From mboxrd@z Thu Jan 1 00:00:00 1970 From: Moritz Fischer Subject: Re: [PATCH v2 22/22] fpga: intel: afu: add FPGA_PORT_DMA_MAP/UNMAP ioctls support Date: Tue, 1 Aug 2017 11:15:48 -0700 Message-ID: References: <1498441938-14046-1-git-send-email-hao.wu@intel.com> <1498441938-14046-23-git-send-email-hao.wu@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: <1498441938-14046-23-git-send-email-hao.wu@intel.com> Sender: linux-kernel-owner@vger.kernel.org To: Wu Hao Cc: Alan Tull , linux-fpga@vger.kernel.org, Linux Kernel Mailing List , linux-api@vger.kernel.org, luwei.kang@intel.com, yi.z.zhang@intel.com, Tim Whisonant , Enno Luebbers , Shiva Rao , Christopher Rauer , Xiao Guangrong List-Id: linux-api@vger.kernel.org Hi Wu, couple of minor things inline below. On Sun, Jun 25, 2017 at 6:52 PM, Wu Hao wrote: > DMA memory regions are required for Accelerated Function Unit (AFU) usage. > These two ioctls allow user space applications to map user memory regions > for dma, and unmap them after use. Iova is returned from driver to user > space application via FPGA_PORT_DMA_MAP ioctl. Application needs to unmap > it after use, otherwise, driver will unmap them in device file release > operation. > > All the mapped regions are managed via a rb tree. > > Ioctl interfaces: > * FPGA_PORT_DMA_MAP > Do the dma mapping per user_addr and length which provided by user. > Return iova in provided struct afu_port_dma_map. > > * FPGA_PORT_DMA_UNMAP > Unmap the dma region per iova provided by user. > > Signed-off-by: Tim Whisonant > Signed-off-by: Enno Luebbers > Signed-off-by: Shiva Rao > Signed-off-by: Christopher Rauer > Signed-off-by: Xiao Guangrong > Signed-off-by: Wu Hao > --- > v2: moved the code to drivers/fpga folder as suggested by Alan Tull. > switched to GPLv2 license. > fixed kbuild warnings. > --- > drivers/fpga/Makefile | 3 +- > drivers/fpga/intel-afu-dma-region.c | 372 ++++++++++++++++++++++++++++++++++++ > drivers/fpga/intel-afu-main.c | 61 +++++- > drivers/fpga/intel-afu.h | 18 ++ > include/uapi/linux/intel-fpga.h | 37 ++++ > 5 files changed, 489 insertions(+), 2 deletions(-) > create mode 100644 drivers/fpga/intel-afu-dma-region.c > > diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile > index 45c0538..339d1f3 100644 > --- a/drivers/fpga/Makefile > +++ b/drivers/fpga/Makefile > @@ -38,4 +38,5 @@ obj-$(CONFIG_INTEL_FPGA_AFU) += intel-fpga-afu.o > > intel-fpga-pci-objs := intel-pcie.o intel-feature-dev.o > intel-fpga-fme-objs := intel-fme-main.o intel-fme-pr.o > -intel-fpga-afu-objs := intel-afu-main.o intel-afu-region.o > +intel-fpga-afu-objs := intel-afu-main.o intel-afu-region.o \ > + intel-afu-dma-region.o > diff --git a/drivers/fpga/intel-afu-dma-region.c b/drivers/fpga/intel-afu-dma-region.c > new file mode 100644 > index 0000000..982a9b5 > --- /dev/null > +++ b/drivers/fpga/intel-afu-dma-region.c > @@ -0,0 +1,372 @@ > +/* > + * Driver for Intel FPGA Accelerated Function Unit (AFU) DMA Region Management > + * > + * Copyright (C) 2017 Intel Corporation, Inc. > + * > + * Authors: > + * Wu Hao > + * Xiao Guangrong > + * > + * This work is licensed under the terms of the GNU GPL version 2. See > + * the COPYING file in the top-level directory. > + */ > + > +#include > +#include > + > +#include "intel-afu.h" > + > +static void put_all_pages(struct page **pages, int npages) > +{ > + int i; > + > + for (i = 0; i < npages; i++) > + if (pages[i] != NULL) if (pages[i]) would do I think > + put_page(pages[i]); > +} > + > +void afu_dma_region_init(struct feature_platform_data *pdata) > +{ > + struct fpga_afu *afu = fpga_pdata_get_private(pdata); > + > + afu->dma_regions = RB_ROOT; > +} > + > +static long afu_dma_adjust_locked_vm(struct device *dev, long npages, bool incr) > +{ > + unsigned