From: suravee.suthikulpanit@amd•com (Suravee Suthikulanit)
To: linux-arm-kernel@lists•infradead.org
Subject: [RFC/RFT PATCH 2/2] ARM64: kernel: pci: implement PCI device resources claiming
Date: Thu, 14 May 2015 21:09:03 -0500 [thread overview]
Message-ID: <5555553F.9070608@amd.com> (raw)
In-Reply-To: <1431614537-16136-2-git-send-email-lorenzo.pieralisi@arm.com>
On 5/14/2015 9:42 AM, Lorenzo Pieralisi wrote:
> When a device is scanned and added to the PCI bus, its resources
> should be claimed to validate the BARs configuration and to assign
> them a parent resource so that the resource hierarchy can be sanity
> checked.
>
> This patch adds code that carries out PCI device resources claiming to
> the ARM64 pcibios_add_device implementation so that device resources
> are claimed by the core PCI layer upon PCI device initialization on
> ARM64 systems.
>
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm•com>
> Cc: Arnd Bergmann <arnd@arndb•de>
> Cc: Will Deacon <will.deacon@arm•com>
> Cc: Liviu Dudau <liviu.dudau@arm•com>
> Cc: Bjorn Helgaas <bhelgaas@google•com>
> ---
> arch/arm64/kernel/pci.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
> index 4095379..c0a88ca 100644
> --- a/arch/arm64/kernel/pci.c
> +++ b/arch/arm64/kernel/pci.c
> @@ -43,8 +43,18 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
> */
> int pcibios_add_device(struct pci_dev *dev)
> {
> + struct resource *res;
> + int i;
> +
> dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
>
> + for (i = 0; i < PCI_NUM_RESOURCES; i++) {
> + res = &dev->resource[i];
> + if (res->parent || !res->flags)
> + continue;
> + pci_claim_resource(dev, i);
> + }
> +
> return 0;
> }
>
>
Lorenzo/Bjorn,
I have tested this patch on top of Jayachandran's V2 patch series
(http://www.spinics.net/lists/linux-pci/msg40811.html) on AMD Seattle
(w/ PROBE_ONLY and non-PROBE_ONLY mode), and your changes here works
with additional changes below.
It seems that when booting w/ PROBE_ONLY case, we need to call
pci_read_bridge_bases() at some point before claiming the resources of
devices underneath the bridge. This is needed to determine the bridge
bases (i.e. bridge io, mmio and mmio_pref bases), and update bridge
resources accordingly.
---- BEGIN PATCH -----
diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
index c0a88ca..57be6aa 100644
--- a/arch/arm64/kernel/pci.c
+++ b/arch/arm64/kernel/pci.c
@@ -48,6 +48,11 @@ int pcibios_add_device(struct pci_dev *dev)
dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
+ if (pci_has_flag(PCI_PROBE_ONLY) &&
+ !pci_is_root_bus(dev->bus) &&
+ !pci_bridge_bases_is_read(dev->bus))
+ pci_read_bridge_bases(dev->bus);
+
for (i = 0; i < PCI_NUM_RESOURCES; i++) {
res = &dev->resource[i];
if (res->parent || !res->flags)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 6675a7a..6cab8be 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -447,6 +447,13 @@ static void pci_read_bridge_mmio_pref(struct
pci_bus *child)
}
}
+bool pci_bridge_bases_is_read(struct pci_bus *bus)
+{
+ return (bus->resource[0]->start ||
+ bus->resource[1]->start ||
+ bus->resource[2]->start);
+}
+
void pci_read_bridge_bases(struct pci_bus *child)
{
struct pci_dev *dev = child->self;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 353db8d..11c674d 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -798,6 +798,7 @@ void pci_device_add(struct pci_dev *dev, struct
pci_bus *bus);
unsigned int pci_scan_child_bus(struct pci_bus *bus);
void pci_bus_add_device(struct pci_dev *dev);
void pci_read_bridge_bases(struct pci_bus *child);
+bool pci_bridge_bases_is_read(struct pci_bus *bus);
struct resource *pci_find_parent_resource(const struct pci_dev *dev,
struct resource *res);
u8 pci_swizzle_interrupt_pin(const struct pci_dev *dev, u8 pin);
---- END PATCH -----
I'm not sure if this is the best place to be reading the bridge bases.
I guess we should be able to do this when adding bridge devices.
Thanks,
Suravee
next prev parent reply other threads:[~2015-05-15 2:09 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-14 14:42 [RFC/RFT PATCH 1/2] ARM: kernel: bios32: implement PCI device resources claiming Lorenzo Pieralisi
2015-05-14 14:42 ` [RFC/RFT PATCH 2/2] ARM64: kernel: pci: " Lorenzo Pieralisi
2015-05-15 2:09 ` Suravee Suthikulanit [this message]
2015-05-18 17:38 ` Lorenzo Pieralisi
2015-05-18 19:44 ` Suravee Suthikulanit
2015-05-20 8:56 ` Lorenzo Pieralisi
2015-05-20 13:02 ` Bjorn Helgaas
2015-05-20 17:48 ` Lorenzo Pieralisi
2015-05-19 23:25 ` Bjorn Helgaas
2015-05-20 9:16 ` Lorenzo Pieralisi
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