Fix nic lock usages around iwm_{read,write}_prph().

The iwm_{read,write}_prph() calls don't grab the nic lock themselves
so make sure to acquire it where necessary.
The iwm_{set,clear}_bits_prph() on the other hand acquire/release the
nic lock themselves. Since the nic lock doesn't do recursive locking
we need to be careful to avoid accidentally releasing the nic lock
too early that way.

Patch by Imre Vadasz.

1 files changed, 36 insertions, 19 deletions

diff --git a/sys/dev/pci/if_iwm.c b/sys/dev/pci/if_iwm.c
index d90ddf0d407..a7332b4392f 100644
--- a/sys/dev/pci/if_iwm.c
+++ b/sys/dev/pci/if_iwm.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_iwm.c,v 1.167 2017/04/04 00:40:52 claudio Exp $	*/
+/*	$OpenBSD: if_iwm.c,v 1.168 2017/04/21 16:39:52 stsp Exp $	*/
 
 /*
  * Copyright (c) 2014, 2016 genua gmbh <info@genua.de>
@@ -1461,11 +1461,17 @@ iwm_apm_init(struct iwm_softc *sc)
 		 * just to discard the value. But that's the way the hardware
 		 * seems to like it.
 		 */
-		iwm_read_prph(sc, IWM_OSC_CLK);
-		iwm_read_prph(sc, IWM_OSC_CLK);
+		if (iwm_nic_lock(sc)) {
+			iwm_read_prph(sc, IWM_OSC_CLK);
+			iwm_read_prph(sc, IWM_OSC_CLK);
+			iwm_nic_unlock(sc);
+		}
 		iwm_set_bits_prph(sc, IWM_OSC_CLK, IWM_OSC_CLK_FORCE_CONTROL);
-		iwm_read_prph(sc, IWM_OSC_CLK);
-		iwm_read_prph(sc, IWM_OSC_CLK);
+		if (iwm_nic_lock(sc)) {
+			iwm_read_prph(sc, IWM_OSC_CLK);
+			iwm_read_prph(sc, IWM_OSC_CLK);
+			iwm_nic_unlock(sc);
+		}
 	}
 
 	/*
@@ -1476,8 +1482,11 @@ iwm_apm_init(struct iwm_softc *sc)
 	 * set by default in "CLK_CTRL_REG" after reset.
 	 */
 	if (sc->sc_device_family == IWM_DEVICE_FAMILY_7000) {
-		iwm_write_prph(sc, IWM_APMG_CLK_EN_REG,
-		    IWM_APMG_CLK_VAL_DMA_CLK_RQT);
+		if (iwm_nic_lock(sc)) {
+			iwm_write_prph(sc, IWM_APMG_CLK_EN_REG,
+			    IWM_APMG_CLK_VAL_DMA_CLK_RQT);
+			iwm_nic_unlock(sc);
+		}
 		DELAY(20);
 
 		/* Disable L1-Active */
@@ -1485,8 +1494,11 @@ iwm_apm_init(struct iwm_softc *sc)
 		    IWM_APMG_PCIDEV_STT_VAL_L1_ACT_DIS);
 
 		/* Clear the interrupt in APMG if the NIC is in RFKILL */
-		iwm_write_prph(sc, IWM_APMG_RTC_INT_STT_REG,
-		    IWM_APMG_RTC_INT_STT_RFKILL);
+		if (iwm_nic_lock(sc)) {
+			iwm_write_prph(sc, IWM_APMG_RTC_INT_STT_REG,
+			    IWM_APMG_RTC_INT_STT_RFKILL);
+			iwm_nic_unlock(sc);
+		}
 	}
  out:
 	if (err)
@@ -1539,11 +1551,11 @@ iwm_stop_device(struct iwm_softc *sc)
 	iwm_disable_interrupts(sc);
 	sc->sc_flags &= ~IWM_FLAG_USE_ICT;
 
-	/* Deactivate TX scheduler. */
-	iwm_write_prph(sc, IWM_SCD_TXFACT, 0);
-
 	/* Stop all DMA channels. */
 	if (iwm_nic_lock(sc)) {
+		/* Deactivate TX scheduler. */
+		iwm_write_prph(sc, IWM_SCD_TXFACT, 0);
+
 		for (chnl = 0; chnl < IWM_FH_TCSR_CHNL_NUM; chnl++) {
 			IWM_WRITE(sc,
 			    IWM_FH_TCSR_CHNL_TX_CONFIG_REG(chnl), 0);
@@ -1566,10 +1578,12 @@ iwm_stop_device(struct iwm_softc *sc)
 	for (qid = 0; qid < nitems(sc->txq); qid++)
 		iwm_reset_tx_ring(sc, &sc->txq[qid]);
 
-	/*
-	 * Power-down device's busmaster DMA clocks
-	 */
-	iwm_write_prph(sc, IWM_APMG_CLK_DIS_REG, IWM_APMG_CLK_VAL_DMA_CLK_RQT);
+	if (iwm_nic_lock(sc)) {
+		/* Power-down device's busmaster DMA clocks */
+		iwm_write_prph(sc, IWM_APMG_CLK_DIS_REG,
+		    IWM_APMG_CLK_VAL_DMA_CLK_RQT);
+		iwm_nic_unlock(sc);
+	}
 	DELAY(5);
 
 	/* Make sure (redundant) we've released our request to stay awake */
@@ -2838,10 +2852,9 @@ iwm_firmware_load_chunk(struct iwm_softc *sc, uint32_t dst_addr,
 		    DEVNAME(sc), dst_addr, byte_cnt);
 
 	if (dst_addr >= IWM_FW_MEM_EXTENDED_START &&
-	    dst_addr <= IWM_FW_MEM_EXTENDED_END && iwm_nic_lock(sc)) {
+	    dst_addr <= IWM_FW_MEM_EXTENDED_END) {
 		iwm_clear_bits_prph(sc, IWM_LMPM_CHICK,
 		    IWM_LMPM_CHICK_EXTENDED_ADDR_SPACE);
-		iwm_nic_unlock(sc);
 	}
 
 	return err;
@@ -2961,7 +2974,11 @@ iwm_load_firmware_8000(struct iwm_softc *sc, enum iwm_ucode_type ucode_type)
 
 	/* configure the ucode to be ready to get the secured image */
 	/* release CPU reset */
-	iwm_write_prph(sc, IWM_RELEASE_CPU_RESET, IWM_RELEASE_CPU_RESET_BIT);
+	if (iwm_nic_lock(sc)) {
+		iwm_write_prph(sc, IWM_RELEASE_CPU_RESET,
+		    IWM_RELEASE_CPU_RESET_BIT);
+		iwm_nic_unlock(sc);
+	}
 
 	/* load to FW the binary Secured sections of CPU1 */
 	err = iwm_load_cpu_sections_8000(sc, fws, 1, &first_ucode_section);