long locked, lock_limit; > + int ret = 0; > + > + /* the task is exiting. */ > + if (!current->mm) > + return 0; > + > + down_write(¤t->mm->mmap_sem); > + > + if (incr) { > + locked = current->mm->locked_vm + npages; > + lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; > + > + if (locked > lock_limit && !capable(CAP_IPC_LOCK)) > + ret = -ENOMEM; > + else > + current->mm->locked_vm += npages; > + } else { > + > + if (WARN_ON_ONCE(npages > current->mm->locked_vm)) > + npages = current->mm->locked_vm; > + current->mm->locked_vm -= npages; > + } > + > + dev_dbg(dev, "[%d] RLIMIT_MEMLOCK %c%ld %ld/%ld%s\n", current->pid, > + incr ? '+' : '-', > + npages << PAGE_SHIFT, > + current->mm->locked_vm << PAGE_SHIFT, > + rlimit(RLIMIT_MEMLOCK), > + ret ? "- execeeded" : ""); > + > + up_write(¤t->mm->mmap_sem); > + > + return ret; > +} > + > +static long afu_dma_pin_pages(struct feature_platform_data *pdata, > + struct fpga_afu_dma_region *region) > +{ > + long npages = region->length >> PAGE_SHIFT; > + struct device *dev = &pdata->dev->dev; > + long ret, pinned; > + > + ret = afu_dma_adjust_locked_vm(dev, npages, true); > + if (ret) > + return ret; > + > + region->pages = kcalloc(npages, sizeof(struct page *), GFP_KERNEL); > + if (!region->pages) { > + afu_dma_adjust_locked_vm(dev, npages, false); You could probably also just have another label in the error handling path. > + return -ENOMEM; > + } > + > + pinned = get_user_pages_fast(region->user_addr, npages, 1, > + region->pages); > + if (pinned < 0) { > + ret = pinned; > + goto err_put_pages; > + } else if (pinned != npages) { > + ret = -EFAULT; > + goto err; > + } > + > + dev_dbg(dev, "%ld pages pinned\n", pinned); > + > + return 0; > + > +err_put_pages: > + put_all_pages(region->pages, pinned); > +err: > + kfree(region->pages); > + afu_dma_adjust_locked_vm(dev, npages, false); > + return ret; > +} > + > +static void afu_dma_unpin_pages(struct feature_platform_data *pdata, > + struct fpga_afu_dma_region *region) > +{ > + long npages = region->length >> PAGE_SHIFT; > + struct device *dev = &pdata->dev->dev; > + > + put_all_pages(region->pages, npages); > + kfree(region->pages); > + afu_dma_adjust_locked_vm(dev, npages, false); > + > + dev_dbg(dev, "%ld pages unpinned\n", npages); > +} > + > +static bool afu_dma_check_continuous_pages(struct fpga_afu_dma_region *region) > +{ > + int npages = region->length >> PAGE_SHIFT; > + int i; > + > + for (i = 0; i < npages - 1; i++) > + if (page_to_pfn(region->pages[i]) + 1 != > + page_to_pfn(region->pages[i+1])) > + return false; > + > + return true; > +} > + > +static bool dma_region_check_iova(struct fpga_afu_dma_region *region, > + u64 iova, u64 size) > +{ > + if (!size && region->iova != iova) > + return false; > + > + return (region->iova <= iova) && > + (region->length + region->iova >= iova + size); > +} > + > +/* Need to be called with pdata->lock held */ Needs > +static int afu_dma_region_add(struct feature_platform_data *pdata, > + struct fpga_afu_dma_region *region) > +{ > + struct fpga_afu *afu = fpga_pdata_get_private(pdata); > + struct rb_node **new, *parent = NULL; > + > + dev_dbg(&pdata->dev->dev, "add region (iova = %llx)\n", > + (unsigned long long)region->iova); > + > + new = &(afu->dma_regions.rb_node); > + > + while (*new) { > + struct fpga_afu_dma_region *this; > + > + this = container_of(*new, struct fpga_afu_dma_region, node); > + > + parent = *new; > + > + if (dma_region_check_iova(this, region->iova, region->length)) > + return -EEXIST; > + > + if (region->iova < this->iova) > + new = &((*new)->rb_left); > + else if (region->iova > this->iova) > + new = &((*new)->rb_right); > + else > + return -EEXIST; > + } > + > + rb_link_node(®ion->node, parent, new); > + rb_insert_color(®ion->node, &afu->dma_regions); > + > + return 