Re: [PATCH 3/4] powerpc/pseries/iommu: Move window-removing part of remove_ddw into remove_dma_window
On Tue, 2020-06-23 at 11:33 +1000, Oliver O'Halloran wrote: > On Tue, Jun 23, 2020 at 11:12 AM Alexey Kardashevskiy wrote: > > On 23/06/2020 04:59, Leonardo Bras wrote: > > > > Also, despite this particular file, the "pdn" name is usually used for > > > > struct pci_dn (not device_node), let's keep it that way. > > > > > > Sure, I got confused for some time about this, as we have: > > > static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn). > > > but on *_ddw() we have "struct pci_dn *pdn". > > > > True again, not the cleanest style here. > > > > > > > I will also add a patch that renames those 'struct device_node *pdn' to > > > something like 'struct device_node *parent_dn'. > > I usually go with "np" or "node". In this case I'd use "parent_np" or > just "parent." As you said pci_dn conventionally uses pdn so that > should be avoided if at all possible. There's some places that just > use "dn" for device_node, but I don't think that's something we should > encourage due to how similar it is to pdn. Sure, I will try that. > > > I would not go that far, we (well, Oliver) are getting rid of many > > occurrences of pci_dn and Oliver may have a stronger opinion here. > > I'm trying to remove the use of pci_dn from non-RTAS platforms which > doesn't apply to pseries. For RTAS platforms having pci_dn sort of > makes sense since it's used to cache data from the device_node and > having it saves you from needing to parse and validate the DT at > runtime since we're supposed to be relying on the FW provided settings > in the DT. I want to get rid of it on PowerNV because it's become a > dumping ground for random bits and pieces of platform specific data. > It's confusing at best and IMO it duplicates a lot of what's already > available in the per-PHB structures which the platform specific stuff > should actually be looking at. > > Oliver Best regards, Leonardo Bras
Re: [PATCH 3/4] powerpc/pseries/iommu: Move window-removing part of remove_ddw into remove_dma_window
On Tue, 2020-06-23 at 11:12 +1000, Alexey Kardashevskiy wrote:
>
> On 23/06/2020 04:59, Leonardo Bras wrote:
> > Hello Alexey, thanks for the feedback!
> >
> > On Mon, 2020-06-22 at 20:02 +1000, Alexey Kardashevskiy wrote:
> > > On 19/06/2020 15:06, Leonardo Bras wrote:
> > > > Move the window-removing part of remove_ddw into a new function
> > > > (remove_dma_window), so it can be used to remove other DMA windows.
> > > >
> > > > It's useful for removing DMA windows that don't create DIRECT64_PROPNAME
> > > > property, like the default DMA window from the device, which uses
> > > > "ibm,dma-window".
> > > >
> > > > Signed-off-by: Leonardo Bras
> > > > ---
> > > > arch/powerpc/platforms/pseries/iommu.c | 53 +++---
> > > > 1 file changed, 31 insertions(+), 22 deletions(-)
> > > >
> > > > diff --git a/arch/powerpc/platforms/pseries/iommu.c
> > > > b/arch/powerpc/platforms/pseries/iommu.c
> > > > index 5e1fbc176a37..de633f6ae093 100644
> > > > --- a/arch/powerpc/platforms/pseries/iommu.c
> > > > +++ b/arch/powerpc/platforms/pseries/iommu.c
> > > > @@ -767,25 +767,14 @@ static int __init disable_ddw_setup(char *str)
> > > >
> > > > early_param("disable_ddw", disable_ddw_setup);
> > > >
> > > > -static void remove_ddw(struct device_node *np, bool remove_prop)
> > > > +static void remove_dma_window(struct device_node *pdn, u32 *ddw_avail,
> > >
> > > You do not need the entire ddw_avail here, pass just the token you need.
> >
> > Well, I just emulated the behavior of create_ddw() and query_ddw() as
> > both just pass the array instead of the token, even though they only
> > use a single token.
>
> True, there is a pattern.
