From: Arnd Bergmann <arnd@arndb.de>
To: Mauri Sandberg <maukka@ext.kapsi.fi>
Cc: linux-pci <linux-pci@vger.kernel.org>,
DTML <devicetree@vger.kernel.org>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
"Linux ARM" <linux-arm-kernel@lists.infradead.org>,
"Bjorn Helgaas" <bhelgaas@google.com>,
"Rob Herring" <robh+dt@kernel.org>,
"Krzysztof Kozlowski" <krzysztof.kozlowski+dt@linaro.org>,
"Andrew Lunn" <andrew@lunn.ch>,
"Sebastian Hesselbarth" <sebastian.hesselbarth@gmail.com>,
"Gregory CLEMENT" <gregory.clement@bootlin.com>,
"Russell King - ARM Linux" <linux@armlinux.org.uk>,
"Lorenzo Pieralisi" <lpieralisi@kernel.org>,
"Krzysztof Wilczyński" <kw@linux.com>,
"Thomas Petazzoni" <thomas.petazzoni@bootlin.com>,
"Pali Rohár" <pali@kernel.org>
Subject: Re: [PATCH 2/2] PCI: mvebu: add support for orion5x
Date: Tue, 19 Jul 2022 10:05:28 +0200 [thread overview]
Message-ID: <CAK8P3a042yoLR0eqt4Bm0KH4X9SJhUsjKDh1S9M+MF6mU1mPNw@mail.gmail.com> (raw)
In-Reply-To: <20220718202843.6766-4-maukka@ext.kapsi.fi>
On Mon, Jul 18, 2022 at 10:28 PM Mauri Sandberg <maukka@ext.kapsi.fi> wrote:
>
> Add support for orion5x PCIe controller.
>
> There is Orion-specific errata that config space via CF8/CFC registers
> is broken. Workaround documented in errata documented (linked from above
> documentation) does not work when DMA is used and instead other
> undocumented workaround is needed which maps config space to memory
> (and therefore avoids usage of broken CF8/CFC memory mapped registers).
>
> Signed-off-by: Mauri Sandberg <maukka@ext.kapsi.fi>
> Cc: Pali Rohár <pali@kernel.org>
Nice job, glad you managed to figure this out!
> diff --git a/arch/arm/mach-orion5x/common.c b/arch/arm/mach-orion5x/common.c
> index 7bcb41137bbf..9d8be5ce1266 100644
> --- a/arch/arm/mach-orion5x/common.c
> +++ b/arch/arm/mach-orion5x/common.c
> @@ -231,19 +231,6 @@ void __init orion5x_init_early(void)
>
> void orion5x_setup_wins(void)
> {
> - /*
> - * The PCIe windows will no longer be statically allocated
> - * here once Orion5x is migrated to the pci-mvebu driver.
> - */
> - mvebu_mbus_add_window_remap_by_id(ORION_MBUS_PCIE_IO_TARGET,
> - ORION_MBUS_PCIE_IO_ATTR,
> - ORION5X_PCIE_IO_PHYS_BASE,
> - ORION5X_PCIE_IO_SIZE,
> - ORION5X_PCIE_IO_BUS_BASE);
> - mvebu_mbus_add_window_by_id(ORION_MBUS_PCIE_MEM_TARGET,
> - ORION_MBUS_PCIE_MEM_ATTR,
> - ORION5X_PCIE_MEM_PHYS_BASE,
> - ORION5X_PCIE_MEM_SIZE);
> mvebu_mbus_add_window_remap_by_id(ORION_MBUS_PCI_IO_TARGET,
> ORION_MBUS_PCI_IO_ATTR,
> ORION5X_PCI_IO_PHYS_BASE,
If the idea is to have the PCI_MVEBU driver only used for the DT based orion5x
machines, but not the legacy board files, I suspect this breaks the legacy
pci driver, unless you move the mbus configuration into the pcie_setup()
function.
> +/* Relevant only for Orion-1/Orion-NAS */
> +#define ORION5X_PCIE_WA_PHYS_BASE 0xf0000000
> +#define ORION5X_PCIE_WA_VIRT_BASE IOMEM(0xfd000000)
You should not need to hardcode these here. The ORION5X_PCIE_WA_PHYS_BASE
should already be part of the DT binding. There is little practical difference
here, but I see no value in taking the shortcut here either.
For the ORION5X_PCIE_WA_VIRT_BASE, you rely on this to match the
definition in arch/arm/mach-orion5x/common.c, and this is rather fragile.
Instead, please use ioremap() to create a mapping at runtime. The ioremap()
implementation on ARM is smart enough to reuse the address from the static
mapping in common.c, but will also keep working if that should go away.
