From patchwork Wed Mar 7 19:41:53 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10264867 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 97F316055B for ; Wed, 7 Mar 2018 19:42:29 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8626C2941F for ; Wed, 7 Mar 2018 19:42:29 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7B0F829504; Wed, 7 Mar 2018 19:42:29 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id DE9602941F for ; Wed, 7 Mar 2018 19:42:28 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 691F46E215; Wed, 7 Mar 2018 19:42:28 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from fireflyinternet.com (mail.fireflyinternet.com [109.228.58.192]) by gabe.freedesktop.org (Postfix) with ESMTPS id EE49B6E214 for ; Wed, 7 Mar 2018 19:42:22 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from haswell.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 10939358-1500050 for multiple; Wed, 07 Mar 2018 19:42:06 +0000 Received: by haswell.alporthouse.com (sSMTP sendmail emulation); Wed, 07 Mar 2018 19:42:06 +0000 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Wed, 7 Mar 2018 19:41:53 +0000 Message-Id: <20180307194202.31099-2-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180307194202.31099-1-chris@chris-wilson.co.uk> References: <20180307194202.31099-1-chris@chris-wilson.co.uk> MIME-Version: 1.0 X-Originating-IP: 78.156.65.138 X-Country: code=GB country="United Kingdom" ip=78.156.65.138 Subject: [Intel-gfx] [PATCH 01/10] drm/i915: Disable preemption and sleeping while using the punit sideband X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Hans de Goede Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP While we talk to the punit over its sideband, we need to prevent the cpu from sleeping in order to prevent a potential machine hang. Note that by itself, it appears that pm_qos_update_request (via intel_idle) doesn't provide a sufficient barrier to ensure that all core are indeed awake (out of Cstate) and that the package is awake. To do so, we need to supplement the pm_qos with a manual ping on_each_cpu. v2: Restrict the heavy-weight wakeup to just the ISOF_PORT_PUNIT, there is insufficient evidence to implicate a wider problem atm. Similarly, restrict the w/a to Valleyview, as Cherryview doesn't have an angry cadre of users. The working theory, courtesy of Ville and Hans, is the issue lies within the power delivery and so is likely to be unit and board specific and occurs when both the unit/fw require extra power at the same time as the cpu package is changing its own power state. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=109051 References: https://bugs.freedesktop.org/show_bug.cgi?id=102657 References: https://bugzilla.kernel.org/show_bug.cgi?id=195255 Signed-off-by: Chris Wilson Cc: Mika Kuoppala Cc: Hans de Goede Cc: Ville Syrjälä --- drivers/gpu/drm/i915/i915_drv.c | 6 +++ drivers/gpu/drm/i915/i915_drv.h | 1 + drivers/gpu/drm/i915/intel_sideband.c | 89 +++++++++++++++++++++++++++-------- 3 files changed, 77 insertions(+), 19 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index d61b51c0bf0b..bfb9d7b6b678 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -913,6 +913,9 @@ static int i915_driver_init_early(struct drm_i915_private *dev_priv, spin_lock_init(&dev_priv->uncore.lock); mutex_init(&dev_priv->sb_lock); + pm_qos_add_request(&dev_priv->sb_qos, + PM_QOS_CPU_DMA_LATENCY, PM_QOS_DEFAULT_VALUE); + mutex_init(&dev_priv->modeset_restore_lock); mutex_init(&dev_priv->av_mutex); mutex_init(&dev_priv->wm.wm_mutex); @@ -964,6 +967,9 @@ static void i915_driver_cleanup_early(struct drm_i915_private *dev_priv) intel_irq_fini(dev_priv); i915_workqueues_cleanup(dev_priv); i915_engines_cleanup(dev_priv); + + pm_qos_remove_request(&dev_priv->sb_qos); + mutex_destroy(&dev_priv->sb_lock); } static int i915_mmio_setup(struct drm_i915_private *dev_priv) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 604389d0b6a3..b8da17304ebe 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -1907,6 +1907,7 @@ struct drm_i915_private { /* Sideband mailbox protection */ struct mutex sb_lock; + struct pm_qos_request sb_qos; /** Cached value of IMR