Re-work the msi_msg DMA allocation logic to use dma_alloc_coherent()
which uses the coherent DMA mask to try and return an allocation within
the DMA mask limits. This allows kernel configurations that disable
ZONE_DMA32 to continue supporting a 32-bit DMA mask. Without this patch,
the PCIe host device will fail to probe when ZONE_DMA32 is disabled.
Fixes: 35797e672ff0 ("PCI: dwc: Fix MSI msi_msg DMA mapping")
Reported-by: Isaac J. Manjarres <isaacmanjarres@xxxxxxxxxx>
Signed-off-by: Will McVicker <willmcvicker@xxxxxxxxxx>
---
.../pci/controller/dwc/pcie-designware-host.c | 23 ++++++++-----------
1 file changed, 9 insertions(+), 14 deletions(-)
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index 7746f94a715f..8f2222f51671 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -272,9 +272,9 @@ static void dw_pcie_free_msi(struct dw_pcie_rp *pp)
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
struct device *dev = pci->dev;
- dma_unmap_page(dev, pp->msi_data, PAGE_SIZE, DMA_FROM_DEVICE);
- if (pp->msi_page)
- __free_page(pp->msi_page);
+ dma_free_coherent(dev, PAGE_SIZE, pp->msi_page, pp->msi_data);
+ pp->msi_data = 0;
+ pp->msi_page = NULL;
}
}
@@ -375,22 +375,17 @@ static int dw_pcie_msi_host_init(struct dw_pcie_rp *pp)
dw_chained_msi_isr, pp);
}
- ret = dma_set_mask(dev, DMA_BIT_MASK(32));
+ ret = dma_set_mask_and_coherent(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");
- pp->msi_page = alloc_page(GFP_DMA32);
- pp->msi_data = dma_map_page(dev, pp->msi_page, 0,
- PAGE_SIZE, DMA_FROM_DEVICE);
- ret = dma_mapping_error(dev, pp->msi_data);
- if (ret) {
- dev_err(pci->dev, "Failed to map MSI data\n");
- __free_page(pp->msi_page);
- pp->msi_page = NULL;
+ pp->msi_page = dma_alloc_coherent(dev, PAGE_SIZE, &pp->msi_data,
+ GFP_KERNEL);
+ if (!pp->msi_page) {
+ dev_err(dev, "Failed to alloc and map MSI data\n");
pp->msi_data = 0;
dw_pcie_free_msi(pp);
-
- return ret;
+ return -ENOMEM;
}
return 0;
--
2.37.1.559.g78731f0fdb-goog
