[PATCH 11/11] powerpc/powernv: Check device-tree for RFI flush settings

[Michael Ellerman]

From: Oliver O'Halloran <oohall at gmail.com>

New device-tree properties are available which tell the hypervisor
settings related to the RFI flush. Use them to determine the
appropriate flush instruction to use, and whether the flush is
required.

Signed-off-by: Oliver O'Halloran <oohall at gmail.com>
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
---
 arch/powerpc/platforms/powernv/setup.c | 49 ++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
index 1edfbc1e40f4..4fb21e17504a 100644
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c
@@ -37,13 +37,62 @@
 #include <asm/kexec.h>
 #include <asm/smp.h>
 #include <asm/tm.h>
+#include <asm/setup.h>
 
 #include "powernv.h"
 
+static void pnv_setup_rfi_flush(void)
+{
+	struct device_node *np, *fw_features;
+	enum l1d_flush_type type;
+	int enable;
+
+	/* Default to fallback in case fw-features are not available */
+	type = L1D_FLUSH_FALLBACK;
+	enable = 1;
+
+	np = of_find_node_by_name(NULL, "ibm,opal");
+	fw_features = of_get_child_by_name(np, "fw-features");
+	of_node_put(np);
+
+	if (fw_features) {
+		np = of_get_child_by_name(fw_features, "inst-l1d-flush-trig2");
+		if (np && of_property_read_bool(np, "enabled"))
+			type = L1D_FLUSH_MTTRIG;
+
+		of_node_put(np);
+
+		np = of_get_child_by_name(fw_features, "inst-l1d-flush-ori30,30,0");
+		if (np && of_property_read_bool(np, "enabled"))
+			type = L1D_FLUSH_ORI;
+
+		of_node_put(np);
+
+		/* Enable unless firmware says NOT to */
+		enable = 2;
+		np = of_get_child_by_name(fw_features, "needs-l1d-flush-msr-hv-1-to-0");
+		if (np && of_property_read_bool(np, "disabled"))
+			enable--;
+
+		of_node_put(np);
+
+		np = of_get_child_by_name(fw_features, "needs-l1d-flush-msr-pr-0-to-1");
+		if (np && of_property_read_bool(np, "disabled"))
+			enable--;
+
+		of_node_put(np);
+		of_node_put(fw_features);
+	}
+
+	setup_rfi_flush(type, enable > 0);
+}
+
 static void __init pnv_setup_arch(void)
 {
 	set_arch_panic_timeout(10, ARCH_PANIC_TIMEOUT);
 
+	pnv_setup_rfi_flush();
+
 	/* Initialize SMP */
 	pnv_smp_init();
 
-- 
2.14.3