Implement suspend/resume support. This will turn off the power domain

associated with a DART when we suspend and turn it back on upon resume.
The DART is reconfigured with the same translation table that was
present when we suspended.

This is only done for DARTs that are under our control; locked DARTs and
DARTs that were enabled at boot time are skipped.

ok patrick@

diff --git a/sys/arch/arm64/dev/apldart.c b/sys/arch/arm64/dev/apldart.c
index b22ca3d..cc8c4b8 100644 (file)
--- a/sys/arch/arm64/dev/apldart.c
+++ b/sys/arch/arm64/dev/apldart.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: apldart.c,v 1.16 2022/07/21 18:24:24 kettenis Exp $   */
+/*     $OpenBSD: apldart.c,v 1.17 2023/07/23 11:47:20 kettenis Exp $   */
 /*
  * Copyright (c) 2021 Mark Kettenis <kettenis@openbsd.org>
  *
@@ -28,6 +28,7 @@
 
 #include <dev/ofw/openfirm.h>
 #include <dev/ofw/ofw_misc.h>
+#include <dev/ofw/ofw_power.h>
 #include <dev/ofw/fdt.h>
 
 /*
@@ -161,6 +162,8 @@ struct apldart_softc {
 
        struct machine_bus_dma_tag sc_bus_dmat;
        struct iommu_device     sc_id;
+
+       int                     sc_do_suspend;
 };
 
 struct apldart_map_state {
@@ -187,9 +190,11 @@ void       apldart_dmamem_free(bus_dma_tag_t, struct apldart_dmamem *);
 
 int    apldart_match(struct device *, void *, void *);
 void   apldart_attach(struct device *, struct device *, void *);
+int    apldart_activate(struct device *, int);
 
 const struct cfattach apldart_ca = {
-       sizeof (struct apldart_softc), apldart_match, apldart_attach
+       sizeof (struct apldart_softc), apldart_match, apldart_attach, NULL,
+       apldart_activate
 };
 
 struct cfdriver apldart_cd = {
@@ -255,8 +260,10 @@ apldart_attach(struct device *parent, struct device *self, void *aux)
        }
 
        sc->sc_dmat = faa->fa_dmat;
-
        sc->sc_node = faa->fa_node;
+
+       power_domain_enable(sc->sc_node);
+
        if (OF_is_compatible(sc->sc_node, "apple,t8110-dart")) {
                params4 = HREAD4(sc, DART_T8110_PARAMS4);
                sc->sc_nsid = params4 & DART_T8110_PARAMS4_NSID_MASK;
@@ -321,6 +328,11 @@ apldart_attach(struct device *parent, struct device *self, void *aux)
                }
        }
 
+       /*
+        * We have full control over this DART, so do suspend it.
+        */
+       sc->sc_do_suspend = 1;
+
        /*
         * Use bypass mode if supported.  This avoids an issue with
         * the USB3 controllers which need mappings entered into two
@@ -433,6 +445,83 @@ apldart_attach(struct device *parent, struct device *self, void *aux)
        iommu_device_register(&sc->sc_id);
 }
 
+void
+apldart_suspend(struct apldart_softc *sc)
+{
+       if (!sc->sc_do_suspend)
+               return;
+
+       power_domain_disable(sc->sc_node);
+}
+
+void
+apldart_resume(struct apldart_softc *sc)
+{
+       paddr_t pa;
+       int ntte, nl1, nl2;
+       uint32_t params2;
+       int sid, idx;
+
+       if (!sc->sc_do_suspend)
+               return;
+
+       power_domain_enable(sc->sc_node);
+
+       params2 = HREAD4(sc, DART_PARAMS2);
+       if (params2 & DART_PARAMS2_BYPASS_SUPPORT) {
+               for (sid = 0; sid < sc->sc_nsid; sid++)
+                       HWRITE4(sc, DART_TCR(sc, sid), sc->sc_tcr_bypass);
+               return;
+       }
+
+       ntte = howmany(sc->sc_dvaend, DART_PAGE_SIZE);
+       nl2 = howmany(ntte, DART_PAGE_SIZE / sizeof(uint64_t));
+       nl1 = howmany(nl2, DART_PAGE_SIZE / sizeof(uint64_t));
+
+       /* Install page tables. */
+       for (sid = 0; sid < sc->sc_nsid; sid++) {
+               pa = APLDART_DMA_DVA(sc->sc_l1);
+               for (idx = 0; idx < nl1; idx++) {
+                       HWRITE4(sc, DART_TTBR(sc, sid, idx),
+                           (pa >> DART_TTBR_SHIFT) | sc->sc_ttbr_valid);
+                       pa += DART_PAGE_SIZE;
+               }
+       }
+       sc->sc_flush_tlb(sc);
+
+       /* Enable all streams. */
+       for (idx = 0; idx < howmany(sc->sc_nsid, 32); idx++)
+               HWRITE4(sc, DART_SID_ENABLE(sc, idx), ~0);
+
+       /* Enable translations. */
+       for (sid = 0; sid < sc->sc_nsid; sid++)
+               HWRITE4(sc, DART_TCR(sc, sid), sc->sc_tcr_translate_enable);
+
+       if (OF_is_compatible(sc->sc_node, "apple,t8110-dart")) {
+               HWRITE4(sc, DART_T8110_ERROR, HREAD4(sc, DART_T8110_ERROR));
+               HWRITE4(sc, DART_T8110_ERROR_MASK, 0);
+       } else {
+               HWRITE4(sc, DART_T8020_ERROR, HREAD4(sc, DART_T8020_ERROR));
+       }
+}
+
+int
+apldart_activate(struct device *self, int act)
+{
+       struct apldart_softc *sc = (struct apldart_softc *)self;
+
+       switch (act) {
+       case DVACT_SUSPEND:
+               apldart_suspend(sc);
+               break;
+       case DVACT_RESUME:
+               apldart_resume(sc);
+               break;
+       }
+
+       return 0;
+}
+
 bus_dma_tag_t
 apldart_map(void *cookie, uint32_t *cells, bus_dma_tag_t dmat)
 {