| Message ID | ea1f3d3feec0dc9c18d43393678370b50b1275f5.1455206840.git.robin.murphy@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Robin, Thank you for the patch. On Thursday 11 February 2016 16:13:45 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> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > --- > drivers/iommu/io-pgtable-arm-v7s.c | 3 +++ > drivers/iommu/io-pgtable-arm.c | 2 ++ > drivers/iommu/io-pgtable.c | 3 +++ > drivers/iommu/io-pgtable.h | 24 ++++++++++++++++++++---- > 4 files changed, 28 insertions(+), 4 deletions(-) > > diff --git a/drivers/iommu/io-pgtable-arm-v7s.c > b/drivers/iommu/io-pgtable-arm-v7s.c index d39a021..9bc607a 100644 > --- a/drivers/iommu/io-pgtable-arm-v7s.c > +++ b/drivers/iommu/io-pgtable-arm-v7s.c > @@ -690,6 +690,9 @@ out_free_data: > struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns = { > .alloc = arm_v7s_alloc_pgtable, > .free = arm_v7s_free_pgtable, > + .supported_quirks = IO_PGTABLE_QUIRK_ARM_NS | > + IO_PGTABLE_QUIRK_NO_PERMS | > + IO_PGTABLE_QUIRK_TLBI_ON_MAP, > }; > > #ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S_SELFTEST > diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c > index 4095af2..32f94f1 100644 > --- a/drivers/iommu/io-pgtable-arm.c > +++ b/drivers/iommu/io-pgtable-arm.c > @@ -863,6 +863,7 @@ arm_32_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, > void *cookie) struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns > = { .alloc = arm_64_lpae_alloc_pgtable_s1, > .free = arm_lpae_free_pgtable, > + .supported_quirks = IO_PGTABLE_QUIRK_ARM_NS, > }; > > struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns = { > @@ -873,6 +874,7 @@ struct io_pgtable_init_fns > io_pgtable_arm_64_lpae_s2_init_fns = { struct io_pgtable_init_fns > io_pgtable_arm_32_lpae_s1_init_fns = { .alloc = > arm_32_lpae_alloc_pgtable_s1, > .free = arm_lpae_free_pgtable, > + .supported_quirks = IO_PGTABLE_QUIRK_ARM_NS, > }; > > struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns = { > diff --git a/drivers/iommu/io-pgtable.c b/drivers/iommu/io-pgtable.c > index 876f6a7..0f57a45 100644 > --- a/drivers/iommu/io-pgtable.c > +++ b/drivers/iommu/io-pgtable.c > @@ -52,6 +52,9 @@ struct io_pgtable_ops *alloc_io_pgtable_ops(enum > io_pgtable_fmt fmt, if (!fns) > return NULL; > > + if (cfg->quirks & ~fns->supported_quirks) > + return NULL; > + > iop = fns->alloc(cfg, cookie); > if (!iop) > return NULL; > diff --git a/drivers/iommu/io-pgtable.h b/drivers/iommu/io-pgtable.h > index 4faee7d..6e7f11e 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 int quirks; > unsigned long pgsize_bitmap; > unsigned int ias; > unsigned int oas; > @@ -173,10 +187,12 @@ static inline void io_pgtable_tlb_sync(struct > io_pgtable *iop) * > * @alloc: Allocate a set of page tables described by cfg. > * @free: Free the page tables associated with iop. > + * @supported_quirks: Bitmap of quirks supported by the format. > */ > struct io_pgtable_init_fns { > struct io_pgtable *(*alloc)(struct io_pgtable_cfg *cfg, void *cookie); > void (*free)(struct io_pgtable *iop); > + unsigned int supported_quirks; > }; > > extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns;
