From f3a296405b6e65fe478144c2f85602dc5668700c Mon Sep 17 00:00:00 2001
From: Ajay Agarwal <ajayagarwal@google.com>
Date: Wed, 21 Feb 2024 21:08:40 +0530
Subject: [PATCH] PCI: dwc: Strengthen the MSI address allocation logic
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There can be platforms that do not use/have 32-bit DMA addresses.
The current implementation of 32-bit IOVA allocation can fail for
such platforms, eventually leading to the probe failure.
Try to allocate a 32-bit msi_data. If this allocation fails,
attempt a 64-bit address allocation. Please note that if the
64-bit MSI address is allocated, then the EPs supporting 32-bit
MSI address only will not work.
Link: https://lore.kernel.org/linux-pci/20240221153840.1789979-1-ajayagarwal@google.com
Tested-by: Will McVicker <willmcvicker@google.com>
Signed-off-by: Ajay Agarwal <ajayagarwal@google.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Will McVicker <willmcvicker@google.com>
---
.../pci/controller/dwc/pcie-designware-host.c | 21 ++++++++++++-------
1 file changed, 13 insertions(+), 8 deletions(-)
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index d5fc31f8345f7..d15a5c2d5b480 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -328,7 +328,7 @@ static int dw_pcie_msi_host_init(struct dw_pcie_rp *pp)
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
struct device *dev = pci->dev;
struct platform_device *pdev = to_platform_device(dev);
- u64 *msi_vaddr;
+ u64 *msi_vaddr = NULL;
int ret;
u32 ctrl, num_ctrls;
@@ -379,15 +379,20 @@ static int dw_pcie_msi_host_init(struct dw_pcie_rp *pp)
* memory.
*/
ret = dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
- if (ret)
- dev_warn(dev, "Failed to set DMA mask to 32-bit. Devices with only 32-bit MSI support may not work properly\n");
+ if (!ret)
+ msi_vaddr = dmam_alloc_coherent(dev, sizeof(u64), &pp->msi_data,
+ GFP_KERNEL);
- msi_vaddr = dmam_alloc_coherent(dev, sizeof(u64), &pp->msi_data,
- GFP_KERNEL);
if (!msi_vaddr) {
- dev_err(dev, "Failed to alloc and map MSI data\n");
- dw_pcie_free_msi(pp);
- return -ENOMEM;
+ dev_warn(dev, "Failed to allocate 32-bit MSI address\n");
+ dma_set_coherent_mask(dev, DMA_BIT_MASK(64));
+ msi_vaddr = dmam_alloc_coherent(dev, sizeof(u64), &pp->msi_data,
+ GFP_KERNEL);
+ if (!msi_vaddr) {
+ dev_err(dev, "Failed to allocate MSI address\n");
+ dw_pcie_free_msi(pp);
+ return -ENOMEM;
+ }
}
return 0;
--
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