>
> > I think it's to make the rest of the code independent of the design of
> > the "ibm,ddw-applicable" array, and if it changes, only local changes
> > on the functions will be needed.
>
> The helper removes a window, if you are going to call other operations
> in remove_dma_window(), then you'll have to change its name ;)
Not only doing new stuff, it can change the order for some reason (as
the order of the output of query), and it would need not change the
caller.
>
>
> > > Also, despite this particular file, the "pdn" name is usually used for
> > > struct pci_dn (not device_node), let's keep it that way.
> >
> > Sure, I got confused for some time about this, as we have:
> > static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn).
> > but on *_ddw() we have "struct pci_dn *pdn".
>
> True again, not the cleanest style here.
>
>
> > I will also add a patch that renames those 'struct device_node *pdn' to
> > something like 'struct device_node *parent_dn'.
>
> I would not go that far, we (well, Oliver) are getting rid of many
> occurrences of pci_dn and Oliver may have a stronger opinion here.
>
>
> > > > + struct property *win)
> > > > {
> > > > struct dynamic_dma_window_prop *dwp;
> > > > - struct property *win64;
> > > > - u32 ddw_avail[3];
> > > > u64 liobn;
> > > > - int ret = 0;
> > > > -
> > > > - ret = of_property_read_u32_array(np, "ibm,ddw-applicable",
> > > > -_avail[0], 3);
> > > > -
> > > > - win64 = of_find_property(np, DIRECT64_PROPNAME, NULL);
> > > > - if (!win64)
> > > > - return;
> > > > -
> > > > - if (ret || win64->length < sizeof(*dwp))
> > > > - goto delprop;
> > > > + int ret;
> > > >
> > > > - dwp = win64->value;
> > > > + dwp = win->value;
> > > > liobn = (u64)be32_to_cpu(dwp->liobn);
> > > >
> > > > /* clear the whole window, note the arg is in kernel pages */
> > > > @@ -793,24 +782,44 @@ static void remove_ddw(struct device_node *np,
> > > > bool remove_prop)
> > > > 1ULL << (be32_to_cpu(dwp->window_shift) - PAGE_SHIFT),
> > > > dwp);
> > > > if (ret)
> > > > pr_warn("%pOF failed to clear tces in window.\n",
> > > > - np);
> > > > + pdn);
> > > > else
> > > > pr_debug("%pOF successfully cleared tces in window.\n",
> > > > -np);
> > > > +pdn);
> > > >
> > > > ret = rtas_call(ddw_avail[2], 1, 1, NULL, liobn);
> > > > if (ret)
> > > > pr_warn("%pOF: failed to remove direct window: rtas
> > > > returned "
> > > > "%d to ibm,remove-pe-dma-window(%x) %llx\n",
> > > > - np, ret, ddw_avail[2], liobn);
> > > > + pdn, ret, ddw_avail[2], liobn);
> > > > else
> > > > pr_debug("%pOF: successfully removed direct window:
> > > > rtas returned "
> > > > "%d to ibm,remove-pe-dma-window(%x) %llx\n",
> > > > - np, ret, ddw_avail[2], liobn);
> > > > + pdn, ret, ddw_avail[2], liobn);
>
Re: [PATCH 3/4] powerpc/pseries/iommu: Move window-removing part of remove_ddw into remove_dma_window
On Tue, Jun 23, 2020 at 11:12 AM Alexey Kardashevskiy wrote: > > On 23/06/2020 04:59, Leonardo Bras wrote: > > > >> Also, despite this particular file, the "pdn" name is usually used for > >> struct pci_dn (not device_node), let's keep it that way. > > > > Sure, I got confused for some time about this, as we have: > > static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn). > > but on *_ddw() we have "struct pci_dn *pdn". > > True again, not the cleanest style here. > > > > I will also add a patch that renames those 'struct device_node *pdn' to > > something like 'struct device_node *parent_dn'. I usually go with "np" or "node". In this case I'd use "parent_np" or just "parent." As you said pci_dn conventionally uses pdn so that should be avoided if at all possible. There's some places that just use "dn" for device_node, but I don't think that's something we should encourage due to how similar it is to pdn. > I would not go that far, we (well, Oliver) are getting rid of many > occurrences of pci_dn and Oliver may have a stronger opinion here. I'm trying to remove the use of pci_dn from non-RTAS platforms which doesn't apply to pseries. For RTAS platforms having pci_dn sort of makes sense since it's used to cache data from the device_node and having it saves you from needing to parse and validate the DT at runtime since we're supposed to be relying on the FW provided settings in the DT. I want to get rid of it on PowerNV because it's become a dumping ground for random bits and pieces of platform specific data. It's confusing at best and IMO it duplicates a lot of what's already available in the per-PHB structures which the platform specific stuff should actually be looking at. Oliver
Re: [PATCH 3/4] powerpc/pseries/iommu: Move window-removing part of remove_ddw into remove_dma_window
On 23/06/2020 04:59, Leonardo Bras wrote:
> Hello Alexey, thanks for the feedback!
