powerpc/pseries: Query hypervisor for RFI flush settings

commit 8989d56878a7735dfdb234707a2fee6faf631085 upstream.

A new hypervisor call is available which tells the guest settings
related to the RFI flush. Use it to query the appropriate flush
instruction(s), and whether the flush is required.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index a8531e0..ae4f596 100644 (file)
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -459,6 +459,39 @@ static void __init find_and_init_phbs(void)
        of_pci_check_probe_only();
 }
 
+static void pseries_setup_rfi_flush(void)
+{
+       struct h_cpu_char_result result;
+       enum l1d_flush_type types;
+       bool enable;
+       long rc;
+
+       /* Enable by default */
+       enable = true;
+
+       rc = plpar_get_cpu_characteristics(&result);
+       if (rc == H_SUCCESS) {
+               types = L1D_FLUSH_NONE;
+
+               if (result.character & H_CPU_CHAR_L1D_FLUSH_TRIG2)
+                       types |= L1D_FLUSH_MTTRIG;
+               if (result.character & H_CPU_CHAR_L1D_FLUSH_ORI30)
+                       types |= L1D_FLUSH_ORI;
+
+               /* Use fallback if nothing set in hcall */
+               if (types == L1D_FLUSH_NONE)
+                       types = L1D_FLUSH_FALLBACK;
+
+               if (!(result.behaviour & H_CPU_BEHAV_L1D_FLUSH_PR))
+                       enable = false;
+       } else {
+               /* Default to fallback if case hcall is not available */
+               types = L1D_FLUSH_FALLBACK;
+       }
+
+       setup_rfi_flush(types, enable);
+}
+
 static void __init pSeries_setup_arch(void)
 {
        set_arch_panic_timeout(10, ARCH_PANIC_TIMEOUT);
@@ -476,6 +509,8 @@ static void __init pSeries_setup_arch(void)
 
        fwnmi_init();
 
+       pseries_setup_rfi_flush();
+
        /* By default, only probe PCI (can be overridden by rtas_pci) */
        pci_add_flags(PCI_PROBE_ONLY);