Re: [PATCH v7 18/50] powerpc/powernv: Remove DMA32 PE list

Alexey Kardashevskiy
2015-11-17T01:54:11Z

On 11/05/2015 12:12 AM, Gavin Shan wrote:
> PEs are put into PHB DMA32 list (phb->ioda.pe_dma_list) according
> to their DMA32 weight. The PEs on the list are iterated to setup
> their TCE32 tables at system booting time. The list is used for
> once and there is no good reason for it to survive.

From the above I concluded that you need a list, just do not need to keep
after the configuration is done but in fact you remove the list completely
so just remove "to survive" (s/for it to survive/for keep having it/) :)

>
> This moves the logic calculating DMA32 weight of PHB and PE to
> pnv_pci_ioda1_setup_dma() to drop PHB's DMA32 list.
>
> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
> ---
> arch/powerpc/platforms/powernv/pci-ioda.c | 150 ++++++++++++++----------------
> arch/powerpc/platforms/powernv/pci.h | 19 ----
> 2 files changed, 68 insertions(+), 101 deletions(-)
>
> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
> index 4c2e023..20ebe6e 100644
> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
> @@ -891,44 +891,6 @@ out:
> return 0;
> }
>
> -static void pnv_ioda_link_pe_by_weight(struct pnv_phb *phb,
> - struct pnv_ioda_pe *pe)
> -{
> - struct pnv_ioda_pe *lpe;
> -
> - list_for_each_entry(lpe, &phb->ioda.pe_dma_list, dma_link) {
> - if (lpe->dma_weight < pe->dma_weight) {
> - list_add_tail(&pe->dma_link, &lpe->dma_link);
> - return;
> - }
> - }
> - list_add_tail(&pe->dma_link, &phb->ioda.pe_dma_list);
> -}
> -
> -static unsigned int pnv_ioda_dma_weight(struct pci_dev *dev)
> -{
> - /* This is quite simplistic. The "base" weight of a device
> - * is 10. 0 means no DMA is to be accounted for it.
> - */
> -
> - /* If it's a bridge, no DMA */
> - if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL)
> - return 0;
> -
> - /* Reduce the weight of slow USB controllers */
> - if (dev->class == PCI_CLASS_SERIAL_USB_UHCI ||
> - dev->class == PCI_CLASS_SERIAL_USB_OHCI ||
> - dev->class == PCI_CLASS_SERIAL_USB_EHCI)
> - return 3;
> -
> - /* Increase the weight of RAID (includes Obsidian) */
> - if ((dev->class >> 8) == PCI_CLASS_STORAGE_RAID)
> - return 15;
> -
> - /* Default */
> - return 10;
> -}
> -
> #ifdef CONFIG_PCI_IOV
> static int pnv_pci_vf_resource_shift(struct pci_dev *dev, int offset)
> {
> @@ -1009,7 +971,6 @@ static void pnv_ioda_setup_same_PE(struct pci_bus *bus, struct pnv_ioda_pe *pe)
> continue;
> }
> pdn->pe_number = pe->pe_number;
> - pe->dma_weight += pnv_ioda_dma_weight(dev);
> if ((pe->flags & PNV_IODA_PE_BUS_ALL) && dev->subordinate)
> pnv_ioda_setup_same_PE(dev->subordinate, pe);
> }
> @@ -1046,10 +1007,8 @@ static void pnv_ioda_setup_bus_PE(struct pci_bus *bus, bool all)
> pe->flags |= (all ? PNV_IODA_PE_BUS_ALL : PNV_IODA_PE_BUS);
> pe->pbus = bus;
> pe->pdev = NULL;
> - pe->tce32_seg = -1;
> pe->mve_number = -1;
> pe->rid = bus->busn_res.start << 8;
> - pe->dma_weight = 0;