On Thu, Feb 11, 2016 at 04:13:45PM +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> > --- > drivers/iommu/io-pgtable-arm-v7s.c | 3 +++ > drivers/iommu/io-pgtable-arm.c | 2 ++ > drivers/iommu/io-pgtable.c | 3 +++ > drivers/iommu/io-pgtable.h | 24 ++++++++++++++++++++---- > 4 files changed, 28 insertions(+), 4 deletions(-) Note that I can't merge this until we've figured out the plan for Yong's driver. > diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c > index d39a021..9bc607a 100644 > --- a/drivers/iommu/io-pgtable-arm-v7s.c > +++ b/drivers/iommu/io-pgtable-arm-v7s.c > @@ -690,6 +690,9 @@ out_free_data: > struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns = { > .alloc = arm_v7s_alloc_pgtable, > .free = arm_v7s_free_pgtable, > + .supported_quirks = IO_PGTABLE_QUIRK_ARM_NS | > + IO_PGTABLE_QUIRK_NO_PERMS | > + IO_PGTABLE_QUIRK_TLBI_ON_MAP, > }; > > #ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S_SELFTEST > diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c > index 4095af2..32f94f1 100644 > --- a/drivers/iommu/io-pgtable-arm.c > +++ b/drivers/iommu/io-pgtable-arm.c > @@ -863,6 +863,7 @@ arm_32_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, void *cookie) > struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns = { > .alloc = arm_64_lpae_alloc_pgtable_s1, > .free = arm_lpae_free_pgtable, > + .supported_quirks = IO_PGTABLE_QUIRK_ARM_NS, > }; > > struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns = { > @@ -873,6 +874,7 @@ struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns = { > struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns = { > .alloc = arm_32_lpae_alloc_pgtable_s1, > .free = arm_lpae_free_pgtable, > + .supported_quirks = IO_PGTABLE_QUIRK_ARM_NS, > }; > > struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns = { > diff --git a/drivers/iommu/io-pgtable.c b/drivers/iommu/io-pgtable.c > index 876f6a7..0f57a45 100644 > --- a/drivers/iommu/io-pgtable.c > +++ b/drivers/iommu/io-pgtable.c > @@ -52,6 +52,9 @@ struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt, > if (!fns) > return NULL; > > + if (cfg->quirks & ~fns->supported_quirks) > + return NULL; > + > iop = fns->alloc(cfg, cookie); > if (!iop) > return NULL; > diff --git a/drivers/iommu/io-pgtable.h b/drivers/iommu/io-pgtable.h > index 4faee7d..6e7f11e 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. > + */ Much better, cheers. > + #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 int quirks; Let's just make this unsigned long. > unsigned long pgsize_bitmap; > unsigned int ias; > unsigned int oas; > @@ -173,10 +187,12 @@ static inline void io_pgtable_tlb_sync(struct io_pgtable *iop) > * > * @alloc: Allocate a set of page tables described by cfg. > * @free: Free the page tables associated with iop. > + * @supported_quirks: Bitmap of quirks supported by the format. > */ > struct io_pgtable_init_fns { > struct io_pgtable *(*alloc)(struct io_pgtable_cfg *cfg, void *cookie); > void (*free)(struct io_pgtable *iop); > + unsigned int supported_quirks; > }; My only gripe here is that this is supposed to be a struct of function pointers... get_supported_quirks() ? Will
