Re: [RFC PATCH v2 1/1] PCI/ACPI: xgene: Add ECAM quirk for X-Gene PCIe controller

From: Bjorn Helgaas
Date: Wed Nov 02 2016 - 12:53:47 EST


Hi Duc,

On Tue, Oct 25, 2016 at 06:24:32PM -0700, Duc Dang wrote:
> PCIe controllers in X-Gene SoCs is not ECAM compliant: software
> needs to configure additional controller's register to address
> device at bus:dev:function.
>
> This patch depends on "ECAM quirks handling for ARM64 platforms"
> series (http://www.spinics.net/lists/arm-kernel/msg530692.html,
> the series was also modified by Bjorn) to address the limitation
> above for X-Gene PCIe controller.
>
> The quirk will only be applied for X-Gene PCIe MCFG table with
> OEM revison 1, 2, 3 or 4 (PCIe controller v1 and v2 on X-Gene SoCs).

The quirks here contain some hard-coded address space consumed by
ECAM. The ECAM quirk itself is not a generic description of that
address space in the sense of a PCI BAR or an ACPI _CRS method, i.e.,
the quirk description is not enough to keep other parts of the kernel
from treating the address space as "available".

Can you add a note here in the changelog about how you are describing
this space generically? The standard solution is a PNP0C02 device
with _CRS that describes it.

It would be ideal if you could open a bugzilla at bugzilla.kernel.org
and attach there a dmesg log, /proc/iomem contents, and DSDT. This
would show both the generic PNP0C02 piece and the ECAM quirk piece.

BTW, I did refresh and re-push the pci/ecam-v6 branch where I'm
collecting this stuff, so if you want to rebase your patch on top of
that and test it, that would be great.

