as a followup to the > short-descriptor[1] and Mediatek IOMMU[2] patches, rather than a > crucial addition, so it can either get picked up along with those > or wait 'til later. > > v2: > - Use unsigned long for the bitmap. > - Do format-specific checks inline. > - Enough of a difference that I don't feel comfortable putting > Laurent's reviewed-by from v1 on it... Here it is again. Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > [1]:http://thread.gmane.org/gmane.linux.kernel.iommu/12007 > [2]:http://thread.gmane.org/gmane.linux.kernel.iommu/11974 > > drivers/iommu/io-pgtable-arm-v7s.c | 5 +++++ > drivers/iommu/io-pgtable-arm.c | 13 +++++++++++-- > drivers/iommu/io-pgtable.h | 22 ++++++++++++++++++---- > 3 files changed, 34 insertions(+), 6 deletions(-) > > diff --git a/drivers/iommu/io-pgtable-arm-v7s.c > b/drivers/iommu/io-pgtable-arm-v7s.c index d39a021..9fcceb1 100644 > --- a/drivers/iommu/io-pgtable-arm-v7s.c > +++ b/drivers/iommu/io-pgtable-arm-v7s.c > @@ -623,6 +623,11 @@ static struct io_pgtable *arm_v7s_alloc_pgtable(struct > io_pgtable_cfg *cfg, if (cfg->ias > ARM_V7S_ADDR_BITS || cfg->oas > > ARM_V7S_ADDR_BITS) return NULL; > > + if (cfg->quirks & ~(IO_PGTABLE_QUIRK_ARM_NS | > + IO_PGTABLE_QUIRK_NO_PERMS | > + IO_PGTABLE_QUIRK_TLBI_ON_MAP)) > + return NULL; > + > data = kmalloc(sizeof(*data), GFP_KERNEL); > if (!data) > return NULL; > diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c > index 4095af2..debdf04 100644 > --- a/drivers/iommu/io-pgtable-arm.c > +++ b/drivers/iommu/io-pgtable-arm.c > @@ -658,8 +658,12 @@ static struct io_pgtable * > arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, void *cookie) > { > u64 reg; > - struct arm_lpae_io_pgtable *data = arm_lpae_alloc_pgtable(cfg); > + struct arm_lpae_io_pgtable *data; > > + if (cfg->quirks & ~IO_PGTABLE_QUIRK_ARM_NS) > + return NULL; > + > + data = arm_lpae_alloc_pgtable(cfg); > if (!data) > return NULL; > > @@ -742,8 +746,13 @@ static struct io_pgtable * > arm_64_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, void *cookie) > { > u64 reg, sl; > - struct arm_lpae_io_pgtable *data = arm_lpae_alloc_pgtable(cfg); > + struct arm_lpae_io_pgtable *data; > > + /* The NS quirk doesn't apply at stage 2 */ > + if (cfg->quirks) > + return NULL; > + > + data = arm_lpae_alloc_pgtable(cfg); > if (!data) > return NULL; > > diff --git a/drivers/iommu/io-pgtable.h b/drivers/iommu/io-pgtable.h > index 4faee7d..d4f5027 100644 > --- a/drivers/iommu/io-pgtable.h > +++ b/drivers/iommu/io-pgtable.h > @@ -47,10 +47,24 @@ struct iommu_gather_ops { > * page table walker. > */ > struct io_pgtable_cfg { > - #define IO_PGTABLE_QUIRK_ARM_NS BIT(0) /* Set NS bit in PTEs */ > - #define IO_PGTABLE_QUIRK_NO_PERMS BIT(1) /* No AP/XN bits */ > - #define IO_PGTABLE_QUIRK_TLBI_ON_MAP BIT(2) /* TLB Inv. on map */ > - int quirks; > + /* > + * IO_PGTABLE_QUIRK_ARM_NS: (ARM formats) Set NS and NSTABLE bits in > + * stage 1 PTEs, for hardware which insists on validating them > + * even in non-secure state where they should normally be ignored. > + * > + * IO_PGTABLE_QUIRK_NO_PERMS: Ignore the IOMMU_READ, IOMMU_WRITE and > + * IOMMU_NOEXEC flags and map everything with full access, for > + * hardware which does not implement the permissions