>
> if (all)
> pe_info(pe, "Secondary bus %d..%d associated with PE#%d\n",
> @@ -1071,17 +1030,6 @@ static void pnv_ioda_setup_bus_PE(struct pci_bus *bus, bool all)
>
> /* Put PE to the list */
> list_add_tail(&pe->list, &phb->ioda.pe_list);
> -
> - /* Account for one DMA PE if at least one DMA capable device exist
> - * below the bridge
> - */
> - if (pe->dma_weight != 0) {
> - phb->ioda.dma_weight += pe->dma_weight;
> - phb->ioda.dma_pe_count++;
> - }
> -
> - /* Link the PE */
> - pnv_ioda_link_pe_by_weight(phb, pe);
> }
>
> static void pnv_ioda_setup_PEs(struct pci_bus *bus)
> @@ -1389,7 +1337,6 @@ static void pnv_ioda_setup_vf_PE(struct pci_dev *pdev, u16 num_vfs)
> pe->flags = PNV_IODA_PE_VF;
> pe->pbus = NULL;
> pe->parent_dev = pdev;
> - pe->tce32_seg = -1;
> pe->mve_number = -1;
> pe->rid = (pci_iov_virtfn_bus(pdev, vf_index) << 8) |
> pci_iov_virtfn_devfn(pdev, vf_index);
> @@ -1842,6 +1789,47 @@ static struct iommu_table_ops pnv_ioda2_iommu_ops = {
> .free = pnv_ioda2_table_free,
> };
>
> +static int pnv_pci_ioda_dev_dma_weight(struct pci_dev *dev, void *data)
> +{
> + unsigned int *weight = (unsigned int *)data;
> +
> + /* This is quite simplistic. The "base" weight of a device
> + * is 10. 0 means no DMA is to be accounted for it.
> + */
> +
> + if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL)
> + return 0;
> +
> + if (dev->class == PCI_CLASS_SERIAL_USB_UHCI ||
> + dev->class == PCI_CLASS_SERIAL_USB_OHCI ||
> + dev->class == PCI_CLASS_SERIAL_USB_EHCI)
> + *weight += 3;
> + else if ((dev->class >> 8) == PCI_CLASS_STORAGE_RAID)
> + *weight += 15;
> + else
> + *weight += 10;
> +
> + return 0;
> +}
> +
> +static unsigned int pnv_pci_ioda_pe_dma_weight(struct pnv_ioda_pe *pe)
> +{
> + unsigned int weight = 0;
> +
> + if ((pe->flags & PNV_IODA_PE_DEV) && pe->pdev) {
> + pnv_pci_ioda_dev_dma_weight(pe->pdev, &weight);
> + } else if ((pe->flags & PNV_IODA_PE_BUS) && pe->pbus) {
> + struct pci_dev *pdev;
> +
> + list_for_each_entry(pdev, &pe->pbus->devices, bus_list)
> + pnv_pci_ioda_dev_dma_weight(pdev, &weight);
> + } else if ((pe->flags & PNV_IODA_PE_BUS_ALL) && pe->pbus) {
> + pci_walk_bus(pe->pbus, pnv_pci_ioda_dev_dma_weight, &weight);
> + }
> +
> + return weight;
> +}
> +
> static void pnv_pci_ioda1_setup_dma_pe(struct pnv_phb *phb,
> struct pnv_ioda_pe *pe,
> unsigned int base,
> @@ -1858,17 +1846,12 @@ static void pnv_pci_ioda1_setup_dma_pe(struct pnv_phb *phb,
> /* XXX FIXME: Provide 64-bit DMA facilities & non-4K TCE tables etc.. */
> /* XXX FIXME: Allocate multi-level tables on PHB3 */
>
> - /* We shouldn't already have a 32-bit DMA associated */
> - if (WARN_ON(pe->tce32_seg >= 0))
> - return;
> -
> tbl = pnv_pci_table_alloc(phb->hose->node);
> iommu_register_group(&pe->table_group, phb->hose->global_number,
> pe->pe_number);
> pnv_pci_link_table_and_group(phb->hose->node, 0, tbl, &pe->table_group);
>
> /* Grab a 32-bit TCE table */
> - pe->tce32_seg = base;