> Signed-off-by: Duc Dang <dhdang@xxxxxxx>
> ---
> v2 changes:
> 1. Get rid of pci-xgene-ecam.c file and fold quirk code into pci-xgene.c
> 2. Redefine fixup array for X-Gene
> 3. Use devm_ioremap_resource to map csr_base
>
> drivers/acpi/pci_mcfg.c | 30 ++++++++
> drivers/pci/host/pci-xgene.c | 165 ++++++++++++++++++++++++++++++++++++++++++-
> include/linux/pci-ecam.h | 5 ++
> 3 files changed, 197 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/acpi/pci_mcfg.c b/drivers/acpi/pci_mcfg.c
> index bb2c508..9dfc937 100644
> --- a/drivers/acpi/pci_mcfg.c
> +++ b/drivers/acpi/pci_mcfg.c
> @@ -96,6 +96,36 @@ struct mcfg_fixup {
> THUNDER_ECAM_MCFG(2, 12),
> THUNDER_ECAM_MCFG(2, 13),
> #endif
> +#ifdef CONFIG_PCI_XGENE
> +#define XGENE_V1_ECAM_MCFG(rev, seg) \
> + {"APM ", "XGENE ", rev, seg, MCFG_BUS_ANY, \
> + &xgene_v1_pcie_ecam_ops }
> +#define XGENE_V2_1_ECAM_MCFG(rev, seg) \
> + {"APM ", "XGENE ", rev, seg, MCFG_BUS_ANY, \
> + &xgene_v2_1_pcie_ecam_ops }
> +#define XGENE_V2_2_ECAM_MCFG(rev, seg) \
> + {"APM ", "XGENE ", rev, seg, MCFG_BUS_ANY, \
> + &xgene_v2_2_pcie_ecam_ops }
> +
> + /* X-Gene SoC with v1 PCIe controller */
> + XGENE_V1_ECAM_MCFG(1, 0),
> + XGENE_V1_ECAM_MCFG(1, 1),
> + XGENE_V1_ECAM_MCFG(1, 2),
> + XGENE_V1_ECAM_MCFG(1, 3),
> + XGENE_V1_ECAM_MCFG(1, 4),
> + XGENE_V1_ECAM_MCFG(2, 0),
> + XGENE_V1_ECAM_MCFG(2, 1),
> + XGENE_V1_ECAM_MCFG(2, 2),
> + XGENE_V1_ECAM_MCFG(2, 3),
> + XGENE_V1_ECAM_MCFG(2, 4),
> + /* X-Gene SoC with v2.1 PCIe controller */
> + XGENE_V2_1_ECAM_MCFG(3, 0),
> + XGENE_V2_1_ECAM_MCFG(3, 1),
> + /* X-Gene SoC with v2.2 PCIe controller */
> + XGENE_V2_2_ECAM_MCFG(4, 0),
> + XGENE_V2_2_ECAM_MCFG(4, 1),
> + XGENE_V2_2_ECAM_MCFG(4, 2),
> +#endif
> };
>
> static char mcfg_oem_id[ACPI_OEM_ID_SIZE];
> diff --git a/drivers/pci/host/pci-xgene.c b/drivers/pci/host/pci-xgene.c
> index 1de23d7..d6aa642 100644
> --- a/drivers/pci/host/pci-xgene.c
> +++ b/drivers/pci/host/pci-xgene.c
> @@ -27,6 +27,8 @@
> #include <linux/of_irq.h>
> #include <linux/of_pci.h>
> #include <linux/pci.h>
> +#include <linux/pci-acpi.h>
> +#include <linux/pci-ecam.h>
> #include <linux/platform_device.h>
> #include <linux/slab.h>
>
> @@ -64,6 +66,7 @@
> /* PCIe IP version */
> #define XGENE_PCIE_IP_VER_UNKN 0
> #define XGENE_PCIE_IP_VER_1 1
> +#define XGENE_PCIE_IP_VER_2 2
>
> struct xgene_pcie_port {
> struct device_node *node;
> @@ -97,7 +100,15 @@ static inline u32 pcie_bar_low_val(u32 addr, u32 flags)
> */
> static void __iomem *xgene_pcie_get_cfg_base(struct pci_bus *bus)
> {
> - struct xgene_pcie_port *port = bus->sysdata;
> + struct pci_config_window *cfg;
> + struct xgene_pcie_port *port;
> +
> + if (acpi_disabled)
> + port = bus->sysdata;
> + else {
> + cfg = bus->sysdata;
> + port = cfg->priv;
> + }
>
> if (bus->number >= (bus->primary + 1))
> return port->cfg_base + AXI_EP_CFG_ACCESS;
> @@ -111,10 +122,18 @@ static void __iomem *xgene_pcie_get_cfg_base(struct pci_bus *bus)
> */
> static void xgene_pcie_set_rtdid_reg(struct pci_bus *bus, uint devfn)
> {
> - struct xgene_pcie_port *port = bus->sysdata;
> + struct pci_config_window *cfg;
> + struct xgene_pcie_port *port;
> unsigned int b, d, f;
> u32 rtdid_val = 0;
>
> + if (acpi_disabled)
> + port = bus->sysdata;
> + else {
> + cfg = bus->sysdata;
> + port = cfg->priv;
> + }
> +
> b = bus->number;
> d = PCI_SLOT(devfn);
> f = PCI_FUNC(devfn);
> @@ -158,7 +177,15 @@ static void __iomem *xgene_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
> static int xgene_pcie_config_read32(struct pci_bus *bus, unsigned int devfn,
> int where, int size, u32 *val)
> {
> - struct xgene_pcie_port *port = bus->sysdata;
> + struct pci_config_window *cfg;
> + struct xgene_pcie_port *port;
> +
> + if (acpi_disabled)
> + port = bus->sysdata;
> + else {
> + cfg = bus->sysdata;
> + port = cfg->priv;
> + }
>
> if (pci_generic_config_read32(bus, devfn, where & ~0x3, 4, val) !=
> PCIBIOS_SUCCESSFUL)
> @@ -189,6 +216,138 @@ static int xgene_pcie_config_read32(struct pci_bus *bus, unsigned int devfn,
> .write = pci_generic_config_write32,
> };
>
> +#ifdef CONFIG_ACPI
> +static struct resource xgene_v1_csr_res[] = {
> + [0] = DEFINE_RES_MEM(0x1f2b0000UL, SZ_64K),
