powerpc/powernv: Check device-tree for RFI flush settings

commit 6e032b350cd1fdb830f18f8320ef0e13b4e24094 upstream.

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@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>

diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
index 20974478f8d042b8b8c204741ce02b09e41646e9..e3c98361e6e4d36f26b06c8cde4eabe128d40ebf 100644 (file)
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c
@@ -38,14 +38,63 @@
 #include <asm/cputhreads.h>
 #include <asm/cpuidle.h>
 #include <asm/code-patching.h>
+#include <asm/setup.h>
 
 #include "powernv.h"
 #include "subcore.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();