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From: Russell King - ARM Linux <linux@armlinux.org.uk>
To: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: "Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
	"Antoine Tenart" <antoine.tenart@bootlin.com>,
	linux-pci@vger.kernel.org,
	"Gregory Clement" <gregory.clement@bootlin.com>,
	"Maxime Chevallier" <maxime.chevallier@bootlin.com>,
	"Nadav Haklai" <nadavh@marvell.com>,
	"Miquèl Raynal" <miquel.raynal@bootlin.com>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCHv2 1/3] PCI: Introduce PCI bridge emulated config space common logic
Date: Fri, 14 Sep 2018 15:38:49 +0100	[thread overview]
Message-ID: <20180914143849.GC30658@n2100.armlinux.org.uk> (raw)
In-Reply-To: <20180912154831.2220-2-thomas.petazzoni@bootlin.com>

On Wed, Sep 12, 2018 at 05:48:29PM +0200, Thomas Petazzoni wrote:
> Some PCI host controllers do not expose a configuration space for the
> root port PCI bridge. Due to this, the Marvell Armada 370/38x/XP PCI
> controller driver (pci-mvebu) emulates a root port PCI bridge
> configuration space, and uses that to (among other things) dynamically
> create the memory windows that correspond to the PCI MEM and I/O
> regions.
> 
> Since we now need to add a very similar logic for the Marvell Armada
> 37xx PCI controller driver (pci-aardvark), instead of duplicating the
> code, we create in this commit a common logic called pci-bridge-emul.
> 
> The idea of this logic is to emulate a root port PCI bridge
> configuration space by providing configuration space read/write
> operations, and faking behind the scenes the configuration space of a
> PCI bridge. A PCI host controller driver simply has to call
> pci_bridge_emul_conf_read() and pci_bridge_emul_conf_write() to
> read/write the configuration space of the bridge.
> 
> By default, the PCI bridge configuration space is simply emulated by a
> chunk of memory, but the PCI host controller can override the behavior
> of the read and write operations on a per-register basis to do
> additional actions if needed. We take care of complying with the
> behavior of the PCI configuration space registers in terms of bits
> that are read-write, read-only, reserved and write-1-to-clear.

Thanks, for the patch.  I don't see anything technically wrong from
a PCIe device behaviour point of view, although I haven't compared
the behaviour tables with the specs.

Reviewed-by: Russell King <rmk+kernel@armlinux.org.uk>

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 13.8Mbps down 630kbps up
According to speedtest.net: 13Mbps down 490kbps up

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WARNING: multiple messages have this Message-ID (diff)
From: Russell King - ARM Linux <linux@armlinux.org.uk>
To: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: "Bjorn Helgaas" <bhelgaas@google.com>,
	"Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
	linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	"Gregory Clement" <gregory.clement@bootlin.com>,
	"Miquèl Raynal" <miquel.raynal@bootlin.com>,
	"Maxime Chevallier" <maxime.chevallier@bootlin.com>,
	"Antoine Tenart" <antoine.tenart@bootlin.com>,
	"Nadav Haklai" <nadavh@marvell.com>
Subject: Re: [PATCHv2 1/3] PCI: Introduce PCI bridge emulated config space common logic
Date: Fri, 14 Sep 2018 15:38:49 +0100	[thread overview]
Message-ID: <20180914143849.GC30658@n2100.armlinux.org.uk> (raw)
Message-ID: <20180914143849.U_GURzCrdInrCfN3SmWkwwsSzGUkaXY9q6TBU6JQyd0@z> (raw)
In-Reply-To: <20180912154831.2220-2-thomas.petazzoni@bootlin.com>

On Wed, Sep 12, 2018 at 05:48:29PM +0200, Thomas Petazzoni wrote:
> Some PCI host controllers do not expose a configuration space for the
> root port PCI bridge. Due to this, the Marvell Armada 370/38x/XP PCI
> controller driver (pci-mvebu) emulates a root port PCI bridge
> configuration space, and uses that to (among other things) dynamically
> create the memory windows that correspond to the PCI MEM and I/O
> regions.
> 
> Since we now need to add a very similar logic for the Marvell Armada
> 37xx PCI controller driver (pci-aardvark), instead of duplicating the
> code, we create in this commit a common logic called pci-bridge-emul.
> 
> The idea of this logic is to emulate a root port PCI bridge
> configuration space by providing configuration space read/write
> operations, and faking behind the scenes the configuration space of a
> PCI bridge. A PCI host controller driver simply has to call
> pci_bridge_emul_conf_read() and pci_bridge_emul_conf_write() to
> read/write the configuration space of the bridge.
> 
> By default, the PCI bridge configuration space is simply emulated by a
> chunk of memory, but the PCI host controller can override the behavior
> of the read and write operations on a per-register basis to do
> additional actions if needed. We take care of complying with the
> behavior of the PCI configuration space registers in terms of bits
> that are read-write, read-only, reserved and write-1-to-clear.

