On 10/31/2017 07:01 AM, Kishon Vijay Abraham I wrote:
> Hi Niklas,
>
> On Monday 30 October 2017 06:12 PM, Niklas Cassel wrote:
>> Certain SoCs need to map the MSI address in raise_irq.
>> To map an address, you first need to call pci_epc_mem_alloc_addr,
>> however, pci_epc_mem_alloc_addr calls ioremap (which can sleep).
>>
>> Since raise_irq is only called from atomic context, we can't call
>> pci_epc_mem_alloc_addr from raise_irq, instead we pre-allocate
>> a page in dw_pcie_ep_init, so this page can later be used to map/unmap
>> the MSI address in raise_irq.
>>
>> Signed-off-by: Niklas Cassel <[email protected]>
>> ---
>> V2:
>> * No change.
>>
>> drivers/pci/dwc/pcie-designware-ep.c | 8 ++++++++
>> drivers/pci/dwc/pcie-designware.h | 2 ++
>> 2 files changed, 10 insertions(+)
>>
>> diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
>> index 3fb34be99715..c291da2a10ba 100644
>> --- a/drivers/pci/dwc/pcie-designware-ep.c
>> +++ b/drivers/pci/dwc/pcie-designware-ep.c
>> @@ -286,6 +286,8 @@ void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
>> {
>> struct pci_epc *epc = ep->epc;
>>
>> + pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem, PAGE_SIZE);
>> +
>> pci_epc_mem_exit(epc);
>> }
>>
>> @@ -341,6 +343,12 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
>> return ret;
>> }
>>
>> + ep->msi_mem = pci_epc_mem_alloc_addr(epc, &ep->msi_mem_phys, PAGE_SIZE);
>
> ep->page_size instead of PAGE_SIZE?
>
It was a really good call of Bjorn not to stress this series,
since I apparently did not properly test this... I'm sorry,
it will not happen again.
ep->page_size is by default set to 0.
__pci_epc_mem_init basically does this:
if ep->page_size < PAGE_SIZE:
epc->mem->page_size = PAGE_SIZE
else
epc->mem->page_size = ep->page_size
So __pci_epc_mem_init is safe to call with ep->page_size 0,
however, the same thing is not true for pci_epc_mem_alloc_addr.
I will need to do a v5 of this patch series.
Kishon, what do you think about doing this instead?
+++ b/drivers/pci/dwc/pcie-designware-ep.c
@@ -321,7 +321,7 @@ void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
struct pci_epc *epc = ep->epc;
pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem,
- ep->page_size);
+ epc->mem->page_size);
pci_epc_mem_exit(epc);
}
@@ -379,7 +379,7 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
}
ep->msi_mem = pci_epc_mem_alloc_addr(epc, &ep->msi_mem_phys,
- ep->page_size);
+ epc->mem->page_size);
if (!ep->msi_mem) {
dev_err(dev, "Failed to reserve memory for MSI\n");
return -ENOMEM;
Regards,
Niklas
From 1582815031198406785@xxx Tue Oct 31 22:47:22 +0000 2017
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