Move this code to its own function for reuse. As a side benefit,
rearrange the comments and spread things out for readability.
Signed-off-by: Reza Arbab <ar...@linux.ibm.com>
---
arch/powerpc/platforms/powernv/pci-ioda.c | 37 +++++++++++++++++++++----------
1 file changed, 25 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c
b/arch/powerpc/platforms/powernv/pci-ioda.c
index 6b932cfc0deb..57e6a43d9a3a 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -1826,6 +1826,30 @@ static int pnv_pci_ioda_dma_64bit_bypass(struct
pnv_ioda_pe *pe)
return -EIO;
}
+/*
+ * 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.
+ */
+static bool pnv_phb3_iommu_bypass_supported(struct pnv_ioda_pe *pe, u64 mask)
+{
+ if (pe->phb->model != PNV_PHB_MODEL_PHB3)
+ return false;
+
+ /* pe->pdev should be set if it's a single device, pe->pbus if not */
+ if (pe->pbus && pe->device_count != 1)
+ return false;
+
+ if (!(mask >> 32))
+ return false;
+
+ /* The device needs to be able to address all of this space. */
+ if (mask <= memory_hotplug_max() + (1ULL << 32))
+ return false;
+
+ return true;
+}
+
static bool pnv_pci_ioda_iommu_bypass_supported(struct pci_dev *pdev,
u64 dma_mask)
{
@@ -1837,18 +1861,7 @@ static bool pnv_pci_ioda_iommu_bypass_supported(struct
pci_dev *pdev,
bypass = pnv_ioda_pe_iommu_bypass_supported(pe, dma_mask);
- /*
- * 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 (!bypass &&
- 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) &&
- pe->phb->model == PNV_PHB_MODEL_PHB3) {
+ if (!bypass && pnv_phb3_iommu_bypass_supported(pe, dma_mask)) {
/* Configure the bypass mode */
if (pnv_pci_ioda_dma_64bit_bypass(pe))
return false;
--
1.8.3.1
