* [RFC PATCH v1] iommu/io-pgtable-arm: Check for leaf entry right after finding it
@ 2017-02-09 13:56 ` Oleksandr Tyshchenko
0 siblings, 0 replies; 10+ messages in thread
From: Oleksandr Tyshchenko @ 2017-02-09 13:56 UTC (permalink / raw)
To: linux-arm-kernel, iommu
Cc: Oleksandr Tyshchenko, vlad.babchuk, joro, will.deacon,
andrii.anisov, andr2000, al1img, robin.murphy, joculator
From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Do a check for already installed leaf entry at the current level before
performing any actions when trying to map.
This check is already present in arm_lpae_init_pte(), i.e. before
installing new leaf entry at the current level if conditions to do so
are met (size == block_size).
But, this might be insufficient in case when we have already
installed block mapping at this level and it is not time to
install new leaf entry (size != block_size).
In that case we continue walking the page table down with wrong pointer
to the next level.
So, move check from arm_lpae_init_pte() to __arm_lpae_map() in order to
avoid all cases.
Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
---
I hope that following actions can help to catch it:
1. Call iommu_map for a block mapping (e.g. 2M) at some address
(e.g. iova 0x80000000 pa 0x80000000).
2. Call iommu_map for a page mapping (4k) at some address from
the previous mapped region (e.g. iova 0x80008000 pa 0x90000000).
I understand that after iommu_map should be iommu_unmap, but
different scenarios may occur).
---
---
drivers/iommu/io-pgtable-arm.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index f5c90e1..ebdb82f 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -272,11 +272,7 @@ static int arm_lpae_init_pte(struct arm_lpae_io_pgtable *data,
arm_lpae_iopte pte = prot;
struct io_pgtable_cfg *cfg = &data->iop.cfg;
- if (iopte_leaf(*ptep, lvl)) {
- /* We require an unmap first */
- WARN_ON(!selftest_running);
- return -EEXIST;
- } else if (iopte_type(*ptep, lvl) == ARM_LPAE_PTE_TYPE_TABLE) {
+ if (iopte_type(*ptep, lvl) == ARM_LPAE_PTE_TYPE_TABLE) {
/*
* We need to unmap and free the old table before
* overwriting it with a block entry.
@@ -315,6 +311,13 @@ static int __arm_lpae_map(struct arm_lpae_io_pgtable *data, unsigned long iova,
/* Find our entry at the current level */
ptep += ARM_LPAE_LVL_IDX(iova, lvl, data);
+ /* Check for already installed leaf entry */
+ if (iopte_leaf(*ptep, lvl)) {
+ /* We require an unmap first */
+ WARN_ON(!selftest_running);
+ return -EEXIST;
+ }
+
/* If we can install a leaf entry at this level, then do so */
if (size == block_size && (size & cfg->pgsize_bitmap))
return arm_lpae_init_pte(data, iova, paddr, prot, lvl, ptep);
--
2.7.4
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [RFC PATCH v1] iommu/io-pgtable-arm: Check for leaf entry right after finding it
@ 2017-02-09 13:56 ` Oleksandr Tyshchenko
0 siblings, 0 replies; 10+ messages in thread
From: Oleksandr Tyshchenko @ 2017-02-09 13:56 UTC (permalink / raw)
To: linux-arm-kernel
From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Do a check for already installed leaf entry at the current level before
performing any actions when trying to map.
This check is already present in arm_lpae_init_pte(), i.e. before
installing new leaf entry at the current level if conditions to do so
are met (size == block_size).
But, this might be insufficient in case when we have already
installed block mapping at this level and it is not time to
install new leaf entry (size != block_size).
In that case we continue walking the page table down with wrong pointer
to the next level.
So, move check from arm_lpae_init_pte() to __arm_lpae_map() in order to
avoid all cases.
Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
---
I hope that following actions can help to catch it:
1. Call iommu_map for a block mapping (e.g. 2M) at some address
(e.g. iova 0x80000000 pa 0x80000000).
2. Call iommu_map for a page mapping (4k) at some address from
the previous mapped region (e.g. iova 0x80008000 pa 0x90000000).
I understand that after iommu_map should be iommu_unmap, but
different scenarios may occur).