>
> On Mon, 2020-06-22 at 20:02 +1000, Alexey Kardashevskiy wrote:
>>
>> On 19/06/2020 15:06, Leonardo Bras wrote:
>>> Move the window-removing part of remove_ddw into a new function
>>> (remove_dma_window), so it can be used to remove other DMA windows.
>>>
>>> It's useful for removing DMA windows that don't create DIRECT64_PROPNAME
>>> property, like the default DMA window from the device, which uses
>>> "ibm,dma-window".
>>>
>>> Signed-off-by: Leonardo Bras
>>> ---
>>> arch/powerpc/platforms/pseries/iommu.c | 53 +++---
>>> 1 file changed, 31 insertions(+), 22 deletions(-)
>>>
>>> diff --git a/arch/powerpc/platforms/pseries/iommu.c
>>> b/arch/powerpc/platforms/pseries/iommu.c
>>> index 5e1fbc176a37..de633f6ae093 100644
>>> --- a/arch/powerpc/platforms/pseries/iommu.c
>>> +++ b/arch/powerpc/platforms/pseries/iommu.c
>>> @@ -767,25 +767,14 @@ static int __init disable_ddw_setup(char *str)
>>>
>>> early_param("disable_ddw", disable_ddw_setup);
>>>
>>> -static void remove_ddw(struct device_node *np, bool remove_prop)
>>> +static void remove_dma_window(struct device_node *pdn, u32 *ddw_avail,
>>
>> You do not need the entire ddw_avail here, pass just the token you need.
>
> Well, I just emulated the behavior of create_ddw() and query_ddw() as
> both just pass the array instead of the token, even though they only
> use a single token.
True, there is a pattern.
> I think it's to make the rest of the code independent of the design of
> the "ibm,ddw-applicable" array, and if it changes, only local changes
> on the functions will be needed.
The helper removes a window, if you are going to call other operations
in remove_dma_window(), then you'll have to change its name ;)
>> Also, despite this particular file, the "pdn" name is usually used for
>> struct pci_dn (not device_node), let's keep it that way.
>
> Sure, I got confused for some time about this, as we have:
> static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn).
> but on *_ddw() we have "struct pci_dn *pdn".
True again, not the cleanest style here.
> I will also add a patch that renames those 'struct device_node *pdn' to
> something like 'struct device_node *parent_dn'.
I would not go that far, we (well, Oliver) are getting rid of many
occurrences of pci_dn and Oliver may have a stronger opinion here.
