Re: [PATCH V4 2/2] PCI/ACPI: hisi: Add ACPI support for HiSilicon SoCs Host Controllers

From: Dongdong Liu
Date: Wed Nov 16 2016 - 20:54:36 EST


Hi Bjorn

å 2016/11/17 3:31, Bjorn Helgaas åé:
On Wed, Nov 16, 2016 at 07:59:38PM +0800, Dongdong Liu wrote:
Hi Bjorn

Many Thanks for your review

å 2016/11/15 7:33, Bjorn Helgaas åé:
On Wed, Nov 09, 2016 at 05:14:57PM +0800, Dongdong Liu wrote:
PCIe controller in Hip05/HIP06/HIP07 SoCs is not ECAM compliant.
It is non ECAM only for the RC bus config space;for any other bus
underneath the root bus we support ECAM access.
Add specific quirks for PCI config space accessors.This involves:
1. New initialization call hisi_pcie_init() to obtain rc base
addresses from PNP0C02 as subdevice of PNP0A03.
2. New entry in common quirk array.

Signed-off-by: Dongdong Liu <liudongdong3@xxxxxxxxxx>
Signed-off-by: Gabriele Paoloni <gabriele.paoloni@xxxxxxxxxx>
---
MAINTAINERS | 1 +
drivers/acpi/pci_mcfg.c | 13 ++++
drivers/pci/host/Kconfig | 8 ++
drivers/pci/host/Makefile | 1 +
drivers/pci/host/pcie-hisi-acpi.c | 157 ++++++++++++++++++++++++++++++++++++++
include/linux/pci-ecam.h | 5 ++
6 files changed, 185 insertions(+)
create mode 100644 drivers/pci/host/pcie-hisi-acpi.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 1cd38a7..b224caa 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9358,6 +9358,7 @@ L: linux-pci@xxxxxxxxxxxxxxx
S: Maintained
F: Documentation/devicetree/bindings/pci/hisilicon-pcie.txt
F: drivers/pci/host/pcie-hisi.c
+F: drivers/pci/host/pcie-hisi-acpi.c

PCIE DRIVER FOR ROCKCHIP
M: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
diff --git a/drivers/acpi/pci_mcfg.c b/drivers/acpi/pci_mcfg.c
index ac21db3..b1b6fc7 100644
--- a/drivers/acpi/pci_mcfg.c
+++ b/drivers/acpi/pci_mcfg.c
@@ -57,6 +57,19 @@ struct mcfg_fixup {
{ "QCOM ", "QDF2432 ", 1, 5, MCFG_BUS_ANY, &pci_32b_ops },
{ "QCOM ", "QDF2432 ", 1, 6, MCFG_BUS_ANY, &pci_32b_ops },
{ "QCOM ", "QDF2432 ", 1, 7, MCFG_BUS_ANY, &pci_32b_ops },
+#ifdef CONFIG_PCI_HISI_ACPI
+ #define PCI_ACPI_QUIRK_QUAD_DOM(table_id, seg, ops) \
+ { "HISI ", table_id, 0, seg + 0, MCFG_BUS_ANY, ops }, \
+ { "HISI ", table_id, 0, seg + 1, MCFG_BUS_ANY, ops }, \
+ { "HISI ", table_id, 0, seg + 2, MCFG_BUS_ANY, ops }, \
+ { "HISI ", table_id, 0, seg + 3, MCFG_BUS_ANY, ops }
+ PCI_ACPI_QUIRK_QUAD_DOM("HIP05 ", 0, &hisi_pcie_ops),
+ PCI_ACPI_QUIRK_QUAD_DOM("HIP06 ", 0, &hisi_pcie_ops),
+ PCI_ACPI_QUIRK_QUAD_DOM("HIP07 ", 0, &hisi_pcie_ops),
+ PCI_ACPI_QUIRK_QUAD_DOM("HIP07 ", 4, &hisi_pcie_ops),
+ PCI_ACPI_QUIRK_QUAD_DOM("HIP07 ", 8, &hisi_pcie_ops),
+ PCI_ACPI_QUIRK_QUAD_DOM("HIP07 ", 12, &hisi_pcie_ops),
+#endif
};

static char mcfg_oem_id[ACPI_OEM_ID_SIZE];
diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index ae98644..9ff2bcd 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -227,6 +227,14 @@ config PCI_HISI
Say Y here if you want PCIe controller support on HiSilicon
Hip05 and Hip06 and Hip07 SoCs

