x86/platform/uv: Update NMI Handler for UV5

Update NMI handler for UV5 hardware. A platform register changed, and
UV5 only uses one of the two NMI methods used on previous hardware.

Signed-off-by: Mike Travis <mike.travis@hpe.com>
Signed-off-by: Steve Wahl <steve.wahl@hpe.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220406195149.228164-2-steve.wahl@hpe.com

diff --git a/arch/x86/platform/uv/uv_nmi.c b/arch/x86/platform/uv/uv_nmi.c
index 1e9ff28bc2e04c270ab594fa82f11dbc3590bc0d..61ec3be773281e4e8eafc885d039daa3e89951ac 100644 (file)
--- a/arch/x86/platform/uv/uv_nmi.c
+++ b/arch/x86/platform/uv/uv_nmi.c
@@ -244,8 +244,10 @@ static inline bool uv_nmi_action_is(const char *action)
 /* Setup which NMI support is present in system */
 static void uv_nmi_setup_mmrs(void)
 {
+       bool new_nmi_method_only = false;
+
        /* First determine arch specific MMRs to handshake with BIOS */
-       if (UVH_EVENT_OCCURRED0_EXTIO_INT0_MASK) {
+       if (UVH_EVENT_OCCURRED0_EXTIO_INT0_MASK) {      /* UV2,3,4 setup */
                uvh_nmi_mmrx = UVH_EVENT_OCCURRED0;
                uvh_nmi_mmrx_clear = UVH_EVENT_OCCURRED0_ALIAS;
                uvh_nmi_mmrx_shift = UVH_EVENT_OCCURRED0_EXTIO_INT0_SHFT;
@@ -255,26 +257,25 @@ static void uv_nmi_setup_mmrs(void)
                uvh_nmi_mmrx_req = UVH_BIOS_KERNEL_MMR_ALIAS_2;
                uvh_nmi_mmrx_req_shift = 62;
 
-       } else if (UVH_EVENT_OCCURRED1_EXTIO_INT0_MASK) {
+       } else if (UVH_EVENT_OCCURRED1_EXTIO_INT0_MASK) { /* UV5+ setup */
                uvh_nmi_mmrx = UVH_EVENT_OCCURRED1;
                uvh_nmi_mmrx_clear = UVH_EVENT_OCCURRED1_ALIAS;
                uvh_nmi_mmrx_shift = UVH_EVENT_OCCURRED1_EXTIO_INT0_SHFT;
                uvh_nmi_mmrx_type = "OCRD1-EXTIO_INT0";
 
-               uvh_nmi_mmrx_supported = UVH_EXTIO_INT0_BROADCAST;
-               uvh_nmi_mmrx_req = UVH_BIOS_KERNEL_MMR_ALIAS_2;
-               uvh_nmi_mmrx_req_shift = 62;
+               new_nmi_method_only = true;             /* Newer nmi always valid on UV5+ */
+               uvh_nmi_mmrx_req = 0;                   /* no request bit to clear */
 
        } else {
-               pr_err("UV:%s:cannot find EVENT_OCCURRED*_EXTIO_INT0\n",
-                       __func__);
+               pr_err("UV:%s:NMI support not available on this system\n", __func__);
                return;
        }
 
        /* Then find out if new NMI is supported */
-       if (likely(uv_read_local_mmr(uvh_nmi_mmrx_supported))) {
-               uv_write_local_mmr(uvh_nmi_mmrx_req,
-                                       1UL << uvh_nmi_mmrx_req_shift);
+       if (new_nmi_method_only || uv_read_local_mmr(uvh_nmi_mmrx_supported)) {
+               if (uvh_nmi_mmrx_req)
+                       uv_write_local_mmr(uvh_nmi_mmrx_req,
+                                               1UL << uvh_nmi_mmrx_req_shift);
                nmi_mmr = uvh_nmi_mmrx;
                nmi_mmr_clear = uvh_nmi_mmrx_clear;
                nmi_mmr_pending = 1UL << uvh_nmi_mmrx_shift;