>
>>> + struct property *win)
>>> {
>>> struct dynamic_dma_window_prop *dwp;
>>> - struct property *win64;
>>> - u32 ddw_avail[3];
>>> u64 liobn;
>>> - int ret = 0;
>>> -
>>> - ret = of_property_read_u32_array(np, "ibm,ddw-applicable",
>>> -_avail[0], 3);
>>> -
>>> - win64 = of_find_property(np, DIRECT64_PROPNAME, NULL);
>>> - if (!win64)
>>> - return;
>>> -
>>> - if (ret || win64->length < sizeof(*dwp))
>>> - goto delprop;
>>> + int ret;
>>>
>>> - dwp = win64->value;
>>> + dwp = win->value;
>>> liobn = (u64)be32_to_cpu(dwp->liobn);
>>>
>>> /* clear the whole window, note the arg is in kernel pages */
>>> @@ -793,24 +782,44 @@ static void remove_ddw(struct device_node *np, bool
>>> remove_prop)
>>> 1ULL << (be32_to_cpu(dwp->window_shift) - PAGE_SHIFT), dwp);
>>> if (ret)
>>> pr_warn("%pOF failed to clear tces in window.\n",
>>> - np);
>>> + pdn);
>>> else
>>> pr_debug("%pOF successfully cleared tces in window.\n",
>>> -np);
>>> +pdn);
>>>
>>> ret = rtas_call(ddw_avail[2], 1, 1, NULL, liobn);
>>> if (ret)
>>> pr_warn("%pOF: failed to remove direct window: rtas returned "
>>> "%d to ibm,remove-pe-dma-window(%x) %llx\n",
>>> - np, ret, ddw_avail[2], liobn);
>>> + pdn, ret, ddw_avail[2], liobn);
>>> else
>>> pr_debug("%pOF: successfully removed direct window: rtas
>>> returned "
>>> "%d to ibm,remove-pe-dma-window(%x) %llx\n",
>>> - np, ret, ddw_avail[2], liobn);
>>> + pdn, ret, ddw_avail[2], liobn);
>>> +}
>>> +
>>> +static void remove_ddw(struct device_node *np, bool remove_prop)
>>> +{
>>> + struct property *win;
>>> + u32 ddw_avail[3];
>>> + int ret = 0;
>>> +
>>> + ret = of_property_read_u32_array(np, "ibm,ddw-applicable",
>>> +_avail[0], 3);
>>> + if (ret)
>>> + return;
>>> +
>>> + win = of_find_property(np, DIRECT64_PROPNAME, NULL);
>>> + if (!win)
>>> + return;
>>> +
>>> + if (win->length >= sizeof(struct dynamic_dma_window_prop))
>>
>> Any good reason not to make it "=="? Is there something optional or we
>> expect extension (which may not grow from the end but may add cells in
>> between). Thanks,
>
> Well, it comes from the old behavior of
Re: [PATCH 3/4] powerpc/pseries/iommu: Move window-removing part of remove_ddw into remove_dma_window
Hello Alexey, thanks for the feedback!
On Mon, 2020-06-22 at 20:02 +1000, Alexey Kardashevskiy wrote:
>
> On 19/06/2020 15:06, Leonardo Bras wrote:
> > Move the window-removing part of remove_ddw into a new function
> > (remove_dma_window), so it can be used to remove other DMA windows.
> >
> > It's useful for removing DMA windows that don't create DIRECT64_PROPNAME
> > property, like the default DMA window from the device, which uses
> > "ibm,dma-window".
> >
> > Signed-off-by: Leonardo Bras
> > ---
> > arch/powerpc/platforms/pseries/iommu.c | 53 +++---
> > 1 file changed, 31 insertions(+), 22 deletions(-)
> >
> > diff --git a/arch/powerpc/platforms/pseries/iommu.c
> > b/arch/powerpc/platforms/pseries/iommu.c
> > index 5e1fbc176a37..de633f6ae093 100644
> > --- a/arch/powerpc/platforms/pseries/iommu.c
> > +++ b/arch/powerpc/platforms/pseries/iommu.c
> > @@ -767,25 +767,14 @@ static int __init disable_ddw_setup(char *str)
> >
> > early_param("disable_ddw", disable_ddw_setup);
> >
> > -static void remove_ddw(struct device_node *np, bool remove_prop)
> > +static void remove_dma_window(struct device_node *pdn, u32 *ddw_avail,
>
> You do not need the entire ddw_avail here, pass just the token you need.
Well, I just emulated the behavior of create_ddw() and query_ddw() as
both just pass the array instead of the token, even though they only
use a single token.