+config PCI_HISI_ACPI
+ depends on ACPI && ARM64
+ bool "HiSilicon Hip05 and Hip06 and Hip07 SoCs ACPI PCIe controllers"
+ select PNP
+ help
+ Say Y here if you want ACPI PCIe controller support on HiSilicon
+ Hip05 and Hip06 and Hip07 SoCs
+
config PCIE_QCOM
bool "Qualcomm PCIe controller"
depends on ARCH_QCOM && OF
diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
index 084cb49..9402858 100644
--- a/drivers/pci/host/Makefile
+++ b/drivers/pci/host/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_PCIE_IPROC_BCMA) += pcie-iproc-bcma.o
obj-$(CONFIG_PCIE_ALTERA) += pcie-altera.o
obj-$(CONFIG_PCIE_ALTERA_MSI) += pcie-altera-msi.o
obj-$(CONFIG_PCI_HISI) += pcie-hisi.o
+obj-$(CONFIG_PCI_HISI_ACPI) += pcie-hisi-acpi.o
obj-$(CONFIG_PCIE_QCOM) += pcie-qcom.o
obj-$(CONFIG_PCI_HOST_THUNDER_ECAM) += pci-thunder-ecam.o
obj-$(CONFIG_PCI_HOST_THUNDER_PEM) += pci-thunder-pem.o
diff --git a/drivers/pci/host/pcie-hisi-acpi.c b/drivers/pci/host/pcie-hisi-acpi.c
new file mode 100644
index 0000000..aade4b5
--- /dev/null
+++ b/drivers/pci/host/pcie-hisi-acpi.c
@@ -0,0 +1,157 @@
+/*
+ * PCIe host controller driver for HiSilicon HipXX SoCs
+ *
+ * Copyright (C) 2016 HiSilicon Co., Ltd. http://www.hisilicon.com
+ *
+ * Author: Dongdong Liu <liudongdong3@xxxxxxxxxx>
+ * Gabriele Paoloni <gabriele.paoloni@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/pci.h>
+#include <linux/pci-acpi.h>
+#include <linux/pci-ecam.h>
+
+#define DEBUG0 0x728
+#define PCIE_LTSSM_LINKUP_STATE 0x11
+#define PCIE_LTSSM_STATE_MASK 0x3F

These are now unused.

Thanks for pointing that, will delete them.


