Re: [PATCH v7 17/50] powerpc/powernv: Avoid calculating DMA32 segments on PHB3

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

On Tue, Nov 17, 2015 at 12:07:17PM +1100, Alexey Kardashevskiy wrote:
>On 11/05/2015 12:12 AM, Gavin Shan wrote:
>>In pnv_ioda_setup_dma(), it's unnecessary to calculate the DMA32
>>segments for PEs on PHB3 as the whole available DMA32 space can
>>be assigned to one specific PE on PHB3.
>>
>>This splits pnv_ioda_setup_dma() to pnv_pci_ioda1_setup_dma() and
>>pnv_pci_ioda2_setup_dma() in order to avoid calculating DMA32
>>segments for PEs on PHB3. No logical changes introduced.
>
>
>This patch is not needed as
>
>[PATCH v7 20/50] powerpc/powernv: Improve DMA32 segment calculation
>
>moves this calculation to another place (which already makes this patch
>unnecessary) and
>

I don't follow your comments, can you tell me how to split/merge the patches?

>[PATCH v7 26/50] powerpc/powernv: Create PEs at PCI hot plugging time
>
>removes just introduced pnv_pci_ioda1_setup_dma() - if you remove it, then
>there is no point in fixing it in the first place.
>

This function isn't removed in 26/50, could you double check?

>>
>>Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
>>---
>>  arch/powerpc/platforms/powernv/pci-ioda.c | 41 ++++++++++++++++++-------------
>>  1 file changed, 24 insertions(+), 17 deletions(-)
>>
>>diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>>index 5a08e20..4c2e023 100644
>>--- a/arch/powerpc/platforms/powernv/pci-ioda.c
>>+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>>@@ -2383,7 +2383,7 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
>>  		pnv_ioda_setup_bus_dma(pe, pe->pbus);
>>  }
>>
>>-static void pnv_ioda_setup_dma(struct pnv_phb *phb)
>>+static void pnv_pci_ioda1_setup_dma(struct pnv_phb *phb)
>>  {
>>  	struct pci_controller *hose = phb->hose;
>>  	unsigned int residual, remaining, segs, tw, base;
>>@@ -2428,26 +2428,30 @@ static void pnv_ioda_setup_dma(struct pnv_phb *phb)
>>  				segs = remaining;
>>  		}
>>
>>-		/*
>>-		 * For IODA2 compliant PHB3, we needn't care about the weight.
>>-		 * The all available 32-bits DMA space will be assigned to
>>-		 * the specific PE.
>>-		 */
>>-		if (phb->type == PNV_PHB_IODA1) {
>>-			pe_info(pe, "DMA weight %d, assigned %d DMA32 segments\n",
>>-				pe->dma_weight, segs);
>>-			pnv_pci_ioda1_setup_dma_pe(phb, pe, base, segs);
>>-		} else {
>>-			pe_info(pe, "Assign DMA32 space\n");
>>-			segs = 0;
>>-			pnv_pci_ioda2_setup_dma_pe(phb, pe);
>>-		}
>>+		pe_info(pe, "DMA weight %d, assigned %d DMA32 segments\n",
>>+			pe->dma_weight, segs);
>>+		pnv_pci_ioda1_setup_dma_pe(phb, pe, base, segs);
>>
>>  		remaining -= segs;
>>  		base += segs;
>>  	}
>>  }
>>
>>+static void pnv_pci_ioda2_setup_dma(struct pnv_phb *phb)
>>+{
>>+	struct pnv_ioda_pe *pe;
>>+
>>+	pnv_pci_ioda_setup_opal_tce_kill(phb);
>>+
>>+	list_for_each_entry(pe, &phb->ioda.pe_dma_list, dma_link) {
>>+		if (!pe->dma_weight)
>>+			continue;
>>+
>>+		pe_info(pe, "Assign DMA32 space\n");
>>+		pnv_pci_ioda2_setup_dma_pe(phb, pe);
>>+	}
>>+}
>>+
>>  #ifdef CONFIG_PCI_MSI
>>  static void pnv_ioda2_msi_eoi(struct irq_data *d)
>>  {
>>@@ -2931,10 +2935,13 @@ static void pnv_pci_ioda_setup_DMA(void)
>>  	struct pnv_phb *phb;
>>
>>  	list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
>>-		pnv_ioda_setup_dma(hose->private_data);
>>+		phb = hose->private_data;
>>+		if (phb->type == PNV_PHB_IODA1)
>>+			pnv_pci_ioda1_setup_dma(phb);
>>+		else
>>+			pnv_pci_ioda2_setup_dma(phb);
>>
>>  		/* Mark the PHB initialization done */
>>-		phb = hose->private_data;
>>  		phb->initialized = 1;
>>  	}
>>  }
>>
>
>
>-- 
>Alexey
>