Re: [PATCH v7 26/50] powerpc/powernv: Create PEs at PCI hot plugging time

Gavin Shan
2015-11-17T09:13:05Z

On Tue, Nov 17, 2015 at 06:57:20PM +1100, Alexey Kardashevskiy wrote:
>On 11/05/2015 12:12 AM, Gavin Shan wrote:
>>Currently, the PEs and their associated resources are assigned
>>in ppc_md.pcibios_fixup() except those used by SRIOV VFs. The
>>function is called for once after PCI probing and resources
>>assignment is completed. So it isn't hotplug friendly.
>>
>>This creates PEs dynamically by ppc_md.pcibios_setup_bridge(), which
>>is called on the event during system bootup and PCI hotplug: updating
>>PCI bridge's windows after resource assignment/reassignment are done.
>>For partial hotplug case, where not all PCI devices belonging to the
>>PE are unplugged and plugged again, we just need unbinding/binding
>>the affected PCI devices with the corresponding PE without creating
>>new one.
>>
>>As there is no upstream bridge for root bus that needs to be covered
>>by PE,
>
>
>Does "that needs" part relate to a root bus or a an upstream bridge?
>

root bus.

>>we have to create PE for root bus in ppc_md.pcibios_setup_bridge()
>>before any other PEs can be created, as PE for root bus is the ancestor
>>to anyone else.
>>
>>On the other hand, the windows of root port or the upstream port
>
>s/On the other hand, /Also/ ?
>

It's fine to keep "On the other hand".

>>of PCIe switch behind root port are extended to be PHB's aperatuses
>
>apertures?
>

Will fix in next revision.

>>to accommodate the additonal resources needed by newly plugged devices
>
>s/additonal/additional
>

Will fix in next revision.

>>based on the fact: hotpluggable slot is behind root port or downstream
>>port of the PCIe switch behind root port. The extension for those
>>PCI brdiges' windows is done in ppc_md.pcibios_setup_bridge() as
>>well.
>
>
>I find it quite difficult to separate "cut-n-paste" changes from functional
>changes... May be it is just me.
>I would suggest splitting this patch into several. First define the
>setup_bridge() callback, then rework pnv_pci_ioda_setup_PEs(),
>pnv_pci_ioda_setup_seg(), pnv_pci_ioda_setup_DMA(), and then add "partial
>hotplug" handling may be.
>
>Or just get "reviewed-by" from Ben :)
>

Ok. I'll try to split it accordingly in next revision. Nope, I need your
reviewed-by :-)