> +#define ORION5X_PCIE_WA_SIZE SZ_16M
> +#define ORION_MBUS_PCIE_WA_TARGET 0x04
> +#define ORION_MBUS_PCIE_WA_ATTR 0x79
> +
> +static int mvebu_pcie_child_rd_conf_wa(struct pci_bus *bus, u32 devfn, int where, int size, u32 *val)
> +{
> + struct mvebu_pcie *pcie = bus->sysdata;
> + struct mvebu_pcie_port *port;
> +
> + port = mvebu_pcie_find_port(pcie, bus, devfn);
> + if (!port)
> + return PCIBIOS_DEVICE_NOT_FOUND;
> +
> + if (!mvebu_pcie_link_up(port))
> + return PCIBIOS_DEVICE_NOT_FOUND;
> +
> + /*
> + * We only support access to the non-extended configuration
> + * space when using the WA access method (or we would have to
> + * sacrifice 256M of CPU virtual address space.)
> + */
> + if (where >= 0x100) {
> + *val = 0xffffffff;
> + return PCIBIOS_DEVICE_NOT_FOUND;
> + }
> +
> + return orion_pcie_rd_conf_wa(ORION5X_PCIE_WA_VIRT_BASE, bus, devfn, where, size, val);
> +}
> +
This is probably good enough here, though I think you could also use
the trick from drivers/pci/ecam.c and map each bus at a time.
Arnd
next prev parent reply other threads:[~2022-07-19 8:34 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-18 20:28 [PATCH 0/2] PCI: mvebu: add support for orion soc Mauri Sandberg
2022-07-18 20:28 ` [PATCH 1/2] dt-bindings: PCI: mvebu: Add orion5x compatible Mauri Sandberg
2022-07-22 0:27 ` Rob Herring
2022-07-18 20:28 ` [PATCH 1/6] dt-bindings: PCI: mvebu: Add orion compatible Mauri Sandberg
2022-07-18 20:33 ` Mauri Sandberg
2022-07-18 20:28 ` [PATCH 2/2] PCI: mvebu: add support for orion5x Mauri Sandberg
2022-07-19 8:05 ` Arnd Bergmann [this message]
2022-07-19 9:46 ` Pali Rohár
2022-07-19 10:16 ` Arnd Bergmann
2022-07-20 16:13 ` Pali Rohár
2022-07-20 16:43 ` Andrew Lunn
2022-07-20 17:11 ` Arnd Bergmann
2022-07-20 17:40 ` Rob Herring
2022-07-20 17:53 ` Pali Rohár
2022-07-20 11:36 ` [PATCH 0/2] PCI: mvebu: add support for orion soc Arnd Bergmann
2022-07-29 17:22 ` Bjorn Helgaas
2022-07-30 13:21 ` Mauri Sandberg
2022-08-02 17:34 ` [PATCH v2 " Mauri Sandberg
2022-08-02 17:34 ` [PATCH v2 1/2] dt-bindings: PCI: mvebu: Add orion5x compatible Mauri Sandberg
2022-08-02 17:34 ` [PATCH v2 2/2] PCI: mvebu: add support for orion5x Mauri Sandberg
2022-08-25 15:15 ` Lorenzo Pieralisi
2022-08-25 16:00 ` Pali Rohár
2022-08-26 8:42 ` Lorenzo Pieralisi
2022-08-02 17:49 ` [PATCH v2 0/2] PCI: mvebu: add support for orion soc Pali Rohár
2022-09-05 19:23 ` [PATCH v3 0/7] " Pali Rohár
2022-09-05 19:23 ` [PATCH v3 1/7] ARM: orion: Move PCIe mbus window mapping from orion5x_setup_wins() to pcie_setup() Pali Rohár
2022-09-05 19:23 ` [PATCH v3 2/7] bus: mvebu-mbus: add configuration space aperture Pali Rohár
2022-09-05 19:23 ` [PATCH v3 3/7] dt-bindings: PCI: mvebu: Add orion5x compatible Pali Rohár
2022-09-06 16:20 ` Rob Herring
2022-09-05 19:23 ` [PATCH v3 4/7] PCI: mvebu: Remove unused busn member Pali Rohár
2022-09-05 19:23 ` [PATCH v3 5/7] PCI: mvebu: Cleanup error handling in mvebu_pcie_probe() Pali Rohár
2022-09-05 19:23 ` [PATCH v3 6/7] PCI: mvebu: Add support for Orion PCIe controller Pali Rohár
2022-09-05 19:23 ` [PATCH v3 7/7] ARM: dts: orion5x: Add PCIe node Pali Rohár
2022-09-16 12:25 ` [PATCH v3 0/7] PCI: mvebu: add support for orion soc Lorenzo Pieralisi
2022-10-27 14:10 ` Lorenzo Pieralisi
2022-11-06 23:28 ` Pali Rohár
2022-11-11 12:49 ` Lorenzo Pieralisi
2022-11-11 16:54 ` Pali Rohár
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