On Friday 12 February 2016 12:08:58 Will Deacon wrote: > On Thu, Feb 11, 2016 at 04:13:45PM +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> > > --- > > > > drivers/iommu/io-pgtable-arm-v7s.c | 3 +++ > > drivers/iommu/io-pgtable-arm.c | 2 ++ > > drivers/iommu/io-pgtable.c | 3 +++ > > drivers/iommu/io-pgtable.h | 24 ++++++++++++++++++++---- > > 4 files changed, 28 insertions(+), 4 deletions(-) > > Note that I can't merge this until we've figured out the plan for Yong's > driver. > > > diff --git a/drivers/iommu/io-pgtable-arm-v7s.c > > b/drivers/iommu/io-pgtable-arm-v7s.c index d39a021..9bc607a 100644 > > --- a/drivers/iommu/io-pgtable-arm-v7s.c > > +++ b/drivers/iommu/io-pgtable-arm-v7s.c > > > > @@ -690,6 +690,9 @@ out_free_data: > > struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns = { > > > > .alloc = arm_v7s_alloc_pgtable, > > .free = arm_v7s_free_pgtable, > > > > + .supported_quirks = IO_PGTABLE_QUIRK_ARM_NS | > > + IO_PGTABLE_QUIRK_NO_PERMS | > > + IO_PGTABLE_QUIRK_TLBI_ON_MAP, > > > > }; > > > > #ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S_SELFTEST > > > > diff --git a/drivers/iommu/io-pgtable-arm.c > > b/drivers/iommu/io-pgtable-arm.c index 4095af2..32f94f1 100644 > > --- a/drivers/iommu/io-pgtable-arm.c > > +++ b/drivers/iommu/io-pgtable-arm.c > > @@ -863,6 +863,7 @@ arm_32_lpae_alloc_pgtable_s2(struct io_pgtable_cfg > > *cfg, void *cookie)> > > struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns = { > > > > .alloc = arm_64_lpae_alloc_pgtable_s1, > > .free = arm_lpae_free_pgtable, > > > > + .supported_quirks = IO_PGTABLE_QUIRK_ARM_NS, > > > > }; > > > > struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns = { > > > > @@ -873,6 +874,7 @@ struct io_pgtable_init_fns > > io_pgtable_arm_64_lpae_s2_init_fns = {> > > struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns = { > > > > .alloc = arm_32_lpae_alloc_pgtable_s1, > > .free = arm_lpae_free_pgtable, > > > > + .supported_quirks = IO_PGTABLE_QUIRK_ARM_NS, > > > > }; > > > > struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns = { > > > > diff --git a/drivers/iommu/io-pgtable.c b/drivers/iommu/io-pgtable.c > > index 876f6a7..0f57a45 100644 > > --- a/drivers/iommu/io-pgtable.c > > +++ b/drivers/iommu/io-pgtable.c > > @@ -52,6 +52,9 @@ struct io_pgtable_ops *alloc_io_pgtable_ops(enum > > io_pgtable_fmt fmt,> > > if (!fns) > > > > return NULL; > > > > + if (cfg->quirks & ~fns->supported_quirks) > > + return NULL; > > + > > > > iop = fns->alloc(cfg, cookie); > > if (!iop) > > > > return NULL; > > > > diff --git a/drivers/iommu/io-pgtable.h b/drivers/iommu/io-pgtable.h > > index 4faee7d..6e7f11e 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. > > + */ > > Much better, cheers. > > > + #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 int quirks; > > Let's just make this unsigned long. > > > unsigned long pgsize_bitmap; > > unsigned int ias; > > unsigned int oas; > > > > @@ -173,10 +187,12 @@ static inline void io_pgtable_tlb_sync(struct > > io_pgtable *iop) > > * > > * @alloc: Allocate a set of page tables described by cfg. > > * @free: Free the page tables associated with iop. > > + * @supported_quirks: Bitmap of quirks supported by the format. > > */ > > struct io_pgtable_init_fns { > > struct io_pgtable *(*alloc)(struct io_pgtable_cfg *cfg, void *cookie); > > void (*free)(struct io_pgtable *iop); > > + unsigned int supported_quirks; > > }; > > My only gripe here is that this is supposed to be a struct of function > pointers... get_supported_quirks() ? Can't we instead say it's a struct of function pointers and static data ? :-) A function to retrieve the supported quirks will just contribute to kernel bloat without adding any extra benefit.
