From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f45.google.com (mail-ej1-f45.google.com [209.85.218.45]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B9D0D2F82 for ; Tue, 27 Apr 2021 13:25:28 +0000 (UTC) Received: by mail-ej1-f45.google.com with SMTP id u3so10806601eja.12 for ; Tue, 27 Apr 2021 06:25:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=ox97eQahZzXAKhDhV83RnJG9UlXriZW0N3GFvMTDDRY=; b=PqcDQe91kPsyWJo6gdTIZKgJ+AiBJb8Y0Ch1VIpEO/XL6a+vuMJHPTtGV03zmbqY3y leYaYqT2SGzNBk8HwkZHoPuPSOyKixM96fZ7JBZG9ATjOr4ey+aw+t9AroEkWsDkh8RC +jYebJzXlNUnqvsSp5Fw9kQ15YYj4xBoQ/9dK7qiv49NSOIoPazp7Vek3mp+CIYFo1wl jof7l/Y0RN4zJ7hFXjuXM5O+kHKZGEuCk2g1wCSeyWuR2VFatJpvzUS0hwlov5MNMHcM EzQNcuAerxbtpG2NuxGfxC+Oxlo5skm/WXmCXI6015WZ0sba+GLCi1NBsTGfbQUcr4tQ UC+A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=ox97eQahZzXAKhDhV83RnJG9UlXriZW0N3GFvMTDDRY=; b=XOVXmnyZjswkIFy11e1eWU8fvEr1NA/wK1/BNWnOig1KkqO6fs8j9a3UzHjjUo9SdW UAS7rjTGObPzjkfDnO+3HKdk3bCHYRTNArM5rIvvD/7odK3hen3xmnBl+KgngNHX2a31 fJsKj+VDnMhZh2mX8pbnWgL6JClp/DlHTj8Php1BoXv+Z6JluZFUfiNvANnzQJv7w4b7 u5wDlXRUtCKUP8LgnxdkFXDaeKxGiBIIM5HAq0DI0Vl9kMISlhQrwbWfInHybsFxbauh tRcTxcRr4ZOMQb2ycJxodIYcF4KrDhspVoVC0+OajWE1w7GsIi8jVMgEvx2zxf7Anq0C Jxkw== X-Gm-Message-State: AOAM532bGjUtycwUfqrf1yKKkbxUK5neq/flV7XU68bTqpT6/gc3a+YX XtZTcuUazyCo0qUv0rg4PHE= X-Google-Smtp-Source: ABdhPJzX5KtPak9gY3SoeqiwP3LhEduHcYS5J9dRaGYeTWmlSCj+y7HX+4QX0LNcTxzIvX2lPruYjw== X-Received: by 2002:a17:906:2c55:: with SMTP id f21mr10774146ejh.41.1619529927216; Tue, 27 Apr 2021 06:25:27 -0700 (PDT) Received: from linux.local (host-79-52-107-152.retail.telecomitalia.it. [79.52.107.152]) by smtp.gmail.com with ESMTPSA id r5sm2414458eds.44.2021.04.27.06.25.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 27 Apr 2021 06:25:26 -0700 (PDT) From: "Fabio M. De Francesco" To: outreachy-kernel@googlegroups.com, David Kershner , Greg Kroah-Hartman , linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org, Daniel Vetter , Matthew Wilcox Cc: "Fabio M. De Francesco" Subject: [Outreachy kernel] [PATCH v4] staging: unisys: visorhba: Convert module from IDR to XArray Date: Tue, 27 Apr 2021 15:25:22 +0200 Message-Id: <20210427132522.14547-1-fmdefrancesco@gmail.com> X-Mailer: git-send-email 2.31.1 X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Converted visorhba from IDR to XArray. The abstract data type XArray is more memory-efficient, parallelisable and cache friendly. It takes advantage of RCU to perform lookups without locking. Signed-off-by: Fabio M. De Francesco --- Changes from v3: Matthew Wilcox found that the XArray was not initialized: now it is. Changed types handles from u64 to u32 because they can't work as arguments of xa_alloc_irq() and u32 is enough large for storing XArray indexes. Changes from v2: Some residual errors from v1 were not fixed in v2. Now they have been removed. Changes from v1: After a first review by Matthew Wilcox, who found a series of errors and gave suggestions on how to fix them, I rewrote a larger part of the patch. drivers/staging/unisys/include/iochannel.h | 4 +- .../staging/unisys/visorhba/visorhba_main.c | 89 ++++++------------- 2 files changed, 28 insertions(+), 65 deletions(-) diff --git a/drivers/staging/unisys/include/iochannel.h b/drivers/staging/unisys/include/iochannel.h index 9ef812c0bc42..fac89eac148b 100644 --- a/drivers/staging/unisys/include/iochannel.h +++ b/drivers/staging/unisys/include/iochannel.h @@ -474,8 +474,8 @@ struct uiscmdrsp_scsitaskmgmt { enum task_mgmt_types tasktype; struct uisscsi_dest vdest; u64 handle; - u64 notify_handle; - u64 