---
---
drivers/iommu/io-pgtable-arm.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index f5c90e1..ebdb82f 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -272,11 +272,7 @@ static int arm_lpae_init_pte(struct arm_lpae_io_pgtable *data,
arm_lpae_iopte pte = prot;
struct io_pgtable_cfg *cfg = &data->iop.cfg;
- if (iopte_leaf(*ptep, lvl)) {
- /* We require an unmap first */
- WARN_ON(!selftest_running);
- return -EEXIST;
- } else if (iopte_type(*ptep, lvl) == ARM_LPAE_PTE_TYPE_TABLE) {
+ if (iopte_type(*ptep, lvl) == ARM_LPAE_PTE_TYPE_TABLE) {
/*
* We need to unmap and free the old table before
* overwriting it with a block entry.
@@ -315,6 +311,13 @@ static int __arm_lpae_map(struct arm_lpae_io_pgtable *data, unsigned long iova,
/* Find our entry at the current level */
ptep += ARM_LPAE_LVL_IDX(iova, lvl, data);
+ /* Check for already installed leaf entry */
+ if (iopte_leaf(*ptep, lvl)) {
+ /* We require an unmap first */
+ WARN_ON(!selftest_running);
+ return -EEXIST;
+ }
+
/* If we can install a leaf entry at this level, then do so */
if (size == block_size && (size & cfg->pgsize_bitmap))
return arm_lpae_init_pte(data, iova, paddr, prot, lvl, ptep);
--
2.7.4
^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [RFC PATCH v1] iommu/io-pgtable-arm: Check for leaf entry right after finding it
2017-02-09 13:56 ` Oleksandr Tyshchenko
@ 2017-02-13 11:07 ` Oleksandr Tyshchenko
-1 siblings, 0 replies; 10+ messages in thread
From: Oleksandr Tyshchenko @ 2017-02-13 11:07 UTC (permalink / raw)
To: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA
Cc: Oleksandr Tyshchenko, Volodymyr Babchuk, will.deacon-5wv7dgnIgG8,
Andrii Anisov, Oleksandr Andrushchenko, al1img, Artem Mygaiev
Hi, all.
Any comments?
On Thu, Feb 9, 2017 at 3:56 PM, Oleksandr Tyshchenko
<olekstysh-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> From: Oleksandr Tyshchenko <oleksandr_tyshchenko-uRwfk40T5oI@public.gmane.org>
>
> Do a check for already installed leaf entry at the current level before
> performing any actions when trying to map.
>
> This check is already present in arm_lpae_init_pte(), i.e. before
> installing new leaf entry at the current level if conditions to do so
> are met (size == block_size).
>
> But, this might be insufficient in case when we have already
> installed block mapping at this level and it is not time to
> install new leaf entry (size != block_size).
> In that case we continue walking the page table down with wrong pointer
> to the next level.
>
> So, move check from arm_lpae_init_pte() to __arm_lpae_map() in order to
> avoid all cases.
>
> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko-uRwfk40T5oI@public.gmane.org>
> ---
> I hope that following actions can help to catch it:
> 1. Call iommu_map for a block mapping (e.g. 2M) at some address
> (e.g. iova 0x80000000 pa 0x80000000).
> 2. Call iommu_map for a page mapping (4k) at some address from
> the previous mapped region (e.g. iova 0x80008000 pa 0x90000000).
>
> I understand that after iommu_map should be iommu_unmap, but
> different scenarios may occur).
> ---
> ---
> drivers/iommu/io-pgtable-arm.c | 13 ++++++++-----
> 1 file changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
> index f5c90e1..ebdb82f 100644
> --- a/drivers/iommu/io-pgtable-arm.c
> +++ b/drivers/iommu/io-pgtable-arm.c
> @@ -272,11 +272,7 @@ static int arm_lpae_init_pte(struct arm_lpae_io_pgtable *data,
> arm_lpae_iopte pte = prot;
> struct io_pgtable_cfg *cfg = &data->iop.cfg;
>
> - if (iopte_leaf(*ptep, lvl)) {
> - /* We require an unmap first */
> - WARN_ON(!selftest_running);
> - return -EEXIST;
> - } else if (iopte_type(*ptep, lvl) == ARM_LPAE_PTE_TYPE_TABLE) {
> + if (iopte_type(*ptep, lvl) == ARM_LPAE_PTE_TYPE_TABLE) {
> /*
> * We need to unmap and free the old table before
> * overwriting it with a block entry.
