Re: [PATCH v1 07/10] powerpc/pseries/iommu: Allow DDW windows starting at 0x00
On 29/08/2020 00:04, Leonardo Bras wrote:
> On Mon, 2020-08-24 at 13:44 +1000, Alexey Kardashevskiy wrote:
>>
>>> On 18/08/2020 09:40, Leonardo Bras wrote:
>>> enable_ddw() currently returns the address of the DMA window, which is
>>> considered invalid if has the value 0x00.
>>>
>>> Also, it only considers valid an address returned from find_existing_ddw
>>> if it's not 0x00.
>>>
>>> Changing this behavior makes sense, given the users of enable_ddw() only
>>> need to know if direct mapping is possible. It can also allow a DMA window
>>> starting at 0x00 to be used.
>>>
>>> This will be helpful for using a DDW with indirect mapping, as the window
>>> address will be different than 0x00, but it will not map the whole
>>> partition.
>>>
>>> Signed-off-by: Leonardo Bras
>>> ---
>>> arch/powerpc/platforms/pseries/iommu.c | 30 --
>>> 1 file changed, 14 insertions(+), 16 deletions(-)
>>>
>>> diff --git a/arch/powerpc/platforms/pseries/iommu.c
>>> b/arch/powerpc/platforms/pseries/iommu.c
>>> index fcdefcc0f365..4031127c9537 100644
>>> --- a/arch/powerpc/platforms/pseries/iommu.c
>>> +++ b/arch/powerpc/platforms/pseries/iommu.c
>>> @@ -852,24 +852,25 @@ static void remove_ddw(struct device_node *np, bool
>>> remove_prop)
>>> np, ret);
>>> }
>>> -static u64 find_existing_ddw(struct device_node *pdn)
>>> +static bool find_existing_ddw(struct device_node *pdn, u64 *dma_addr)
>>> {
>>> struct direct_window *window;
>>> const struct dynamic_dma_window_prop *direct64;
>>> - u64 dma_addr = 0;
>>> + bool found = false;
>>>
>>> spin_lock(_window_list_lock);
>>> /* check if we already created a window and dupe that config if so */
>>> list_for_each_entry(window, _window_list, list) {
>>> if (window->device == pdn) {
>>> direct64 = window->prop;
>>> - dma_addr = be64_to_cpu(direct64->dma_base);
>>> + *dma_addr = be64_to_cpu(direct64->dma_base);
>>> + found = true;
>>> break;
>>> }
>>> }
>>> spin_unlock(_window_list_lock);
>>>
>>> - return dma_addr;
>>> + return found;
>>> }
>>>
>>> static struct direct_window *ddw_list_add(struct device_node *pdn,
>>> @@ -1131,15 +1132,15 @@ static void reset_dma_window(struct pci_dev *dev,
>>> struct device_node *par_dn)
>>> * pdn: the parent pe node with the ibm,dma_window property
>>> * Future: also check if we can remap the base window for our base page
>>> size
>>> *
>>> - * returns the dma offset for use by the direct mapped DMA code.
>>> + * returns true if can map all pages (direct mapping), false otherwise..
>>> */
>>> -static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
>>> +static bool enable_ddw(struct pci_dev *dev, struct device_node *pdn)
>>> {
>>> int len, ret;
>>> struct ddw_query_response query;
>>> struct ddw_create_response create;
>>> int page_shift;
>>> - u64 dma_addr, max_addr;
>>> + u64 max_addr;
>>> struct device_node *dn;
>>> u32 ddw_avail[DDW_APPLICABLE_SIZE];
>>> struct direct_window *window;
>>> @@ -1150,8 +1151,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct
>>> device_node *pdn)
>>>
>>> mutex_lock(_window_init_mutex);
>>>
>>> - dma_addr = find_existing_ddw(pdn);
>>> - if (dma_addr != 0)
>>> + if (find_existing_ddw(pdn, >dev.archdata.dma_offset))
>>> goto out_unlock;
>>>
>>> /*
>>> @@ -1292,7 +1292,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct
>>> device_node *pdn)
>>> goto out_free_window;
>>> }
>>>
>>> - dma_addr = be64_to_cpu(ddwprop->dma_base);
>>> + dev->dev.archdata.dma_offset = be64_to_cpu(ddwprop->dma_base);
>>
>> Do not you need the same chunk in the find_existing_ddw() case above as
>> well? Thanks,
>
> The new signature of find_existing_ddw() is
> static bool find_existing_ddw(struct device_node *pdn, u64 *dma_addr)
>
> And on enable_ddw(), we call
> find_existing_ddw(pdn, >dev.archdata.dma_offset)
>
> And inside the function we do:
> *dma_addr = be64_to_cpu(direct64->dma_base);
>
> I think it's the same as the chunk before.