> pe_info(pe, " Setting up 32-bit TCE table at %08x..%08x\n",
> base * PNV_IODA1_DMA32_SEGSIZE,
> (base + segs) * PNV_IODA1_DMA32_SEGSIZE - 1);
> @@ -1932,8 +1915,6 @@ static void pnv_pci_ioda1_setup_dma_pe(struct pnv_phb *phb,
> return;
> fail:
> /* XXX Failure: Try to fallback to 64-bit only ? */
> - if (pe->tce32_seg >= 0)
> - pe->tce32_seg = -1;
> if (tce_mem)
> __free_pages(tce_mem, get_order(tce32_segsz * segs));
> if (tbl) {
> @@ -2344,10 +2325,6 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
> {
> int64_t rc;
>
> - /* We shouldn't already have a 32-bit DMA associated */
> - if (WARN_ON(pe->tce32_seg >= 0))
> - return;
> -
> /* TVE #1 is selected by PCI address bit 59 */
> pe->tce_bypass_base = 1ull << 59;
>
> @@ -2355,7 +2332,6 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
> pe->pe_number);
>
> /* The PE will reserve all possible 32-bits space */
> - pe->tce32_seg = 0;
> pe_info(pe, "Setting up 32-bit TCE table at 0..%08x\n",
> phb->ioda.m32_pci_base);
>
> @@ -2371,11 +2347,8 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
> #endif
>
> rc = pnv_pci_ioda2_setup_default_config(pe);
> - if (rc) {
> - if (pe->tce32_seg >= 0)
> - pe->tce32_seg = -1;
> + if (rc)
> return;
> - }
>
> if (pe->flags & PNV_IODA_PE_DEV)
> iommu_add_device(&pe->pdev->dev);
> @@ -2386,24 +2359,34 @@ static void pnv_pci_ioda2_setup_dma_pe(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;
> + unsigned int weight, total_weight, dma_pe_count;
> + unsigned int residual, remaining, segs, base;
> struct pnv_ioda_pe *pe;
>
> + total_weight = 0;
> + dma_pe_count = 0;
> + list_for_each_entry(pe, &phb->ioda.pe_list, list) {
> + weight = pnv_pci_ioda_pe_dma_weight(pe);
> + if (weight > 0)
> + dma_pe_count++;
> +
> + total_weight += weight;
> + }
> +
> /* If we have more PE# than segments available, hand out one
> * per PE until we run out and let the rest fail. If not,
> * then we assign at least one segment per PE, plus more based
> * on the amount of devices under that PE
> */
> - if (phb->ioda.dma_pe_count > phb->ioda.tce32_count)
> + if (dma_pe_count > phb->ioda.tce32_count)
> residual = 0;
> else
> - residual = phb->ioda.tce32_count -
> - phb->ioda.dma_pe_count;
> + residual = phb->ioda.tce32_count - dma_pe_count;
>
> pr_info("PCI: Domain %04x has %ld available 32-bit DMA segments\n",
> hose->global_number, phb->ioda.tce32_count);
> pr_info("PCI: %d PE# for a total weight of %d\n",
> - phb->ioda.dma_pe_count, phb->ioda.dma_weight);
> + dma_pe_count, total_weight);
>
> pnv_pci_ioda_setup_opal_tce_kill(phb);
>
> @@ -2412,24 +2395,26 @@ static void pnv_pci_ioda1_setup_dma(struct pnv_phb *phb)
> * weight
> */
> remaining = phb->ioda.tce32_count;
> - tw = phb->ioda.dma_weight;
> base = 0;
> - list_for_each_entry(pe, &phb->ioda.pe_dma_list, dma_link) {
> - if (!pe->dma_weight)
> + list_for_each_entry(pe, &phb->ioda.pe_list, list) {
> + weight = pnv_pci_ioda_pe_dma_weight(pe);
> + if (!weight)
> continue;
> +

Unrelated new line.

--
Alexey