to avoid reads in updating the bitfield */ union { diff --git a/drivers/gpu/drm/i915/intel_sideband.c b/drivers/gpu/drm/i915/intel_sideband.c index 75c872bb8cc9..d56eda33734e 100644 --- a/drivers/gpu/drm/i915/intel_sideband.c +++ b/drivers/gpu/drm/i915/intel_sideband.c @@ -22,6 +22,8 @@ * */ +#include + #include "i915_drv.h" #include "intel_drv.h" @@ -39,18 +41,48 @@ /* Private register write, double-word addressing, non-posted */ #define SB_CRWRDA_NP 0x07 -static int vlv_sideband_rw(struct drm_i915_private *dev_priv, u32 devfn, - u32 port, u32 opcode, u32 addr, u32 *val) +static void ping(void *info) { - u32 cmd, be = 0xf, bar = 0; - bool is_read = (opcode == SB_MRD_NP || opcode == SB_CRRDDA_NP); +} - cmd = (devfn << IOSF_DEVFN_SHIFT) | (opcode << IOSF_OPCODE_SHIFT) | - (port << IOSF_PORT_SHIFT) | (be << IOSF_BYTE_ENABLES_SHIFT) | - (bar << IOSF_BAR_SHIFT); +static void __vlv_punit_get(struct drm_i915_private *dev_priv) +{ + iosf_mbi_punit_acquire(); - WARN_ON(!mutex_is_locked(&dev_priv->sb_lock)); + /* + * Prevent the cpu from sleeping while we use this sideband, otherwise + * the punit may cause a machine hang. The issue appears to be isolated + * with changing the power state of the CPU package while changing + * the power state via the punit, and we have only observed it + * reliably on 4-core Baytail systems suggesting the issue is in the + * power delivery mechanism and likely to be be board/function + * specific. Hence we presume the workaround needs only be applied + * to the Valleyview P-unit and not all sideband communications. + */ + if (IS_VALLEYVIEW(dev_priv)) { + pm_qos_update_request(&dev_priv->sb_qos, 0); + on_each_cpu(ping, NULL, 1); + } +} + +static void __vlv_punit_put(struct drm_i915_private *dev_priv) +{ + if (IS_VALLEYVIEW(dev_priv)) + pm_qos_update_request(&dev_priv->sb_qos, PM_QOS_DEFAULT_VALUE); + iosf_mbi_punit_release(); +} + +static int vlv_sideband_rw(struct drm_i915_private *dev_priv, + u32 devfn, u32 port, u32 opcode, + u32 addr, u32 *val) +{ + const bool is_read = (opcode == SB_MRD_NP || opcode == SB_CRRDDA_NP); + int err; + + lockdep_assert_held(&dev_priv->sb_lock); + + /* Flush the previous comms, just in case it failed last time. */ if (intel_wait_for_register(dev_priv, VLV_IOSF_DOORBELL_REQ, IOSF_SB_BUSY, 0, 5)) { @@ -59,22 +91,33 @@ static int vlv_sideband_rw(struct drm_i915_private *dev_priv, u32 devfn, return -EAGAIN; } - I915_WRITE(VLV_IOSF_ADDR, addr); - I915_WRITE(VLV_IOSF_DATA, is_read ? 0 : *val); - I915_WRITE(VLV_IOSF_DOORBELL_REQ, cmd); - - if (intel_wait_for_register(dev_priv, - VLV_IOSF_DOORBELL_REQ, IOSF_SB_BUSY, 0, - 5)) { + preempt_disable(); + + I915_WRITE_FW(VLV_IOSF_ADDR, addr); + I915_WRITE_FW(VLV_IOSF_DATA, is_read ? 0 : *val); + I915_WRITE_FW(VLV_IOSF_DOORBELL_REQ, + (devfn << IOSF_DEVFN_SHIFT) | + (opcode << IOSF_OPCODE_SHIFT) | + (port << IOSF_PORT_SHIFT) | + (0xf << IOSF_BYTE_ENABLES_SHIFT) | + (0 << IOSF_BAR_SHIFT) | + IOSF_SB_BUSY); + + if (__intel_wait_for_register_fw(dev_priv, + VLV_IOSF_DOORBELL_REQ, IOSF_SB_BUSY, 0, + 10000, 0, NULL) == 0) { + if (is_read) + *val = I915_READ_FW(VLV_IOSF_DATA); + err = 0; + } else { DRM_DEBUG_DRIVER("IOSF sideband finish wait (%s) timed out\n", is_read ? "read" : "write"); - return -ETIMEDOUT; + err = -ETIMEDOUT; } - if (is_read) - *val = I915_READ(VLV_IOSF_DATA); + preempt_enable(); - return 0; + return err; } u32 vlv_punit_read(struct drm_i915_private *dev_priv, u32 addr) @@ -84,8 +127,12 @@ u32 vlv_punit_read(struct drm_i915_private *dev_priv, u32 addr) WARN_ON(!mutex_is_locked(&dev_priv->pcu_lock)); mutex_lock(&dev_priv->sb_lock); + __vlv_punit_get(dev_priv); + vlv_sideband_rw(dev_priv, PCI_DEVFN(0, 0), IOSF_PORT_PUNIT, SB_CRRDDA_NP, addr, &val); + + __vlv_punit_put(dev_priv); mutex_unlock(&dev_priv->sb_lock); return val; @@ -98,8 +145,12 @@ int vlv_punit_write(struct drm_i915_private *dev_priv, u32 addr, u32 val) WARN_ON(!mutex_is_locked(&dev_priv->pcu_lock)); mutex_lock(&dev_priv->sb_lock); + __vlv_punit_get(dev_priv); + err = vlv_sideband_rw(dev_priv, PCI_DEVFN(0, 0), IOSF_PORT_PUNIT, SB_CRWRDA_NP, addr, &val); + + __vlv_punit_put(dev_priv); mutex_unlock(&dev_priv->sb_lock); return err;