I think it's to make the rest of the code independent of the design of
the "ibm,ddw-applicable" array, and if it changes, only local changes
on the functions will be needed.
> Also, despite this particular file, the "pdn" name is usually used for
> struct pci_dn (not device_node), let's keep it that way.
Sure, I got confused for some time about this, as we have:
static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn).
but on *_ddw() we have "struct pci_dn *pdn".
I will also add a patch that renames those 'struct device_node *pdn' to
something like 'struct device_node *parent_dn'.
> > + struct property *win)
> > {
> > struct dynamic_dma_window_prop *dwp;
> > - struct property *win64;
> > - u32 ddw_avail[3];
> > u64 liobn;
> > - int ret = 0;
> > -
> > - ret = of_property_read_u32_array(np, "ibm,ddw-applicable",
> > -_avail[0], 3);
> > -
> > - win64 = of_find_property(np, DIRECT64_PROPNAME, NULL);
> > - if (!win64)
> > - return;
> > -
> > - if (ret || win64->length < sizeof(*dwp))
> > - goto delprop;
> > + int ret;
> >
> > - dwp = win64->value;
> > + dwp = win->value;
> > liobn = (u64)be32_to_cpu(dwp->liobn);
> >
> > /* clear the whole window, note the arg is in kernel pages */
> > @@ -793,24 +782,44 @@ static void remove_ddw(struct device_node *np, bool
> > remove_prop)
> > 1ULL << (be32_to_cpu(dwp->window_shift) - PAGE_SHIFT), dwp);
> > if (ret)
> > pr_warn("%pOF failed to clear tces in window.\n",
> > - np);
> > + pdn);
> > else
> > pr_debug("%pOF successfully cleared tces in window.\n",
> > -np);
> > +pdn);
> >
> > ret = rtas_call(ddw_avail[2], 1, 1, NULL, liobn);
> > if (ret)
> > pr_warn("%pOF: failed to remove direct window: rtas returned "
> > "%d to ibm,remove-pe-dma-window(%x) %llx\n",
> > - np, ret, ddw_avail[2], liobn);
> > + pdn, ret, ddw_avail[2], liobn);
> > else
> > pr_debug("%pOF: successfully removed direct window: rtas
> > returned "
> > "%d to ibm,remove-pe-dma-window(%x) %llx\n",
> > - np, ret, ddw_avail[2], liobn);
> > + pdn, ret, ddw_avail[2], liobn);
> > +}
> > +
> > +static void remove_ddw(struct device_node *np, bool remove_prop)
> > +{
> > + struct property *win;
> > + u32 ddw_avail[3];
> > + int ret = 0;
> > +
> > + ret = of_property_read_u32_array(np, "ibm,ddw-applicable",
> > +_avail[0], 3);
> > + if (ret)
> > + return;
> > +
> > + win = of_find_property(np, DIRECT64_PROPNAME, NULL);
> > + if (!win)
> > + return;
> > +
> > + if (win->length >= sizeof(struct dynamic_dma_window_prop))
>
> Any good reason not to make it "=="? Is there something optional or we
> expect extension (which may not grow from the end but may add cells in
> between). Thanks,
Well, it comes from the old behavior of remove_ddw():
- if (ret || win64->length < sizeof(*dwp))
- goto delprop;
As I reversed the logic from 'if (test) go out' to 'if (!test) do
stuff', I also reversed (a < b) to !(a < b) => (a >= b).
I have no problem changing that to '==', but it will produce a
different behavior than before.
>
>
> > + remove_dma_window(np, ddw_avail, win);
> > +
> > + if (!remove_prop)
> > + return;
> >
> >
Re: [PATCH 3/4] powerpc/pseries/iommu: Move window-removing part of remove_ddw into remove_dma_window
On 19/06/2020 15:06, Leonardo Bras wrote:
> Move the window-removing part of remove_ddw into a new function
> (remove_dma_window), so it can be used to remove other DMA windows.
