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

Alexey Kardashevskiy
2015-11-17T01:07:25Z

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

[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.

>
> 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