sdhc: avoid taking adaptive mutex while holding spin mutex

the clock_bus pre- and post- callbacks used in sdhc_bus_clock_ddr()
are called with a spin mutex held, and the new sdhc@acpi ends up
calling into (sleeping) ACPI code, triggering lockdebug assertion.

introduce an adaptive mutex that is held around these callbacks,
and reduce the spin mutex held time in sdhc_bus_clock_ddr().


Index: sys/dev/sdmmc/sdhc.c
===================================================================
RCS file: /cvsroot/src/sys/dev/sdmmc/sdhc.c,v
retrieving revision 1.113
diff -p -u -r1.113 sdhc.c
--- sys/dev/sdmmc/sdhc.c	15 Jan 2022 14:33:36 -0000	1.113
+++ sys/dev/sdmmc/sdhc.c	15 Jan 2022 22:26:58 -0000
@@ -77,6 +77,7 @@ struct sdhc_host {
 	uint16_t intr_status;		/* soft interrupt status */
 	uint16_t intr_error_status;	/* soft error status */
 	kmutex_t intr_lock;
+	kmutex_t bus_clock_lock;
 	kcondvar_t intr_cv;
 
 	callout_t tuning_timer;
@@ -296,6 +297,7 @@ sdhc_host_found(struct sdhc_softc *sc, b
 	hp->dmat = sc->sc_dmat;
 
 	mutex_init(&hp->intr_lock, MUTEX_DEFAULT, IPL_SDMMC);
+	mutex_init(&hp->bus_clock_lock, MUTEX_DEFAULT, IPL_NONE);
 	cv_init(&hp->intr_cv, "sdhcintr");
 	callout_init(&hp->tuning_timer, CALLOUT_MPSAFE);
 	callout_setfunc(&hp->tuning_timer, sdhc_tuning_timer, hp);
@@ -650,6 +652,7 @@ adma_done:
 err:
 	callout_destroy(&hp->tuning_timer);
 	cv_destroy(&hp->intr_cv);
+	mutex_destroy(&hp->bus_clock_lock);
 	mutex_destroy(&hp->intr_lock);
 	free(hp, M_DEVBUF);
 	sc->sc_host[--sc->sc_nhosts] = NULL;
@@ -1097,8 +1100,6 @@ sdhc_bus_clock_ddr(sdmmc_chipset_handle_
 	int error = 0;
 	bool present __diagused;
 
-	mutex_enter(&hp->intr_lock);
-
 #ifdef DIAGNOSTIC
 	present = ISSET(HREAD4(hp, SDHC_PRESENT_STATE), SDHC_CMD_INHIBIT_MASK);
 
@@ -1110,11 +1111,15 @@ sdhc_bus_clock_ddr(sdmmc_chipset_handle_
 #endif
 
 	if (hp->sc->sc_vendor_bus_clock) {
+		mutex_enter(&hp->bus_clock_lock);
 		error = (*hp->sc->sc_vendor_bus_clock)(hp->sc, freq);
+		mutex_exit(&hp->bus_clock_lock);
 		if (error != 0)
-			goto out;
+			return error;
 	}
 
+	mutex_enter(&hp->intr_lock);
+
 	/*
 	 * Stop SD clock before changing the frequency.
 	 */
@@ -1275,11 +1280,14 @@ sdhc_bus_clock_ddr(sdmmc_chipset_handle_
 			HCLR1(hp, SDHC_HOST_CTL, SDHC_HIGH_SPEED);
 	}
 
+	mutex_exit(&hp->intr_lock);
+
 	if (hp->sc->sc_vendor_bus_clock_post) {
+		mutex_enter(&hp->bus_clock_lock);
 		error = (*hp->sc->sc_vendor_bus_clock_post)(hp->sc, freq);
-		if (error != 0)
-			goto out;
+		mutex_exit(&hp->bus_clock_lock);
 	}
+	return error;
 
 out:
 	mutex_exit(&hp->intr_lock);