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authorAndrew Donnellan <andrew.donnellan@au1.ibm.com>2016-07-28 08:39:41 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2016-08-09 09:52:02 +0300
commit164793379ad3b7ef5fc5a28260c111358892dff3 (patch)
tree007c1bc56c5541efe87ee836f86ec58423bc4bef /drivers
parentcbd74e1bc8129efb9908f130a8a6e60fd95d2106 (diff)
downloadlinux-164793379ad3b7ef5fc5a28260c111358892dff3.tar.xz
cxl: Fix NULL dereference in cxl_context_init() on PowerVM guests
Commit f67a6722d650 ("cxl: Workaround PE=0 hardware limitation in Mellanox CX4") added a "min_pe" field to struct cxl_service_layer_ops, to allow us to work around a Mellanox CX-4 hardware limitation. When allocating the PE number in cxl_context_init(), we read from ctx->afu->adapter->native->sl_ops->min_pe to get the minimum PE number. Unsurprisingly, in a PowerVM guest ctx->afu->adapter->native is NULL, and guests don't have a cxl_service_layer_ops struct anywhere. Move min_pe from struct cxl_service_layer_ops to struct cxl so it's accessible in both native and PowerVM environments. For the Mellanox CX-4, set the min_pe value in set_sl_ops(). Fixes: f67a6722d650 ("cxl: Workaround PE=0 hardware limitation in Mellanox CX4") Reported-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/misc/cxl/context.c3
-rw-r--r--drivers/misc/cxl/cxl.h2
-rw-r--r--drivers/misc/cxl/pci.c3
3 files changed, 4 insertions, 4 deletions
diff --git a/drivers/misc/cxl/context.c b/drivers/misc/cxl/context.c
index bdee9a01ef35..c466ee2b0c97 100644
--- a/drivers/misc/cxl/context.c
+++ b/drivers/misc/cxl/context.c
@@ -90,8 +90,7 @@ int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master,
*/
mutex_lock(&afu->contexts_lock);
idr_preload(GFP_KERNEL);
- i = idr_alloc(&ctx->afu->contexts_idr, ctx,
- ctx->afu->adapter->native->sl_ops->min_pe,
+ i = idr_alloc(&ctx->afu->contexts_idr, ctx, ctx->afu->adapter->min_pe,
ctx->afu->num_procs, GFP_NOWAIT);
idr_preload_end();
mutex_unlock(&afu->contexts_lock);
diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h
index de090533f18c..344a0ff8f8c7 100644
--- a/drivers/misc/cxl/cxl.h
+++ b/drivers/misc/cxl/cxl.h
@@ -561,7 +561,6 @@ struct cxl_service_layer_ops {
u64 (*timebase_read)(struct cxl *adapter);
int capi_mode;
bool needs_reset_before_disable;
- int min_pe;
};
struct cxl_native {
@@ -603,6 +602,7 @@ struct cxl {
struct bin_attribute cxl_attr;
int adapter_num;
int user_irqs;
+ int min_pe;
u64 ps_size;
u16 psl_rev;
u16 base_image;
diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index d152e2de8c93..1d0347c36e6d 100644
--- a/drivers/misc/cxl/pci.c
+++ b/drivers/misc/cxl/pci.c
@@ -1521,14 +1521,15 @@ static const struct cxl_service_layer_ops xsl_ops = {
.write_timebase_ctrl = write_timebase_ctrl_xsl,
.timebase_read = timebase_read_xsl,
.capi_mode = OPAL_PHB_CAPI_MODE_DMA,
- .min_pe = 1, /* Workaround for Mellanox CX4 HW bug */
};
static void set_sl_ops(struct cxl *adapter, struct pci_dev *dev)
{
if (dev->vendor == PCI_VENDOR_ID_MELLANOX && dev->device == 0x1013) {
+ /* Mellanox CX-4 */
dev_info(&adapter->dev, "Device uses an XSL\n");
adapter->native->sl_ops = &xsl_ops;
+ adapter->min_pe = 1; /* Workaround for CX-4 hardware bug */
} else {
dev_info(&adapter->dev, "Device uses a PSL\n");
adapter->native->sl_ops = &psl_ops;