> @@ -315,6 +311,13 @@ static int __arm_lpae_map(struct arm_lpae_io_pgtable *data, unsigned long iova,
> /* Find our entry at the current level */
> ptep += ARM_LPAE_LVL_IDX(iova, lvl, data);
>
> + /* Check for already installed leaf entry */
> + if (iopte_leaf(*ptep, lvl)) {
> + /* We require an unmap first */
> + WARN_ON(!selftest_running);
> + return -EEXIST;
> + }
> +
> /* If we can install a leaf entry at this level, then do so */
> if (size == block_size && (size & cfg->pgsize_bitmap))
> return arm_lpae_init_pte(data, iova, paddr, prot, lvl, ptep);
> --
> 2.7.4
>
--
Regards,
Oleksandr Tyshchenko
^ permalink raw reply [flat|nested] 10+ messages in thread
* [RFC PATCH v1] iommu/io-pgtable-arm: Check for leaf entry right after finding it
@ 2017-02-13 11:07 ` Oleksandr Tyshchenko
0 siblings, 0 replies; 10+ messages in thread
From: Oleksandr Tyshchenko @ 2017-02-13 11:07 UTC (permalink / raw)
To: linux-arm-kernel
Hi, all.
Any comments?
On Thu, Feb 9, 2017 at 3:56 PM, Oleksandr Tyshchenko
<olekstysh@gmail.com> wrote:
> From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
>
> Do a check for already installed leaf entry at the current level before
> performing any actions when trying to map.
>
> This check is already present in arm_lpae_init_pte(), i.e. before
> installing new leaf entry at the current level if conditions to do so
> are met (size == block_size).
>
> But, this might be insufficient in case when we have already
> installed block mapping at this level and it is not time to
> install new leaf entry (size != block_size).
> In that case we continue walking the page table down with wrong pointer
> to the next level.
>
> So, move check from arm_lpae_init_pte() to __arm_lpae_map() in order to
> avoid all cases.
>
> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
> ---
> I hope that following actions can help to catch it:
> 1. Call iommu_map for a block mapping (e.g. 2M) at some address
> (e.g. iova 0x80000000 pa 0x80000000).
> 2. Call iommu_map for a page mapping (4k) at some address from
> the previous mapped region (e.g. iova 0x80008000 pa 0x90000000).
>
> I understand that after iommu_map should be iommu_unmap, but
> different scenarios may occur).
> ---
> ---
> drivers/iommu/io-pgtable-arm.c | 13 ++++++++-----
> 1 file changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
> index f5c90e1..ebdb82f 100644
> --- a/drivers/iommu/io-pgtable-arm.c
> +++ b/drivers/iommu/io-pgtable-arm.c
> @@ -272,11 +272,7 @@ static int arm_lpae_init_pte(struct arm_lpae_io_pgtable *data,
> arm_lpae_iopte pte = prot;
> struct io_pgtable_cfg *cfg = &data->iop.cfg;
>
> - if (iopte_leaf(*ptep, lvl)) {
> - /* We require an unmap first */
> - WARN_ON(!selftest_running);
> - return -EEXIST;
> - } else if (iopte_type(*ptep, lvl) == ARM_LPAE_PTE_TYPE_TABLE) {
> + if (iopte_type(*ptep, lvl) == ARM_LPAE_PTE_TYPE_TABLE) {
> /*
> * We need to unmap and free the old table before
> * overwriting it with a block entry.