> + [1] = DEFINE_RES_MEM(0x1f2c0000UL, SZ_64K),
> + [2] = DEFINE_RES_MEM(0x1f2d0000UL, SZ_64K),
> + [3] = DEFINE_RES_MEM(0x1f500000UL, SZ_64K),
> + [4] = DEFINE_RES_MEM(0x1f510000UL, SZ_64K),
> +};
> +
> +static int xgene_v1_pcie_ecam_init(struct pci_config_window *cfg)
> +{
> + struct acpi_device *adev = to_acpi_device(cfg->parent);
> + struct acpi_pci_root *root = acpi_driver_data(adev);
> + struct device *dev = cfg->parent;
> + struct xgene_pcie_port *port;
> + struct resource *csr;
> +
> + port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
> + if (!port)
> + return -ENOMEM;
> +
> + csr = &xgene_v1_csr_res[root->segment];
> + port->csr_base = devm_ioremap_resource(dev, csr);
> + if (IS_ERR(port->csr_base)) {
> + kfree(port);
> + return -ENOMEM;
> + }
> +
> + port->cfg_base = cfg->win;
> + port->version = XGENE_PCIE_IP_VER_1;
> +
> + cfg->priv = port;
> +
> + return 0;
> +}
> +
> +struct pci_ecam_ops xgene_v1_pcie_ecam_ops = {
> + .bus_shift = 16,
> + .init = xgene_v1_pcie_ecam_init,
> + .pci_ops = {
> + .map_bus = xgene_pcie_map_bus,
> + .read = xgene_pcie_config_read32,
> + .write = pci_generic_config_write,
> + }
> +};
> +
> +static struct resource xgene_v2_1_csr_res[] = {
> + [0] = DEFINE_RES_MEM(0x1f2b0000UL, SZ_64K),
> + [1] = DEFINE_RES_MEM(0x1f2c0000UL, SZ_64K),
> +};
> +
> +static int xgene_v2_1_pcie_ecam_init(struct pci_config_window *cfg)
> +{
> + struct acpi_device *adev = to_acpi_device(cfg->parent);
> + struct acpi_pci_root *root = acpi_driver_data(adev);
> + struct device *dev = cfg->parent;
> + struct xgene_pcie_port *port;
> + struct resource *csr;
> +
> + port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
> + if (!port)
> + return -ENOMEM;
> +
> + csr = &xgene_v2_1_csr_res[root->segment];
> + port->csr_base = devm_ioremap_resource(dev, csr);
> + if (IS_ERR(port->csr_base)) {
> + kfree(port);
> + return -ENOMEM;
> + }
> +
> + port->cfg_base = cfg->win;
> + port->version = XGENE_PCIE_IP_VER_2;
> +
> + cfg->priv = port;
> +
> + return 0;
> +}
> +
> +struct pci_ecam_ops xgene_v2_1_pcie_ecam_ops = {
> + .bus_shift = 16,
> + .init = xgene_v2_1_pcie_ecam_init,
> + .pci_ops = {
> + .map_bus = xgene_pcie_map_bus,
> + .read = xgene_pcie_config_read32,
> + .write = pci_generic_config_write,
> + }
> +};
> +
> +static struct resource xgene_v2_2_csr_res[] = {
> + [0] = DEFINE_RES_MEM(0x1f2b0000UL, SZ_64K),
> + [1] = DEFINE_RES_MEM(0x1f500000UL, SZ_64K),
> + [2] = DEFINE_RES_MEM(0x1f2d0000UL, SZ_64K),
> +};
> +
> +static int xgene_v2_2_pcie_ecam_init(struct pci_config_window *cfg)
> +{
> + struct acpi_device *adev = to_acpi_device(cfg->parent);
> + struct acpi_pci_root *root = acpi_driver_data(adev);
> + struct device *dev = cfg->parent;
> + struct xgene_pcie_port *port;
> + struct resource *csr;
> +
> + port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
> + if (!port)
> + return -ENOMEM;
> +
> + csr = &xgene_v2_2_csr_res[root->segment];
> + port->csr_base = devm_ioremap_resource(dev, csr);
> + if (IS_ERR(port->csr_base)) {
> + kfree(port);
> + return -ENOMEM;
> + }
> +
> + port->cfg_base = cfg->win;
> + port->version = XGENE_PCIE_IP_VER_2;
> +
> + cfg->priv = port;
> +
> + return 0;
> +}
> +
> +struct pci_ecam_ops xgene_v2_2_pcie_ecam_ops = {
> + .bus_shift = 16,
> + .init = xgene_v2_2_pcie_ecam_init,
> + .pci_ops = {
> + .map_bus = xgene_pcie_map_bus,
> + .read = xgene_pcie_config_read32,
> + .write = pci_generic_config_write,
> + }
> +};
> +#endif
> +
> static u64 xgene_pcie_set_ib_mask(struct xgene_pcie_port *port, u32 addr,
> u32 flags, u64 size)
> {
> diff --git a/include/linux/pci-ecam.h b/include/linux/pci-ecam.h
> index 35f0e81..40da3e7 100644
> --- a/include/linux/pci-ecam.h
> +++ b/include/linux/pci-ecam.h
> @@ -65,6 +65,11 @@ void __iomem *pci_ecam_map_bus(struct pci_bus *bus, unsigned int devfn,
> #ifdef CONFIG_PCI_HOST_THUNDER_ECAM
> extern struct pci_ecam_ops pci_thunder_ecam_ops;
> #endif
> +#ifdef CONFIG_PCI_XGENE
> +extern struct pci_ecam_ops xgene_v1_pcie_ecam_ops;
> +extern struct pci_ecam_ops xgene_v2_1_pcie_ecam_ops;
> +extern struct pci_ecam_ops xgene_v2_2_pcie_ecam_ops;
> +#endif
>
> #ifdef CONFIG_PCI_HOST_GENERIC
> /* for DT-based PCI controllers that support ECAM */
> --
> 1.9.1
>