0; > +} > + > +/* Need to be called with pdata->lock held */ Ditto > +static void afu_dma_region_remove(struct feature_platform_data *pdata, > + struct fpga_afu_dma_region *region) > +{ > + struct fpga_afu *afu; > + > + dev_dbg(&pdata->dev->dev, "del region (iova = %llx)\n", > + (unsigned long long)region->iova); > + > + afu = fpga_pdata_get_private(pdata); > + rb_erase(®ion->node, &afu->dma_regions); > +} > + > +/* Need to be called with pdata->lock held */ Ditto. > +void afu_dma_region_destroy(struct feature_platform_data *pdata) > +{ > + struct fpga_afu *afu = fpga_pdata_get_private(pdata); > + struct rb_node *node = rb_first(&afu->dma_regions); > + struct fpga_afu_dma_region *region; > + > + while (node) { > + region = container_of(node, struct fpga_afu_dma_region, node); > + > + dev_dbg(&pdata->dev->dev, "del region (iova = %llx)\n", > + (unsigned long long)region->iova); > + > + rb_erase(node, &afu->dma_regions); > + > + if (region->iova) > + dma_unmap_page(fpga_pdata_to_pcidev(pdata), > + region->iova, region->length, > + DMA_BIDIRECTIONAL); > + > + if (region->pages) > + afu_dma_unpin_pages(pdata, region); > + > + node = rb_next(node); > + kfree(region); > + } > +} > + > +/* > + * It finds the dma region from the rbtree based on @iova and @size: > + * - if @size == 0, it finds the dma region which starts from @iova > + * - otherwise, it finds the dma region which fully contains > + * [@iova, @iova+size) > + * If nothing is matched returns NULL. > + * > + * Need to be called with pdata->lock held. > + */ > +struct fpga_afu_dma_region * > +afu_dma_region_find(struct feature_platform_data *pdata, u64 iova, u64 size) > +{ > + struct fpga_afu *afu = fpga_pdata_get_private(pdata); > + struct rb_node *node = afu->dma_regions.rb_node; > + struct device *dev = &pdata->dev->dev; > + > + while (node) { > + struct fpga_afu_dma_region *region; > + > + region = container_of(node, struct fpga_afu_dma_region, node); > + > + if (dma_region_check_iova(region, iova, size)) { > + dev_dbg(dev, "find region (iova = %llx)\n", > + (unsigned long long)region->iova); > + return region; > + } > + > + if (iova < region->iova) > + node = node->rb_left; > + else if (iova > region->iova) > + node = node->rb_right; > + else > + /* the iova region is not fully covered. */ > + break; > + } > + > + dev_dbg(dev, "region with iova %llx and size %llx is not found\n", > + (unsigned long long)iova, (unsigned long long)size); > + return NULL; > +} > + > +static struct fpga_afu_dma_region * > +afu_dma_region_find_iova(struct feature_platform_data *pdata, u64 iova) > +{ > + return afu_dma_region_find(pdata, iova, 0); > +} > + > +long afu_dma_map_region(struct feature_platform_data *pdata, > + u64 user_addr, u64 length, u64 *iova) > +{ > + struct fpga_afu_dma_region *region; > + int ret; > + > + /* > + * Check Inputs, only accept page-aligned user memory region with > + * valid length. > + */ > + if (!PAGE_ALIGNED(user_addr) || !PAGE_ALIGNED(length) || !length) > + return -EINVAL; > + > + /* Check overflow */ > + if (user_addr + length < user_addr) > + return -EINVAL; > + > + if (!access_ok(VERIFY_WRITE, (void __user *)(unsigned long)user_addr, > + length)) > + return -EINVAL; > + > + region = kzalloc(sizeof(*region), GFP_KERNEL); > + if (!region) > + return -ENOMEM; > + > + region->user_addr = user_addr; > + region->length = length; > + > + /* Pin the user memory region */ > + ret = afu_dma_pin_pages(pdata, region); > + if (ret) { > + dev_err(&pdata->dev->dev, "fail to pin memory region\n"); > + goto free_region; > + } > + > + /* Only accept continuous pages, return error if no */ return error else > + if (!afu_dma_check_continuous_pages(region)) { > + dev_err(&pdata->dev->dev, "pages