On systems where GIC support two security states, both the register
GICR_WAKE and GICD_IGROUPR accesses are RAZ/WI from non-secure.
The function gic_enable_redist() to wake/sleep redistributor is not
harmful at all, but it is confusing looking at the code. The current
code checks the single security state based on bit GICD_CTLR.DS which
is absolutely incorrect. The disable security bit GICD_CTLR.DS is RAZ
to non-secure. The GICD_TYPE.SecurityExtn indicates whether the GIC
implementation supports two security states or only one security
state.
Let's introduce a new helper function gic_has_security_extn() to
know GIC security state. Use this function to bypass the code that
is touching the registers GICR_WAKE and GICD_IGROUPR.
Signed-off-by: Shanker Donthineni <shank...@codeaurora.org>
---
Changes since v1:
Edit comments.
Do explicit writes to IGRPMODR if GIC security is disabled.
drivers/irqchip/irq-gic-v3.c | 40 +++++++++++++++++++++++++++++++-------
include/linux/irqchip/arm-gic-v3.h | 1 +
2 files changed, 34 insertions(+), 7 deletions(-)
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index c132f29..31b54ab 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -130,12 +130,28 @@ static u64 __maybe_unused gic_read_iar(void)
}
#endif
+/**
+ * Check whether the GIC implementation supports two security
+ * states or only one security state.
+ * return true if it has two security states else return false.
+ */
+static bool gic_has_security_extn(void)
+{
+ u32 typer = readl_relaxed(gic_data.dist_base + GICD_TYPER);
+
+ return !!(typer & GICD_TYPER_SECURITY_EXTN);
+}
+
static void gic_enable_redist(bool enable)
{
void __iomem *rbase;
u32 count = 1000000; /* 1s! */
u32 val;
+ /* With only one security state, GICR_WAKE is RAZ/WI to non-secure */
+ if (gic_has_security_extn())
+ return;
+
rbase = gic_data_rdist_rd_base();
val = readl_relaxed(rbase + GICR_WAKER);
@@ -399,14 +415,24 @@ static void __init gic_dist_init(void)
/*
* Configure SPIs as non-secure Group-1. This will only matter
- * if the GIC only has a single security state. This will not
- * do the right thing if the kernel is running in secure mode,
- * but that's not the intended use case anyway.
+ * if the GIC only has a single security state. This will do
+ * the right thing if the kernel is running in secure mode and
+ * with assumption all the SPIs are allocated to Linux, but
+ * that's not the intended use case anyway.
+ *
+ * IGRPMODR IGROUPR Definition ShortName
+ * 0 0 Secure Group0 G0S
+ * 0 1 Non-secure Group1 G1NS
+ * 1 0 Secure Group1 G1S
+ * 1 1 Reserved treated as G1NS
*/
- for (i = 32; i < gic_data.irq_nr; i += 32)
- writel_relaxed(~0, base + GICD_IGROUPR + i / 8);
-
- gic_dist_config(base, gic_data.irq_nr, gic_dist_wait_for_rwp);
+ if (!gic_has_security_extn()) {
+ for (i = 32; i < gic_data.irq_nr; i += 32) {
+ writel_relaxed(0, base + GICD_IGRPMODR + i / 8);
+ writel_relaxed(~0, base + GICD_IGROUPR + i / 8);
+ }
+ gic_dist_config(base, gic_data.irq_nr, gic_dist_wait_for_rwp);
+ }
/* Enable distributor with ARE, Group1 */
writel_relaxed(GICD_CTLR_ARE_NS | GICD_CTLR_ENABLE_G1A |
GICD_CTLR_ENABLE_G1,
diff --git a/include/linux/irqchip/arm-gic-v3.h
b/include/linux/irqchip/arm-gic-v3.h
index e808f8a..aab00e5 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -70,6 +70,7 @@
#define GICD_TYPER_LPIS (1U << 17)
#define GICD_TYPER_MBIS (1U << 16)
+#define GICD_TYPER_SECURITY_EXTN (1U << 10)
#define GICD_TYPER_ID_BITS(typer) ((((typer) >> 19) & 0x1f) + 1)
#define GICD_TYPER_IRQS(typer) ((((typer) & 0x1f) + 1) * 32)
--
Qualcomm Datacenter Technologies, Inc. on behalf of the Qualcomm Technologies,
Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux
Foundation Collaborative Project.