> Am I missing something?
ah no, sorry, you are not missing anything.
Reviewed-by: Alexey Kardashevskiy
--
Alexey
Re: [PATCH v1 07/10] powerpc/pseries/iommu: Allow DDW windows starting at 0x00
On Mon, 2020-08-24 at 13:44 +1000, Alexey Kardashevskiy wrote:
>
> > On 18/08/2020 09:40, Leonardo Bras wrote:
> > enable_ddw() currently returns the address of the DMA window, which is
> > considered invalid if has the value 0x00.
> >
> > Also, it only considers valid an address returned from find_existing_ddw
> > if it's not 0x00.
> >
> > Changing this behavior makes sense, given the users of enable_ddw() only
> > need to know if direct mapping is possible. It can also allow a DMA window
> > starting at 0x00 to be used.
> >
> > This will be helpful for using a DDW with indirect mapping, as the window
> > address will be different than 0x00, but it will not map the whole
> > partition.
> >
> > Signed-off-by: Leonardo Bras
> > ---
> > arch/powerpc/platforms/pseries/iommu.c | 30 --
> > 1 file changed, 14 insertions(+), 16 deletions(-)
> >
> > diff --git a/arch/powerpc/platforms/pseries/iommu.c
> > b/arch/powerpc/platforms/pseries/iommu.c
> > index fcdefcc0f365..4031127c9537 100644
> > --- a/arch/powerpc/platforms/pseries/iommu.c
> > +++ b/arch/powerpc/platforms/pseries/iommu.c
> > @@ -852,24 +852,25 @@ static void remove_ddw(struct device_node *np, bool
> > remove_prop)
> > np, ret);
> > }
> > >
> > -static u64 find_existing_ddw(struct device_node *pdn)
> > +static bool find_existing_ddw(struct device_node *pdn, u64 *dma_addr)
> > {
> > struct direct_window *window;
> > const struct dynamic_dma_window_prop *direct64;
> > - u64 dma_addr = 0;
> > + bool found = false;
> >
> > spin_lock(_window_list_lock);
> > /* check if we already created a window and dupe that config if so */
> > list_for_each_entry(window, _window_list, list) {
> > if (window->device == pdn) {
> > direct64 = window->prop;
> > - dma_addr = be64_to_cpu(direct64->dma_base);
> > + *dma_addr = be64_to_cpu(direct64->dma_base);
> > + found = true;
> > break;
> > }
> > }
> > spin_unlock(_window_list_lock);
> >
> > - return dma_addr;
> > + return found;
> > }
> >
> > static struct direct_window *ddw_list_add(struct device_node *pdn,
> > @@ -1131,15 +1132,15 @@ static void reset_dma_window(struct pci_dev *dev,
> > struct device_node *par_dn)
> > * pdn: the parent pe node with the ibm,dma_window property
> > * Future: also check if we can remap the base window for our base page
> > size
> > *
> > - * returns the dma offset for use by the direct mapped DMA code.
> > + * returns true if can map all pages (direct mapping), false otherwise..
> > */
> > -static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
> > +static bool enable_ddw(struct pci_dev *dev, struct device_node *pdn)
> > {
> > int len, ret;
> > struct ddw_query_response query;
> > struct ddw_create_response create;
> > int page_shift;
> > - u64 dma_addr, max_addr;
> > + u64 max_addr;
> > struct device_node *dn;
> > u32 ddw_avail[DDW_APPLICABLE_SIZE];
> > struct direct_window *window;
> > @@ -1150,8 +1151,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct
> > device_node *pdn)
> >
> > mutex_lock(_window_init_mutex);
> >
> > - dma_addr = find_existing_ddw(pdn);
> > - if (dma_addr != 0)
> > + if (find_existing_ddw(pdn, >dev.archdata.dma_offset))
> > goto out_unlock;
> >
> > /*
> > @@ -1292,7 +1292,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct
> > device_node *pdn)
> > goto out_free_window;
> > }
> >
> > - dma_addr = be64_to_cpu(ddwprop->dma_base);
> > + dev->dev.archdata.dma_offset = be64_to_cpu(ddwprop->dma_base);
>
> Do not you need the same chunk in the find_existing_ddw() case above as
> well? Thanks,
The new signature of find_existing_ddw() is
static bool find_existing_ddw(struct device_node *pdn, u64 *dma_addr)
And on enable_ddw(), we call
find_existing_ddw(pdn, >dev.archdata.dma_offset)
And inside the function we do:
*dma_addr = be64_to_cpu(direct64->dma_base);
I think it's the same as the chunk before.
Am I missing something?
