Re: [PATCH kernel v10 03/34] powerpc/powernv/ioda: Clean up IOMMU group registration

[Gavin Shan <gwshan@linux.vnet.ibm.com>]

On Tue, May 12, 2015 at 01:38:52AM +1000, Alexey Kardashevskiy wrote:
>The existing code has 3 calls to iommu_register_group() and
>all 3 branches actually cover all possible cases.
>
>This replaces 3 calls with one and moves the registration earlier;
>the latter will make more sense when we add TCE table sharing.
>
>Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>

Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>

Thanks,
Gavin

>---
> arch/powerpc/platforms/powernv/pci-ioda.c | 28 ++++++++--------------------
> 1 file changed, 8 insertions(+), 20 deletions(-)
>
>diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>index 9a77f3c..8ca7abd 100644
>--- a/arch/powerpc/platforms/powernv/pci-ioda.c
>+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>@@ -1784,6 +1784,9 @@ static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb,
> 	if (WARN_ON(pe->tce32_seg >= 0))
> 		return;
>
>+	tbl = pe->tce32_table;
>+	iommu_register_group(tbl, phb->hose->global_number, pe->pe_number);
>+
> 	/* Grab a 32-bit TCE table */
> 	pe->tce32_seg = base;
> 	pe_info(pe, " Setting up 32-bit TCE table at %08x..%08x\n",
>@@ -1818,7 +1821,6 @@ static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb,
> 	}
>
> 	/* Setup linux iommu table */
>-	tbl = pe->tce32_table;
> 	pnv_pci_setup_iommu_table(tbl, addr, TCE32_TABLE_SIZE * segs,
> 				  base << 28, IOMMU_PAGE_SHIFT_4K);
>
>@@ -1840,8 +1842,6 @@ static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb,
> 	iommu_init_table(tbl, phb->hose->node);
>
> 	if (pe->flags & PNV_IODA_PE_DEV) {
>-		iommu_register_group(tbl, phb->hose->global_number,
>-				     pe->pe_number);
> 		/*
> 		 * Setting table base here only for carrying iommu_group
> 		 * further down to let iommu_add_device() do the job.
>@@ -1849,14 +1849,8 @@ static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb,
> 		 */
> 		set_iommu_table_base(&pe->pdev->dev, tbl);
> 		iommu_add_device(&pe->pdev->dev);
>-	} else if (pe->flags & (PNV_IODA_PE_BUS | PNV_IODA_PE_BUS_ALL)) {
>-		iommu_register_group(tbl, phb->hose->global_number,
>-				     pe->pe_number);
>+	} else if (pe->flags & (PNV_IODA_PE_BUS | PNV_IODA_PE_BUS_ALL))
> 		pnv_ioda_setup_bus_dma(pe, pe->pbus);
>-	} else if (pe->flags & PNV_IODA_PE_VF) {
>-		iommu_register_group(tbl, phb->hose->global_number,
>-				     pe->pe_number);
>-	}
>
> 	return;
>  fail:
>@@ -1923,6 +1917,9 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
> 	if (WARN_ON(pe->tce32_seg >= 0))
> 		return;
>
>+	tbl = pe->tce32_table;
>+	iommu_register_group(tbl, phb->hose->global_number, pe->pe_number);
>+
> 	/* The PE will reserve all possible 32-bits space */
> 	pe->tce32_seg = 0;
> 	end = (1 << ilog2(phb->ioda.m32_pci_base));
>@@ -1954,7 +1951,6 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
> 	}
>
> 	/* Setup linux iommu table */
>-	tbl = pe->tce32_table;
> 	pnv_pci_setup_iommu_table(tbl, addr, tce_table_size, 0,
> 			IOMMU_PAGE_SHIFT_4K);
>
>@@ -1974,8 +1970,6 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
> 	iommu_init_table(tbl, phb->hose->node);
>
> 	if (pe->flags & PNV_IODA_PE_DEV) {
>-		iommu_register_group(tbl, phb->hose->global_number,
>-				     pe->pe_number);
> 		/*
> 		 * Setting table base here only for carrying iommu_group
> 		 * further down to let iommu_add_device() do the job.
>@@ -1983,14 +1977,8 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
> 		 */
> 		set_iommu_table_base(&pe->pdev->dev, tbl);
> 		iommu_add_device(&pe->pdev->dev);
>-	} else if (pe->flags & (PNV_IODA_PE_BUS | PNV_IODA_PE_BUS_ALL)) {
>-		iommu_register_group(tbl, phb->hose->global_number,
>-				     pe->pe_number);
>+	} else if (pe->flags & (PNV_IODA_PE_BUS | PNV_IODA_PE_BUS_ALL))
> 		pnv_ioda_setup_bus_dma(pe, pe->pbus);
>-	} else if (pe->flags & PNV_IODA_PE_VF) {
>-		iommu_register_group(tbl, phb->hose->global_number,
>-				     pe->pe_number);
>-	}
>
> 	/* Also create a bypass window */
> 	if (!pnv_iommu_bypass_disabled)
>-- 
>2.4.0.rc3.8.gfb3e7d5
>