Commit 423511ec authored by Will McVicker's avatar Will McVicker Committed by Lorenzo Pieralisi
Browse files

PCI: dwc: Drop dependency on ZONE_DMA32 

Re-work the msi_msg DMA allocation logic to use dmam_alloc_coherent() which
uses the coherent DMA mask to try to return an allocation within the DMA
mask limits. With that, we now can drop the msi_page parameter in struct
dw_pcie_rp. 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.

Link: https://lore.kernel.org/r/20220825235404.4132818-2-willmcvicker@google.com


Fixes: 35797e67 ("PCI: dwc: Fix MSI msi_msg DMA mapping")
Reported-by: default avatarIsaac J. Manjarres <isaacmanjarres@google.com>
Signed-off-by: default avatarWill McVicker <willmcvicker@google.com>
Signed-off-by: default avatarLorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: default avatarRob Herring <robh@kernel.org>
Acked-by: default avatarJingoo Han <jingoohan1@gmail.com>
parent 568035b0

drivers/pci/controller/dwc/pcie-designware-host.c

+7 −21
Original line number Diff line number Diff line
@@ -267,15 +267,6 @@ static void dw_pcie_free_msi(struct dw_pcie_rp *pp) 


	irq_domain_remove(pp->msi_domain);

	irq_domain_remove(pp->irq_domain);



	if (pp->msi_data) {

		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);

	}

}



static void dw_pcie_msi_init(struct dw_pcie_rp *pp)
@@ -336,6 +327,7 @@ 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;

	int ret;

	u32 ctrl, num_ctrls;
@@ -375,22 +367,16 @@ 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_data = 0;

	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 ret;

		return -ENOMEM;

	}



	return 0;

drivers/pci/controller/dwc/pcie-designware.h

+0 −1
Original line number Diff line number Diff line
@@ -243,7 +243,6 @@ struct dw_pcie_rp { 
	struct irq_domain	*irq_domain;

	struct irq_domain	*msi_domain;

	dma_addr_t		msi_data;

	struct page		*msi_page;

	struct irq_chip		*msi_irq_chip;

	u32			num_vectors;

	u32			irq_mask[MAX_MSI_CTRLS];