are not continuous\n"); > + ret = -EINVAL; > + goto unpin_pages; > + } > + > + /* As pages are continuous then start to do DMA mapping */ > + region->iova = dma_map_page(fpga_pdata_to_pcidev(pdata), > + region->pages[0], 0, > + region->length, > + DMA_BIDIRECTIONAL); > + if (dma_mapping_error(&pdata->dev->dev, region->iova)) { > + dev_err(&pdata->dev->dev, "fail to map dma mapping\n"); 'failed to map for dma' ? :) > + ret = -EFAULT; > + goto unpin_pages; > + } > + > + *iova = region->iova; > + > + mutex_lock(&pdata->lock); > + ret = afu_dma_region_add(pdata, region); > + mutex_unlock(&pdata->lock); > + if (ret) { > + dev_err(&pdata->dev->dev, "fail to add dma region\n"); > + goto unmap_dma; > + } > + > + return 0; > + > +unmap_dma: > + dma_unmap_page(fpga_pdata_to_pcidev(pdata), > + region->iova, region->length, DMA_BIDIRECTIONAL); > +unpin_pages: > + afu_dma_unpin_pages(pdata, region); > +free_region: > + kfree(region); > + return ret; > +} > + > +long afu_dma_unmap_region(struct feature_platform_data *pdata, u64 iova) > +{ > + struct fpga_afu_dma_region *region; > + > + mutex_lock(&pdata->lock); > + region = afu_dma_region_find_iova(pdata, iova); > + if (!region) { > + mutex_unlock(&pdata->lock); > + return -EINVAL; > + } > + > + if (region->in_use) { > + mutex_unlock(&pdata->lock); > + return -EBUSY; > + } > + > + afu_dma_region_remove(pdata, region); > + mutex_unlock(&pdata->lock); > + > + dma_unmap_page(fpga_pdata_to_pcidev(pdata), > + region->iova, region->length, DMA_BIDIRECTIONAL); > + afu_dma_unpin_pages(pdata, region); > + kfree(region); > + > + return 0; > +} > diff --git a/drivers/fpga/intel-afu-main.c b/drivers/fpga/intel-afu-main.c > index 8c7aa70..d9f1ebf 100644 > --- a/drivers/fpga/intel-afu-main.c > +++ b/drivers/fpga/intel-afu-main.c > @@ -175,7 +175,11 @@ static int afu_release(struct inode *inode, struct file *filp) > > dev_dbg(&pdev->dev, "Device File Release\n"); > > - fpga_port_reset(pdev); > + mutex_lock(&pdata->lock); > + __fpga_port_reset(pdev); > + afu_dma_region_destroy(pdata); > + mutex_unlock(&pdata->lock); > + > feature_dev_use_end(pdata); > return 0; > } > @@ -245,6 +249,55 @@ static long afu_ioctl_check_extension(struct feature_platform_data *pdata, > return 0; > } > > +static long > +afu_ioctl_dma_map(struct feature_platform_data *pdata, void __user *arg) > +{ > + struct fpga_port_dma_map map; > + unsigned long minsz; > + long ret; > + > + minsz = offsetofend(struct fpga_port_dma_map, iova); > + > + if (copy_from_user(&map, arg, minsz)) > + return -EFAULT; > + > + if (map.argsz < minsz || map.flags) > + return -EINVAL; > + > + ret = afu_dma_map_region(pdata, map.user_addr, map.length, &map.iova); > + if (ret) > + return ret; > + > + if (copy_to_user(arg, &map, sizeof(map))) { > + afu_dma_unmap_region(pdata, map.iova); > + return -EFAULT; > + } > + > + dev_dbg(&pdata->dev->dev, "dma map: ua=%llx, len=%llx, iova=%llx\n", > + (unsigned long long)map.user_addr, > + (unsigned long long)map.length, > + (unsigned long long)map.iova); > + > + return 0; > +} > + > +static long > +afu_ioctl_dma_unmap(struct feature_platform_data *pdata, void __user *arg) > +{ > + struct fpga_port_dma_unmap unmap; > + unsigned long minsz; > + > + minsz = offsetofend(struct fpga_port_dma_unmap, iova); > + > + if (copy_from_user(&unmap, arg, minsz)) > + return -EFAULT; > + > + if (unmap.argsz < minsz || unmap.flags) > + return -EINVAL; > + > + return afu_dma_unmap_region(pdata, unmap.iova); > +} > + > static long afu_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) > { > struct platform_device *pdev = filp->private_data; > @@ -263,6 +316,10 @@ static long afu_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) > return afu_ioctl_get_info(pdata, (void __user *)arg); > case