From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932821AbbCEL76 (ORCPT ); Thu, 5 Mar 2015 06:59:58 -0500 Received: from mail-wi0-f182.google.com ([209.85.212.182]:37414 "EHLO mail-wi0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751516AbbCEL7z (ORCPT ); Thu, 5 Mar 2015 06:59:55 -0500 Message-ID: <54F84538.8080500@plexistor.com> Date: Thu, 05 Mar 2015 13:59:52 +0200 From: Boaz Harrosh User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Ingo Molnar , x86@kernel.org, linux-kernel , "Roger C. Pao" , Dan Williams , Thomas Gleixner , linux-nvdimm , "H. Peter Anvin" , Matthew Wilcox , Andy Lutomirski , Christoph Hellwig CC: Ross Zwisler Subject: [PATCH 7/8] pmem: Add support for page structs References: <54F82CE0.4040502@plexistor.com> <54F830D4.7030205@plexistor.com> In-Reply-To: <54F830D4.7030205@plexistor.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org One of the current shortcomings of the NVDIMM/PMEM support is that this memory does not have a page-struct(s) associated with its memory and therefor cannot be passed to a block-device or network or DMAed in any way through another device in the system. The use of add_persistent_memory() fixes all this. After this patch an FS can do: bdev_direct_access(,&pfn,); page = pfn_to_page(pfn); And use that page for a lock_page(), set_page_dirty(), and/or anything else one might do with a page *. (Note that with brd one can already do this) [pmem-pages-ref-count] pmem will serve it's pages with ref==0. Once an FS does an blkdev_get_XXX(,FMODE_EXCL,), that memory is own by the FS. The FS needs to manage its allocation, just as it already does for its disk blocks. The fs should set page->count = 2, before submission to any Kernel subsystem so when it returns it will never be released to the Kernel's page-allocators. (page_freeze) Signed-off-by: Boaz Harrosh --- drivers/block/Kconfig | 13 +++++++++++++ drivers/block/pmem.c | 20 ++++++++++++++++++++ 2 files changed, 33 insertions(+) diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig index 1530c2a..635fa6a 100644 --- a/drivers/block/Kconfig +++ b/drivers/block/Kconfig @@ -422,6 +422,19 @@ config BLK_DEV_PMEM Most normal users won't need this functionality, and can thus say N here. +config BLK_DEV_PMEM_USE_PAGES + bool "Enable use of page struct pages with pmem" + depends on BLK_DEV_PMEM + depends on PERSISTENT_MEMORY_DEPENDENCY + select DRIVER_NEEDS_PERSISTENT_MEMORY + default y + help + If a user of PMEM device needs "struct page" associated + with its memory, so this memory can be sent to other + block devices, or sent on the network, or be DMA transferred + to other devices in the system, then you must say "Yes" here. + If unsure leave as Yes. + config CDROM_PKTCDVD tristate "Packet writing on CD/DVD media" depends on !UML diff --git a/drivers/block/pmem.c b/drivers/block/pmem.c index f0f0ba0..d0c80f4 100644 --- a/drivers/block/pmem.c +++ b/drivers/block/pmem.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include #include @@ -141,6 +142,24 @@ MODULE_PARM_DESC(map, static LIST_HEAD(pmem_devices); +#ifdef CONFIG_BLK_DEV_PMEM_USE_PAGES +/* pmem->phys_addr and pmem->size need to be set. + * Will then set pmem->virt_addr if successful. + */ +int pmem_mapmem(struct pmem_device *pmem) +{ + return add_persistent_memory(pmem->phys_addr, pmem->size, + &pmem->virt_addr); +} + +static void pmem_unmapmem(struct pmem_device *pmem) +{ + remove_persistent_memory(pmem->phys_addr, pmem->size); +} + +#define PMEM_ALIGNMEM (1UL << SECTION_SIZE_BITS) +#else /* !CONFIG_BLK_DEV_PMEM_USE_PAGES */ + /* pmem->phys_addr and pmem->size need to be set. * Will then set virt_addr if successful. */ @@ -180,6 +199,7 @@ void pmem_unmapmem(struct pmem_device *pmem) } #define PMEM_ALIGNMEM PAGE_SIZE +#endif /* ! CONFIG_BLK_DEV_PMEM_USE_PAGES */ static struct pmem_device *pmem_alloc(phys_addr_t phys_addr, size_t disk_size, int i) -- 1.9.3