of a given > + * format, and/or requires some format-specific default value. > + * > + * IO_PGTABLE_QUIRK_TLBI_ON_MAP: If the format forbids caching invalid > + * (unmapped) entries but the hardware might do so anyway, perform > + * TLB maintenance when mapping as well as when unmapping. > + */ > + #define IO_PGTABLE_QUIRK_ARM_NS BIT(0) > + #define IO_PGTABLE_QUIRK_NO_PERMS BIT(1) > + #define IO_PGTABLE_QUIRK_TLBI_ON_MAP BIT(2) > + unsigned long quirks; > unsigned long pgsize_bitmap; > unsigned int ias; > unsigned int oas;
On 12/02/16 17:24, Laurent Pinchart wrote: > Hi Robin, > > Thank you for the patch. > > On Friday 12 February 2016 17:09:46 Robin Murphy wrote: >> As the number of io-pgtable implementations grows beyond 1, it's time >> to rationalise the quirks mechanism before things have a chance to >> start getting really ugly and out-of-hand. >> >> To that end: >> - Indicate exactly which quirks each format can/does support. >> - Fail creating a table if a caller wants unsupported quirks. >> - Properly document where each quirk applies and why. >> >> Signed-off-by: Robin Murphy <robin.murphy@arm.com> >> --- >> >> Just to allay any confusion, I intend this as a followup to the >> short-descriptor[1] and Mediatek IOMMU[2] patches, rather than a >> crucial addition, so it can either get picked up along with those >> or wait 'til later. >> >> v2: >> - Use unsigned long for the bitmap. >> - Do format-specific checks inline. >> - Enough of a difference that I don't feel comfortable putting >> Laurent's reviewed-by from v1 on it... > > Here it is again. > > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Thanks! Robin.
On Fri, Feb 12, 2016 at 05:09:46PM +0000, Robin Murphy wrote: > As the number of io-pgtable implementations grows beyond 1, it's time > to rationalise the quirks mechanism before things have a chance to > start getting really ugly and out-of-hand. > > To that end: > - Indicate exactly which quirks each format can/does support. > - Fail creating a table if a caller wants unsupported quirks. > - Properly document where each quirk applies and why. > > Signed-off-by: Robin Murphy <robin.murphy@arm.com> > --- > > Just to allay any confusion, I intend this as a followup to the > short-descriptor[1] and Mediatek IOMMU[2] patches, rather than a > crucial addition, so it can either get picked up along with those > or wait 'til later. I'd like to see it included in whichever tree takes the short-descriptor code so, in case that's not my tree: Acked-by: Will Deacon <will.deacon@arm.com> Will
diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c index d39a021..9fcceb1 100644 --- a/drivers/iommu/io-pgtable-arm-v7s.c +++ b/drivers/iommu/io-pgtable-arm-v7s.c @@ -623,6 +623,11 @@ static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg, if (cfg->ias > ARM_V7S_ADDR_BITS || cfg->oas > ARM_V7S_ADDR_BITS) return NULL; + if (cfg->quirks & ~(IO_PGTABLE_QUIRK_ARM_NS | + IO_PGTABLE_QUIRK_NO_PERMS | + IO_PGTABLE_QUIRK_TLBI_ON_MAP)) + return NULL; + data = kmalloc(sizeof(*data), GFP_KERNEL); if (!data) return NULL; diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c index 4095af2..debdf04 100644 --- a/drivers/iommu/io-pgtable-arm.c +++ b/drivers/iommu/io-pgtable-arm.c @@ -658,8 +658,12 @@ static struct io_pgtable * arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, void *cookie) { u64 reg; - struct arm_lpae_io_pgtable *data = arm_lpae_alloc_pgtable(cfg); + struct arm_lpae_io_pgtable *data; + if (cfg->quirks & ~IO_PGTABLE_QUIRK_ARM_NS) + return NULL; + + data = arm_lpae_alloc_pgtable(cfg); if (!data) return NULL; @@ -742,8 +746,13 @@ static struct io_pgtable * arm_64_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, void *cookie) { u64 reg, sl; - struct arm_lpae_io_pgtable *data = arm_lpae_alloc_pgtable(cfg); + struct arm_lpae_io_pgtable *data; + /* The NS quirk doesn't apply at stage 2 */ + if (cfg->quirks) + return NULL; + + data = arm_lpae_alloc_pgtable(cfg); if (!data) return NULL; diff --git a/drivers/iommu/io-pgtable.h b/drivers/iommu/io-pgtable.h index 4faee7d..d4f5027 100644 --- a/drivers/iommu/io-pgtable.h +++ b/drivers/iommu/io-pgtable.h @@ -47,10 +47,24 @@ struct iommu_gather_ops { * page table walker. */ struct io_pgtable_cfg { - #define IO_PGTABLE_QUIRK_ARM_NS BIT(0) /* Set NS bit in PTEs */ - #define IO_PGTABLE_QUIRK_NO_PERMS BIT(1) /* No AP/XN bits */ - #define IO_PGTABLE_QUIRK_TLBI_ON_MAP BIT(2) /* TLB Inv. on map */ - int quirks; + /* + * IO_PGTABLE_QUIRK_ARM_NS: (ARM formats) Set NS and NSTABLE bits in + * stage 1 PTEs, for hardware which insists on validating them + * even in non-secure state where they should normally be ignored. + * + * IO_PGTABLE_QUIRK_NO_PERMS: Ignore the IOMMU_READ, IOMMU_WRITE and + * IOMMU_NOEXEC flags and map everything with full access, for + * hardware which does not implement the permissions of a given + * format, and/or requires some format-specific default value. + * + * IO_PGTABLE_QUIRK_TLBI_ON_MAP: If the format forbids caching invalid + * (unmapped) entries but the hardware might do so anyway, perform + * TLB maintenance when mapping as well as when unmapping. + */ + #define IO_PGTABLE_QUIRK_ARM_NS BIT(0) + #define IO_PGTABLE_QUIRK_NO_PERMS BIT(1) + #define IO_PGTABLE_QUIRK_TLBI_ON_MAP BIT(2) + unsigned long quirks; unsigned long pgsize_bitmap; unsigned int ias; unsigned int oas;
As the number of io-pgtable implementations grows beyond 1, it's time to rationalise the quirks mechanism before things have a chance to start getting really ugly and out-of-hand. To that end: - Indicate exactly which quirks each format can/does support. - Fail creating a table if a caller wants unsupported quirks. - Properly document where each quirk applies and why. Signed-off-by: Robin Murphy <robin.murphy@arm.com> --- Just to allay any confusion, I intend this as a followup to the short-descriptor[1] and Mediatek IOMMU[2] patches, rather than a crucial addition, so it can either get picked up along with those or wait 'til later. v2: - Use unsigned long for the bitmap. - Do format-specific checks inline. - Enough of a difference that I don't feel comfortable putting Laurent's reviewed-by from v1 on it... Robin. [1]:http://thread.gmane.org/gmane.linux.kernel.iommu/12007 [2]:http://thread.gmane.org/gmane.linux.kernel.iommu/11974 drivers/iommu/io-pgtable-arm-v7s.c | 5 +++++ drivers/iommu/io-pgtable-arm.c | 13 +++++++++++-- drivers/iommu/io-pgtable.h | 22 ++++++++++++++++++---- 3 files changed, 34 insertions(+), 6 deletions(-)