ionic: check cmd_regs before copying in or out

Since we now have potential cases of NULL cmd_regs and info_regs
during a reset recovery, and left NULL if a reset recovery has
failed, we need to check that they exist before we use them.
Most of the cases were covered in the original patch where we
verify before doing the ioreadb() for health or cmd status.
However, we need to protect a few uses of io mem that could
be hit in error recovery or asynchronous threads calls as well
(e.g. ethtool or devlink handlers).

Fixes: 219e183272b4 ("ionic: no fw read when PCI reset failed")
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_dev.c b/drivers/net/ethernet/pensando/ionic/ionic_dev.c
index 1e7c71f7f081..746072b4dbd0 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_dev.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_dev.c
@@ -319,22 +319,32 @@ do_check_time:
 
 u8 ionic_dev_cmd_status(struct ionic_dev *idev)
 {
+	if (!idev->dev_cmd_regs)
+		return (u8)PCI_ERROR_RESPONSE;
 	return ioread8(&idev->dev_cmd_regs->comp.comp.status);
 }
 
 bool ionic_dev_cmd_done(struct ionic_dev *idev)
 {
+	if (!idev->dev_cmd_regs)
+		return false;
 	return ioread32(&idev->dev_cmd_regs->done) & IONIC_DEV_CMD_DONE;
 }
 
 void ionic_dev_cmd_comp(struct ionic_dev *idev, union ionic_dev_cmd_comp *comp)
 {
+	if (!idev->dev_cmd_regs)
+		return;
 	memcpy_fromio(comp, &idev->dev_cmd_regs->comp, sizeof(*comp));
 }
 
 void ionic_dev_cmd_go(struct ionic_dev *idev, union ionic_dev_cmd *cmd)
 {
 	idev->opcode = cmd->cmd.opcode;
+
+	if (!idev->dev_cmd_regs)
+		return;
+
 	memcpy_toio(&idev->dev_cmd_regs->cmd, cmd, sizeof(*cmd));
 	iowrite32(0, &idev->dev_cmd_regs->done);
 	iowrite32(1, &idev->dev_cmd_regs->doorbell);