Subject: Re: [RFC PATCH V3 11/17] ppc/pnv: Expand VF resources according to the number of total_pe

From: Gavin Shan <[email-masked]>
Date: Mon, 23 Jun 2014 16:07:07 +1000

On Tue, Jun 10, 2014 at 09:56:33AM +0800, Wei Yang wrote:
>On PHB3, VF resources will be covered by M64 BAR to have better PE isolation.
>Mostly the total_pe number is different from the total_VFs, which will lead to
>a conflict between MMIO space and the PE number.
>
>This patch expands the VF resource size to reserve total_pe number of VFs'
>resource, which prevents the conflict.
>
>Signed-off-by: Wei Yang <[email-masked]>
>---
> arch/powerpc/include/asm/machdep.h        |    6 +++
> arch/powerpc/include/asm/pci-bridge.h     |    3 ++
> arch/powerpc/kernel/pci-common.c          |   15 ++++++
> arch/powerpc/platforms/powernv/pci-ioda.c |   83 +++++++++++++++++++++++++++++
> 4 files changed, 107 insertions(+)
>
>diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h
>index ad3025d..2f2e770 100644
>--- a/arch/powerpc/include/asm/machdep.h
>+++ b/arch/powerpc/include/asm/machdep.h
>@@ -234,9 +234,15 @@ struct machdep_calls {
>
> 	/* Called after scan and before resource survey */
> 	void (*pcibios_fixup_phb)(struct pci_controller *hose);
>+#ifdef CONFIG_PCI_IOV
>+	void (*pcibios_fixup_sriov)(struct pci_bus *bus);
>+#endif /* CONFIG_PCI_IOV */
>
> 	/* Called during PCI resource reassignment */
> 	resource_size_t (*pcibios_window_alignment)(struct pci_bus *, unsigned long type);
>+#ifdef CONFIG_PCI_IOV
>+	resource_size_t (*__pci_sriov_resource_size)(struct pci_dev *, int resno);

	resource_size_t (*pcibios_sriov_resource_size)(struct pci_dev *, int resno);

You probably can put all SRIOV related functions together:

#ifdef CONFIG_PCI_IOV
	func_a;
	func_b;
	 :
#endif

>+#endif /* CONFIG_PCI_IOV */
>
> 	/* Called to shutdown machine specific hardware not already controlled
> 	 * by other drivers.
>diff --git a/arch/powerpc/include/asm/pci-bridge.h b/arch/powerpc/include/asm/pci-bridge.h
>index 4ca90a3..8c849d8 100644
>--- a/arch/powerpc/include/asm/pci-bridge.h
>+++ b/arch/powerpc/include/asm/pci-bridge.h
>@@ -168,6 +168,9 @@ struct pci_dn {
> #define IODA_INVALID_PE		(-1)
> #ifdef CONFIG_PPC_POWERNV
> 	int	pe_number;
>+#ifdef CONFIG_PCI_IOV
>+	u16     vfs;
>+#endif /* CONFIG_PCI_IOV */
> #endif
> };
>
>diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
>index c449a26..c4e2e92 100644
>--- a/arch/powerpc/kernel/pci-common.c
>+++ b/arch/powerpc/kernel/pci-common.c
>@@ -120,6 +120,16 @@ resource_size_t pcibios_window_alignment(struct pci_bus *bus,
> 	return 1;
> }
>
>+#ifdef CONFIG_PCI_IOV
>+resource_size_t pcibios_sriov_resource_size(struct pci_dev *pdev, int resno)
>+{
>+	if (ppc_md.__pci_sriov_resource_size)
>+		return ppc_md.__pci_sriov_resource_size(pdev, resno);
>+
>+	return 0;
>+}
>+#endif /* CONFIG_PCI_IOV */
>+
> static resource_size_t pcibios_io_size(const struct pci_controller *hose)
> {
> #ifdef CONFIG_PPC64
>@@ -1675,6 +1685,11 @@ void pcibios_scan_phb(struct pci_controller *hose)
> 	if (ppc_md.pcibios_fixup_phb)
> 		ppc_md.pcibios_fixup_phb(hose);
>
>+#ifdef CONFIG_PCI_IOV
>+	if (ppc_md.pcibios_fixup_sriov)
>+		ppc_md.pcibios_fixup_sriov(bus);

One question I probably asked before: why we can't put the logic
of ppc_md.pcibios_fixup_sriov() to ppc_md.pcibios_fixup_phb()?

