bus: mvebu: pass the coherency availability information at init time

Until now, the mvebu-mbus was guessing by itself whether hardware I/O
coherency was available or not by poking into the Device Tree to see
if the coherency fabric Device Tree node was present or not.

However, on some upcoming SoCs, the presence or absence of the
coherency fabric DT node isn't sufficient: in CONFIG_SMP, the
coherency can be enabled, but not in !CONFIG_SMP.

In order to clean this up, the mvebu_mbus_dt_init() function is
extended to get a boolean argument telling whether coherency is
enabled or not. Therefore, the logic to decide whether coherency is
available or not now belongs to the core SoC code instead of the
mvebu-mbus driver itself, which is much better.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1397483228-25625-4-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

1 files changed, 3 insertions, 8 deletions

diff --git a/drivers/bus/mvebu-mbus.c b/drivers/bus/mvebu-mbus.c
index 293e2e0a0a87..ff02fc90fc21 100644
--- a/drivers/bus/mvebu-mbus.c
+++ b/drivers/bus/mvebu-mbus.c
@@ -694,7 +694,6 @@ static int __init mvebu_mbus_common_init(struct mvebu_mbus_state *mbus,
                                          phys_addr_t sdramwins_phys_base,
                                          size_t sdramwins_size)
 {
-        struct device_node *np;
         int win;
 
         mbus->mbuswins_base = ioremap(mbuswins_phys_base, mbuswins_size);
@@ -707,12 +706,6 @@ static int __init mvebu_mbus_common_init(struct mvebu_mbus_state *mbus,
                 return -ENOMEM;
         }
 
-        np = of_find_compatible_node(NULL, NULL, "marvell,coherency-fabric");
-        if (np) {
-                mbus->hw_io_coherency = 1;
-                of_node_put(np);
-        }
-
         for (win = 0; win < mbus->soc->num_wins; win++)
                 mvebu_mbus_disable_window(mbus, win);
 
@@ -882,7 +875,7 @@ static void __init mvebu_mbus_get_pcie_resources(struct device_node *np,
         }
 }
 
-int __init mvebu_mbus_dt_init(void)
+int __init mvebu_mbus_dt_init(bool is_coherent)
 {
         struct resource mbuswins_res, sdramwins_res;
         struct device_node *np, *controller;
@@ -920,6 +913,8 @@ int __init mvebu_mbus_dt_init(void)
                 return -EINVAL;
         }
 
+        mbus_state.hw_io_coherency = is_coherent;
+
         /* Get optional pcie-{mem,io}-aperture properties */
         mvebu_mbus_get_pcie_resources(np, &mbus_state.pcie_mem_aperture,
                                           &mbus_state.pcie_io_aperture);