FPGA_PORT_GET_REGION_INFO: > return afu_ioctl_get_region_info(pdata, (void __user *)arg); > + case FPGA_PORT_DMA_MAP: > + return afu_ioctl_dma_map(pdata, (void __user *)arg); > + case FPGA_PORT_DMA_UNMAP: > + return afu_ioctl_dma_unmap(pdata, (void __user *)arg); > default: > /* > * Let sub-feature's ioctl function to handle the cmd > @@ -337,6 +394,7 @@ static int afu_dev_init(struct platform_device *pdev) > mutex_lock(&pdata->lock); > fpga_pdata_set_private(pdata, afu); > afu_region_init(pdata); > + afu_dma_region_init(pdata); > mutex_unlock(&pdata->lock); > return 0; > } > @@ -349,6 +407,7 @@ static int afu_dev_destroy(struct platform_device *pdev) > mutex_lock(&pdata->lock); > afu = fpga_pdata_get_private(pdata); > afu_region_destroy(pdata); > + afu_dma_region_destroy(pdata); > fpga_pdata_set_private(pdata, NULL); > mutex_unlock(&pdata->lock); > > diff --git a/drivers/fpga/intel-afu.h b/drivers/fpga/intel-afu.h > index 3417780d..23f7e24 100644 > --- a/drivers/fpga/intel-afu.h > +++ b/drivers/fpga/intel-afu.h > @@ -30,11 +30,21 @@ struct fpga_afu_region { > struct list_head node; > }; > > +struct fpga_afu_dma_region { > + u64 user_addr; > + u64 length; > + u64 iova; > + struct page **pages; > + struct rb_node node; > + bool in_use; > +}; > + > struct fpga_afu { > u64 region_cur_offset; > int num_regions; > u8 num_umsgs; > struct list_head regions; > + struct rb_root dma_regions; > > struct feature_platform_data *pdata; > }; > @@ -49,4 +59,12 @@ int afu_get_region_by_offset(struct feature_platform_data *pdata, > u64 offset, u64 size, > struct fpga_afu_region *pregion); > > +void afu_dma_region_init(struct feature_platform_data *pdata); > +void afu_dma_region_destroy(struct feature_platform_data *pdata); > +long afu_dma_map_region(struct feature_platform_data *pdata, > + u64 user_addr, u64 length, u64 *iova); > +long afu_dma_unmap_region(struct feature_platform_data *pdata, u64 iova); > +struct fpga_afu_dma_region *afu_dma_region_find( > + struct feature_platform_data *pdata, u64 iova, u64 size); > + > #endif > diff --git a/include/uapi/linux/intel-fpga.h b/include/uapi/linux/intel-fpga.h > index a2ad332..b97ea02 100644 > --- a/include/uapi/linux/intel-fpga.h > +++ b/include/uapi/linux/intel-fpga.h > @@ -111,6 +111,43 @@ struct fpga_port_region_info { > > #define FPGA_PORT_GET_REGION_INFO _IO(FPGA_MAGIC, PORT_BASE + 2) > > +/** > + * FPGA_PORT_DMA_MAP - _IOWR(FPGA_MAGIC, PORT_BASE + 3, > + * struct fpga_port_dma_map) > + * > + * Map the dma memory per user_addr and length which are provided by caller. > + * Driver fills the iova in provided struct afu_port_dma_map. > + * This interface only accepts page-size aligned user memory for dma mapping. > + * Return: 0 on success, -errno on failure. > + */ > +struct fpga_port_dma_map { > + /* Input */ > + __u32 argsz; /* Structure length */ > + __u32 flags; /* Zero for now */ > + __u64 user_addr; /* Process virtual address */ > + __u64 length; /* Length of mapping (bytes)*/ > + /* Output */ > + __u64 iova; /* IO virtual address */ > +}; > + > +#define FPGA_PORT_DMA_MAP _IO(FPGA_MAGIC, PORT_BASE + 3) > + > +/** > + * FPGA_PORT_DMA_UNMAP - _IOW(FPGA_MAGIC, PORT_BASE + 4, > + * struct fpga_port_dma_unmap) > + * > + * Unmap the dma memory per iova provided by caller. > + * Return: 0 on success, -errno on failure. > + */ > +struct fpga_port_dma_unmap { > + /* Input */ > + __u32 argsz; /* Structure length */ > + __u32 flags; /* Zero for now */ > + __u64 iova; /* IO virtual address */ > +}; > + > +#define FPGA_PORT_DMA_UNMAP _IO(FPGA_MAGIC, PORT_BASE + 4) > + > /* IOCTLs for FME file descriptor */ > > /** > -- > 1.8.3.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-fpga" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html Thanks, Moritz