Hi Mark

-----Original Message-----
From: Mark Rutland [mailto:mark.rutland at arm.com]
Sent: 09 February 2016 18:24
To: Gabriele Paoloni
Cc: Guohanjun (Hanjun Guo); Wangzhou (B); liudongdong (C); Linuxarm;
qiujiang; bhelgaas at google.com; arnd at arndb.de;
Lorenzo.Pieralisi at arm.com; tn at semihalf.com; linux-pci at vger.kernel.org;
linux-kernel at vger.kernel.org; xuwei (O); linux-acpi at vger.kernel.org;
jcm at redhat.com; zhangjukuo; Liguozhu (Kenneth); linux-arm-
kernel at lists.infradead.org
Subject: Re: [RFC PATCH v3 3/3] PCI/ACPI: hisi: Add ACPI support for
HiSilicon SoCs Host Controllers

On Tue, Feb 09, 2016 at 05:34:20PM +0000, Gabriele Paoloni wrote:

quoted

From: gabriele paoloni <redacted>

This patch adds specific quirks for PCI config space accessors,
it uses _HID to decide whether to hook pci_ops or not.

If I understand correctly, this would mean that it's not actually ECAM
compliant, then?

Correct we need out own methods to read/write the RC config space...see
for example:

+	if (bus->number == root->secondary.start)
+		return hisi_pcie_common_cfg_read(reg_base, where, size, val);
+
+	return pci_generic_config_read(bus, devfn, where, size, val);

quoted

Signed-off-by: Dongdong Liu <redacted>
Signed-off-by: Gabriele Paoloni <redacted>
---
 MAINTAINERS                       |   1 +
 drivers/pci/host/Kconfig          |   8 ++
 drivers/pci/host/Makefile         |   1 +
 drivers/pci/host/pcie-hisi-acpi.c | 188

++++++++++++++++++++++++++++++++++++++

quoted

 drivers/pci/host/pcie-hisi.c      |   2 -
 drivers/pci/host/pcie-hisi.h      |   2 +
 6 files changed, 200 insertions(+), 2 deletions(-)
 create mode 100644 drivers/pci/host/pcie-hisi-acpi.c

diff --git a/MAINTAINERS b/MAINTAINERS
index d69f436..f184c3e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS

@@ -8412,6 +8412,7 @@ F:

	Documentation/devicetree/bindings/pci/hisilicon-pcie.txt

quoted

 F:	drivers/pci/host/pcie-hisi.h
 F:	drivers/pci/host/pcie-hisi.c
 F:	drivers/pci/host/pcie-hisi-common.c
+F:	drivers/pci/host/pcie-hisi-acpi.c

 PCIE DRIVER FOR QUALCOMM MSM
 M:     Stanimir Varbanov [off-list ref]

diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index 75a6054..65b1add 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig

@@ -181,6 +181,14 @@ config PCI_HISI
 	  Say Y here if you want PCIe controller support on HiSilicon
 	  Hip05 and Hip06 SoCs

+config PCI_HISI_ACPI
+	depends on ACPI
+	bool "HiSilicon Hip05 and Hip06 SoCs ACPI PCIe controllers"
+	select ACPI_PCI_HOST_GENERIC
+	help
+	  Say Y here if you want ACPI PCIe controller support on

HiSilicon

quoted

+	  Hip05 and Hip06 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 8c93c0f..57e4379 100644
--- a/drivers/pci/host/Makefile
+++ b/drivers/pci/host/Makefile

