From: Bharat Kumar Gogada <bharatku@xilinx.com>
To: Marc Zyngier <maz@kernel.org>,
"lorenzo.pieralisi@arm.com" <lorenzo.pieralisi@arm.com>,
Bjorn Helgaas <bhelgaas@google.com>
Cc: Frank Wunderlich <frank-w@public-files.de>,
Thierry Reding <treding@nvidia.com>,
Thomas Gleixner <tglx@linutronix.de>,
Rob Herring <robh@kernel.org>, Will Deacon <will@kernel.org>,
"K. Y. Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Stephen Hemminger <sthemmin@microsoft.com>,
Michael Kelley <mikelley@microsoft.com>,
Wei Liu <wei.liu@kernel.org>,
Thierry Reding <thierry.reding@gmail.com>,
Jonathan Hunter <jonathanh@nvidia.com>,
Ryder Lee <ryder.lee@mediatek.com>,
Marek Vasut <marek.vasut+renesas@gmail.com>,
Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
Michal Simek <michals@xilinx.com>,
Paul Walmsley <paul.walmsley@sifive.com>,
"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
"linux-tegra@vger.kernel.org" <linux-tegra@vger.kernel.org>,
"linux-mediatek@lists.infradead.org"
<linux-mediatek@lists.infradead.org>,
"linux-renesas-soc@vger.kernel.org"
<linux-renesas-soc@vger.kernel.org>,
"kernel-team@android.com" <kernel-team@android.com>
Subject: RE: [PATCH v2 04/15] PCI: xilinx: Don't allocate extra memory for the MSI capture address
Date: Wed, 24 Mar 2021 12:35:58 +0000 [thread overview]
Message-ID: <BYAPR02MB5559D4117C9096D70C5FFE76A5639@BYAPR02MB5559.namprd02.prod.outlook.com> (raw)
In-Reply-To: <20210322184614.802565-5-maz@kernel.org>
Thanks Marc for the patch.
> Subject: [PATCH v2 04/15] PCI: xilinx: Don't allocate extra memory for the
> MSI capture address
>
> A long cargo-culted behaviour of PCI drivers is to allocate memory to obtain
> an address that is fed to the controller as the MSI capture address (i.e. the
> MSI doorbell).
>
> But there is no actual requirement for this address to be RAM.
> All it needs to be is a suitable aligned address that will
> *not* be DMA'd to.
>
> Use the physical address of the 'port' data structure as the MSI capture
> address.
>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> drivers/pci/controller/pcie-xilinx.c | 18 ++++++------------
> 1 file changed, 6 insertions(+), 12 deletions(-)
...
> - msg.address_hi = 0;
> - msg.address_lo = msg_addr;
> + msg.address_hi = upper_32_bits(msg_addr);
> + msg.address_lo = lower_32_bits(msg_addr);
The XILINX_PCIE_REG_MSIBASE2 register expects 4KB aligned address.
The lower 12-bits are always set to 0 in this register. So we need to mask the address
while programming address to EP.
#define XILINX_PCIE_MSI_ADDR_MASK GENMASK(31, 12)
msg.address_lo = lower_32_bits(msg_addr) & XILINX_PCIE_MSI_ADDR_MASK;
> msg.data = irq;
>
Regards,
Bharat
next prev parent reply other threads:[~2021-03-24 12:36 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-22 18:45 [PATCH v2 00/15] PCI/MSI: Getting rid of msi_controller, and other cleanups Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 01/15] PCI: tegra: Convert to MSI domains Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 02/15] PCI: rcar: Don't allocate extra memory for the MSI capture address Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 03/15] PCI: rcar: Convert to MSI domains Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 04/15] PCI: xilinx: Don't allocate extra memory for the MSI capture address Marc Zyngier
2021-03-24 12:35 ` Bharat Kumar Gogada [this message]
2021-03-24 12:55 ` Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 05/15] PCI: xilinx: Convert to MSI domains Marc Zyngier
2021-03-24 12:42 ` Bharat Kumar Gogada
2021-03-24 13:15 ` Marc Zyngier
2021-03-24 13:56 ` Bharat Kumar Gogada
2021-03-24 14:45 ` Marc Zyngier
2021-03-25 4:13 ` Bharat Kumar Gogada
2021-03-22 18:46 ` [PATCH v2 06/15] PCI: hv: Drop msi_controller structure Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 07/15] PCI/MSI: Drop use of msi_controller from core code Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 08/15] PCI/MSI: Kill msi_controller structure Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 09/15] PCI/MSI: Kill default_teardown_msi_irqs() Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 10/15] PCI/MSI: Let PCI host bridges declare their lack of MSI handling Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 11/15] PCI: mediatek: Advertise " Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 12/15] PCI/MSI: Let PCI host bridges declare their reliance on MSI domains Marc Zyngier
2021-03-23 11:45 ` Robin Murphy
2021-03-23 18:09 ` Marc Zyngier
2021-03-23 19:04 ` Robin Murphy
2021-03-24 13:19 ` Lorenzo Pieralisi
2021-03-24 16:11 ` Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 13/15] PCI/MSI: Make pci_host_common_probe() declare its " Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 14/15] PCI/MSI: Document the various ways of ending up with NO_MSI Marc Zyngier
2021-03-22 18:46 ` [PATCH v2 15/15] PCI: Refactor HT advertising of NO_MSI flag Marc Zyngier
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