Re: [PATCH v2 1/6] powerpc/pseries/iommu: Create defines for operations in ibm,ddw-applicable

2020-07-01 Thread Leonardo Bras
On Thu, 2020-07-02 at 10:43 +1000, Alexey Kardashevskiy wrote:
> > Or should one stick to #define in this case?
> 
> imho a matter of taste but after some grepping it feels like #define is
> mostly used which does not mean it is a good idea. Keep it enum and see
> if it passed mpe's filter :)

Good idea :)

Thanks !



Re: [PATCH v2 1/6] powerpc/pseries/iommu: Create defines for operations in ibm,ddw-applicable

2020-07-01 Thread Alexey Kardashevskiy



On 02/07/2020 10:36, Leonardo Bras wrote:
> On Thu, 2020-07-02 at 10:21 +1000, Alexey Kardashevskiy wrote:
>>> enum {
>>>DDW_QUERY_PE_DMA_WIN,
>>>DDW_CREATE_PE_DMA_WIN,
>>>DDW_REMOVE_PE_DMA_WIN,
>>>
>>>DDW_APPLICABLE_SIZE
>>> }
>>> IMO, it looks better than all the defines before.
>>>
>>> What do you think?
>>
>> No, not really, these come from a binary interface so the reader of this
>> cares about absolute numbers and rather wants to see them explicitly.
> 
> Makes sense to me.
> I am still getting experience on where to use enum vs define. Thanks
> for the tip!
> 
> Using something like 
> enum {
>   DDW_QUERY_PE_DMA_WIN = 0,
>   DDW_CREATE_PE_DMA_WIN = 1,
>   DDW_REMOVE_PE_DMA_WIN = 2,
> 
>   DDW_APPLICABLE_SIZE
> };
> 
> would be fine too?


This is fine too.


> Or should one stick to #define in this case?

imho a matter of taste but after some grepping it feels like #define is
mostly used which does not mean it is a good idea. Keep it enum and see
if it passed mpe's filter :)



-- 
Alexey


Re: [PATCH v2 1/6] powerpc/pseries/iommu: Create defines for operations in ibm,ddw-applicable

2020-07-01 Thread Leonardo Bras
On Thu, 2020-07-02 at 10:21 +1000, Alexey Kardashevskiy wrote:
> > enum {
> >DDW_QUERY_PE_DMA_WIN,
> >DDW_CREATE_PE_DMA_WIN,
> >DDW_REMOVE_PE_DMA_WIN,
> > 
> >DDW_APPLICABLE_SIZE
> > }
> > IMO, it looks better than all the defines before.
> > 
> > What do you think?
> 
> No, not really, these come from a binary interface so the reader of this
> cares about absolute numbers and rather wants to see them explicitly.

Makes sense to me.
I am still getting experience on where to use enum vs define. Thanks
for the tip!

Using something like 
enum {
DDW_QUERY_PE_DMA_WIN = 0,
DDW_CREATE_PE_DMA_WIN = 1,
DDW_REMOVE_PE_DMA_WIN = 2,

DDW_APPLICABLE_SIZE
};

would be fine too?
Or should one stick to #define in this case?

Thank you,



Re: [PATCH v2 1/6] powerpc/pseries/iommu: Create defines for operations in ibm,ddw-applicable

2020-07-01 Thread Alexey Kardashevskiy



On 01/07/2020 23:28, Leonardo Bras wrote:
> On Wed, 2020-07-01 at 18:16 +1000, Alexey Kardashevskiy wrote:
>>
>> On 24/06/2020 16:24, Leonardo Bras wrote:
>>> Create defines to help handling ibm,ddw-applicable values, avoiding
>>> confusion about the index of given operations.
>>>
>>> Signed-off-by: Leonardo Bras 
>>> ---
>>>  arch/powerpc/platforms/pseries/iommu.c | 40 +++---
>>>  1 file changed, 23 insertions(+), 17 deletions(-)
>>>
>>> diff --git a/arch/powerpc/platforms/pseries/iommu.c 
>>> b/arch/powerpc/platforms/pseries/iommu.c
>>> index 6d47b4a3ce39..68d2aa9c71a8 100644
>>> --- a/arch/powerpc/platforms/pseries/iommu.c
>>> +++ b/arch/powerpc/platforms/pseries/iommu.c
>>> @@ -39,6 +39,11 @@
>>>  
>>>  #include "pseries.h"
>>>  
>>> +#define DDW_QUERY_PE_DMA_WIN   0
>>> +#define DDW_CREATE_PE_DMA_WIN  1
>>> +#define DDW_REMOVE_PE_DMA_WIN  2
>>> +#define DDW_APPLICABLE_SIZE3
>>
>> #define DDW_APPLICABLE_SIZE  (DDW_REMOVE_PE_DMA_WIN + 1)
>>
>> thanks,
> 
> Thanks for the feedback!
> About this (and patch #2), would it be better to use enum ?
> enum {
>   DDW_QUERY_PE_DMA_WIN,
>   DDW_CREATE_PE_DMA_WIN,
>   DDW_REMOVE_PE_DMA_WIN,
> 
>   DDW_APPLICABLE_SIZE
> }
> IMO, it looks better than all the defines before.
> 
> What do you think?

