[PATCH] arm64: gic: Add power up sequence for GIC-600

[Venkatesh Yadav Abbarapu]

Arm's GIC-600 features a Power Register (GICR_PWRR),
which needs to be programmed to enable redistributor
operation. Power on the redistributor and  wait until
the power on state is reflected by checking the bit
GICR_PWRR.RDPD == 0. While running U-Boot in EL3
without enabling this register, GICR_WAKER.ChildrenAsleep
bit is not getting cleared and loops infinitely.
This register(GICR_PWRR) must be programmed to mark the frame
as powered on, before accessing other registers in the frame.
Rest of initialization sequence remains the same.

ARM GIC-600 IP complies with ARM GICv3 architecture.
Enable this config if GIC-600 IP present.

Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu at amd.com>
---
 arch/arm/Kconfig                 |  9 +++++++++
 arch/arm/include/asm/gic.h       |  1 +
 arch/arm/lib/gic_64.S            | 10 +++++++++-
 arch/arm/mach-versal-net/Kconfig |  3 +++
 4 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 01d6556c42..8374cb7acc 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -122,6 +122,15 @@ config GIC_V3_ITS
 	  ARM GICV3 has limitation, once the LPI table is enabled, LPI
 	  configuration table can not be re-programmed, unless GICV3 reset.
 
+config GICV3_SUPPORT_GIC600
+	bool "ARM GICV3 GIC600 SUPPORT"
+	help
+	  ARM GIC-600 IP complies with ARM GICv3 architecture, but among others,
+	  implements a power control register in the Redistributor frame.This
+	  register must be programmed to mark the frame as powered on, before
+	  accessing other registers in the frame. Rest of initialization sequence
+	  remains the same.
+
 config STATIC_RELA
 	bool
 	default y if ARM64
diff --git a/arch/arm/include/asm/gic.h b/arch/arm/include/asm/gic.h
index bd3a80cdf7..fb64ba076d 100644
--- a/arch/arm/include/asm/gic.h
+++ b/arch/arm/include/asm/gic.h
@@ -57,6 +57,7 @@
 #define GICR_TYPER		0x0008
 #define GICR_STATUSR		0x0010
 #define GICR_WAKER		0x0014
+#define GICR_PWRR              0x0024
 #define GICR_SETLPIR		0x0040
 #define GICR_CLRLPIR		0x0048
 #define GICR_SEIR		0x0068
diff --git a/arch/arm/lib/gic_64.S b/arch/arm/lib/gic_64.S
index 86cd882fc7..7fa48648d9 100644
--- a/arch/arm/lib/gic_64.S
+++ b/arch/arm/lib/gic_64.S
@@ -92,8 +92,16 @@ ENTRY(gic_init_secure_percpu)
 	add	x9, x9, #(2 << 16)
 	b	1b
 
+2:
+#if defined(CONFIG_GICV3_SUPPORT_GIC600)
+        mov     w10, #0x0               /* Power on redistributor */
+        str     w10, [x9, GICR_PWRR]
+5:      ldr     w10, [x9, GICR_PWRR]    /* Wait until the power on state is reflected */
+        tbnz    w10, #1, 5b             /* If RDPD == 0 then powered on */
+#endif
+
 	/* x9: ReDistributor Base Address of Current CPU */
-2:	mov	w10, #~0x2
+	mov	w10, #~0x2
 	ldr	w11, [x9, GICR_WAKER]
 	and	w11, w11, w10		/* Clear ProcessorSleep */
 	str	w11, [x9, GICR_WAKER]
diff --git a/arch/arm/mach-versal-net/Kconfig b/arch/arm/mach-versal-net/Kconfig
index edff5b039e..31d6443e9f 100644
--- a/arch/arm/mach-versal-net/Kconfig
+++ b/arch/arm/mach-versal-net/Kconfig
@@ -43,6 +43,9 @@ config SYS_MEM_RSVD_FOR_MMU
 config GICV3
 	def_bool y
 
+config GICV3_SUPPORT_GIC600
+	def_bool y
+
 config SYS_MALLOC_LEN
 	default 0x2000000
 
-- 
2.25.1