>
>>
>>Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
>>---
>> arch/powerpc/platforms/powernv/pci-ioda.c | 240 +++++++++++++++++-------------
>> arch/powerpc/platforms/powernv/pci.h | 1 +
>> 2 files changed, 138 insertions(+), 103 deletions(-)
>>
>>diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>>index 5e6745f..0bb0056 100644
>>--- a/arch/powerpc/platforms/powernv/pci-ioda.c
>>+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>>@@ -975,6 +975,15 @@ static void pnv_ioda_setup_same_PE(struct pci_bus *bus, struct pnv_ioda_pe *pe)
>> pci_name(dev));
>> continue;
>> }
>>+
>>+ /*
>>+ * In partial hotplug case, the PCI device might be still
>>+ * associated with the PE and needn't be attached to the
>>+ * PE again.
>>+ */
>>+ if (pdn->pe_number != IODA_INVALID_PE)
>>+ continue;
>>+
>> pdn->pe_number = pe->pe_number;
>> if ((pe->flags & PNV_IODA_PE_BUS_ALL) && dev->subordinate)
>> pnv_ioda_setup_same_PE(dev->subordinate, pe);
>>@@ -992,9 +1001,26 @@ static struct pnv_ioda_pe *pnv_ioda_setup_bus_PE(struct pci_bus *bus, bool all)
>> struct pci_controller *hose = pci_bus_to_host(bus);
>> struct pnv_phb *phb = hose->private_data;
>> struct pnv_ioda_pe *pe = NULL;
>>+ int pe_num;
>>+
>>+ /*
>>+ * In partial hotplug case, the PE instance might be still alive.
>>+ * We should reuse it instead of allocating a new one.
>>+ */
>>+ pe_num = phb->ioda.pe_rmap[bus->number << 8];
>>+ if (pe_num != IODA_INVALID_PE) {
>>+ pe = &phb->ioda.pe_array[pe_num];
>>+ pnv_ioda_setup_same_PE(bus, pe);
>>+ return NULL;
>>+ }
>>+
>>+ /* PE number for root bus should have been reserved */
>>+ if (pci_is_root_bus(bus) &&
>>+ phb->ioda.root_pe_idx != IODA_INVALID_PE)
>>+ pe = &phb->ioda.pe_array[phb->ioda.root_pe_idx];
>>
>> /* Check if PE is determined by M64 */
>>- if (phb->pick_m64_pe)
>>+ if (!pe && phb->pick_m64_pe)
>> pe = phb->pick_m64_pe(bus, all);
>>
>> /* The PE number isn't pinned by M64 */
>>@@ -1036,46 +1062,6 @@ static struct pnv_ioda_pe *pnv_ioda_setup_bus_PE(struct pci_bus *bus, bool all)
>> return pe;
>> }
>>
>>-static void pnv_ioda_setup_PEs(struct pci_bus *bus)
>>-{
>>- struct pci_dev *dev;
>>-
>>- pnv_ioda_setup_bus_PE(bus, false);
>>-
>>- list_for_each_entry(dev, &bus->devices, bus_list) {
>>- if (dev->subordinate) {
>>- if (pci_pcie_type(dev) == PCI_EXP_TYPE_PCI_BRIDGE)
>>- pnv_ioda_setup_bus_PE(dev->subordinate, true);
>>- else
>>- pnv_ioda_setup_PEs(dev->subordinate);
>>- }
>>- }
>>-}
>>-
>>-/*
>>- * Configure PEs so that the downstream PCI buses and devices
>>- * could have their associated PE#. Unfortunately, we didn't
>>- * figure out the way to identify the PLX bridge yet. So we
>>- * simply put the PCI bus and the subordinate behind the root
>>- * port to PE# here. The game rule here is expected to be changed
>>- * as soon as we can detected PLX bridge correctly.
>>- */
>>-static void pnv_pci_ioda_setup_PEs(void)
>>-{
>>- struct pci_controller *hose, *tmp;
>>- struct pnv_phb *phb;
>>-
>>- list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
>>- phb = hose->private_data;
>>-
>>- /* M64 layout might affect PE allocation */
>>- if (phb->reserve_m64_pe)
>>- phb->reserve_m64_pe(hose->bus, NULL, true);
>>-
>>- pnv_ioda_setup_PEs(hose->bus);
>>- }
>>-}
>>-
>> #ifdef CONFIG_PCI_IOV
>> static int pnv_pci_vf_release_m64(struct pci_dev *pdev, u16 num_vfs)
>> {
