From: Ram Pai <linuxram@us.ibm.com>
To: jbarnes@virtuousgeek.org, torvalds@linux-foundation.org
Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
yinghai@kernel.org, Ram Pai <linuxram@us.ibm.com>
Subject: [PATCH] PCI: conditional resource-reallocation through kernel parameter pci=realloc
Date: Thu, 30 Jun 2011 01:09:39 -0700 [thread overview]
Message-ID: <1309421379-24995-1-git-send-email-linuxram@us.ibm.com> (raw)
Multiple attempts to dynamically reallocate pci resources have unfortunately
lead to regressions. Though we continue to fix the regressions and fine tune the
dynamic-reallocation behavior, we have not reached a acceptable state yet.
This patch provides a interim solution. It disables dynamic-reallocation; by
default, with the ability to enable it through pci=realloc kernel command line
parameter.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
---
Documentation/kernel-parameters.txt | 2 ++
arch/x86/pci/common.c | 4 ++++
drivers/pci/setup-bus.c | 7 +++++++
include/linux/pci.h | 2 ++
4 files changed, 15 insertions(+), 0 deletions(-)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index fd248a3..aa47be7 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2015,6 +2015,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
the default.
off: Turn ECRC off
on: Turn ECRC on.
+ realloc reallocate PCI resources if allocations done by BIOS
+ are erroneous.
pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
Management.
diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
index 5fe7502..9645290 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -31,6 +31,7 @@ int noioapicreroute = 0;
int noioapicreroute = 1;
#endif
int pcibios_last_bus = -1;
+int pci_realloc = 0;
unsigned long pirq_table_addr;
struct pci_bus *pci_root_bus;
struct pci_raw_ops *raw_pci_ops;
@@ -602,6 +603,9 @@ char * __devinit pcibios_setup(char *str)
if (noioapicreroute != -1)
noioapicreroute = 1;
return NULL;
+ } else if (!strcmp(str, "realloc")) {
+ pci_realloc = 1;
+ return NULL;
}
return str;
}
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 40e94d5..a65c2ad 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1135,6 +1135,13 @@ again:
/* any device complain? */
if (!head.next)
goto enable_and_dump;
+
+ /* don't realloc if asked to do so */
+ if (!pci_realloc) {
+ free_list(resource_list_x, &head);
+ goto enable_and_dump;
+ }
+
failed_type = 0;
for (list = head.next; list;) {
failed_type |= list->flags;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index f39d894..08b9af0 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1427,6 +1427,8 @@ extern u8 pci_cache_line_size;
extern unsigned long pci_hotplug_io_size;
extern unsigned long pci_hotplug_mem_size;
+extern int pci_realloc;
+
int pcibios_add_platform_entries(struct pci_dev *dev);
void pcibios_disable_device(struct pci_dev *dev);
int pcibios_set_pcie_reset_state(struct pci_dev *dev,
--
1.7.0.4
next reply other threads:[~2011-06-30 8:09 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-30 8:09 Ram Pai [this message]
2011-06-30 17:04 ` [PATCH] PCI: conditional resource-reallocation through kernel parameter pci=realloc Oliver Hartkopp
2011-06-30 17:07 ` Jesse Barnes
2011-06-30 17:12 ` Oliver Hartkopp
2011-06-30 18:38 ` Ram Pai
2011-06-30 20:24 ` Bjorn Helgaas
2011-06-30 20:26 ` Jesse Barnes
2011-07-06 9:06 ` Ram Pai
2011-07-06 16:07 ` Jesse Barnes
2011-07-07 1:00 ` Stephen Rothwell
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