Alexey Kardashevskiy <[email protected]> writes:
> diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
> index e4198700ed1a..91112e748491 100644
> --- a/arch/powerpc/platforms/pseries/iommu.c
> +++ b/arch/powerpc/platforms/pseries/iommu.c
> @@ -1111,11 +1112,13 @@ static void reset_dma_window(struct pci_dev *dev, struct device_node *par_dn)
> */
> static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
> {
> - int len, ret;
> + int len = 0, ret;
> + bool pmem_present = of_find_node_by_type(NULL, "ibm,pmemory") != NULL;
That leaks a reference on the returned node.
dn = of_find_node_by_type(NULL, "ibm,pmemory");
pmem_present = dn != NULL;
of_node_put(dn);
> @@ -1126,7 +1129,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
>
> mutex_lock(&direct_window_init_mutex);
>
> - dma_addr = find_existing_ddw(pdn);
> + dma_addr = find_existing_ddw(pdn, &len);
I don't see len used anywhere?
> if (dma_addr != 0)
> goto out_unlock;
>
> @@ -1212,14 +1215,26 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
> }
> /* verify the window * number of ptes will map the partition */
> /* check largest block * page size > max memory hotplug addr */
> - max_addr = ddw_memory_hotplug_max();
> - if (query.largest_available_block < (max_addr >> page_shift)) {
> - dev_dbg(&dev->dev, "can't map partition max 0x%llx with %llu "
> - "%llu-sized pages\n", max_addr, query.largest_available_block,
> - 1ULL << page_shift);
> + /*
> + * The "ibm,pmemory" can appear anywhere in the address space.
> + * Assuming it is still backed by page structs, try MAX_PHYSMEM_BITS
> + * for the upper limit and fallback to max RAM otherwise but this
> + * disables device::dma_ops_bypass.
> + */
> + len = max_ram_len;
Here you override whatever find_existing_ddw() wrote to len?
> + if (pmem_present) {
> + if (query.largest_available_block >=
> + (1ULL << (MAX_PHYSMEM_BITS - page_shift)))
> + len = MAX_PHYSMEM_BITS - page_shift;
> + else
> + dev_info(&dev->dev, "Skipping ibm,pmemory");
> + }
> +
> + if (query.largest_available_block < (1ULL << (len - page_shift))) {
> + dev_dbg(&dev->dev, "can't map partition max 0x%llx with %llu %llu-sized pages\n",
> + 1ULL << len, query.largest_available_block, 1ULL << page_shift);
> goto out_failed;
> }
> - len = order_base_2(max_addr);
> win64 = kzalloc(sizeof(struct property), GFP_KERNEL);
> if (!win64) {
> dev_info(&dev->dev,
cheers
On 29/10/2020 11:40, Michael Ellerman wrote:
> Alexey Kardashevskiy <[email protected]> writes:
>> diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
>> index e4198700ed1a..91112e748491 100644
>> --- a/arch/powerpc/platforms/pseries/iommu.c
>> +++ b/arch/powerpc/platforms/pseries/iommu.c
>> @@ -1111,11 +1112,13 @@ static void reset_dma_window(struct pci_dev *dev, struct device_node *par_dn)
>> */
>> static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
>> {
>> - int len, ret;
>> + int len = 0, ret;
>> + bool pmem_present = of_find_node_by_type(NULL, "ibm,pmemory") != NULL;
>
> That leaks a reference on the returned node.
>
> dn = of_find_node_by_type(NULL, "ibm,pmemory");
> pmem_present = dn != NULL;
> of_node_put(dn);
ah, true. v4 then.
>
>
>> @@ -1126,7 +1129,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
>>
>> mutex_lock(&direct_window_init_mutex);
>>
>> - dma_addr = find_existing_ddw(pdn);
>> + dma_addr = find_existing_ddw(pdn, &len);
>
> I don't see len used anywhere?
>
>> if (dma_addr != 0)
>> goto out_unlock;
>>
>> @@ -1212,14 +1215,26 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
>> }
>> /* verify the window * number of ptes will map the partition */
>> /* check largest block * page size > max memory hotplug addr */
>> - max_addr = ddw_memory_hotplug_max();
>> - if (query.largest_available_block < (max_addr >> page_shift)) {
>> - dev_dbg(&dev->dev, "can't map partition max 0x%llx with %llu "
>> - "%llu-sized pages\n", max_addr, query.largest_available_block,
>> - 1ULL << page_shift);
>> + /*
>> + * The "ibm,pmemory" can appear anywhere in the address space.
>> + * Assuming it is still backed by page structs, try MAX_PHYSMEM_BITS
>> + * for the upper limit and fallback to max RAM otherwise but this
>> + * disables device::dma_ops_bypass.
>> + */
>> + len = max_ram_len;
>
> Here you override whatever find_existing_ddw() wrote to len?
Not always, there is a bunch of gotos before this line to the end of the
function and one (which returns the existing window) is legit. Thanks,
>
>> + if (pmem_present) {
>> + if (query.largest_available_block >=
>> + (1ULL << (MAX_PHYSMEM_BITS - page_shift)))
>> + len = MAX_PHYSMEM_BITS - page_shift;
>> + else
>> + dev_info(&dev->dev, "Skipping ibm,pmemory");
>> + }
>> +
>> + if (query.largest_available_block < (1ULL << (len - page_shift))) {
>> + dev_dbg(&dev->dev, "can't map partition max 0x%llx with %llu %llu-sized pages\n",
>> + 1ULL << len, query.largest_available_block, 1ULL << page_shift);
>> goto out_failed;
>> }
>> - len = order_base_2(max_addr);
>> win64 = kzalloc(sizeof(struct property), GFP_KERNEL);
>> if (!win64) {
>> dev_info(&dev->dev,
>
>
> cheers
>
--
Alexey
Alexey Kardashevskiy <[email protected]> writes:
> On 29/10/2020 11:40, Michael Ellerman wrote:
>> Alexey Kardashevskiy <[email protected]> writes:
>>> @@ -1126,7 +1129,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
>>>
>>> mutex_lock(&direct_window_init_mutex);
>>>
>>> - dma_addr = find_existing_ddw(pdn);
>>> + dma_addr = find_existing_ddw(pdn, &len);
>>
>> I don't see len used anywhere?
>>
>>> if (dma_addr != 0)
>>> goto out_unlock;
>>>
>>> @@ -1212,14 +1215,26 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
>>> }
>>> /* verify the window * number of ptes will map the partition */
>>> /* check largest block * page size > max memory hotplug addr */
>>> - max_addr = ddw_memory_hotplug_max();
>>> - if (query.largest_available_block < (max_addr >> page_shift)) {
>>> - dev_dbg(&dev->dev, "can't map partition max 0x%llx with %llu "
>>> - "%llu-sized pages\n", max_addr, query.largest_available_block,
>>> - 1ULL << page_shift);
>>> + /*
>>> + * The "ibm,pmemory" can appear anywhere in the address space.
>>> + * Assuming it is still backed by page structs, try MAX_PHYSMEM_BITS
>>> + * for the upper limit and fallback to max RAM otherwise but this
>>> + * disables device::dma_ops_bypass.
>>> + */
>>> + len = max_ram_len;
>>
>> Here you override whatever find_existing_ddw() wrote to len?
>
> Not always, there is a bunch of gotos before this line to the end of the
> function and one (which returns the existing window) is legit. Thanks,
Ah yep I see it.
Gotos considered confusing ;)
cheers