Thanks, for the patch.  I don't see anything technically wrong from
a PCIe device behaviour point of view, although I haven't compared
the behaviour tables with the specs.

Reviewed-by: Russell King <rmk+kernel@armlinux.org.uk>

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 13.8Mbps down 630kbps up
According to speedtest.net: 13Mbps down 490kbps up

WARNING: multiple messages have this Message-ID (diff)
From: linux@armlinux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCHv2 1/3] PCI: Introduce PCI bridge emulated config space common logic
Date: Fri, 14 Sep 2018 15:38:49 +0100	[thread overview]
Message-ID: <20180914143849.GC30658@n2100.armlinux.org.uk> (raw)
In-Reply-To: <20180912154831.2220-2-thomas.petazzoni@bootlin.com>

On Wed, Sep 12, 2018 at 05:48:29PM +0200, Thomas Petazzoni wrote:
> Some PCI host controllers do not expose a configuration space for the
> root port PCI bridge. Due to this, the Marvell Armada 370/38x/XP PCI
> controller driver (pci-mvebu) emulates a root port PCI bridge
> configuration space, and uses that to (among other things) dynamically
> create the memory windows that correspond to the PCI MEM and I/O
> regions.
> 
> Since we now need to add a very similar logic for the Marvell Armada
> 37xx PCI controller driver (pci-aardvark), instead of duplicating the
> code, we create in this commit a common logic called pci-bridge-emul.
> 
> The idea of this logic is to emulate a root port PCI bridge
> configuration space by providing configuration space read/write
> operations, and faking behind the scenes the configuration space of a
> PCI bridge. A PCI host controller driver simply has to call
> pci_bridge_emul_conf_read() and pci_bridge_emul_conf_write() to
> read/write the configuration space of the bridge.
> 
> By default, the PCI bridge configuration space is simply emulated by a
> chunk of memory, but the PCI host controller can override the behavior
> of the read and write operations on a per-register basis to do
> additional actions if needed. We take care of complying with the
> behavior of the PCI configuration space registers in terms of bits
> that are read-write, read-only, reserved and write-1-to-clear.

Thanks, for the patch.  I don't see anything technically wrong from
a PCIe device behaviour point of view, although I haven't compared
the behaviour tables with the specs.

Reviewed-by: Russell King <rmk+kernel@armlinux.org.uk>

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 13.8Mbps down 630kbps up
According to speedtest.net: 13Mbps down 490kbps up

  parent reply	other threads:[~2018-09-14 14:38 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-12 15:48 [PATCHv2 0/3] PCI: emulated PCI bridge config space Thomas Petazzoni
2018-09-12 15:48 ` Thomas Petazzoni
2018-09-12 15:48 ` [PATCHv2 1/3] PCI: Introduce PCI bridge emulated config space common logic Thomas Petazzoni
2018-09-12 15:48   ` Thomas Petazzoni
2018-09-12 18:53   ` Bjorn Helgaas
2018-09-12 18:53     ` Bjorn Helgaas
2018-09-14 14:38   ` Russell King - ARM Linux [this message]
2018-09-14 14:38     ` Russell King - ARM Linux
2018-09-14 14:38     ` Russell King - ARM Linux
2018-09-12 15:48 ` [PATCHv2 2/3] PCI: mvebu: Convert to PCI emulated bridge config space Thomas Petazzoni
2018-09-12 15:48   ` Thomas Petazzoni
2018-09-14 14:44   ` Russell King - ARM Linux
2018-09-14 14:44     ` Russell King - ARM Linux
2018-09-18 16:17   ` Lorenzo Pieralisi
2018-09-18 16:17     ` Lorenzo Pieralisi
2018-09-18 16:17     ` Lorenzo Pieralisi
2018-10-04 10:48     ` Lorenzo Pieralisi
2018-10-04 10:48       ` Lorenzo Pieralisi
2018-10-04 11:13       ` Thomas Petazzoni
2018-10-04 11:13         ` Thomas Petazzoni
2018-10-04 11:26         ` Russell King - ARM Linux
2018-10-04 11:26           ` Russell King - ARM Linux
2018-09-12 15:48 ` [PATCHv2 3/3] PCI: aardvark: Implement emulated root PCI " Thomas Petazzoni
2018-09-12 15:48   ` Thomas Petazzoni

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