>
>
> > goto out_unlock;
> >
> > out_free_window:
> > @@ -1309,6 +1309,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct
> > device_node *pdn)
> > kfree(win64->name);
> > kfree(win64->value);
> > kfree(win64);
> > + win64 = NULL;
> >
> > out_failed:
> > if (default_win_removed)
> > @@ -1322,7 +1323,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct
> > device_node *pdn)
> >
> > out_unlock:
> > mutex_unlock(_window_init_mutex);
> > - return dma_addr;
> > + return win64;
> > }
> >
> > static void pci_dma_dev_setup_pSeriesLP(struct pci_dev *dev)
> > @@ -1401,11 +1402,8 @@ static bool iommu_bypass_supported_pSeriesLP(struct
> > pci_dev *pdev, u64 dma_mask)
> > break;
> > }
> >
> > - if (pdn && PCI_DN(pdn)) {
> > -
Re: [PATCH v1 07/10] powerpc/pseries/iommu: Allow DDW windows starting at 0x00
On 18/08/2020 09:40, Leonardo Bras wrote:
> enable_ddw() currently returns the address of the DMA window, which is
> considered invalid if has the value 0x00.
>
> Also, it only considers valid an address returned from find_existing_ddw
> if it's not 0x00.
>
> Changing this behavior makes sense, given the users of enable_ddw() only
> need to know if direct mapping is possible. It can also allow a DMA window
> starting at 0x00 to be used.
>
> This will be helpful for using a DDW with indirect mapping, as the window
> address will be different than 0x00, but it will not map the whole
> partition.
>
> Signed-off-by: Leonardo Bras
> ---
> arch/powerpc/platforms/pseries/iommu.c | 30 --
> 1 file changed, 14 insertions(+), 16 deletions(-)
>
> diff --git a/arch/powerpc/platforms/pseries/iommu.c
> b/arch/powerpc/platforms/pseries/iommu.c
> index fcdefcc0f365..4031127c9537 100644
> --- a/arch/powerpc/platforms/pseries/iommu.c
> +++ b/arch/powerpc/platforms/pseries/iommu.c
> @@ -852,24 +852,25 @@ static void remove_ddw(struct device_node *np, bool
> remove_prop)
> np, ret);
> }
>
> -static u64 find_existing_ddw(struct device_node *pdn)
> +static bool find_existing_ddw(struct device_node *pdn, u64 *dma_addr)
> {
> struct direct_window *window;
> const struct dynamic_dma_window_prop *direct64;
> - u64 dma_addr = 0;
> + bool found = false;
>
> spin_lock(_window_list_lock);
> /* check if we already created a window and dupe that config if so */
> list_for_each_entry(window, _window_list, list) {
> if (window->device == pdn) {
> direct64 = window->prop;
> - dma_addr = be64_to_cpu(direct64->dma_base);
> + *dma_addr = be64_to_cpu(direct64->dma_base);
> + found = true;
> break;
> }
> }
> spin_unlock(_window_list_lock);
>
> - return dma_addr;
> + return found;
> }
>
> static struct direct_window *ddw_list_add(struct device_node *pdn,
> @@ -1131,15 +1132,15 @@ static void reset_dma_window(struct pci_dev *dev,
> struct device_node *par_dn)
> * pdn: the parent pe node with the ibm,dma_window property
> * Future: also check if we can remap the base window for our base page size
> *
> - * returns the dma offset for use by the direct mapped DMA code.
> + * returns true if can map all pages (direct mapping), false otherwise..
> */
> -static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
> +static bool enable_ddw(struct pci_dev *dev, struct device_node *pdn)
> {
> int len, ret;
> struct ddw_query_response query;
> struct ddw_create_response create;
> int page_shift;
> - u64 dma_addr, max_addr;
> + u64 max_addr;
> struct device_node *dn;
> u32 ddw_avail[DDW_APPLICABLE_SIZE];
> struct direct_window *window;
> @@ -1150,8 +1151,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct
> device_node *pdn)
>
> mutex_lock(_window_init_mutex);
>
> - dma_addr = find_existing_ddw(pdn);
> - if (dma_addr != 0)
> + if (find_existing_ddw(pdn, >dev.archdata.dma_offset))
> goto out_unlock;
>
> /*
> @@ -1292,7 +1292,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct
> device_node *pdn)
> goto out_free_window;
> }
>
> - dma_addr = be64_to_cpu(ddwprop->dma_base);
> + dev->dev.archdata.dma_offset = be64_to_cpu(ddwprop->dma_base);
Do not you need the same chunk in the find_existing_ddw() case above as
well? Thanks,
> goto out_unlock;
>
> out_free_window:
> @@ -1309,6 +1309,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct
> device_node *pdn)
> kfree(win64->name);
> kfree(win64->value);
> kfree(win64);
> + win64 = NULL;
>
> out_failed:
> if (default_win_removed)
> @@ -1322,7 +1323,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct
> device_node *pdn)
>
> out_unlock:
> mutex_unlock(_window_init_mutex);
> - return dma_addr;
> + return win64;
> }
>
> static void pci_dma_dev_setup_pSeriesLP(struct pci_dev *dev)
> @@ -1401,11 +1402,8 @@ static bool iommu_bypass_supported_pSeriesLP(struct
> pci_dev *pdev, u64 dma_mask)
> break;
> }
>
> - if (pdn && PCI_DN(pdn)) {
> - pdev->dev.archdata.dma_offset = enable_ddw(pdev, pdn);
> - if (pdev->dev.archdata.dma_offset)
> - return true;
> - }
> + if (pdn && PCI_DN(pdn))
> + return enable_ddw(pdev, pdn);
>
> return false;
> }
>
--
Alexey
[PATCH v1 07/10] powerpc/pseries/iommu: Allow DDW windows starting at 0x00
enable_ddw() currently returns the address of the DMA window, which is
considered invalid if has the value 0x00.