@@ -21,4 +21,5 @@ 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 pcie-hisi-common.o
+obj-$(CONFIG_PCI_HISI_ACPI) += pcie-hisi-acpi.o pcie-hisi-common.o
 obj-$(CONFIG_PCIE_QCOM) += pcie-qcom.o

diff --git a/drivers/pci/host/pcie-hisi-acpi.c

b/drivers/pci/host/pcie-hisi-acpi.c

quoted

new file mode 100644
index 0000000..3605260

--- /dev/null
+++ b/drivers/pci/host/pcie-hisi-acpi.c

@@ -0,0 +1,188 @@
+/*
+ * PCIe host controller driver for HiSilicon HipXX SoCs
+ *
+ * Copyright (C) 2016 HiSilicon Co., Ltd. http://www.hisilicon.com
+ *
+ * Author: Dongdong Liu <liudongdong3@huawei.com>
+ *         Gabriele Paoloni <gabriele.paoloni@huawei.com>
+ *
+ * This program is free software; you can redistribute it and/or

modify

quoted

+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/interrupt.h>
+#include <linux/acpi.h>
+#include <linux/ecam.h>
+#include <linux/pci.h>
+#include <linux/pci-acpi.h>
+#include "pcie-hisi.h"
+
+#define GET_PCIE_LINK_STATUS  0x0
+
+/* uuid 6d30f553-836c-408e-b6ad-45bccc957949 */
+const u8 hisi_pcie_acpi_dsm_uuid[] = {
+	0x53, 0xf5, 0x30, 0x6d, 0x6c, 0x83, 0x8e, 0x40,
+	0xb6, 0xad, 0x45, 0xbc, 0xcc, 0x95, 0x79, 0x49
+};
+
+static const struct acpi_device_id hisi_pcie_ids[] = {
+	{"HISI0080", 0},
+	{"", 0},
+};
+
+static int hisi_pcie_get_addr(struct acpi_pci_root *root, const char

*name,

quoted

+				void __iomem **addr)
+{
+	struct acpi_device *device;
+	u64 base;
+	u64 size;
+	u32 buf[4];
+	int ret;
+
+	device =  root->device;
+	ret = fwnode_property_read_u32_array(&device->fwnode, name,
+					buf, ARRAY_SIZE(buf));
+	if (ret) {
+		dev_err(&device->dev, "can't get %s\n", name);
+		return ret;
+	}
+
+	base = ((u64)buf[0] << 32) | buf[1];
+	size =  ((u64)buf[2] << 32) | buf[3];
+	*addr = devm_ioremap(&device->dev, base, size);
+	if (!(*addr)) {
+		dev_err(&device->dev, "error with ioremap\n");
+		return -ENOMEM;
+	}

This does not seem like the correct way of describing an addres in
ACPI.

Ok I guess this is related to the comment below...

quoted

+
+	return 0;
+}
+
+
+static int hisi_pcie_link_up_acpi(struct acpi_pci_root *root)
+{
+	u32 val;
+	struct acpi_device *device;
+	union acpi_object *obj;
+
+	device = root->device;
+	obj = acpi_evaluate_dsm(device->handle,
+		hisi_pcie_acpi_dsm_uuid, 0,
+		GET_PCIE_LINK_STATUS, NULL);
+
+	if (!obj  ||  obj->type != ACPI_TYPE_INTEGER)  {
+		dev_err(&device->dev, "can't get link status from _DSM\n");
+		return 0;
+	}
+	val = obj->integer.value;
+
+	return ((val & PCIE_LTSSM_STATE_MASK) ==

PCIE_LTSSM_LINKUP_STATE);

quoted

+
+}
+
+/*
+ * Retrieve rc_dbi base and size from _DSD
+ * Name (_DSD, Package () {
+ *	ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+ *	Package () {
+ *	Package () {"rc-dbi", Package () { 0x0, 0xb0080000, 0x0, 0x10000

}},

quoted

+ *	}
+ *	})
+ */

As above, this does not look right. ACPI has standard mechanisms for
describing addresses. Making something up like this is not a good idea.

 
I am quite new to ACPI, may I ask you to explain a bit? 
In our case we need to put somewhere in the ACPI table the value of 
the base register address used to read/write the RC config space... 

Do you have any suggestion about the correct place to put it?

Many Thanks

Gab

Mark.