>>@@ -2391,8 +2377,13 @@ static void pnv_pci_ioda2_table_free_pages(struct iommu_table *tbl)
>> static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
>> struct pnv_ioda_pe *pe)
>> {
>>+ unsigned int weight;
>> int64_t rc;
>>
>>+ weight = pnv_pci_ioda_pe_dma_weight(pe);
>>+ if (!weight)
>>+ return;
>>+
>> /* TVE #1 is selected by PCI address bit 59 */
>> pe->tce_bypass_base = 1ull << 59;
>>
>>@@ -2424,33 +2415,6 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
>> pnv_ioda_setup_bus_dma(pe, pe->pbus);
>> }
>>
>>-static void pnv_pci_ioda1_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_list, list)
>>- pnv_pci_ioda1_setup_dma_pe(phb, pe);
>>-}
>>-
>>-static void pnv_pci_ioda2_setup_dma(struct pnv_phb *phb)
>>-{
>>- struct pnv_ioda_pe *pe;
>>- unsigned int weight;
>>-
>>- pnv_pci_ioda_setup_opal_tce_kill(phb);
>>-
>>- list_for_each_entry(pe, &phb->ioda.pe_list, list) {
>>- weight = pnv_pci_ioda_pe_dma_weight(pe);
>>- if (!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)
>> {
>>@@ -2914,37 +2878,6 @@ static void pnv_ioda_setup_pe_seg(struct pnv_ioda_pe *pe)
>> }
>> }
>>
>>-static void pnv_pci_ioda_setup_seg(void)
>>-{
>>- struct pci_controller *tmp, *hose;
>>- struct pnv_phb *phb;
>>- struct pnv_ioda_pe *pe;
>>-
>>- list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
>>- phb = hose->private_data;
>>- list_for_each_entry(pe, &phb->ioda.pe_list, list) {
>>- pnv_ioda_setup_pe_seg(pe);
>>- }
>>- }
>>-}
>>-
>>-static void pnv_pci_ioda_setup_DMA(void)
>>-{
>>- struct pci_controller *hose, *tmp;
>>- struct pnv_phb *phb;
>>-
>>- list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
>>- 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->initialized = 1;
>>- }
>>-}
>>-
>> static void pnv_pci_ioda_create_dbgfs(void)
>> {
>> #ifdef CONFIG_DEBUG_FS
>>@@ -2955,6 +2888,9 @@ static void pnv_pci_ioda_create_dbgfs(void)
>> list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
>> phb = hose->private_data;
>>
>>+ /* Notify initialization of PHB done */
>>+ phb->initialized = 1;
>>+
>> sprintf(name, "PCI%04x", hose->global_number);
>> phb->dbgfs = debugfs_create_dir(name, powerpc_debugfs_root);
>> if (!phb->dbgfs)
>>@@ -2966,10 +2902,6 @@ static void pnv_pci_ioda_create_dbgfs(void)
>>
>> static void pnv_pci_ioda_fixup(void)
>> {
>>- pnv_pci_ioda_setup_PEs();
>>- pnv_pci_ioda_setup_seg();
>>- pnv_pci_ioda_setup_DMA();
>>-
>> pnv_pci_ioda_create_dbgfs();
>>
>> #ifdef CONFIG_EEH
>>@@ -3019,6 +2951,104 @@ static resource_size_t pnv_pci_window_alignment(struct pci_bus *bus,
>> return phb->ioda.io_segsize;
>> }
>>
>>+/*
>>+ * We are updating root port or the upstream port of the
>>+ * bridge behind the root port with PHB's windows in order
>>+ * to accommodate the changes on required resources during
>>+ * PCI (slot) hotplug, which is connected to either root
>>+ * port or the downstream ports of PCIe switch behind the
>>+ * root port.
>>+ */
>>+static void pnv_pci_fixup_bridge_resources(struct pci_bus *bus,
>>+ unsigned long type)
>>+{
>>+ struct pci_controller *hose = pci_bus_to_host(bus);
>>+ struct pnv_phb *phb = hose->private_data;
>>+ struct pci_dev *bridge = bus->self;
>>+ struct resource *r, *w;
>>+ int i;
>>+
>>+ /* Check if we need apply fixup to the bridge's windows */
>>+ if (!pci_is_root_bus(bridge->bus) &&
>>+ !pci_is_root_bus(bridge->bus->self->bus))
>>+ return;
>>+
>>+ /* Fixup the resoureces */
>
>
>s/resoureces/resources/
>

