From: Arnd Bergmann <arnd@arndb.de>
To: Dongdong Liu <liudongdong3@huawei.com>
Cc: helgaas@kernel.org, rafael@kernel.org, Lorenzo.Pieralisi@arm.com,
tn@semihalf.com, wangzhou1@hisilicon.com,
pratyush.anand@gmail.com, linux-pci@vger.kernel.org,
linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org,
jcm@redhat.com, gabriele.paoloni@huawei.com,
charles.chenxin@huawei.com, hanjun.guo@linaro.org,
linuxarm@huawei.com
Subject: Re: [RFC PATCH V2 1/3] PCI: hisi: re-architect Hip05/Hip06 controllers driver to preapare for ACPI
Date: Thu, 01 Sep 2016 16:02:19 +0200 [thread overview]
Message-ID: <6532722.cVEMfv9Kqj@wuerfel> (raw)
In-Reply-To: <57C822C1.9000203@huawei.com>
On Thursday, September 1, 2016 8:44:49 PM CEST Dongdong Liu wrote:
> 在 2016/9/1 15:41, Arnd Bergmann 写道:
> > On Thursday, September 1, 2016 10:05:29 AM CEST Dongdong Liu wrote:
> >> 在 2016/8/31 19:45, Arnd Bergmann 写道:
> >>> On Wednesday, August 31, 2016 7:48:12 PM CEST Dongdong Liu wrote:
> I know your point.
>
> 1. For our host bridge , ".map_bus = pci_ecam_map_bus" is only suitable for
> accessing the EP config space.
> pci_generic_config_read32() need to call "addr = bus->ops->map_bus(bus, devfn, where & ~0x3);",
>
> drivers/pci/host/pcie-hisi-acpi.c
> static struct pci_ops hisi_pcie_ops = {
> .map_bus = pci_ecam_map_bus,
> .read = hisi_pcie_acpi_rd_conf,
> .write = hisi_pcie_acpi_wr_conf,
> };
>
> Yes, we can change ".map_bus = pci_ecam_map_bus" to ".map_bus = hisi_pci_map_bus", and implentment hisi_pci_map_bus as below,
> then we will not need to call hisi_pcie_common_cfg_read().
>
> void __iomem *hisi_pci_map_bus(struct pci_bus *bus, unsigned int devfn, int where)
> {
> struct pci_config_window *cfg = bus->sysdata;
> void __iomem *reg_base = cfg->priv;
>
> /* for RC config access*/
> if (bus->number == cfg->busr.start)
> return reg_base + (where & ~0x3);
> else
> /* for EP config access */
> return pci_ecam_map_bus(bus, devfn, where);
> }
>
> and hisi_pcie_acpi_rd_conf() need to change as below.
> 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;
>
> if (hisi_pcie_acpi_valid_config(cfg, bus, PCI_SLOT(devfn)) == 0)
> return PCIBIOS_DEVICE_NOT_FOUND;
>
> /* access RC config space */
> if (bus->number == cfg->busr.start)
> return pci_generic_config_read32(bus, devfn, where, size, val);
>
> /* access EP config space */
> return pci_generic_config_read(bus, devfn, where, size, val);
> }
Right, this is what I had in mind.
> 2. We need to backward compatible with the old dt way config access as below code,
> so we have to call hisi_pcie_common_cfg_read() when accessing the RC config space.
> For this, we have to call hisi_pcie_common_cfg_read().
>
> drivers/pci/host/pcie-hisi.c
> static inline int hisi_pcie_cfg_read(struct pcie_port *pp, int where,
> int size, u32 *val)
> {
> struct hisi_pcie *pcie = to_hisi_pcie(pp);
>
> return hisi_pcie_common_cfg_read(pcie->reg_base, where, size, val);
> }
>
> static struct pcie_host_ops hisi_pcie_host_ops = {
> .rd_own_conf = hisi_pcie_cfg_read,
> .wr_own_conf = hisi_pcie_cfg_write,
> .link_up = hisi_pcie_link_up,
> };
I think this would be easier if you separate the ACPI code from the
DT code and not try to have a common file used for both.
Sharing the config space accessors really isn't worth it when both
variants are fairly simple to do, but they don't fit in a common
model because one is called from the ACPI quirks and the other
is called from the dw-pcie driver with completely different calling
conventions.
ARnd
next prev parent reply other threads:[~2016-09-01 14:02 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-31 11:48 [RFC PATCH V2 0/3] Add ACPI support for Hisilicon PCIe Host Controller Dongdong Liu
2016-08-31 11:48 ` [RFC PATCH V2 1/3] PCI: hisi: re-architect Hip05/Hip06 controllers driver to preapare for ACPI Dongdong Liu
2016-08-31 11:45 ` Arnd Bergmann
2016-09-01 2:05 ` Dongdong Liu
2016-09-01 7:41 ` Arnd Bergmann
2016-09-01 12:44 ` Dongdong Liu
2016-09-01 14:02 ` Arnd Bergmann [this message]
2016-09-02 2:02 ` Dongdong Liu
2016-09-20 9:45 ` Gabriele Paoloni
2016-09-20 13:22 ` Arnd Bergmann
2016-08-31 11:48 ` [RFC PATCH V2 2/3] PCI: hisi: Add ECAM support for devices that are not RC Dongdong Liu
2016-08-31 11:48 ` [RFC PATCH V2 3/3] PCI/ACPI: hisi: Add ACPI support for HiSilicon SoCs Host Controllers Dongdong Liu
2016-08-31 11:48 ` Arnd Bergmann
2016-09-01 2:16 ` Dongdong Liu
2016-08-31 22:56 ` Rafael J. Wysocki
2016-09-01 3:23 ` Dongdong Liu
2016-09-01 23:38 ` Rafael J. Wysocki
2016-09-02 3:49 ` Dongdong Liu
-- strict thread matches above, loose matches on Subject: below --
2016-02-08 12:41 [RFC PATCH v2 0/3] Add ACPI support for HiSilicon PCIe " Gabriele Paoloni
2016-02-08 12:41 ` [RFC PATCH v2 1/3] PCI: hisi: re-architect Hip05/Hip06 controllers driver to preapare for ACPI Gabriele Paoloni
2016-02-08 13:50 ` Arnd Bergmann
2016-02-08 16:06 ` Gabriele Paoloni
2016-02-08 16:32 ` Arnd Bergmann
2016-02-08 16:51 ` Gabriele Paoloni
2016-02-09 16:27 ` Arnd Bergmann
2016-02-09 16:52 ` Gabriele Paoloni
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