Subject: Re: [PATCH v8 22/45] powerpc/powernv/ioda1: Support releasing IODA1 TCE table

From: Alexey Kardashevskiy <[email-masked]>
Date: Wed, 20 Apr 2016 13:17:01 +1000

On 04/20/2016 11:15 AM, Gavin Shan wrote:
> On Tue, Apr 19, 2016 at 02:28:51PM +1000, Alexey Kardashevskiy wrote:
>> On 02/17/2016 02:44 PM, Gavin Shan wrote:
>>> pnv_pci_ioda_table_free_pages() can be reused to release the IODA1
>>> TCE table when releasing IODA1 PE in subsequent patches.
>>>
>>> This renames the following functions to support releasing IODA1 TCE
>>> table: pnv_pci_ioda2_table_free_pages() to pnv_pci_ioda_table_free_pages(),
>>> pnv_pci_ioda2_table_do_free_pages() to pnv_pci_ioda_table_do_free_pages().
>>> No logical changes introduced.
>>
>> I can only see renaming here but it seems (from
>> IODA_architecture_04-14-2008.pdf) that IODA1 does not support multi-level TCE
>> tables in the way IODA2 does.
>>
>
> Note that the change was proposed by you in last round.

Hm. I do not recall proposing exactly that :-/

> Yes, TVE on P7IOC
> doesn't support multiple levels of TCE tables.

I thought it supports 2 levels.

> In this case, we will always
> have "tbl->it_indirect_levels" to 1, right?

Nope, it will be 0. But it is still ugly to use release function but not to 
use its allocating counterpart which is pnv_pci_ioda2_table_alloc_pages().

I suggest having pnv_pci_ioda1_table_free_pages() which will be just a 
single free_pages() call. If you need some ioda*-common code to free a 
table, then define pnv_ioda1_iommu_ops::free().

>
>>>
>>> Signed-off-by: Gavin Shan <[email-masked]>
>>> ---
>>>   arch/powerpc/platforms/powernv/pci-ioda.c | 18 +++++++++---------
>>>   1 file changed, 9 insertions(+), 9 deletions(-)
>>>
>>> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>>> index d360607..077f9db 100644
>>> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
>>> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>>> @@ -51,7 +51,7 @@
>>>   #define POWERNV_IOMMU_DEFAULT_LEVELS	1
>>>   #define POWERNV_IOMMU_MAX_LEVELS	5
>>>
>>> -static void pnv_pci_ioda2_table_free_pages(struct iommu_table *tbl);
>>> +static void pnv_pci_ioda_table_free_pages(struct iommu_table *tbl);
>>>
>>>   static void pe_level_printk(const struct pnv_ioda_pe *pe, const char *level,
>>>   			    const char *fmt, ...)
>>> @@ -1352,7 +1352,7 @@ static void pnv_pci_ioda2_release_dma_pe(struct pci_dev *dev, struct pnv_ioda_pe
>>>   		iommu_group_put(pe->table_group.group);
>>>   		BUG_ON(pe->table_group.group);
>>>   	}
>>> -	pnv_pci_ioda2_table_free_pages(tbl);
>>> +	pnv_pci_ioda_table_free_pages(tbl);
>>>   	iommu_free_table(tbl, of_node_full_name(dev->dev.of_node));
>>>   }
>>>
>>> @@ -1946,7 +1946,7 @@ static void pnv_ioda2_tce_free(struct iommu_table *tbl, long index,
>>>
>>>   static void pnv_ioda2_table_free(struct iommu_table *tbl)
>>>   {
>>> -	pnv_pci_ioda2_table_free_pages(tbl);
>>> +	pnv_pci_ioda_table_free_pages(tbl);
>>>   	iommu_free_table(tbl, "pnv");
>>>   }
>>>
>>> @@ -2448,7 +2448,7 @@ static __be64 *pnv_pci_ioda2_table_do_alloc_pages(int nid, unsigned shift,
>>>   	return addr;
>>>   }
>>>
>>> -static void pnv_pci_ioda2_table_do_free_pages(__be64 *addr,
>>> +static void pnv_pci_ioda_table_do_free_pages(__be64 *addr,
>>>   		unsigned long size, unsigned level);
>>>
>>>   static long pnv_pci_ioda2_table_alloc_pages(int nid, __u64 bus_offset,
>>> @@ -2487,7 +2487,7 @@ static long pnv_pci_ioda2_table_alloc_pages(int nid, __u64 bus_offset,
>>>   	 * release partially allocated table.
>>>   	 */
>>>   	if (offset < tce_table_size) {
>>> -		pnv_pci_ioda2_table_do_free_pages(addr,
>>> +		pnv_pci_ioda_table_do_free_pages(addr,
>>>   				1ULL << (level_shift - 3), levels - 1);
>>>   		return -ENOMEM;
>>>   	}
>>> @@ -2505,7 +2505,7 @@ static long pnv_pci_ioda2_table_alloc_pages(int nid, __u64 bus_offset,
>>>   	return 0;
>>>   }
>>>
>>> -static void pnv_pci_ioda2_table_do_free_pages(__be64 *addr,
>>> +static void pnv_pci_ioda_table_do_free_pages(__be64 *addr,
>>>   		unsigned long size, unsigned level)
>>>   {
>>>   	const unsigned long addr_ul = (unsigned long) addr &
>>> @@ -2521,7 +2521,7 @@ static void pnv_pci_ioda2_table_do_free_pages(__be64 *addr,
>>>   			if (!(hpa & (TCE_PCI_READ | TCE_PCI_WRITE)))
>>>   				continue;
>>>
>>> -			pnv_pci_ioda2_table_do_free_pages(__va(hpa), size,
>>> +			pnv_pci_ioda_table_do_free_pages(__va(hpa), size,
>>>   					level - 1);
>>>   		}
>>>   	}
>>> @@ -2529,7 +2529,7 @@ static void pnv_pci_ioda2_table_do_free_pages(__be64 *addr,
>>>   	free_pages(addr_ul, get_order(size << 3));
>>>   }
>>>
>>> -static void pnv_pci_ioda2_table_free_pages(struct iommu_table *tbl)
>>> +static void pnv_pci_ioda_table_free_pages(struct iommu_table *tbl)
>>>   {
>>>   	const unsigned long size = tbl->it_indirect_levels ?
>>>   			tbl->it_level_size : tbl->it_size;
>>> @@ -2537,7 +2537,7 @@ static void pnv_pci_ioda2_table_free_pages(struct iommu_table *tbl)
>>>   	if (!tbl->it_size)
>>>   		return;
>>>
>>> -	pnv_pci_ioda2_table_do_free_pages((__be64 *)tbl->it_base, size,
>>> +	pnv_pci_ioda_table_do_free_pages((__be64 *)tbl->it_base, size,
>>>   			tbl->it_indirect_levels);
>>>   }
>>>
>>>
>>
>>
>> --
>> Alexey
>>
>

-- 
Alexey