* [PATCH 2/2 v3] powerpc/iommu: Remove the dependency on EEH struct in DDW mechanism
2016-04-11 19:17 [PATCH 1/2 v3] Revert "powerpc/eeh: Fix crash in eeh_add_device_early() on Cell" Guilherme G. Piccoli
@ 2016-04-11 19:17 ` Guilherme G. Piccoli
2016-05-12 11:32 ` [2/2, " Michael Ellerman
2016-05-12 11:32 ` [1/2, v3] Revert "powerpc/eeh: Fix crash in eeh_add_device_early() on Cell" Michael Ellerman
1 sibling, 1 reply; 4+ messages in thread
From: Guilherme G. Piccoli @ 2016-04-11 19:17 UTC (permalink / raw)
To: linuxppc-dev; +Cc: gwshan, mpe, benh, paulus, nfont
Commit 39baadbf36ce ("powerpc/eeh: Remove eeh information from pci_dn")
changed the pci_dn struct by removing its EEH-related members.
As part of this clean-up, DDW mechanism was modified to read the device
configuration address from eeh_dev struct.
As a consequence, now if we disable EEH mechanism on kernel command-line
for example, the DDW mechanism will fail, generating a kernel oops by
dereferencing a NULL pointer (which turns to be the eeh_dev pointer).
This patch just changes the configuration address calculation on DDW
functions to a manual calculation based on pci_dn members instead of
using eeh_dev-based address.
No functional changes were made. This was tested on pSeries, both
in PHyp and qemu guest.
Fixes: 39baadbf36ce ("powerpc/eeh: Remove eeh information from pci_dn")
Cc: stable@vger.kernel.org
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
---
arch/powerpc/platforms/pseries/iommu.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index bd98ce2..b7dfc13 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -912,7 +912,8 @@ machine_arch_initcall(pseries, find_existing_ddw_windows);
static int query_ddw(struct pci_dev *dev, const u32 *ddw_avail,
struct ddw_query_response *query)
{
- struct eeh_dev *edev;
+ struct device_node *dn;
+ struct pci_dn *pdn;
u32 cfg_addr;
u64 buid;
int ret;
@@ -923,11 +924,10 @@ static int query_ddw(struct pci_dev *dev, const u32 *ddw_avail,
* Retrieve them from the pci device, not the node with the
* dma-window property
*/
- edev = pci_dev_to_eeh_dev(dev);
- cfg_addr = edev->config_addr;
- if (edev->pe_config_addr)
- cfg_addr = edev->pe_config_addr;
- buid = edev->phb->buid;
+ dn = pci_device_to_OF_node(dev);
+ pdn = PCI_DN(dn);
+ buid = pdn->phb->buid;
+ cfg_addr = (pdn->busno << 8) | pdn->devfn;
ret = rtas_call(ddw_avail[0], 3, 5, (u32 *)query,
cfg_addr, BUID_HI(buid), BUID_LO(buid));
@@ -941,7 +941,8 @@ static int create_ddw(struct pci_dev *dev, const u32 *ddw_avail,
struct ddw_create_response *create, int page_shift,
int window_shift)
{
- struct eeh_dev *edev;
+ struct device_node *dn;
+ struct pci_dn *pdn;
u32 cfg_addr;
u64 buid;
int ret;
@@ -952,11 +953,10 @@ static int create_ddw(struct pci_dev *dev, const u32 *ddw_avail,
* Retrieve them from the pci device, not the node with the
* dma-window property
*/
- edev = pci_dev_to_eeh_dev(dev);
- cfg_addr = edev->config_addr;
- if (edev->pe_config_addr)
- cfg_addr = edev->pe_config_addr;
- buid = edev->phb->buid;
+ dn = pci_device_to_OF_node(dev);
+ pdn = PCI_DN(dn);
+ buid = pdn->phb->buid;
+ cfg_addr = (pdn->busno << 8) | pdn->devfn;
do {
/* extra outputs are LIOBN and dma-addr (hi, lo) */
--
2.1.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [1/2, v3] Revert "powerpc/eeh: Fix crash in eeh_add_device_early() on Cell"
2016-04-11 19:17 [PATCH 1/2 v3] Revert "powerpc/eeh: Fix crash in eeh_add_device_early() on Cell" Guilherme G. Piccoli
2016-04-11 19:17 ` [PATCH 2/2 v3] powerpc/iommu: Remove the dependency on EEH struct in DDW mechanism Guilherme G. Piccoli
@ 2016-05-12 11:32 ` Michael Ellerman
1 sibling, 0 replies; 4+ messages in thread
From: Michael Ellerman @ 2016-05-12 11:32 UTC (permalink / raw)
To: Guilherme G. Piccoli, linuxppc-dev; +Cc: paulus, gwshan, nfont
On Mon, 2016-11-04 at 19:17:22 UTC, "Guilherme G. Piccoli" wrote:
> This reverts commit 89a51df5ab1d38b257300b8ac940bbac3bb0eb9b.
>
> The function eeh_add_device_early() is used to perform EEH initialization in
> devices added later on the system, like in hotplug/DLPAR scenarios. Since the
> commit 89a51df5ab1d ("powerpc/eeh: Fix crash in eeh_add_device_early() on Cell")
> a new check was introduced in this function - Cell has no EEH capabilities
> which led to kernel oops if hotplug was performed, so checking for
> eeh_enabled() was introduced to avoid the issue.
>
> However, in architectures that EEH is present like pSeries or PowerNV, we might
> reach a case in which no PCI devices are present on boot time and so EEH is not
> initialized. Then, if a device is added via DLPAR for example,
> eeh_add_device_early() fails because eeh_enabled() is false, and EEH end up
> not being enabled at all.
>
> This reverts the aforementioned patch since a new verification was introduced by
> the commit d91dafc02f42 ("powerpc/eeh: Delay probing EEH device during hotplug")
> and so the original Cell issue does not happen anymore.
>
> Cc: stable@vger.kernel.org
> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
> Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
Applied to powerpc next, thanks.
https://git.kernel.org/powerpc/c/c2078d9ef600bdbe568c89e5dd
cheers
^ permalink raw reply [flat|nested] 4+ messages in thread