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

Commit 6f5e193 ("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
ep->msi_mem + 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().

Link: https://lore.kernel.org/linux-pci/20231128132231.2221614-1-nks@flawful.org
Fixes: 6f5e193 ("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>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: stable@vger.kernel.org # 5.7
Cc: Kishon Vijay Abraham I <kishon@kernel.org>

Author: Niklas Cassel

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)