allwinner: Move sunxi_cpu_power_off_self() into platforms
The code to power the current core off when SCPI is not available is now
different for the two supported SoC families.
To make adding new platforms easier, move sunxi_cpu_power_off_self()
into the SoC directory, so we don't need to carry definitions for both
methods for all SoCs.
On the H6 we just need to trigger the CPUIDLE hardware, so can get rid
of all the code to program the ARISC, which is now only needed for the
A64 version.
Change-Id: Id2a1ac7dcb375e2fd021b441575ce86b4d7edf2c
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/plat/allwinner/sun50i_a64/sunxi_power.c b/plat/allwinner/sun50i_a64/sunxi_power.c
index 80a69c3..0fdb62d 100644
--- a/plat/allwinner/sun50i_a64/sunxi_power.c
+++ b/plat/allwinner/sun50i_a64/sunxi_power.c
@@ -14,6 +14,7 @@
#include <drivers/allwinner/sunxi_rsb.h>
#include <lib/mmio.h>
+#include <core_off_arisc.h>
#include <sunxi_def.h>
#include <sunxi_mmap.h>
#include <sunxi_private.h>
@@ -205,3 +206,55 @@
}
}
+
+/* This lock synchronises access to the arisc management processor. */
+static DEFINE_BAKERY_LOCK(arisc_lock);
+
+/*
+ * If we are supposed to turn ourself off, tell the arisc SCP to do that
+ * work for us. Without any SCPI provider running there, we place some
+ * OpenRISC code into SRAM, put the address of that into the reset vector
+ * and release the arisc reset line. The SCP will wait for the core to enter
+ * WFI, then execute that code and pull the line up again.
+ * The code expects the core mask to be patched into the first instruction.
+ */
+void sunxi_cpu_power_off_self(void)
+{
+ u_register_t mpidr = read_mpidr();
+ unsigned int core = MPIDR_AFFLVL0_VAL(mpidr);
+ uintptr_t arisc_reset_vec = SUNXI_SRAM_A2_BASE + 0x100;
+ uint32_t *code = arisc_core_off;
+
+ do {
+ bakery_lock_get(&arisc_lock);
+ /* Wait until the arisc is in reset state. */
+ if (!(mmio_read_32(SUNXI_R_CPUCFG_BASE) & BIT(0)))
+ break;
+
+ bakery_lock_release(&arisc_lock);
+ } while (1);
+
+ /* Patch up the code to feed in an input parameter. */
+ code[0] = (code[0] & ~0xffff) | BIT_32(core);
+ clean_dcache_range((uintptr_t)code, sizeof(arisc_core_off));
+
+ /*
+ * The OpenRISC unconditional branch has opcode 0, the branch offset
+ * is in the lower 26 bits, containing the distance to the target,
+ * in instruction granularity (32 bits).
+ */
+ mmio_write_32(arisc_reset_vec, ((uintptr_t)code - arisc_reset_vec) / 4);
+ clean_dcache_range(arisc_reset_vec, 4);
+
+ /* De-assert the arisc reset line to let it run. */
+ mmio_setbits_32(SUNXI_R_CPUCFG_BASE, BIT(0));
+
+ /*
+ * We release the lock here, although the arisc is still busy.
+ * But as long as it runs, the reset line is high, so other users
+ * won't leave the loop above.
+ * Once it has finished, the code is supposed to clear the reset line,
+ * to signal this to other users.
+ */
+ bakery_lock_release(&arisc_lock);
+}