> @@ -315,6 +311,13 @@ static int __arm_lpae_map(struct arm_lpae_io_pgtable *data, unsigned long iova,
> /* Find our entry at the current level */
> ptep += ARM_LPAE_LVL_IDX(iova, lvl, data);
>
> + /* Check for already installed leaf entry */
> + if (iopte_leaf(*ptep, lvl)) {
> + /* We require an unmap first */
> + WARN_ON(!selftest_running);
> + return -EEXIST;
> + }
> +
> /* If we can install a leaf entry at this level, then do so */
> if (size == block_size && (size & cfg->pgsize_bitmap))
> return arm_lpae_init_pte(data, iova, paddr, prot, lvl, ptep);
> --
> 2.7.4
>
--
Regards,
Oleksandr Tyshchenko
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [RFC PATCH v1] iommu/io-pgtable-arm: Check for leaf entry right after finding it
2017-02-13 11:07 ` Oleksandr Tyshchenko
@ 2017-02-13 11:27 ` Will Deacon
-1 siblings, 0 replies; 10+ messages in thread
From: Will Deacon @ 2017-02-13 11:27 UTC (permalink / raw)
To: Oleksandr Tyshchenko
Cc: Oleksandr Tyshchenko, Volodymyr Babchuk, joro, iommu,
Andrii Anisov, Oleksandr Andrushchenko, al1img, robin.murphy,
linux-arm-kernel, Artem Mygaiev
On Mon, Feb 13, 2017 at 01:07:02PM +0200, Oleksandr Tyshchenko wrote:
> Any comments?
Looks fine to me, but I don't think it's urgent and I already sent my
SMMU pull for 4.11. I'll send this as a fix after the merge window.
I suspect we need something similar for io-pgtable-arm-v7s.c, too.
Will
^ permalink raw reply [flat|nested] 10+ messages in thread
* [RFC PATCH v1] iommu/io-pgtable-arm: Check for leaf entry right after finding it
@ 2017-02-13 11:27 ` Will Deacon
0 siblings, 0 replies; 10+ messages in thread
From: Will Deacon @ 2017-02-13 11:27 UTC (permalink / raw)
To: linux-arm-kernel
On Mon, Feb 13, 2017 at 01:07:02PM +0200, Oleksandr Tyshchenko wrote:
> Any comments?
Looks fine to me, but I don't think it's urgent and I already sent my
SMMU pull for 4.11. I'll send this as a fix after the merge window.
I suspect we need something similar for io-pgtable-arm-v7s.c, too.
Will
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [RFC PATCH v1] iommu/io-pgtable-arm: Check for leaf entry right after finding it
2017-02-13 11:27 ` Will Deacon
@ 2017-02-13 11:50 ` Oleksandr Tyshchenko
-1 siblings, 0 replies; 10+ messages in thread
From: Oleksandr Tyshchenko @ 2017-02-13 11:50 UTC (permalink / raw)
To: Will Deacon
Cc: Oleksandr Tyshchenko, Volodymyr Babchuk,
iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA, Andrii Anisov,
Oleksandr Andrushchenko, al1img,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r, Artem Mygaiev
On Mon, Feb 13, 2017 at 1:27 PM, Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org> wrote:
> On Mon, Feb 13, 2017 at 01:07:02PM +0200, Oleksandr Tyshchenko wrote:
>> Any comments?
>
> Looks fine to me, but I don't think it's urgent and I already sent my
> SMMU pull for 4.11. I'll send this as a fix after the merge window.
OK. Thank you.
>
> I suspect we need something similar for io-pgtable-arm-v7s.c, too.
Agree. On the whole I will be able to make similar patch for arm-v7s,
but I won't be 100% sure
since I don't have any boards where arm-v7s compatible IOMMU installed.
Shall I make patch for arm-v7s too?
>
> Will
--
Regards,
Oleksandr Tyshchenko
^ permalink raw reply [flat|nested] 10+ messages in thread
* [RFC PATCH v1] iommu/io-pgtable-arm: Check for leaf entry right after finding it
@ 2017-02-13 11:50 ` Oleksandr Tyshchenko
0 siblings, 0 replies; 10+ messages in thread
From: Oleksandr Tyshchenko @ 2017-02-13 11:50 UTC (permalink / raw)
To: linux-arm-kernel
On Mon, Feb 13, 2017 at 1:27 PM, Will Deacon <will.deacon@arm.com> wrote:
> On Mon, Feb 13, 2017 at 01:07:02PM +0200, Oleksandr Tyshchenko wrote:
>> Any comments?
>
> Looks fine to me, but I don't think it's urgent and I already sent my
> SMMU pull for 4.11. I'll send this as a fix after the merge window.
OK. Thank you.
>
> I suspect we need something similar for io-pgtable-arm-v7s.c, too.
