Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754666AbdCPPNR (ORCPT ); Thu, 16 Mar 2017 11:13:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35648 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752918AbdCPPMQ (ORCPT ); Thu, 16 Mar 2017 11:12:16 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 2354DC1C5DE6 Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=jglisse@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 2354DC1C5DE6 From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= To: akpm@linux-foundation.org, , linux-mm@kvack.org Cc: John Hubbard , Naoya Horiguchi , David Nellans , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Evgeny Baskakov , Mark Hairgrove , Sherry Cheung , Subhash Gutti Subject: [HMM 16/16] mm/hmm/devmem: dummy HMM device for ZONE_DEVICE memory v2 Date: Thu, 16 Mar 2017 12:05:35 -0400 Message-Id: <1489680335-6594-17-git-send-email-jglisse@redhat.com> In-Reply-To: <1489680335-6594-1-git-send-email-jglisse@redhat.com> References: <1489680335-6594-1-git-send-email-jglisse@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Thu, 16 Mar 2017 15:04:09 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4859 Lines: 178 This introduce a dummy HMM device class so device driver can use it to create hmm_device for the sole purpose of registering device memory. It is usefull to device driver that want to manage multiple physical device memory under same struct device umbrella. Changed since v1: - Improve commit message - Add drvdata parameter to set on struct device Signed-off-by: Jérôme Glisse Signed-off-by: Evgeny Baskakov Signed-off-by: John Hubbard Signed-off-by: Mark Hairgrove Signed-off-by: Sherry Cheung Signed-off-by: Subhash Gutti --- include/linux/hmm.h | 22 +++++++++++- mm/hmm.c | 96 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 117 insertions(+), 1 deletion(-) diff --git a/include/linux/hmm.h b/include/linux/hmm.h index 3054ce7..e4e6b36 100644 --- a/include/linux/hmm.h +++ b/include/linux/hmm.h @@ -79,11 +79,11 @@ #if IS_ENABLED(CONFIG_HMM) +#include #include #include #include - struct hmm; /* @@ -433,6 +433,26 @@ static inline unsigned long hmm_devmem_page_get_drvdata(struct page *page) return drvdata[1]; } + + +/* + * struct hmm_device - fake device to hang device memory onto + * + * @device: device struct + * @minor: device minor number + */ +struct hmm_device { + struct device device; + unsigned minor; +}; + +/* + * Device driver that wants to handle multiple devices memory through a single + * fake device can use hmm_device to do so. This is purely a helper and it + * is not needed to make use of any HMM functionality. + */ +struct hmm_device *hmm_device_new(void *drvdata); +void hmm_device_put(struct hmm_device *hmm_device); #endif /* IS_ENABLED(CONFIG_HMM_DEVMEM) */ diff --git a/mm/hmm.c b/mm/hmm.c index 019f379..c477bd1 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include #include @@ -1132,4 +1133,99 @@ int hmm_devmem_fault_range(struct hmm_devmem *devmem, return 0; } EXPORT_SYMBOL(hmm_devmem_fault_range); + +/* + * A device driver that wants to handle multiple devices memory through a + * single fake device can use hmm_device to do so. This is purely a helper + * and it is not needed to make use of any HMM functionality. + */ +#define HMM_DEVICE_MAX 256 + +static DECLARE_BITMAP(hmm_device_mask, HMM_DEVICE_MAX); +static DEFINE_SPINLOCK(hmm_device_lock); +static struct class *hmm_device_class; +static dev_t hmm_device_devt; + +static void hmm_device_release(struct device *device) +{ + struct hmm_device *hmm_device; + + hmm_device = container_of(device, struct hmm_device, device); + spin_lock(&hmm_device_lock); + clear_bit(hmm_device->minor, hmm_device_mask); + spin_unlock(&hmm_device_lock); + + kfree(hmm_device); +} + +struct hmm_device *hmm_device_new(void *drvdata) +{ + struct hmm_device *hmm_device; + int ret; + + hmm_device = kzalloc(sizeof(*hmm_device), GFP_KERNEL); + if (!hmm_device) + return ERR_PTR(-ENOMEM); + + ret = alloc_chrdev_region(&hmm_device->device.devt,0,1,"hmm_device"); + if (ret < 0) { + kfree(hmm_device); + return NULL; + } + + spin_lock(&hmm_device_lock); + hmm_device->minor=find_first_zero_bit(hmm_device_mask,HMM_DEVICE_MAX); + if (hmm_device->minor >= HMM_DEVICE_MAX) { + spin_unlock(&hmm_device_lock); + kfree(hmm_device); + return NULL; + } + set_bit(hmm_device->minor, hmm_device_mask); + spin_unlock(&hmm_device_lock); + + dev_set_name(&hmm_device->device, "hmm_device%d", hmm_device->minor); + hmm_device->device.devt = MKDEV(MAJOR(hmm_device_devt), + hmm_device->minor); + hmm_device->device.release = hmm_device_release; + dev_set_drvdata(&hmm_device->device, drvdata); + hmm_device->device.class = hmm_device_class; + device_initialize(&hmm_device->device); + + return hmm_device; +} +EXPORT_SYMBOL(hmm_device_new); + +void hmm_device_put(struct hmm_device *hmm_device) +{ + put_device(&hmm_device->device); +} +EXPORT_SYMBOL(hmm_device_put); + +static int __init hmm_init(void) +{ + int ret; + + ret = alloc_chrdev_region(&hmm_device_devt, 0, + HMM_DEVICE_MAX, + "hmm_device"); + if (ret) + return ret; + + hmm_device_class = class_create(THIS_MODULE, "hmm_device"); + if (IS_ERR(hmm_device_class)) { + unregister_chrdev_region(hmm_device_devt, HMM_DEVICE_MAX); + return PTR_ERR(hmm_device_class); + } + return 0; +} + +static void __exit hmm_exit(void) +{ + unregister_chrdev_region(hmm_device_devt, HMM_DEVICE_MAX); + class_destroy(hmm_device_class); +} + +module_init(hmm_init); +module_exit(hmm_exit); +MODULE_LICENSE("GPL"); #endif /* IS_ENABLED(CONFIG_HMM_DEVMEM) */ -- 2.4.11