irqchip: gicv3: Add GICv3 access control Kconfig option

Some SOCs(System-on-chip) S/W configurations restricts the access
to particular set of the GIC registers to prevent invalid
accesses for the security reasons. Provide a configuration
option for the GICv3 driver and also restrict the access
of the GICR_WAKER registers from the non-secure world.

If this Kconfig option is not selected then it means that
access control configuration is enabled from the secure world.

CRs-Fixed: 958251
Change-Id: I91f06484b6b6bf58d05e6b621ee84610a71fe3e7
[abhimany: minor merge conflict resolution]
Signed-off-by: Trilok Soni <tsoni@codeaurora.org>
Signed-off-by: Abhimanyu Kapur <abhimany@codeaurora.org>

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 463dbf3..ef3e3c9 100644 (file)
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -27,6 +27,18 @@ config ARM_GIC_V3_ITS
        bool
        select PCI_MSI_IRQ_DOMAIN
 
+config ARM_GIC_V3_NO_ACCESS_CONTROL
+       bool "GICv3 No Access Control Configuration"
+       depends on ARM_GIC_V3
+       help
+         On some SOCs with the access control configurations it is
+         not allowed to access certain set of the GIC registers
+         from non-secure world. Provide a common flag to protect
+         those functionalities and compile them out for such
+         configurations, so that specific registers are not touched.
+
+         For production kernels, you should say 'N' here.
+
 config ARM_NVIC
        bool
        select IRQ_DOMAIN

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 1a1d7ce..6bcf428 100644 (file)
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -126,6 +126,7 @@ static u64 __maybe_unused gic_read_iar(void)
 }
 #endif
 
+#ifdef CONFIG_ARM_GIC_V3_NO_ACCESS_CONTROL
 static void gic_enable_redist(bool enable)
 {
        void __iomem *rbase;
@@ -159,6 +160,9 @@ static void gic_enable_redist(bool enable)
                pr_err_ratelimited("redistributor failed to %s...\n",
                                   enable ? "wakeup" : "sleep");
 }
+#else
+static void gic_enable_redist(bool enable) { }
+#endif
 
 /*
  * Routines to disable, enable, EOI and route interrupts