No, not really, these come from a binary interface so the reader of this
cares about absolute numbers and rather wants to see them explicitly.


-- 
Alexey


Re: [PATCH v2 1/6] powerpc/pseries/iommu: Create defines for operations in ibm,ddw-applicable

2020-07-01 Thread Leonardo Bras
On Wed, 2020-07-01 at 18:16 +1000, Alexey Kardashevskiy wrote:
> 
> On 24/06/2020 16:24, Leonardo Bras wrote:
> > Create defines to help handling ibm,ddw-applicable values, avoiding
> > confusion about the index of given operations.
> > 
> > Signed-off-by: Leonardo Bras 
> > ---
> >  arch/powerpc/platforms/pseries/iommu.c | 40 +++---
> >  1 file changed, 23 insertions(+), 17 deletions(-)
> > 
> > diff --git a/arch/powerpc/platforms/pseries/iommu.c 
> > b/arch/powerpc/platforms/pseries/iommu.c
> > index 6d47b4a3ce39..68d2aa9c71a8 100644
> > --- a/arch/powerpc/platforms/pseries/iommu.c
> > +++ b/arch/powerpc/platforms/pseries/iommu.c
> > @@ -39,6 +39,11 @@
> >  
> >  #include "pseries.h"
> >  
> > +#define DDW_QUERY_PE_DMA_WIN   0
> > +#define DDW_CREATE_PE_DMA_WIN  1
> > +#define DDW_REMOVE_PE_DMA_WIN  2
> > +#define DDW_APPLICABLE_SIZE3
> 
> #define DDW_APPLICABLE_SIZE  (DDW_REMOVE_PE_DMA_WIN + 1)
> 
> thanks,

Thanks for the feedback!
About this (and patch #2), would it be better to use enum ?
enum {
DDW_QUERY_PE_DMA_WIN,
DDW_CREATE_PE_DMA_WIN,
DDW_REMOVE_PE_DMA_WIN,

DDW_APPLICABLE_SIZE
}
IMO, it looks better than all the defines before.

What do you think?

Best regards,



Re: [PATCH v2 1/6] powerpc/pseries/iommu: Create defines for operations in ibm,ddw-applicable

2020-07-01 Thread Alexey Kardashevskiy



On 24/06/2020 16:24, Leonardo Bras wrote:
> Create defines to help handling ibm,ddw-applicable values, avoiding
> confusion about the index of given operations.
> 
> Signed-off-by: Leonardo Bras 
> ---
>  arch/powerpc/platforms/pseries/iommu.c | 40 +++---
>  1 file changed, 23 insertions(+), 17 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/pseries/iommu.c 
> b/arch/powerpc/platforms/pseries/iommu.c
> index 6d47b4a3ce39..68d2aa9c71a8 100644
> --- a/arch/powerpc/platforms/pseries/iommu.c
> +++ b/arch/powerpc/platforms/pseries/iommu.c
> @@ -39,6 +39,11 @@
>  
>  #include "pseries.h"
>  
> +#define DDW_QUERY_PE_DMA_WIN 0
> +#define DDW_CREATE_PE_DMA_WIN1
> +#define DDW_REMOVE_PE_DMA_WIN2
> +#define DDW_APPLICABLE_SIZE  3


