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PCI: dwc: endpoint: Fix dw_pcie_ep_raise_msix_irq() alignment support

Message ID 20231122174856.736329-1-nks@flawful.org
State New
Headers show
Series PCI: dwc: endpoint: Fix dw_pcie_ep_raise_msix_irq() alignment support | expand

Commit Message

Niklas Cassel Nov. 22, 2023, 5:48 p.m. UTC 
From: Niklas Cassel <niklas.cassel@wdc.com>

Commit 6f5e193bfb55 ("PCI: dwc: Fix dw_pcie_ep_raise_msix_irq() to get
correct MSI-X table address") modified dw_pcie_ep_raise_msix_irq() to
support iATUs which require a specific alignment.

However, this support cannot have been properly tested.

The whole point is for the iATU to map an address that is aligned,
using dw_pcie_ep_map_addr(), and then let the writel() write to the
msi_address + aligned_offset.

Thus, modify the address that is mapped such that it is aligned.
With this change, dw_pcie_ep_raise_msix_irq() matches the logic in
dw_pcie_ep_raise_msi_irq().

Fixes: 6f5e193bfb55 ("PCI: dwc: Fix dw_pcie_ep_raise_msix_irq() to get correct MSI-X table address")
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
---
 drivers/pci/controller/dwc/pcie-designware-ep.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Niklas Cassel Nov. 22, 2023, 5:59 p.m. UTC | #1 
On Wed, Nov 22, 2023 at 06:48:55PM +0100, Niklas Cassel wrote:
> From: Niklas Cassel <niklas.cassel@wdc.com>
> 
> Commit 6f5e193bfb55 ("PCI: dwc: Fix dw_pcie_ep_raise_msix_irq() to get
> correct MSI-X table address") modified dw_pcie_ep_raise_msix_irq() to
> support iATUs which require a specific alignment.
> 
> However, this support cannot have been properly tested.
> 
> The whole point is for the iATU to map an address that is aligned,
> using dw_pcie_ep_map_addr(), and then let the writel() write to the
> msi_address + aligned_offset.

Reading this again... I wasn't super clear:
s/msi_address/ep->msi_mem/
makes it more obvious that I do not mean the MSI address in the RC.

> 
> Thus, modify the address that is mapped such that it is aligned.
> With this change, dw_pcie_ep_raise_msix_irq() matches the logic in
> dw_pcie_ep_raise_msi_irq().
> 
> Fixes: 6f5e193bfb55 ("PCI: dwc: Fix dw_pcie_ep_raise_msix_irq() to get correct MSI-X table address")
> Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
> ---
>  drivers/pci/controller/dwc/pcie-designware-ep.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> index f6207989fc6a..bc94d7f39535 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> @@ -615,6 +615,7 @@ int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
>  	}
>  
>  	aligned_offset = msg_addr & (epc->mem->window.page_size - 1);
> +	msg_addr &= ~aligned_offset;
>  	ret = dw_pcie_ep_map_addr(epc, func_no, 0, ep->msi_mem_phys, msg_addr,
>  				  epc->mem->window.page_size);
>  	if (ret)
> -- 
> 2.42.0
>
diff mbox series

Patch

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index f6207989fc6a..bc94d7f39535 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -615,6 +615,7 @@  int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
 	}
 
 	aligned_offset = msg_addr & (epc->mem->window.page_size - 1);
+	msg_addr &= ~aligned_offset;
 	ret = dw_pcie_ep_map_addr(epc, func_no, 0, ep->msi_mem_phys, msg_addr,
 				  epc->mem->window.page_size);
 	if (ret)