>
> It's useful for removing DMA windows that don't create DIRECT64_PROPNAME
> property, like the default DMA window from the device, which uses
> "ibm,dma-window".
>
> Signed-off-by: Leonardo Bras
> ---
> arch/powerpc/platforms/pseries/iommu.c | 53 +++---
> 1 file changed, 31 insertions(+), 22 deletions(-)
>
> diff --git a/arch/powerpc/platforms/pseries/iommu.c
> b/arch/powerpc/platforms/pseries/iommu.c
> index 5e1fbc176a37..de633f6ae093 100644
> --- a/arch/powerpc/platforms/pseries/iommu.c
> +++ b/arch/powerpc/platforms/pseries/iommu.c
> @@ -767,25 +767,14 @@ static int __init disable_ddw_setup(char *str)
>
> early_param("disable_ddw", disable_ddw_setup);
>
> -static void remove_ddw(struct device_node *np, bool remove_prop)
> +static void remove_dma_window(struct device_node *pdn, u32 *ddw_avail,
You do not need the entire ddw_avail here, pass just the token you need.
Also, despite this particular file, the "pdn" name is usually used for
struct pci_dn (not device_node), let's keep it that way.
> + struct property *win)
> {
> struct dynamic_dma_window_prop *dwp;
> - struct property *win64;
> - u32 ddw_avail[3];
> u64 liobn;
> - int ret = 0;
> -
> - ret = of_property_read_u32_array(np, "ibm,ddw-applicable",
> - _avail[0], 3);
> -
> - win64 = of_find_property(np, DIRECT64_PROPNAME, NULL);
> - if (!win64)
> - return;
> -
> - if (ret || win64->length < sizeof(*dwp))
> - goto delprop;
> + int ret;
>
> - dwp = win64->value;
> + dwp = win->value;
> liobn = (u64)be32_to_cpu(dwp->liobn);
>
> /* clear the whole window, note the arg is in kernel pages */
> @@ -793,24 +782,44 @@ static void remove_ddw(struct device_node *np, bool
> remove_prop)
> 1ULL << (be32_to_cpu(dwp->window_shift) - PAGE_SHIFT), dwp);
> if (ret)
> pr_warn("%pOF failed to clear tces in window.\n",
> - np);
> + pdn);
> else
> pr_debug("%pOF successfully cleared tces in window.\n",
> - np);
> + pdn);
>
> ret = rtas_call(ddw_avail[2], 1, 1, NULL, liobn);
> if (ret)
> pr_warn("%pOF: failed to remove direct window: rtas returned "
> "%d to ibm,remove-pe-dma-window(%x) %llx\n",
> - np, ret, ddw_avail[2], liobn);
> + pdn, ret, ddw_avail[2], liobn);
> else
> pr_debug("%pOF: successfully removed direct window: rtas
> returned "
> "%d to ibm,remove-pe-dma-window(%x) %llx\n",
> - np, ret, ddw_avail[2], liobn);
> + pdn, ret, ddw_avail[2], liobn);
> +}
> +
> +static void remove_ddw(struct device_node *np, bool remove_prop)
> +{
> + struct property *win;
> + u32 ddw_avail[3];
> + int ret = 0;
> +
> + ret = of_property_read_u32_array(np, "ibm,ddw-applicable",
> + _avail[0], 3);
> + if (ret)
> + return;
> +
> + win = of_find_property(np, DIRECT64_PROPNAME, NULL);
> + if (!win)
> + return;
> +
> + if (win->length >= sizeof(struct dynamic_dma_window_prop))
Any good reason not to make it "=="? Is there something optional or we
expect extension (which may not grow from the end but may add cells in
between). Thanks,
> + remove_dma_window(np, ddw_avail, win);
> +
> + if (!remove_prop)
> + return;
>
> -delprop:
> - if (remove_prop)
> - ret = of_remove_property(np, win64);
> + ret = of_remove_property(np, win);
> if (ret)
> pr_warn("%pOF: failed to remove direct window property: %d\n",
> np, ret);
>
--
Alexey