#define DDW_APPLICABLE_SIZE  (DDW_REMOVE_PE_DMA_WIN + 1)

thanks,


> +
>  static struct iommu_table_group *iommu_pseries_alloc_group(int node)
>  {
>   struct iommu_table_group *table_group;
> @@ -771,12 +776,12 @@ static void remove_ddw(struct device_node *np, bool 
> remove_prop)
>  {
>   struct dynamic_dma_window_prop *dwp;
>   struct property *win64;
> - u32 ddw_avail[3];
> + u32 ddw_avail[DDW_APPLICABLE_SIZE];
>   u64 liobn;
>   int ret = 0;
>  
>   ret = of_property_read_u32_array(np, "ibm,ddw-applicable",
> -  _avail[0], 3);
> +  _avail[0], DDW_APPLICABLE_SIZE);
>  
>   win64 = of_find_property(np, DIRECT64_PROPNAME, NULL);
>   if (!win64)
> @@ -798,15 +803,15 @@ static void remove_ddw(struct device_node *np, bool 
> remove_prop)
>   pr_debug("%pOF successfully cleared tces in window.\n",
>np);
>  
> - ret = rtas_call(ddw_avail[2], 1, 1, NULL, liobn);
> + ret = rtas_call(ddw_avail[DDW_REMOVE_PE_DMA_WIN], 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);
> + np, ret, ddw_avail[DDW_REMOVE_PE_DMA_WIN], 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);
> + np, ret, ddw_avail[DDW_REMOVE_PE_DMA_WIN], liobn);
>  
>  delprop:
>   if (remove_prop)
> @@ -889,11 +894,11 @@ static int query_ddw(struct pci_dev *dev, const u32 
> *ddw_avail,
>   buid = pdn->phb->buid;
>   cfg_addr = ((pdn->busno << 16) | (pdn->devfn << 8));
>  
> - ret = rtas_call(ddw_avail[0], 3, 5, (u32 *)query,
> -   cfg_addr, BUID_HI(buid), BUID_LO(buid));
> + ret = rtas_call(ddw_avail[DDW_QUERY_PE_DMA_WIN], 3, 5, (u32 *)query,
> + cfg_addr, BUID_HI(buid), BUID_LO(buid));
>   dev_info(>dev, "ibm,query-pe-dma-windows(%x) %x %x %x"
> - " returned %d\n", ddw_avail[0], cfg_addr, BUID_HI(buid),
> - BUID_LO(buid), ret);
> + " returned %d\n", ddw_avail[DDW_QUERY_PE_DMA_WIN], cfg_addr,
> +  BUID_HI(buid), BUID_LO(buid), ret);
>   return ret;
>  }
>  
> @@ -920,15 +925,16 @@ static int create_ddw(struct pci_dev *dev, const u32 
> *ddw_avail,
>  
>   do {
>   /* extra outputs are LIOBN and dma-addr (hi, lo) */
> - ret = rtas_call(ddw_avail[1], 5, 4, (u32 *)create,
> - cfg_addr, BUID_HI(buid), BUID_LO(buid),
> - page_shift, window_shift);
> + ret = rtas_call(ddw_avail[DDW_CREATE_PE_DMA_WIN], 5, 4,
> + (u32 *)create, cfg_addr, BUID_HI(buid),
> + BUID_LO(buid), page_shift, window_shift);
>   } while (rtas_busy_delay(ret));
>   dev_info(>dev,
>   "ibm,create-pe-dma-window(%x) %x %x %x %x %x returned %d "
> - "(liobn = 0x%x starting addr = %x %x)\n", ddw_avail[1],
> -  cfg_addr, BUID_HI(buid), BUID_LO(buid), page_shift,
> -  window_shift, ret, create->liobn, create->addr_hi, 
> create->addr_lo);
> + "(liobn = 0x%x starting addr = %x %x)\n",
> +  ddw_avail[DDW_CREATE_PE_DMA_WIN], cfg_addr, BUID_HI(buid),
> +  BUID_LO(buid), page_shift, window_shift, ret, create->liobn,
> +  create->addr_hi, create->addr_lo);
>  
>   return ret;
>  }
> @@ -996,7 +1002,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct 
> device_node *pdn)
>   int page_shift;
>   u64 dma_addr, max_addr;
>   struct device_node *dn;
> - u32 ddw_avail[3];
> + u32 ddw_avail[DDW_APPLICABLE_SIZE];
>   struct direct_window *window;
>   struct property *win64;
>   struct dynamic_dma_window_prop *ddwprop;
> @@ -1029,7 +1035,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct 
>