Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752250AbdHCHtw (ORCPT ); Thu, 3 Aug 2017 03:49:52 -0400 Received: from mail-pg0-f67.google.com ([74.125.83.67]:35711 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752205AbdHCHtt (ORCPT ); Thu, 3 Aug 2017 03:49:49 -0400 From: Steven Swanson X-Google-Original-From: Steven Swanson Subject: [RFC 14/16] NOVA: Read-only pmem devices To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org Cc: Steven Swanson , dan.j.williams@intel.com Date: Thu, 03 Aug 2017 00:49:46 -0700 Message-ID: <150174658689.104003.120621559635888592.stgit@hn> In-Reply-To: <150174646416.104003.14042713459553361884.stgit@hn> References: <150174646416.104003.14042713459553361884.stgit@hn> User-Agent: StGit/0.17.1-27-g0d46-dirty MIME-Version: 1.0 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 Content-Length: 7051 Lines: 216 Add (and implement) a module command line option to nd_pmem to support read-only pmem devices. Signed-off-by: Steven Swanson --- arch/x86/include/asm/io.h | 1 + arch/x86/mm/ioremap.c | 25 ++++++++++++++++++------- drivers/nvdimm/pmem.c | 14 ++++++++++++-- include/linux/io.h | 2 ++ kernel/memremap.c | 24 ++++++++++++++++++++++++ mm/memory.c | 2 +- mm/mmap.c | 1 + 7 files changed, 59 insertions(+), 10 deletions(-) diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h index 7afb0e2f07f4..7aae48f2e4f1 100644 --- a/arch/x86/include/asm/io.h +++ b/arch/x86/include/asm/io.h @@ -173,6 +173,7 @@ extern void __iomem *ioremap_uc(resource_size_t offset, unsigned long size); #define ioremap_uc ioremap_uc extern void __iomem *ioremap_cache(resource_size_t offset, unsigned long size); +extern void __iomem *ioremap_cache_ro(resource_size_t phys_addr, unsigned long size); extern void __iomem *ioremap_prot(resource_size_t offset, unsigned long size, unsigned long prot_val); /** diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index bbc558b88a88..bcd473801817 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -81,7 +81,8 @@ static int __ioremap_check_ram(unsigned long start_pfn, unsigned long nr_pages, * caller shouldn't need to know that small detail. */ static void __iomem *__ioremap_caller(resource_size_t phys_addr, - unsigned long size, enum page_cache_mode pcm, void *caller) + unsigned long size, enum page_cache_mode pcm, void *caller, + int readonly) { unsigned long offset, vaddr; resource_size_t pfn, last_pfn, last_addr; @@ -172,6 +173,9 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, break; } + if (readonly) + prot = __pgprot((unsigned long)prot.pgprot & ~_PAGE_RW); + /* * Ok, go for it.. */ @@ -239,7 +243,7 @@ void __iomem *ioremap_nocache(resource_size_t phys_addr, unsigned long size) enum page_cache_mode pcm = _PAGE_CACHE_MODE_UC_MINUS; return __ioremap_caller(phys_addr, size, pcm, - __builtin_return_address(0)); + __builtin_return_address(0), 0); } EXPORT_SYMBOL(ioremap_nocache); @@ -272,7 +276,7 @@ void __iomem *ioremap_uc(resource_size_t phys_addr, unsigned long size) enum page_cache_mode pcm = _PAGE_CACHE_MODE_UC; return __ioremap_caller(phys_addr, size, pcm, - __builtin_return_address(0)); + __builtin_return_address(0), 0); } EXPORT_SYMBOL_GPL(ioremap_uc); @@ -289,7 +293,7 @@ EXPORT_SYMBOL_GPL(ioremap_uc); void __iomem *ioremap_wc(resource_size_t phys_addr, unsigned long size) { return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WC, - __builtin_return_address(0)); + __builtin_return_address(0), 0); } EXPORT_SYMBOL(ioremap_wc); @@ -306,23 +310,30 @@ EXPORT_SYMBOL(ioremap_wc); void __iomem *ioremap_wt(resource_size_t phys_addr, unsigned long size) { return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WT, - __builtin_return_address(0)); + __builtin_return_address(0), 