notifyresult_handle; + u32 notify_handle; + u32 notifyresult_handle; char result; #define TASK_MGMT_FAILED 0 diff --git a/drivers/staging/unisys/visorhba/visorhba_main.c b/drivers/staging/unisys/visorhba/visorhba_main.c index 4455d26f7c96..2b6cde254f17 100644 --- a/drivers/staging/unisys/visorhba/visorhba_main.c +++ b/drivers/staging/unisys/visorhba/visorhba_main.c @@ -6,10 +6,10 @@ #include #include -#include #include #include #include +#include #include #include #include @@ -82,7 +82,7 @@ struct visorhba_devdata { * allows us to pass int handles back-and-forth between us and * iovm, instead of raw pointers */ - struct idr idr; + struct xarray xa; struct dentry *debugfs_dir; struct dentry *debugfs_info; @@ -182,71 +182,40 @@ static struct uiscmdrsp *get_scsipending_cmdrsp(struct visorhba_devdata *ddata, return NULL; } -/* - * simple_idr_get - Associate a provided pointer with an int value - * 1 <= value <= INT_MAX, and return this int value; - * the pointer value can be obtained later by passing - * this int value to idr_find() - * @idrtable: The data object maintaining the pointer<-->int mappings - * @p: The pointer value to be remembered - * @lock: A spinlock used when exclusive access to idrtable is needed - * - * Return: The id number mapped to pointer 'p', 0 on failure - */ -static unsigned int simple_idr_get(struct idr *idrtable, void *p, - spinlock_t *lock) -{ - int id; - unsigned long flags; - - idr_preload(GFP_KERNEL); - spin_lock_irqsave(lock, flags); - id = idr_alloc(idrtable, p, 1, INT_MAX, GFP_NOWAIT); - spin_unlock_irqrestore(lock, flags); - idr_preload_end(); - /* failure */ - if (id < 0) - return 0; - /* idr_alloc() guarantees > 0 */ - return (unsigned int)(id); -} - /* * setup_scsitaskmgmt_handles - Stash the necessary handles so that the * completion processing logic for a taskmgmt * cmd will be able to find who to wake up * and where to stash the result - * @idrtable: The data object maintaining the pointer<-->int mappings - * @lock: A spinlock used when exclusive access to idrtable is needed + * @xa: The data object maintaining the pointer<-->int mappings * @cmdrsp: Response from the IOVM * @event: The event handle to associate with an id * @result: The location to place the result of the event handle into */ -static void setup_scsitaskmgmt_handles(struct idr *idrtable, spinlock_t *lock, - struct uiscmdrsp *cmdrsp, +static void setup_scsitaskmgmt_handles(struct xarray *xa, struct uiscmdrsp *cmdrsp, wait_queue_head_t *event, int *result) { - /* specify the event that has to be triggered when this */ - /* cmd is complete */ - cmdrsp->scsitaskmgmt.notify_handle = - simple_idr_get(idrtable, event, lock); - cmdrsp->scsitaskmgmt.notifyresult_handle = - simple_idr_get(idrtable, result, lock); + int ret; + u32 *id; + + /* specify the event that has to be triggered when this cmd is complete */ + id = &cmdrsp->scsitaskmgmt.notify_handle; + ret = xa_alloc_irq(xa, id, event, XA_LIMIT(1, INT_MAX), GFP_KERNEL); + id = &cmdrsp->scsitaskmgmt.notifyresult_handle; + ret = xa_alloc_irq(xa, id, result, XA_LIMIT(1, INT_MAX), GFP_KERNEL); } /* * cleanup_scsitaskmgmt_handles - Forget handles created by * setup_scsitaskmgmt_handles() - * @idrtable: The data object maintaining the pointer<-->int mappings + * @xa: The data object maintaining the pointer<-->int mappings * @cmdrsp: Response from the IOVM */ -static void cleanup_scsitaskmgmt_handles(struct idr *idrtable, +static void cleanup_scsitaskmgmt_handles(struct xarray *xa, struct uiscmdrsp *cmdrsp) { - if (cmdrsp->scsitaskmgmt.notify_handle) - idr_remove(idrtable, cmdrsp->scsitaskmgmt.notify_handle); - if (cmdrsp->scsitaskmgmt.notifyresult_handle) - idr_remove(idrtable, cmdrsp->scsitaskmgmt.notifyresult_handle); + xa_erase(xa, cmdrsp->scsitaskmgmt.notify_handle); + xa_erase(xa, cmdrsp->scsitaskmgmt.notifyresult_handle); } /* @@ -273,8 +242,7 @@ static int forward_taskmgmt_command(enum task_mgmt_types tasktype, if (devdata->serverdown || devdata->serverchangingstate) return FAILED; - scsicmd_id = add_scsipending_entry(devdata, CMD_SCSITASKMGMT_TYPE, - NULL); + scsicmd_id = add_scsipending_entry(devdata, CMD_SCSITASKMGMT_TYPE, NULL); if (scsicmd_id < 0) return FAILED; @@ -284,8 +252,7 @@ static int forward_taskmgmt_command(enum task_mgmt_types tasktype, /* issue TASK_MGMT_ABORT_TASK */ cmdrsp->cmdtype = CMD_SCSITASKMGMT_TYPE; - setup_scsitaskmgmt_handles(&devdata->idr, &devdata->privlock, cmdrsp, - ¬ifyevent, ¬ifyresult); + setup_scsitaskmgmt_handles(&devdata->xa, cmdrsp, ¬ifyevent, ¬ifyresult); /* save destination */ cmdrsp->scsitaskmgmt.tasktype = tasktype; @@ -311,14 +278,14 @@ static int forward_taskmgmt_command(enum task_mgmt_types tasktype, dev_dbg(&scsidev->sdev_gendev, "visorhba: taskmgmt type=%d success; result=0x%x\n", tasktype, notifyresult); - cleanup_scsitaskmgmt_handles(&devdata->idr, cmdrsp); + cleanup_scsitaskmgmt_handles(&devdata->xa, cmdrsp); return SUCCESS; err_del_scsipending_ent: dev_dbg(&scsidev->sdev_gendev, "visorhba: taskmgmt type=%d not executed\n", tasktype); del_scsipending_ent(devdata, scsicmd_id); - cleanup_scsitaskmgmt_handles(&devdata->idr, cmdrsp); + cleanup_scsitaskmgmt_handles(&devdata->xa, cmdrsp); return FAILED; } @@ -654,13 +621,12 @@ DEFINE_SHOW_ATTRIBUTE(info_debugfs); * Service Partition returned the result of the task management * command. Wake up anyone waiting for it. */ -static void complete_taskmgmt_command(struct idr *idrtable, - struct uiscmdrsp *cmdrsp, int result) +static void complete_taskmgmt_command(struct xarray *xa, struct uiscmdrsp *cmdrsp, int result) { wait_queue_head_t *wq = - idr_find(idrtable, cmdrsp->scsitaskmgmt.notify_handle); + xa_load(xa, cmdrsp->scsitaskmgmt.notify_handle); int *scsi_result_ptr = - idr_find(idrtable, cmdrsp->scsitaskmgmt.notifyresult_handle); + xa_load(xa, cmdrsp->scsitaskmgmt.notifyresult_handle); if (unlikely(!(wq && scsi_result_ptr))) { pr_err("visorhba: no completion context; cmd will time out\n"); return; @@ -708,8 +674,7 @@ static void visorhba_serverdown_complete(struct visorhba_devdata *devdata) break; case CMD_SCSITASKMGMT_TYPE: cmdrsp = pendingdel->sent; - complete_taskmgmt_command(&devdata->idr, cmdrsp, - TASK_MGMT_FAILED); + complete_taskmgmt_command(&devdata->xa, cmdrsp, TASK_MGMT_FAILED); break; default: break; @@ -905,7 +870,7 @@ static void drain_queue(struct uiscmdrsp *cmdrsp, if (!del_scsipending_ent(devdata, cmdrsp->scsitaskmgmt.handle)) break; - complete_taskmgmt_command(&devdata->idr, cmdrsp, + complete_taskmgmt_command(&devdata->xa, cmdrsp, cmdrsp->scsitaskmgmt.result); } else if (cmdrsp->cmdtype == CMD_NOTIFYGUEST_TYPE) dev_err_once(&devdata->dev->device, @@ -1053,7 +1018,7 @@ static int visorhba_probe(struct visor_device *dev) if (err) goto err_debugfs_info; - idr_init(&devdata->idr); + xa_init(&devdata->xa); devdata->cmdrsp = kmalloc(sizeof(*devdata->cmdrsp), GFP_ATOMIC); visorbus_enable_channel_interrupts(dev); @@ -1096,8 +1061,6 @@ static void visorhba_remove(struct visor_device *dev) scsi_remove_host(scsihost); scsi_host_put(scsihost); - idr_destroy(&devdata->idr); - dev_set_drvdata(&dev->device, NULL); debugfs_remove(devdata->debugfs_info); debugfs_remove_recursive(devdata->debugfs_dir); -- 2.31.1