Also, it only considers valid an address returned from find_existing_ddw
if it's not 0x00.
Changing this behavior makes sense, given the users of enable_ddw() only
need to know if direct mapping is possible. It can also allow a DMA window
starting at 0x00 to be used.
This will be helpful for using a DDW with indirect mapping, as the window
address will be different than 0x00, but it will not map the whole
partition.
Signed-off-by: Leonardo Bras
---
arch/powerpc/platforms/pseries/iommu.c | 30 --
1 file changed, 14 insertions(+), 16 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/iommu.c
b/arch/powerpc/platforms/pseries/iommu.c
index fcdefcc0f365..4031127c9537 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -852,24 +852,25 @@ static void remove_ddw(struct device_node *np, bool
remove_prop)
np, ret);
}
-static u64 find_existing_ddw(struct device_node *pdn)
+static bool find_existing_ddw(struct device_node *pdn, u64 *dma_addr)
{
struct direct_window *window;
const struct dynamic_dma_window_prop *direct64;
- u64 dma_addr = 0;
+ bool found = false;
spin_lock(_window_list_lock);
/* check if we already created a window and dupe that config if so */
list_for_each_entry(window, _window_list, list) {
if (window->device == pdn) {
direct64 = window->prop;
- dma_addr = be64_to_cpu(direct64->dma_base);
+ *dma_addr = be64_to_cpu(direct64->dma_base);
+ found = true;
break;
}
}
spin_unlock(_window_list_lock);
- return dma_addr;
+ return found;
}
static struct direct_window *ddw_list_add(struct device_node *pdn,
@@ -1131,15 +1132,15 @@ static void reset_dma_window(struct pci_dev *dev,
struct device_node *par_dn)
* pdn: the parent pe node with the ibm,dma_window property
* Future: also check if we can remap the base window for our base page size
*
- * returns the dma offset for use by the direct mapped DMA code.
+ * returns true if can map all pages (direct mapping), false otherwise..
*/
-static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
+static bool enable_ddw(struct pci_dev *dev, struct device_node *pdn)
{
int len, ret;
struct ddw_query_response query;
struct ddw_create_response create;
int page_shift;
- u64 dma_addr, max_addr;
+ u64 max_addr;
struct device_node *dn;
u32 ddw_avail[DDW_APPLICABLE_SIZE];
struct direct_window *window;
@@ -1150,8 +1151,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct
device_node *pdn)
mutex_lock(_window_init_mutex);
- dma_addr = find_existing_ddw(pdn);
- if (dma_addr != 0)
+ if (find_existing_ddw(pdn, >dev.archdata.dma_offset))
goto out_unlock;
/*
@@ -1292,7 +1292,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct
device_node *pdn)
goto out_free_window;
}
- dma_addr = be64_to_cpu(ddwprop->dma_base);
+ dev->dev.archdata.dma_offset = be64_to_cpu(ddwprop->dma_base);
goto out_unlock;
out_free_window:
@@ -1309,6 +1309,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct
device_node *pdn)
kfree(win64->name);
kfree(win64->value);
kfree(win64);
+ win64 = NULL;
out_failed:
if (default_win_removed)
@@ -1322,7 +1323,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct
device_node *pdn)
out_unlock:
mutex_unlock(_window_init_mutex);
- return dma_addr;
+ return win64;
}
static void pci_dma_dev_setup_pSeriesLP(struct pci_dev *dev)
@@ -1401,11 +1402,8 @@ static bool iommu_bypass_supported_pSeriesLP(struct
pci_dev *pdev, u64 dma_mask)
break;
}
- if (pdn && PCI_DN(pdn)) {
- pdev->dev.archdata.dma_offset = enable_ddw(pdev, pdn);
- if (pdev->dev.archdata.dma_offset)
- return true;
- }
+ if (pdn && PCI_DN(pdn))
+ return enable_ddw(pdev, pdn);
return false;
}
--
2.25.4
