mailbox: zynq: Switch to flexible array to simplify code

[ Upstream commit 043f85ce81cb1714e14d31c322c5646513dde3fb ]

Using flexible array is more straight forward. It
  - saves 1 pointer in the 'zynqmp_ipi_pdata' structure
  - saves an indirection when using this array
  - saves some LoC and avoids some always spurious pointer arithmetic

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Stable-dep-of: f72f805e7288 ("mailbox: zynqmp: Fix counts of child nodes")
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/mailbox/zynqmp-ipi-mailbox.c b/drivers/mailbox/zynqmp-ipi-mailbox.c
index e02a4a18e8c298349e7905dca94bf3d333890922..29f09ded6e7391d090b48a7fad701af3391cfedf 100644 (file)
--- a/drivers/mailbox/zynqmp-ipi-mailbox.c
+++ b/drivers/mailbox/zynqmp-ipi-mailbox.c
@@ -110,7 +110,7 @@ struct zynqmp_ipi_pdata {
        unsigned int method;
        u32 local_id;
        int num_mboxes;
-       struct zynqmp_ipi_mbox *ipi_mboxes;
+       struct zynqmp_ipi_mbox ipi_mboxes[];
 };
 
 static struct device_driver zynqmp_ipi_mbox_driver = {
@@ -635,7 +635,7 @@ static int zynqmp_ipi_probe(struct platform_device *pdev)
        int num_mboxes, ret = -EINVAL;
 
        num_mboxes = of_get_child_count(np);
-       pdata = devm_kzalloc(dev, sizeof(*pdata) + (num_mboxes * sizeof(*mbox)),
+       pdata = devm_kzalloc(dev, struct_size(pdata, ipi_mboxes, num_mboxes),
                             GFP_KERNEL);
        if (!pdata)
                return -ENOMEM;
@@ -649,8 +649,6 @@ static int zynqmp_ipi_probe(struct platform_device *pdev)
        }
 
        pdata->num_mboxes = num_mboxes;
-       pdata->ipi_mboxes = (struct zynqmp_ipi_mbox *)
-                           ((char *)pdata + sizeof(*pdata));
 
        mbox = pdata->ipi_mboxes;
        for_each_available_child_of_node(np, nc) {