[PATCH 17/33] powerpc/powernv: use the generic iommu bypass code

Christoph Hellwig
2018-10-09T13:26:14Z

Use the generic iommu bypass code instead of overriding set_dma_mask.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
arch/powerpc/platforms/powernv/pci-ioda.c | 92 ++++++-----------------
1 file changed, 25 insertions(+), 67 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index b6db65917bb4..5748b62e2e86 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -1739,86 +1739,45 @@ static int pnv_pci_ioda_dma_64bit_bypass(struct pnv_ioda_pe *pe)
return -EIO;
}

-static int pnv_pci_ioda_dma_set_mask(struct pci_dev *pdev, u64 dma_mask)
+static bool pnv_pci_ioda_iommu_bypass_supported(struct pci_dev *pdev,
+ u64 dma_mask)
{
struct pci_controller *hose = pci_bus_to_host(pdev->bus);
struct pnv_phb *phb = hose->private_data;
struct pci_dn *pdn = pci_get_pdn(pdev);
struct pnv_ioda_pe *pe;
- uint64_t top;
- bool bypass = false;
- s64 rc;

if (WARN_ON(!pdn || pdn->pe_number == IODA_INVALID_PE))
return -ENODEV;

pe = &phb->ioda.pe_array[pdn->pe_number];
if (pe->tce_bypass_enabled) {
- top = pe->tce_bypass_base + memblock_end_of_DRAM() - 1;
- bypass = (dma_mask >= top);
+ u64 top = pe->tce_bypass_base + memblock_end_of_DRAM() - 1;
+ if (dma_mask >= top)
+ return true;
}

- if (bypass) {
- dev_info(&pdev->dev, "Using 64-bit DMA iommu bypass\n");
- set_dma_ops(&pdev->dev, &dma_nommu_ops);
- } else {
- /*
- * If the device can't set the TCE bypass bit but still wants
- * to access 4GB or more, on PHB3 we can reconfigure TVE#0 to
- * bypass the 32-bit region and be usable for 64-bit DMAs.
- * The device needs to be able to address all of this space.
- */
- if (dma_mask >> 32 &&
- dma_mask > (memory_hotplug_max() + (1ULL << 32)) &&
- /* pe->pdev should be set if it's a single device, pe->pbus if not */
- (pe->device_count == 1 || !pe->pbus) &&
- phb->model == PNV_PHB_MODEL_PHB3) {
- /* Configure the bypass mode */
- rc = pnv_pci_ioda_dma_64bit_bypass(pe);
- if (rc)
- return rc;
- /* 4GB offset bypasses 32-bit space */
- set_dma_offset(&pdev->dev, (1ULL << 32));
- set_dma_ops(&pdev->dev, &dma_nommu_ops);
- } else if (dma_mask >> 32 && dma_mask != DMA_BIT_MASK(64)) {
- /*
- * Fail the request if a DMA mask between 32 and 64 bits
- * was requested but couldn't be fulfilled. Ideally we
- * would do this for 64-bits but historically we have
- * always fallen back to 32-bits.
- */
- return -ENOMEM;
- } else {
- dev_info(&pdev->dev, "Using 32-bit DMA via iommu\n");
- set_dma_ops(&pdev->dev, &dma_iommu_ops);
- }
+ /*
+ * If the device can't set the TCE bypass bit but still wants
+ * to access 4GB or more, on PHB3 we can reconfigure TVE#0 to
+ * bypass the 32-bit region and be usable for 64-bit DMAs.
+ * The device needs to be able to address all of this space.
+ */
+ if (dma_mask >> 32 &&
+ dma_mask > (memory_hotplug_max() + (1ULL << 32)) &&
+ /* pe->pdev should be set if it's a single device, pe->pbus if not */
+ (pe->device_count == 1 || !pe->pbus) &&
+ phb->model == PNV_PHB_MODEL_PHB3) {
+ /* Configure the bypass mode */
+ s64 rc = pnv_pci_ioda_dma_64bit_bypass(pe);
+ if (rc)
+ return rc;
+ /* 4GB offset bypasses 32-bit space */
+ set_dma_offset(&pdev->dev, (1ULL << 32));
+ return true;
}
- *pdev->dev.dma_mask = dma_mask;

- return 0;
-}
-
-static u64 pnv_pci_ioda_dma_get_required_mask(struct pci_dev *pdev)
-{
- struct pci_controller *hose = pci_bus_to_host(pdev->bus);
- struct pnv_phb *phb = hose->private_data;
- struct pci_dn *pdn = pci_get_pdn(pdev);
- struct pnv_ioda_pe *pe;
- u64 end, mask;
-
- if (WARN_ON(!pdn || pdn->pe_number == IODA_INVALID_PE))
- return 0;
-
- pe = &phb->ioda.pe_array[pdn->pe_number];
- if (!pe->tce_bypass_enabled)
- return __dma_get_required_mask(&pdev->dev);
-
-
- end = pe->tce_bypass_base + memblock_end_of_DRAM();
- mask = 1ULL << (fls64(end) - 1);
- mask += mask - 1;
-
- return mask;
+ return false;
}

static void pnv_ioda_setup_bus_dma(struct pnv_ioda_pe *pe,
@@ -3456,6 +3415,7 @@ static void pnv_pci_ioda_shutdown(struct pci_controller *hose)
static const struct pci_controller_ops pnv_pci_ioda_controller_ops = {
.dma_dev_setup = pnv_pci_dma_dev_setup,
.dma_bus_setup = pnv_pci_dma_bus_setup,
+ .iommu_bypass_supported = pnv_pci_ioda_iommu_bypass_supported,
#ifdef CONFIG_PCI_MSI
.setup_msi_irqs = pnv_setup_msi_irqs,
.teardown_msi_irqs = pnv_teardown_msi_irqs,
@@ -3465,8 +3425,6 @@ static const struct pci_controller_ops pnv_pci_ioda_controller_ops = {
.window_alignment = pnv_pci_window_alignment,
.setup_bridge = pnv_pci_setup_bridge,
.reset_secondary_bus = pnv_pci_reset_secondary_bus,
- .dma_set_mask = pnv_pci_ioda_dma_set_mask,
- .dma_get_required_mask = pnv_pci_ioda_dma_get_required_mask,
.shutdown = pnv_pci_ioda_shutdown,
};

--
2.19.0