On 12/02/16 12:32, Laurent Pinchart wrote: > On Friday 12 February 2016 12:08:58 Will Deacon wrote: >> On Thu, Feb 11, 2016 at 04:13:45PM +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> >>> --- >>> >>> drivers/iommu/io-pgtable-arm-v7s.c | 3 +++ >>> drivers/iommu/io-pgtable-arm.c | 2 ++ >>> drivers/iommu/io-pgtable.c | 3 +++ >>> drivers/iommu/io-pgtable.h | 24 ++++++++++++++++++++---- >>> 4 files changed, 28 insertions(+), 4 deletions(-) >> >> Note that I can't merge this until we've figured out the plan for Yong's >> driver. Indeed (hence 4/3) - it just ended up seeming like a significant enough change to warrant its own patch, but not critical enough to warrant splitting it for the sake of applying the parts touching the existing code right now. >>> diff --git a/drivers/iommu/io-pgtable-arm-v7s.c >>> b/drivers/iommu/io-pgtable-arm-v7s.c index d39a021..9bc607a 100644 >>> --- a/drivers/iommu/io-pgtable-arm-v7s.c >>> +++ b/drivers/iommu/io-pgtable-arm-v7s.c >>> >>> @@ -690,6 +690,9 @@ out_free_data: >>> struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns = { >>> >>> .alloc = arm_v7s_alloc_pgtable, >>> .free = arm_v7s_free_pgtable, >>> >>> + .supported_quirks = IO_PGTABLE_QUIRK_ARM_NS | >>> + IO_PGTABLE_QUIRK_NO_PERMS | >>> + IO_PGTABLE_QUIRK_TLBI_ON_MAP, >>> >>> }; >>> >>> #ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S_SELFTEST >>> >>> diff --git a/drivers/iommu/io-pgtable-arm.c >>> b/drivers/iommu/io-pgtable-arm.c index 4095af2..32f94f1 100644 >>> --- a/drivers/iommu/io-pgtable-arm.c >>> +++ b/drivers/iommu/io-pgtable-arm.c >>> @@ -863,6 +863,7 @@ arm_32_lpae_alloc_pgtable_s2(struct io_pgtable_cfg >>> *cfg, void *cookie)> >>> struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns = { >>> >>> .alloc = arm_64_lpae_alloc_pgtable_s1, >>> .free = arm_lpae_free_pgtable, >>> >>> + .supported_quirks = IO_PGTABLE_QUIRK_ARM_NS, >>> >>> }; >>> >>> struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns = { >>> >>> @@ -873,6 +874,7 @@ struct io_pgtable_init_fns >>> io_pgtable_arm_64_lpae_s2_init_fns = {> >>> struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns = { >>> >>> .alloc = arm_32_lpae_alloc_pgtable_s1, >>> .free = arm_lpae_free_pgtable, >>> >>> + .supported_quirks = IO_PGTABLE_QUIRK_ARM_NS, >>> >>> }; >>> >>> struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns = { >>> >>> diff --git a/drivers/iommu/io-pgtable.c b/drivers/iommu/io-pgtable.c >>> index 876f6a7..0f57a45 100644 >>> --- a/drivers/iommu/io-pgtable.c >>> +++ b/drivers/iommu/io-pgtable.c >>> @@ -52,6 +52,9 @@ struct io_pgtable_ops *alloc_io_pgtable_ops(enum >>> io_pgtable_fmt fmt,> >>> if (!fns) >>> >>> return NULL; >>> >>> + if (cfg->quirks & ~fns->supported_quirks) >>> + return NULL; >>> + >>> >>> iop = fns->alloc(cfg, cookie); >>> if (!iop) >>> >>> return NULL; >>> >>> diff --git a/drivers/iommu/io-pgtable.h b/drivers/iommu/io-pgtable.h >>> index 4faee7d..6e7f11e 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. >>> + */ >> >> Much better, cheers. >> >>> + #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 int quirks; >> >> Let's just make this unsigned long. >> >>> unsigned long pgsize_bitmap; >>> unsigned int ias; >>> unsigned int oas; >>> >>> @@ -173,10 +187,12 @@ static inline void io_pgtable_tlb_sync(struct >>> io_pgtable *iop) >>> * >>> * @alloc: Allocate a set of page tables described by cfg. >>> * @free: Free the page tables associated with iop. >>> + * @supported_quirks: Bitmap of quirks supported by the format. >>> */ >>> struct io_pgtable_init_fns { >>> struct io_pgtable *(*alloc)(struct io_pgtable_cfg *cfg, void > *cookie); >>> void (*free)(struct io_pgtable *iop); >>> + unsigned int supported_quirks; >>> }; >> >> My only gripe here is that this is supposed to be a struct of function >> pointers... get_supported_quirks() ? > > Can't we instead say it's a struct of function pointers and static data ? :-) > A function to retrieve the supported quirks will just contribute to kernel > bloat without adding any extra benefit. Bleh - personally I think it's marginally more obvious and readable to have the information looking like data, but I'd much sooner just have a hard-coded "if (cfq->quirks & ..." check in every format's alloc function than introduce a whole new callback. Does that sound like a reasonable compromise? Robin.
