On 09/15/2015 01:17 PM, Yinghai Lu wrote:
On Tue, Sep 15, 2015 at 9:51 AM, Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
On 09/15/2015 09:30 AM, Lorenzo Pieralisi wrote:
It looks like me and Yinghai disagree how the problem I was trying to fix
should be handled, I don't understand Yinghai's concerns, and unfortunately
I just don't have the time I would need to get a better understanding.
It is fine with me to revert your patch and abandon mine.
I put one simplified version in one my branch.
https://git.kernel.org/cgit/linux/kernel/git/yinghai/linux-yinghai.git/patch/?id=cdf4bfbc1ce12d826abd49a8987eb3ca7e129332
and will sent that later if needed.
From cdf4bfbc1ce12d826abd49a8987eb3ca7e129332 Mon Sep 17 00:00:00 2001
From: Guenter Roeck <linux@xxxxxxxxxxxx>
Yinghai,
that isn't really my patch, so you should not send it under my name.
Thanks,
Guenter
Date: Tue, 15 Sep 2015 12:59:11 -0700
Subject: PCI: Only try to assign io port only for root bus that support it
The PCI subsystem always assumes that I/O is supported on root bus and
tries to assign an I/O window to each child bus even if that is not the
case.
This may result in messages such as:
pcieport 0000:02:00.0: res[7]=[io 0x1000-0x0fff] get_res_add_size
add_size 1000
pcieport 0000:02:00.0: BAR 7: no space for [io size 0x1000]
pcieport 0000:02:00.0: BAR 7: failed to assign [io size 0x1000]
for each bridge port, even if root does not support I/O in the first place.
To avoid this message, check if root bus supports I/O, then child bus
will inherit the setting from parent bus, and later during sizing and
assigning, check that bus flags and skip those resources.
[bhelgaas: reverse sense of new pci_bus_flags_t value]
[yinghai: only check root bus io port, and use flag on sizing and assigning]
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
CC: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index c4c6947..5d946bd 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -339,6 +339,9 @@ static void pci_read_bridge_io(struct pci_bus *child)
struct pci_bus_region region;
struct resource *res;
+ if (!(child->bus_flags & PCI_BUS_FLAGS_ROOT_SUPPORTS_IO))
+ return;
+
io_mask = PCI_IO_RANGE_MASK;
io_granularity = 0x1000;
if (dev->io_window_1k) {
@@ -2126,6 +2129,8 @@ struct pci_bus *pci_create_root_bus(struct
device *parent, int bus,
} else
bus_addr[0] = '\0';
dev_info(&b->dev, "root bus resource %pR%s\n", res, bus_addr);
+ if (resource_type(res) == IORESOURCE_IO)
+ b->bus_flags |= PCI_BUS_FLAGS_ROOT_SUPPORTS_IO;
}
resource_list_for_each_entry(window, &bridge->windows) {
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 9d5e415..8ee5d17 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -223,6 +223,10 @@ static void pdev_assign_resources_prepare(struct
pci_dev *dev,
if (r->flags & IORESOURCE_PCI_FIXED)
continue;
+ if ((r->flags & IORESOURCE_IO) &&
+ !(dev->bus->bus_flags & PCI_BUS_FLAGS_ROOT_SUPPORTS_IO))
+ continue;
+
if (resource_disabled(r) || r->parent)
continue;
@@ -1178,6 +1182,11 @@ static void pbus_size_io(struct pci_bus *bus,
resource_size_t min_size,
min_size = 0;
}
+ if (!(bus->bus_flags & PCI_BUS_FLAGS_ROOT_SUPPORTS_IO)) {
+ b_res->flags |= IORESOURCE_UNSET | IORESOURCE_DISABLED;
+ return;
+ }
+
min_align = window_alignment(bus, IORESOURCE_IO);
list_for_each_entry(dev, &bus->devices, bus_list) {
int i;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 5ed9bf1..790c534 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -193,6 +193,7 @@ typedef unsigned short __bitwise pci_bus_flags_t;
enum pci_bus_flags {
PCI_BUS_FLAGS_NO_MSI = (__force pci_bus_flags_t) 1,
PCI_BUS_FLAGS_NO_MMRBC = (__force pci_bus_flags_t) 2,
+ PCI_BUS_FLAGS_ROOT_SUPPORTS_IO = (__force pci_bus_flags_t) 4,
};
/* These values come from the PCI Express Spec */
--
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