Remove EL2/EL1 GICv3 register updates
From Linux 3.17 onwards, the mainline kernel has support for GICv3
systems and if EL3 exists, it only needs to initialise ICC_SRE_EL3.SRE
and ICC_SRE_EL3.Enable to 1. Hence, this patch removes the redundant
updates of ICC_SRE_EL2 and ICC_PMR_EL1.
NOTE: For partner software's which enter kernel in EL1,
ICC_SRE_EL2.Enable and ICC_SRE_EL2.SRE bit needs to be set to 1
in EL2 before jumping to linux.
Change-Id: I09ed47869351b08a3b034735f532bc677eaa6917
diff --git a/drivers/arm/gic/arm_gic.c b/drivers/arm/gic/arm_gic.c
index 90fc8b5..ecd5a93 100644
--- a/drivers/arm/gic/arm_gic.c
+++ b/drivers/arm/gic/arm_gic.c
@@ -62,7 +62,7 @@
******************************************************************************/
static void gicv3_cpuif_setup(void)
{
- unsigned int scr_val, val;
+ unsigned int val;
uintptr_t base;
/*
@@ -93,35 +93,9 @@
while (val & WAKER_CA)
val = gicr_read_waker(base);
- /*
- * We need to set SCR_EL3.NS in order to see GICv3 non-secure state.
- * Restore SCR_EL3.NS again before exit.
- */
- scr_val = read_scr();
- write_scr(scr_val | SCR_NS_BIT);
- isb(); /* ensure NS=1 takes effect before accessing ICC_SRE_EL2 */
-
- /*
- * By default EL2 and NS-EL1 software should be able to enable GICv3
- * System register access without any configuration at EL3. But it turns
- * out that GICC PMR as set in GICv2 mode does not affect GICv3 mode. So
- * we need to set it here again. In order to do that we need to enable
- * register access. We leave it enabled as it should be fine and might
- * prevent problems with later software trying to access GIC System
- * Registers.
- */
val = read_icc_sre_el3();
write_icc_sre_el3(val | ICC_SRE_EN | ICC_SRE_SRE);
-
- val = read_icc_sre_el2();
- write_icc_sre_el2(val | ICC_SRE_EN | ICC_SRE_SRE);
-
- write_icc_pmr_el1(GIC_PRI_MASK);
- isb(); /* commit ICC_* changes before setting NS=0 */
-
- /* Restore SCR_EL3 */
- write_scr(scr_val);
- isb(); /* ensure NS=0 takes effect immediately */
+ isb();
}
/*******************************************************************************