Agree. On the whole I will be able to make similar patch for arm-v7s,
but I won't be 100% sure
since I don't have any boards where arm-v7s compatible IOMMU installed.
Shall I make patch for arm-v7s too?
>
> Will
--
Regards,
Oleksandr Tyshchenko
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [RFC PATCH v1] iommu/io-pgtable-arm: Check for leaf entry right after finding it
2017-02-13 11:50 ` Oleksandr Tyshchenko
@ 2017-02-13 12:00 ` Will Deacon
-1 siblings, 0 replies; 10+ messages in thread
From: Will Deacon @ 2017-02-13 12:00 UTC (permalink / raw)
To: Oleksandr Tyshchenko
Cc: Oleksandr Tyshchenko, Volodymyr Babchuk, joro, iommu,
Andrii Anisov, Oleksandr Andrushchenko, al1img, robin.murphy,
linux-arm-kernel, Artem Mygaiev
On Mon, Feb 13, 2017 at 01:50:29PM +0200, Oleksandr Tyshchenko wrote:
> On Mon, Feb 13, 2017 at 1:27 PM, Will Deacon <will.deacon@arm.com> wrote:
> > On Mon, Feb 13, 2017 at 01:07:02PM +0200, Oleksandr Tyshchenko wrote:
> >> Any comments?
> >
> > Looks fine to me, but I don't think it's urgent and I already sent my
> > SMMU pull for 4.11. I'll send this as a fix after the merge window.
> OK. Thank you.
>
> >
> > I suspect we need something similar for io-pgtable-arm-v7s.c, too.
> Agree. On the whole I will be able to make similar patch for arm-v7s,
> but I won't be 100% sure
> since I don't have any boards where arm-v7s compatible IOMMU installed.
>
> Shall I make patch for arm-v7s too?
Yes, please. Robin seems to enjoy using short-descriptor, so he might
give it a spin for you if you ask nicely.
Will
^ permalink raw reply [flat|nested] 10+ messages in thread
* [RFC PATCH v1] iommu/io-pgtable-arm: Check for leaf entry right after finding it
@ 2017-02-13 12:00 ` Will Deacon
0 siblings, 0 replies; 10+ messages in thread
From: Will Deacon @ 2017-02-13 12:00 UTC (permalink / raw)
To: linux-arm-kernel
On Mon, Feb 13, 2017 at 01:50:29PM +0200, Oleksandr Tyshchenko wrote:
> On Mon, Feb 13, 2017 at 1:27 PM, Will Deacon <will.deacon@arm.com> wrote:
> > On Mon, Feb 13, 2017 at 01:07:02PM +0200, Oleksandr Tyshchenko wrote:
> >> Any comments?
> >
> > Looks fine to me, but I don't think it's urgent and I already sent my
> > SMMU pull for 4.11. I'll send this as a fix after the merge window.
> OK. Thank you.
>
> >
> > I suspect we need something similar for io-pgtable-arm-v7s.c, too.
> Agree. On the whole I will be able to make similar patch for arm-v7s,
> but I won't be 100% sure
> since I don't have any boards where arm-v7s compatible IOMMU installed.
>
> Shall I make patch for arm-v7s too?
Yes, please. Robin seems to enjoy using short-descriptor, so he might
give it a spin for you if you ask nicely.
Will
^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2017-02-13 12:00 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-02-09 13:56 [RFC PATCH v1] iommu/io-pgtable-arm: Check for leaf entry right after finding it Oleksandr Tyshchenko
2017-02-09 13:56 ` Oleksandr Tyshchenko
[not found] ` <1486648600-27457-1-git-send-email-olekstysh-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2017-02-13 11:07 ` Oleksandr Tyshchenko
2017-02-13 11:07 ` Oleksandr Tyshchenko
2017-02-13 11:27 ` Will Deacon
2017-02-13 11:27 ` Will Deacon
[not found] ` <20170213112728.GH1512-5wv7dgnIgG8@public.gmane.org>
2017-02-13 11:50 ` Oleksandr Tyshchenko
2017-02-13 11:50 ` Oleksandr Tyshchenko
2017-02-13 12:00 ` Will Deacon
2017-02-13 12:00 ` Will Deacon
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