BMC/Intel-BMC/linux.git/drivers/misc/cxl, branch dev

cxl: Check if afu is not null in cxl_slbia

2015-07-10T01:44:25+00:00

The pointer to an AFU in the adapter's list of AFUs can be null if we're in the process of removing AFUs. The afu_list_lock doesn't guard against this. Say we have 2 slices, and we're in the process of removing cxl. - We remove the AFUs in order (see cxl_remove). In cxl_remove_afu for AFU 0, we take the lock, set adapter->afu[0] = NULL, and release the lock. - Then we get an slbia. In cxl_slbia we take the lock, and set afu = adapter->afu[0], which is NULL. - Therefore our attempt to check afu->enabled will blow up. Therefore, check if afu is a null pointer before dereferencing it. Cc: stable@vger.kernel.org Signed-off-by: Daniel Axtens Acked-by: Michael Neuling Acked-by: Ian Munsie Signed-off-by: Michael Ellerman

cxl: Fix off by one error allowing subsequent mmap page to be accessed

2015-07-08T05:17:47+00:00

It was discovered that if a process mmaped their problem state area they were able to access one page more than expected, potentially allowing them to access the problem state area of an unrelated process. This was due to a simple off by one error in the mmap fault handler introduced in 0712dc7e73e59d79bcead5d5520acf4e9e917e87 ("cxl: Fix issues when unmapping contexts"), which is fixed in this patch. Cc: stable@vger.kernel.org Fixes: 0712dc7e73e5 ("cxl: Fix issues when unmapping contexts") Signed-off-by: Ian Munsie Signed-off-by: Michael Ellerman

cxl: Fail mmap if requested mapping is larger than assigned problem state area

2015-07-08T05:17:46+00:00

This patch makes the mmap call fail outright if the requested region is larger than the problem state area assigned to the context so the error is reported immediately rather than waiting for an attempt to access an address out of bounds. Although we never expect users to map more than the assigned problem state area and are not aware of anyone doing this (other than for testing), this does have the potential to break users if someone has used a larger range regardless. I'm submitting it for consideration, but if this change is not considered acceptable the previous patch is sufficient to prevent access out of bounds without breaking anyone. Signed-off-by: Ian Munsie Signed-off-by: Michael Ellerman

cxl: Fix refcounting in kernel API

2015-07-07T09:38:37+00:00

Currently the kernel API AFU dev refcounting is done on context start and stop. This patch moves this refcounting to context init and release, bringing it inline with how the userspace API does it. Without this we've seen the refcounting on the AFU get out of whack between the user and kernel API usage. This causes the AFU structures to be freed when they are actually still in use. This fixes some kref warnings we've been seeing and spurious ErrIVTE IRQs. Signed-off-by: Michael Neuling Acked-by: Ian Munsie Signed-off-by: Michael Ellerman

cxl: Test the correct mmio space before unmapping

2015-07-06T10:24:35+00:00

Before freeing p2n, test p2n, not p1n. Signed-off-by: Daniel Axtens Acked-by: Ian Munsie Signed-off-by: Michael Ellerman

cxl/vphb.c: Use phb pointer after NULL check

2015-07-06T10:24:34+00:00

static Anlaysis detected below error:- (error) Possible null pointer dereference: phb So, Use phb after NULL check. Signed-off-by: Maninder Singh Acked-by: Ian Munsie Signed-off-by: Michael Ellerman

cxl: Fix typo in debug print

2015-06-19T07:10:30+00:00

Fix typo in debug print. p1_base() should be p2_base(). No change other than to the debug output. Signed-off-by: Michael Neuling Acked-by: Ian Munsie Signed-off-by: Michael Ellerman

cxl: Add CXL_KERNEL_API config option

2015-06-19T07:10:30+00:00

Add CXL_KERNEL_API config option so drivers which depend on this new functionality won't be enabled until this is visible. This is useful for merging the cxlflash driver which comes in via the SCSI tree. The cxlflash driver can depend on CXL_KERNEL_API, hence it won't be enabled in the SCSI tree until this new config option is merged via the powerpc tree. Hence all trees will be bisectable at all times. Signed-off-by: Michael Neuling Signed-off-by: Michael Ellerman

cxl: Reset default context for vPHB on release

2015-06-07T09:12:39+00:00

When we release the device, we should also invalidate the default context. With this cxl_get_context() will return null after removal. Signed-off-by: Michael Neuling Signed-off-by: Michael Ellerman

cxl: Add AFU virtual PHB and kernel API

2015-06-03T03:27:20+00:00

This patch does two things. Firstly it presents the Accelerator Function Unit (AFUs) behind the POWER Service Layer (PSL) as PCI devices on a virtual PCI Host Bridge (vPHB). This in in addition to the PSL being a PCI device itself. As part of the Coherent Accelerator Interface Architecture (CAIA) AFUs can provide an AFU configuration. This AFU configuration recored is architected to be the same as a PCI config space. This patch sets discovers the AFU configuration records, provides AFU config space read/write functions to these configuration records. It then enumerates the PCI bus. It also hooks in PCI ops where appropriate. It also destroys the vPHB when the physical card is removed. Secondly, it add an in kernel API for AFU to use CXL. AFUs must present a driver that firstly binds as a PCI device. This PCI device can then be using to do CXL specific operations (that can't sit in the PCI ops) using this API. Signed-off-by: Michael Neuling Acked-by: Ian Munsie Signed-off-by: Michael Ellerman