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authorIan Munsie <imunsie@au1.ibm.com>2014-12-08 19:18:01 +1100
committerMichael Ellerman <mpe@ellerman.id.au>2014-12-12 13:06:48 +1100
commitb123429e6a9e8d03aacf888d23262835f0081448 (patch)
treeb1b9c9eb381437982de078d061c274264a25c104
parenta98e6e9f4e0224d85b4d951edc44af16dfe6094a (diff)
downloadop-kernel-dev-b123429e6a9e8d03aacf888d23262835f0081448.zip
op-kernel-dev-b123429e6a9e8d03aacf888d23262835f0081448.tar.gz
cxl: Unmap MMIO regions when detaching a context
If we need to force detach a context (e.g. due to EEH or simply force unbinding the driver) we should prevent the userspace contexts from being able to access the Problem State Area MMIO region further, which they may have mapped with mmap(). This patch unmaps any mapped MMIO regions when detaching a userspace context. Cc: stable@vger.kernel.org Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
-rw-r--r--drivers/misc/cxl/context.c11
-rw-r--r--drivers/misc/cxl/cxl.h7
-rw-r--r--drivers/misc/cxl/file.c6
3 files changed, 21 insertions, 3 deletions
diff --git a/drivers/misc/cxl/context.c b/drivers/misc/cxl/context.c
index 4aa31a3..51fd6b5 100644
--- a/drivers/misc/cxl/context.c
+++ b/drivers/misc/cxl/context.c
@@ -34,7 +34,8 @@ struct cxl_context *cxl_context_alloc(void)
/*
* Initialises a CXL context.
*/
-int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master)
+int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master,
+ struct address_space *mapping)
{
int i;
@@ -42,6 +43,8 @@ int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master)
ctx->afu = afu;
ctx->master = master;
ctx->pid = NULL; /* Set in start work ioctl */
+ mutex_init(&ctx->mapping_lock);
+ ctx->mapping = mapping;
/*
* Allocate the segment table before we put it in the IDR so that we
@@ -147,6 +150,12 @@ static void __detach_context(struct cxl_context *ctx)
afu_release_irqs(ctx);
flush_work(&ctx->fault_work); /* Only needed for dedicated process */
wake_up_all(&ctx->wq);
+
+ /* Release Problem State Area mapping */
+ mutex_lock(&ctx->mapping_lock);
+ if (ctx->mapping)
+ unmap_mapping_range(ctx->mapping, 0, 0, 1);
+ mutex_unlock(&ctx->mapping_lock);
}
/*
diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h
index 7c05239..28078f8 100644
--- a/drivers/misc/cxl/cxl.h
+++ b/drivers/misc/cxl/cxl.h
@@ -398,6 +398,10 @@ struct cxl_context {
phys_addr_t psn_phys;
u64 psn_size;
+ /* Used to unmap any mmaps when force detaching */
+ struct address_space *mapping;
+ struct mutex mapping_lock;
+
spinlock_t sste_lock; /* Protects segment table entries */
struct cxl_sste *sstp;
u64 sstp0, sstp1;
@@ -599,7 +603,8 @@ int cxl_alloc_sst(struct cxl_context *ctx);
void init_cxl_native(void);
struct cxl_context *cxl_context_alloc(void);
-int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master);
+int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master,
+ struct address_space *mapping);
void cxl_context_free(struct cxl_context *ctx);
int cxl_context_iomap(struct cxl_context *ctx, struct vm_area_struct *vma);
diff --git a/drivers/misc/cxl/file.c b/drivers/misc/cxl/file.c
index 378b099..e9f2f10 100644
--- a/drivers/misc/cxl/file.c
+++ b/drivers/misc/cxl/file.c
@@ -77,7 +77,7 @@ static int __afu_open(struct inode *inode, struct file *file, bool master)
goto err_put_afu;
}
- if ((rc = cxl_context_init(ctx, afu, master)))
+ if ((rc = cxl_context_init(ctx, afu, master, inode->i_mapping)))
goto err_put_afu;
pr_devel("afu_open pe: %i\n", ctx->pe);
@@ -113,6 +113,10 @@ static int afu_release(struct inode *inode, struct file *file)
__func__, ctx->pe);
cxl_context_detach(ctx);
+ mutex_lock(&ctx->mapping_lock);
+ ctx->mapping = NULL;
+ mutex_unlock(&ctx->mapping_lock);
+
put_device(&ctx->afu->dev);
/*
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