0); } EXPORT_SYMBOL(ioremap_wt); void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size) { return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WB, - __builtin_return_address(0)); + __builtin_return_address(0), 0); } EXPORT_SYMBOL(ioremap_cache); +void __iomem *ioremap_cache_ro(resource_size_t phys_addr, unsigned long size) +{ + return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WB, + __builtin_return_address(0), 1); +} +EXPORT_SYMBOL(ioremap_cache_ro); + void __iomem *ioremap_prot(resource_size_t phys_addr, unsigned long size, unsigned long prot_val) { return __ioremap_caller(phys_addr, size, pgprot2cachemode(__pgprot(prot_val)), - __builtin_return_address(0)); + __builtin_return_address(0), 0); } EXPORT_SYMBOL(ioremap_prot); diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index c544d466ea51..a6b29c731c53 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -35,6 +35,11 @@ #include "pfn.h" #include "nd.h" +int readonly; + +module_param(readonly, int, S_IRUGO); +MODULE_PARM_DESC(readonly, "Mount readonly"); + static struct device *to_dev(struct pmem_device *pmem) { /* @@ -324,9 +329,14 @@ static int pmem_attach_disk(struct device *dev, addr = devm_memremap_pages(dev, &nsio->res, &q->q_usage_counter, NULL); pmem->pfn_flags |= PFN_MAP; - } else - addr = devm_memremap(dev, pmem->phys_addr, + } else { + if (readonly == 0) + addr = devm_memremap(dev, pmem->phys_addr, pmem->size, ARCH_MEMREMAP_PMEM); + else + addr = devm_memremap_ro(dev, pmem->phys_addr, + pmem->size, ARCH_MEMREMAP_PMEM); + } /* * At release time the queue must be frozen before diff --git a/include/linux/io.h b/include/linux/io.h index 2195d9ea4aaa..00641aef9ab3 100644 --- a/include/linux/io.h +++ b/include/linux/io.h @@ -86,6 +86,8 @@ void devm_ioremap_release(struct device *dev, void *res); void *devm_memremap(struct device *dev, resource_size_t offset, size_t size, unsigned long flags); +void *devm_memremap_ro(struct device *dev, resource_size_t offset, + size_t size, unsigned long flags); void devm_memunmap(struct device *dev, void *addr); void *__devm_memremap_pages(struct device *dev, struct resource *res); diff --git a/kernel/memremap.c b/kernel/memremap.c index 23a6483c3666..68371a9a40e5 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -162,6 +162,30 @@ void *devm_memremap(struct device *dev, resource_size_t offset, } EXPORT_SYMBOL(devm_memremap); +void *devm_memremap_ro(struct device *dev, resource_size_t offset, + size_t size, unsigned long flags) +{ + void **ptr, *addr; + + printk("%s\n", __func__); + ptr = devres_alloc_node(devm_memremap_release, sizeof(*ptr), GFP_KERNEL, + dev_to_node(dev)); + if (!ptr) + return ERR_PTR(-ENOMEM); + + addr = ioremap_cache_ro(offset, size); + if (addr) { + *ptr = addr; + devres_add(dev, ptr); + } else { + devres_free(ptr); + return ERR_PTR(-ENXIO); + } + + return addr; +} +EXPORT_SYMBOL(devm_memremap_ro); + void devm_memunmap(struct device *dev, void *addr) { WARN_ON(devres_release(dev, devm_memremap_release, diff --git a/mm/memory.c b/mm/memory.c index bb11c474857e..625623a90f08 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1793,7 +1793,7 @@ static int remap_pte_range(struct mm_struct *mm, pmd_t *pmd, return -ENOMEM; arch_enter_lazy_mmu_mode(); do { - BUG_ON(!pte_none(*pte)); +// BUG_ON(!pte_none(*pte)); set_pte_at(mm, addr, pte, pte_mkspecial(pfn_pte(pfn, prot))); pfn++; } while (pte++, addr += PAGE_SIZE, addr != end); diff --git a/mm/mmap.c b/mm/mmap.c index a5e3dcd75e79..5423e3340e59 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -126,6 +126,7 @@ void vma_set_page_prot(struct vm_area_struct *vma) /* remove_protection_ptes reads vma->vm_page_prot without mmap_sem */ WRITE_ONCE(vma->vm_page_prot, vm_page_prot); } +EXPORT_SYMBOL(vma_set_page_prot); /* * Requires inode->i_mapping->i_mmap_rwsem