On Fri, Feb 12, 2016 at 03:23:04PM +0000, Robin Murphy wrote: > On 12/02/16 12:32, Laurent Pinchart wrote: > >On Friday 12 February 2016 12:08:58 Will Deacon wrote: > >>On Thu, Feb 11, 2016 at 04:13:45PM +0000, Robin Murphy wrote: > >>>@@ -173,10 +187,12 @@ static inline void io_pgtable_tlb_sync(struct > >>>io_pgtable *iop) > >>> * > >>> * @alloc: Allocate a set of page tables described by cfg. > >>> * @free: Free the page tables associated with iop. > >>>+ * @supported_quirks: Bitmap of quirks supported by the format. > >>> */ > >>> struct io_pgtable_init_fns { > >>> struct io_pgtable *(*alloc)(struct io_pgtable_cfg *cfg, void > >*cookie); > >>> void (*free)(struct io_pgtable *iop); > >>>+ unsigned int supported_quirks; > >>> }; > >> > >>My only gripe here is that this is supposed to be a struct of function > >>pointers... get_supported_quirks() ? > > > >Can't we instead say it's a struct of function pointers and static data ? :-) > >A function to retrieve the supported quirks will just contribute to kernel > >bloat without adding any extra benefit. > > Bleh - personally I think it's marginally more obvious and readable to have > the information looking like data, but I'd much sooner just have a > hard-coded "if (cfq->quirks & ..." check in every format's alloc function > than introduce a whole new callback. Does that sound like a reasonable > compromise? Yeah, do that. You never know, there could be quirks that are only supported based on other things in the cfg, so it's more extensible that way too. Will
diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c index d39a021..9bc607a 100644 --- a/drivers/iommu/io-pgtable-arm-v7s.c +++ b/drivers/iommu/io-pgtable-arm-v7s.c @@ -690,6 +690,9 @@ out_free_data: struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns = { .alloc = arm_v7s_alloc_pgtable, .free = arm_v7s_free_pgtable, + .supported_quirks = IO_PGTABLE_QUIRK_ARM_NS | + IO_PGTABLE_QUIRK_NO_PERMS | + IO_PGTABLE_QUIRK_TLBI_ON_MAP, }; #ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S_SELFTEST diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c index 4095af2..32f94f1 100644 --- a/drivers/iommu/io-pgtable-arm.c +++ b/drivers/iommu/io-pgtable-arm.c @@ -863,6 +863,7 @@ arm_32_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, void *cookie) struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns = { .alloc = arm_64_lpae_alloc_pgtable_s1, .free = arm_lpae_free_pgtable, + .supported_quirks = IO_PGTABLE_QUIRK_ARM_NS, }; struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns = { @@ -873,6 +874,7 @@ struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns = { struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns = { .alloc = arm_32_lpae_alloc_pgtable_s1, .free = arm_lpae_free_pgtable, + .supported_quirks = IO_PGTABLE_QUIRK_ARM_NS, }; struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns = { diff --git a/drivers/iommu/io-pgtable.c b/drivers/iommu/io-pgtable.c index 876f6a7..0f57a45 100644 --- a/drivers/iommu/io-pgtable.c +++ b/drivers/iommu/io-pgtable.c @@ -52,6 +52,9 @@ struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt, if (!fns) return NULL; + if (cfg->quirks & ~fns->supported_quirks) + return NULL; + iop = fns->alloc(cfg, cookie); if (!iop) return NULL; diff --git a/drivers/iommu/io-pgtable.h b/drivers/iommu/io-pgtable.h index 4faee7d..6e7f11e 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 int quirks; unsigned long pgsize_bitmap; unsigned int ias; unsigned int oas; @@ -173,10 +187,12 @@ static inline void io_pgtable_tlb_sync(struct io_pgtable *iop) * * @alloc: Allocate a set of page tables described by cfg. * @free: Free the page tables associated with iop. + * @supported_quirks: Bitmap of quirks supported by the format. */ struct io_pgtable_init_fns { struct io_pgtable *(*alloc)(struct io_pgtable_cfg *cfg, void *cookie); void (*free)(struct io_pgtable *iop); + unsigned int supported_quirks; }; extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns;
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> --- drivers/iommu/io-pgtable-arm-v7s.c | 3 +++ drivers/iommu/io-pgtable-arm.c | 2 ++ drivers/iommu/io-pgtable.c | 3 +++ drivers/iommu/io-pgtable.h | 24 ++++++++++++++++++++---- 4 files changed, 28 insertions(+), 4 deletions(-)