Will fix.

>>+ for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++) {
>>+ r = &bridge->resource[PCI_BRIDGE_RESOURCES + i];
>>+ if (!r->flags || !r->parent)
>>+ continue;
>>+
>>+ w = NULL;
>>+ if (r->flags & type & IORESOURCE_IO)
>>+ w = &hose->io_resource;
>>+ else if (pnv_pci_is_mem_pref_64(r->flags) &&
>>+ (type & IORESOURCE_PREFETCH) &&
>>+ phb->ioda.m64_segsize)
>>+ w = &hose->mem_resources[1];
>>+ else if (r->flags & type & IORESOURCE_MEM)
>>+ w = &hose->mem_resources[0];
>>+
>>+ r->start = w->start;
>>+ r->end = w->end;
>>+ }
>>+}
>>+
>>+static void pnv_pci_setup_bridge(struct pci_bus *bus,
>>+ unsigned long type)
>>+{
>>+ struct pci_controller *hose = pci_bus_to_host(bus);
>>+ struct pnv_phb *phb = hose->private_data;
>>+ struct pci_dev *bridge = bus->self;
>>+ struct pnv_ioda_pe *pe;
>>+ bool all = (pci_pcie_type(bridge) == PCI_EXP_TYPE_PCI_BRIDGE);
>>+
>>+ /* The PE for root bus should be realized before any one else */
>>+ if (!phb->ioda.root_pe_populated) {
>>+ pe = pnv_ioda_setup_bus_PE(phb->hose->bus, false);
>>+ if (pe) {
>>+ phb->ioda.root_pe_idx = pe->pe_number;
>>+ phb->ioda.root_pe_populated = true;
>>+ }
>>+ }
>>+
>>+ /* Extend bridge's windows if necessary */
>>+ pnv_pci_fixup_bridge_resources(bus, type);
>>+
>>+ /* Don't assign PE to PCI bus, which doesn't have subordinate devices */
>>+ if (list_empty(&bus->devices))
>>+ return;
>>+
>>+ /* Reserve PEs according to used M64 resources */
>>+ if (phb->reserve_m64_pe)
>>+ phb->reserve_m64_pe(bus, NULL, all);
>>+
>>+ /*
>>+ * Assign PE. We might run here because of partial hotplug.
>>+ * For the case, we just pick up the existing PE and should
>>+ * not allocate resources again.
>>+ */
>>+ pe = pnv_ioda_setup_bus_PE(bus, all);
>>+ if (!pe)
>>+ return;
>>+
>>+ /* Setup MMIO mapping */
>>+ pnv_ioda_setup_pe_seg(pe);
>>+
>>+ /* Setup DMA */
>>+ switch (phb->type) {
>>+ case PNV_PHB_IODA1:
>>+ pnv_pci_ioda1_setup_dma_pe(phb, pe);
>>+ break;
>>+ case PNV_PHB_IODA2:
>>+ pnv_pci_ioda2_setup_dma_pe(phb, pe);
>>+ break;
>>+ default:
>>+ pr_warn("%s: No DMA for PHB#%d (type %d)\n",
>>+ __func__, phb->hose->global_number, phb->type);
>>+ }
>>+}
>>+
>> #ifdef CONFIG_PCI_IOV
>> static resource_size_t pnv_pci_iov_resource_alignment(struct pci_dev *pdev,
>> int resno)
>>@@ -3095,6 +3125,7 @@ static const struct pci_controller_ops pnv_pci_ioda_controller_ops = {
>> #endif
>> .enable_device_hook = pnv_pci_enable_device_hook,
>> .window_alignment = pnv_pci_window_alignment,
>>+ .setup_bridge = pnv_pci_setup_bridge,
>> .reset_secondary_bus = pnv_pci_reset_secondary_bus,
>> .dma_set_mask = pnv_pci_ioda_dma_set_mask,
>> .dma_get_required_mask = pnv_pci_ioda_dma_get_required_mask,
>>@@ -3168,6 +3199,9 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
>> if (phb->regs == NULL)
>> pr_err(" Failed to map registers !\n");
>>
>>+ /* Initialize TCE kill register */
>>+ pnv_pci_ioda_setup_opal_tce_kill(phb);
>>+
>> /* Initialize more IODA stuff */
>> phb->ioda.total_pe_num = 1;
>> prop32 = of_get_property(np, "ibm,opal-num-pes", NULL);
>>diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
>>index a8ba97f..ef5271a 100644
>>--- a/arch/powerpc/platforms/powernv/pci.h
>>+++ b/arch/powerpc/platforms/powernv/pci.h
>>@@ -121,6 +121,7 @@ struct pnv_phb {
>> unsigned int total_pe_num;
>> unsigned int reserved_pe_idx;
>> unsigned int root_pe_idx;
>>+ bool root_pe_populated;
>>
>> /* 32-bit MMIO window */
>> unsigned int m32_size;
>>

Thanks,
Gavin