+static const struct acpi_device_id hisi_pcie_rc_res_ids[] = {
+ {"HISI0081", 0},
+ {"", 0},
+};
+
+static int hisi_pcie_acpi_rd_conf(struct pci_bus *bus, u32 devfn, int where,
+ int size, u32 *val)
+{
+ struct pci_config_window *cfg = bus->sysdata;
+ int dev = PCI_SLOT(devfn);
+
+ if (bus->number == cfg->busr.start) {
+ /* access only one slot on each root port */
+ if (dev > 0)
+ return PCIBIOS_DEVICE_NOT_FOUND;
+ else
+ return pci_generic_config_read32(bus, devfn, where,
+ size, val);
+ }
+
+ return pci_generic_config_read(bus, devfn, where, size, val);
+}
+
+static int hisi_pcie_acpi_wr_conf(struct pci_bus *bus, u32 devfn,
+ int where, int size, u32 val)
+{
+ struct pci_config_window *cfg = bus->sysdata;
+ int dev = PCI_SLOT(devfn);
+
+ if (bus->number == cfg->busr.start) {
+ /* access only one slot on each root port */
+ if (dev > 0)
+ return PCIBIOS_DEVICE_NOT_FOUND;
+ else
+ return pci_generic_config_write32(bus, devfn, where,
+ size, val);
+ }
+
+ return pci_generic_config_write(bus, devfn, where, size, val);
+}
+
+static void __iomem *hisi_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
+ int where)
+{
+ struct pci_config_window *cfg = bus->sysdata;
+ void __iomem *reg_base = cfg->priv;
+
+ if (bus->number == cfg->busr.start)
+ return reg_base + where;
+ else
+ return pci_ecam_map_bus(bus, devfn, where);
+}
+
+/*
+ * Retrieve RC base and size from sub-device under the RC
+ * Device (RES1)
+ * {
+ * Name (_HID, "HISI0081")
+ * Name (_CID, "PNP0C02")
+ * Name (_CRS, ResourceTemplate (){
+ * Memory32Fixed (ReadWrite, 0xb0080000, 0x10000)
+ * })
+ * }
+ */
+static int hisi_pcie_rc_addr_get(struct acpi_device *adev,
+ void __iomem **addr)
+{
+ struct acpi_device *child_adev;
+ struct list_head list;
+ struct resource *res;
+ struct resource_entry *entry;
+ unsigned long flags;
+ int ret;
+
+ list_for_each_entry(child_adev, &adev->children, node) {
+ ret = acpi_match_device_ids(child_adev, hisi_pcie_rc_res_ids);
+ if (ret)
+ continue;
+
+ INIT_LIST_HEAD(&list);
+ flags = IORESOURCE_MEM;
+ ret = acpi_dev_get_resources(child_adev, &list,
+ acpi_dev_filter_resource_type_cb,
+ (void *)flags);
+ if (ret < 0) {
+ dev_err(&child_adev->dev,
+ "failed to parse _CRS method, error code %d\n",
+ ret);
+ return ret;
+ } else if (ret == 0) {
+ dev_err(&child_adev->dev,
+ "no IO and memory resources present in _CRS\n");
+ return -EINVAL;
+ }
+
+ entry = list_first_entry(&list, struct resource_entry, node);
+ res = entry->res;
+ *addr = devm_ioremap(&child_adev->dev,
+ res->start, resource_size(res));
+ acpi_dev_free_resource_list(&list);
+ if (IS_ERR(*addr)) {
+ dev_err(&child_adev->dev, "error with ioremap\n");
+ return -ENOMEM;
+ }
+
+ return 0;
+ }
+
+ return -EINVAL;
+}

OK, so MCFG (with the possible help of quirks) tells us where *most*
of this RC's ECAM space is, but it doesn't tell us where the root bus
ECAM space is, which is why we need this block of ugly code. Right?
Yes, correct.

Is there any way we can compute the root bus reg_base from the address
we got from MCFG?

No, we can not,because RC base addresses are sequntial and MCFG impose a 4k boundaries.

I understand the "no" part, but not the "because ..." part :)

I think the regions described by MCFG are aligned on 1MB boundaries,
not 4K, because MCFG tells you about ECAM space for a given bus number
range. Each bus can have 256 devices (5 bit device number + 3 bit
function number), and each device has 4K of config space. 256 * 4KB =
1MB.

Yes, your are right, thanks for your explanation.


In any case, it wouldn't have to be a simple function like this:

reg_base = pci_mcfg_lookup(seg, [bus 01]) - 1MB

It could be *anything*, e.g.,

reg_base = 0x00100000 + (bus_num * 4096);

Our hip06 SoC has 4 RCs. Each RCs has one root port. The RCs base addresses are as below.

RC0 0xa0090000~0xa009ffff
RC2 0xa00a0000~0xa00affff
RC3 0xa00b0000~0xa00bffff
RC1 0xa0200000~0xa020ffff

The size is 64K ,the base addresses can be changed by UEFI but the size is fixed.
4k is for RC itself config space, the left 60K spaces are for other uses.

The regions described by MCFG are aligned on 1MB boundaries,
So we can not get our RC base adreses from MCFG.

Is it a constant that realistically is not going to be modified?

Yes, this is a hardware limitation

If there's only one RC and the address is a constant, maybe you can
just hard-code the address in the .map_bus() function?

As above said, the base adresses can be changed by UEFI but the size is fixed.
hard-code maybe not a good way.

Thanks
Dongdong

Bjorn
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