diff mbox

[RFC,2/4] x86, acpi, pci: Isolate new PCI mmconfig entry insertion.

Message ID 1415366876-30811-3-git-send-email-tomasz.nowicki@linaro.org (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Tomasz Nowicki Nov. 7, 2014, 1:27 p.m. UTC
Add special pci_mmcfg_insert_lock mutex since pci_mmcfg_lock was moved
to common file. No functional changes.

Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
---
 arch/x86/pci/mmconfig-shared.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

Comments

Arnd Bergmann Nov. 7, 2014, 2:09 p.m. UTC | #1
On Friday 07 November 2014 14:27:54 Tomasz Nowicki wrote:
> Add special pci_mmcfg_insert_lock mutex since pci_mmcfg_lock was moved
> to common file. No functional changes.
> 
> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
> 

What is the new lock protecting against? You no longer have a mutual
exclusion with the other code, which looks like it is a functional
change, and also incorrect.

It also sounds like the code was broken after the first patch and
you need this one to make it compile again. You can't do that, and
instead need to change the locking rules first.

	Arnd
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Tomasz Nowicki Nov. 7, 2014, 2:43 p.m. UTC | #2
On 07.11.2014 15:09, Arnd Bergmann wrote:
> On Friday 07 November 2014 14:27:54 Tomasz Nowicki wrote:
>> Add special pci_mmcfg_insert_lock mutex since pci_mmcfg_lock was moved
>> to common file. No functional changes.
>>
>> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
>>
>
> What is the new lock protecting against? You no longer have a mutual
> exclusion with the other code, which looks like it is a functional
> change, and also incorrect.
>
> It also sounds like the code was broken after the first patch and
> you need this one to make it compile again. You can't do that, and
> instead need to change the locking rules first.

Oh, that's right! Sorry I will take a look again.

Tomasz
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diff mbox

Patch

diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
index 94c3d38..d1e45e7 100644
--- a/arch/x86/pci/mmconfig-shared.c
+++ b/arch/x86/pci/mmconfig-shared.c
@@ -28,6 +28,7 @@ 
 /* Indicate if the mmcfg resources have been placed into the resource table. */
 static bool pci_mmcfg_running_state;
 static bool pci_mmcfg_arch_init_failed;
+static DEFINE_MUTEX(pci_mmcfg_insert_lock);
 
 static const char *__init pci_mmcfg_e7520(void)
 {
@@ -566,7 +567,7 @@  int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
 	if (start > end)
 		return -EINVAL;
 
-	mutex_lock(&pci_mmcfg_lock);
+	mutex_lock(&pci_mmcfg_insert_lock);
 	cfg = pci_mmconfig_lookup(seg, start);
 	if (cfg) {
 		if (cfg->end_bus < end)
@@ -575,12 +576,12 @@  int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
 				 "domain %04x [bus %02x-%02x] "
 				 "only partially covers this bridge\n",
 				  cfg->segment, cfg->start_bus, cfg->end_bus);
-		mutex_unlock(&pci_mmcfg_lock);
+		mutex_unlock(&pci_mmcfg_insert_lock);
 		return -EEXIST;
 	}
 
 	if (!addr) {
-		mutex_unlock(&pci_mmcfg_lock);
+		mutex_unlock(&pci_mmcfg_insert_lock);
 		return -EINVAL;
 	}
 
@@ -621,7 +622,7 @@  int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
 		kfree(cfg);
 	}
 
-	mutex_unlock(&pci_mmcfg_lock);
+	mutex_unlock(&pci_mmcfg_insert_lock);
 
 	return rc;
 }