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UPSTREAM: PCI: dwc: Fix MSI msi_msg DMA mapping

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As of 07940c369a ("PCI: dwc: Fix MSI page leakage in suspend/resume"),
the PCIe designware host driver has been using the driver data
allocation for the msi_msg DMA mapping which can result in
a DMA_MAPPING_ERROR due to the DMA overflow check in
dma_direct_map_page() when the address is greater than 32 bits (reported
in [1]). The commit was trying to address a memory leak on
suspend/resume by moving the MSI mapping to dw_pcie_host_init(), but
subsequently dropped the page allocation thinking it wasn't needed.

To fix the DMA mapping issue as well as make msi_msg DMA'able, switch
back to allocating a 32-bit page for the msi_msg. To avoid the
suspend/resume leak, allocate the page in dw_pcie_host_init() since that
shouldn't be called during suspend/resume.

[1] https://lore.kernel.org/all/Yo0soniFborDl7+C@google.com/

Signed-off-by: Will McVicker <willmcvicker@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Change-Id: I48f48d069ff27a391cf0043bc23cfe4ac8c32593
(cherry picked from commit 35797e672f)
This commit is contained in:
Will McVicker
2022-06-13 17:26:11 -05:00
parent 374734b63a
commit c126f1fdc0
2 changed files with 10 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
drivers/pci/controller/dwc/pcie-designware-host.c
View File

@@ -268,8 +268,9 @@ static void dw_pcie_free_msi(struct pcie_port *pp)
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
struct device *dev = pci->dev;
dma_unmap_single_attrs(dev, pp->msi_data, sizeof(pp->msi_msg),
DMA_FROM_DEVICE, DMA_ATTR_SKIP_CPU_SYNC);
dma_unmap_page(dev, pp->msi_data, PAGE_SIZE, DMA_FROM_DEVICE);
if (pp->msi_page)
__free_page(pp->msi_page);
}
}
@@ -377,13 +378,14 @@ int dw_pcie_host_init(struct pcie_port *pp)
if (ret)
dev_warn(pci->dev, "Failed to set DMA mask to 32-bit. Devices with only 32-bit MSI support may not work properly\n");
pp->msi_data = dma_map_single_attrs(pci->dev, &pp->msi_msg,
sizeof(pp->msi_msg),
DMA_FROM_DEVICE,
DMA_ATTR_SKIP_CPU_SYNC);
ret = dma_mapping_error(pci->dev, pp->msi_data);
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_data = 0;
goto err_free_msi;
}

2
drivers/pci/controller/dwc/pcie-designware.h
View File

@@ -190,8 +190,8 @@ struct pcie_port {
int msi_irq;
struct irq_domain *irq_domain;
struct irq_domain *msi_domain;
u16 msi_msg;
dma_addr_t msi_data;
struct page *msi_page;
struct irq_chip *msi_irq_chip;
u32 num_vectors;
u32 irq_mask[MAX_MSI_CTRLS];