>+#endif /* CONFIG_PCI_IOV */
>+
> 	/* Configure PCI Express settings */
> 	if (bus && !pci_has_flag(PCI_PROBE_ONLY)) {
> 		struct pci_bus *child;
>diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>index 87cb3089..7dfad6a 100644
>--- a/arch/powerpc/platforms/powernv/pci-ioda.c
>+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>@@ -1298,6 +1298,67 @@ static void pnv_pci_init_ioda_msis(struct pnv_phb *phb)
> static void pnv_pci_init_ioda_msis(struct pnv_phb *phb) { }
> #endif /* CONFIG_PCI_MSI */
>
>+#ifdef CONFIG_PCI_IOV
>+static void pnv_pci_ioda_fixup_iov_resources(struct pci_dev *pdev)
>+{
>+	struct pci_controller *hose;
>+	struct pnv_phb *phb;
>+	struct resource *res;
>+	int i;
>+	resource_size_t size;
>+	struct pci_dn *pdn;
>+
>+	if (!pdev->is_physfn || pdev->is_added)
>+		return;
>+
>+	hose = pci_bus_to_host(pdev->bus);
>+	if (!hose) {
>+		dev_err(&pdev->dev, "%s: NULL pci_controller\n", __func__);
>+		return;
>+	}
>+
>+	phb = hose->private_data;
>+	if (!phb) {
>+		dev_err(&pdev->dev, "%s: NULL PHB\n", __func__);
>+		return;
>+	}
>+
>+	pdn = pci_get_pdn(pdev);
>+	pdn->vfs = 0;
>+
>+	for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++) {
>+		res = &pdev->resource[i];
>+		if (!res->flags || res->parent)
>+			continue;
>+
>+		if (!is_mem_pref_64_type(res->flags))
>+			continue;
>+
>+		dev_info(&pdev->dev, "PowerNV: Fixing VF BAR[%d] %pR to\n",
>+				i, res);
>+		size = pci_sriov_resource_size(pdev, i);
>+		res->end = res->start + size * phb->ioda.total_pe - 1;
>+		dev_info(&pdev->dev, "                       %pR\n", res);
>+	}
>+	pdn->vfs = phb->ioda.total_pe;
>+}
>+
>+static void pnv_pci_ioda_fixup_sriov(struct pci_bus *bus)
>+{
>+	struct pci_dev *pdev;
>+	struct pci_bus *b;
>+
>+	list_for_each_entry(pdev, &bus->devices, bus_list) {
>+		b = pdev->subordinate;
>+
>+		if (b)
>+			pnv_pci_ioda_fixup_sriov(b);
>+
>+		pnv_pci_ioda_fixup_iov_resources(pdev);
>+	}
>+}
>+#endif /* CONFIG_PCI_IOV */
>+
> /*
>  * This function is supposed to be called on basis of PE from top
>  * to bottom style. So the the I/O or MMIO segment assigned to
>@@ -1498,6 +1559,22 @@ static resource_size_t pnv_pci_window_alignment(struct pci_bus *bus,
> 	return phb->ioda.io_segsize;
> }
>
>+#ifdef CONFIG_PCI_IOV
>+static resource_size_t __pnv_pci_sriov_resource_size(struct pci_dev *pdev, int resno)
>+{
>+	struct pci_dn *pdn = pci_get_pdn(pdev);
>+	u64 size = 0;
>+
>+	if (!pdn->vfs)
>+		return size;
>+
>+	size = resource_size(pdev->resource + resno);
>+	do_div(size, pdn->vfs);
>+
>+	return size;
>+}
>+#endif /* CONFIG_PCI_IOV */
>+
> /* Prevent enabling devices for which we couldn't properly
>  * assign a PE
>  */
>@@ -1692,9 +1769,15 @@ void __init pnv_pci_init_ioda_phb(struct device_node *np,
> 	 * for the P2P bridge bars so that each PCI bus (excluding
> 	 * the child P2P bridges) can form individual PE.
> 	 */
>+#ifdef CONFIG_PCI_IOV
>+	ppc_md.pcibios_fixup_sriov = pnv_pci_ioda_fixup_sriov;
>+#endif /* CONFIG_PCI_IOV */
> 	ppc_md.pcibios_fixup = pnv_pci_ioda_fixup;
> 	ppc_md.pcibios_enable_device_hook = pnv_pci_enable_device_hook;
> 	ppc_md.pcibios_window_alignment = pnv_pci_window_alignment;
>+#ifdef CONFIG_PCI_IOV
>+	ppc_md.__pci_sriov_resource_size = __pnv_pci_sriov_resource_size;
>+#endif /* CONFIG_PCI_IOV */
> 	pci_add_flags(PCI_REASSIGN_ALL_RSRC);
>
> 	/* Reset IODA tables to a clean state */

Thanks,
Gavin