From: Anthony Yznaga <anthony.yznaga@oracle.com> To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, rppt@kernel.org, akpm@linux-foundation.org, ebiederm@xmission.com, keescook@chromium.org, graf@amazon.com, jason.zeng@intel.com, lei.l.li@intel.com, steven.sistare@oracle.com, fam.zheng@bytedance.com, mgalaxy@akamai.com, kexec@lists.infradead.org Subject: [RFC v3 03/21] mm: PKRAM: implement object load and save functions Date: Wed, 26 Apr 2023 17:08:39 -0700 [thread overview] Message-ID: <1682554137-13938-4-git-send-email-anthony.yznaga@oracle.com> (raw) In-Reply-To: <1682554137-13938-1-git-send-email-anthony.yznaga@oracle.com> PKRAM nodes are further divided into a list of objects. After a save operation has been initiated for a node, a save operation for an object associated with the node is initiated by calling pkram_prepare_save_obj(). A new object is created and linked to the node. The save operation for the object is committed by calling pkram_finish_save_obj(). After a load operation has been initiated, pkram_prepare_load_obj() is called to delete the next object from the node and prepare the corresponding stream for loading data from it. After the load of object has been finished, pkram_finish_load_obj() is called to free the object. Objects are also deleted when a save operation is discarded. Signed-off-by: Anthony Yznaga <anthony.yznaga@oracle.com> --- include/linux/pkram.h | 2 ++ mm/pkram.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++--- 2 files changed, 70 insertions(+), 4 deletions(-) diff --git a/include/linux/pkram.h b/include/linux/pkram.h index 8def9017b16a..83718ad0e416 100644 --- a/include/linux/pkram.h +++ b/include/linux/pkram.h @@ -7,6 +7,7 @@ #include <linux/mm_types.h> struct pkram_node; +struct pkram_obj; /** * enum pkram_data_flags - definition of data types contained in a pkram obj @@ -19,6 +20,7 @@ enum pkram_data_flags { struct pkram_stream { gfp_t gfp_mask; struct pkram_node *node; + struct pkram_obj *obj; }; struct pkram_access; diff --git a/mm/pkram.c b/mm/pkram.c index bbfd8df0874e..6e3895cb9872 100644 --- a/mm/pkram.c +++ b/mm/pkram.c @@ -6,9 +6,14 @@ #include <linux/mm.h> #include <linux/mutex.h> #include <linux/pkram.h> +#include <linux/sched.h> #include <linux/string.h> #include <linux/types.h> +struct pkram_obj { + __u64 obj_pfn; /* points to the next object in the list */ +}; + /* * Preserved memory is divided into nodes that can be saved or loaded * independently of each other. The nodes are identified by unique name @@ -18,6 +23,7 @@ */ struct pkram_node { __u32 flags; + __u64 obj_pfn; /* points to the first obj of the node */ __u8 name[PKRAM_NAME_MAX]; }; @@ -62,6 +68,21 @@ static struct pkram_node *pkram_find_node(const char *name) return NULL; } +static void pkram_truncate_node(struct pkram_node *node) +{ + unsigned long obj_pfn; + struct pkram_obj *obj; + + obj_pfn = node->obj_pfn; + while (obj_pfn) { + obj = pfn_to_kaddr(obj_pfn); + obj_pfn = obj->obj_pfn; + pkram_free_page(obj); + cond_resched(); + } + node->obj_pfn = 0; +} + static void pkram_stream_init(struct pkram_stream *ps, struct pkram_node *node, gfp_t gfp_mask) { @@ -124,12 +145,31 @@ int pkram_prepare_save(struct pkram_stream *ps, const char *name, gfp_t gfp_mask * * Returns 0 on success, -errno on failure. * + * Error values: + * %ENOMEM: insufficient memory available + * * After the save has finished, pkram_finish_save_obj() (or pkram_discard_save() * in case of failure) is to be called. */ int pkram_prepare_save_obj(struct pkram_stream *ps, enum pkram_data_flags flags) { - return -EINVAL; + struct pkram_node *node = ps->node; + struct pkram_obj *obj; + struct page *page; + + BUG_ON((node->flags & PKRAM_ACCMODE_MASK) != PKRAM_SAVE); + + page = pkram_alloc_page(ps->gfp_mask | __GFP_ZERO); + if (!page) + return -ENOMEM; + obj = page_address(page); + + if (node->obj_pfn) + obj->obj_pfn = node->obj_pfn; + node->obj_pfn = page_to_pfn(page); + + ps->obj = obj; + return 0; } /** @@ -137,7 +177,9 @@ int pkram_prepare_save_obj(struct pkram_stream *ps, enum pkram_data_flags flags) */ void pkram_finish_save_obj(struct pkram_stream *ps) { - WARN_ON_ONCE(1); + struct pkram_node *node = ps->node; + + BUG_ON((node->flags & PKRAM_ACCMODE_MASK) != PKRAM_SAVE); } /** @@ -168,6 +210,7 @@ void pkram_discard_save(struct pkram_stream *ps) pkram_delete_node(node); mutex_unlock(&pkram_mutex); + pkram_truncate_node(node); pkram_free_page(node); } @@ -215,11 +258,26 @@ int pkram_prepare_load(struct pkram_stream *ps, const char *name) * * Returns 0 on success, -errno on failure. * + * Error values: + * %ENODATA: Stream @ps has no preserved memory objects + * * After the load has finished, pkram_finish_load_obj() is to be called. */ int pkram_prepare_load_obj(struct pkram_stream *ps) { - return -EINVAL; + struct pkram_node *node = ps->node; + struct pkram_obj *obj; + + BUG_ON((node->flags & PKRAM_ACCMODE_MASK) != PKRAM_LOAD); + + if (!node->obj_pfn) + return -ENODATA; + + obj = pfn_to_kaddr(node->obj_pfn); + node->obj_pfn = obj->obj_pfn; + + ps->obj = obj; + return 0; } /** @@ -229,7 +287,12 @@ int pkram_prepare_load_obj(struct pkram_stream *ps) */ void pkram_finish_load_obj(struct pkram_stream *ps) { - WARN_ON_ONCE(1); + struct pkram_node *node = ps->node; + struct pkram_obj *obj = ps->obj; + + BUG_ON((node->flags & PKRAM_ACCMODE_MASK) != PKRAM_LOAD); + + pkram_free_page(obj); } /** @@ -243,6 +306,7 @@ void pkram_finish_load(struct pkram_stream *ps) BUG_ON((node->flags & PKRAM_ACCMODE_MASK) != PKRAM_LOAD); + pkram_truncate_node(node); pkram_free_page(node); } -- 1.9.4
WARNING: multiple messages have this Message-ID (diff)
From: Anthony Yznaga <anthony.yznaga@oracle.com> To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, rppt@kernel.org, akpm@linux-foundation.org, ebiederm@xmission.com, keescook@chromium.org, graf@amazon.com, jason.zeng@intel.com, lei.l.li@intel.com, steven.sistare@oracle.com, fam.zheng@bytedance.com, mgalaxy@akamai.com, kexec@lists.infradead.org Subject: [RFC v3 03/21] mm: PKRAM: implement object load and save functions Date: Wed, 26 Apr 2023 17:08:39 -0700 [thread overview] Message-ID: <1682554137-13938-4-git-send-email-anthony.yznaga@oracle.com> (raw) In-Reply-To: <1682554137-13938-1-git-send-email-anthony.yznaga@oracle.com> PKRAM nodes are further divided into a list of objects. After a save operation has been initiated for a node, a save operation for an object associated with the node is initiated by calling pkram_prepare_save_obj(). A new object is created and linked to the node. The save operation for the object is committed by calling pkram_finish_save_obj(). After a load operation has been initiated, pkram_prepare_load_obj() is called to delete the next object from the node and prepare the corresponding stream for loading data from it. After the load of object has been finished, pkram_finish_load_obj() is called to free the object. Objects are also deleted when a save operation is discarded. Signed-off-by: Anthony Yznaga <anthony.yznaga@oracle.com> --- include/linux/pkram.h | 2 ++ mm/pkram.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++--- 2 files changed, 70 insertions(+), 4 deletions(-) diff --git a/include/linux/pkram.h b/include/linux/pkram.h index 8def9017b16a..83718ad0e416 100644 --- a/include/linux/pkram.h +++ b/include/linux/pkram.h @@ -7,6 +7,7 @@ #include <linux/mm_types.h> struct pkram_node; +struct pkram_obj; /** * enum pkram_data_flags - definition of data types contained in a pkram obj @@ -19,6 +20,7 @@ enum pkram_data_flags { struct pkram_stream { gfp_t gfp_mask; struct pkram_node *node; + struct pkram_obj *obj; }; struct pkram_access; diff --git a/mm/pkram.c b/mm/pkram.c index bbfd8df0874e..6e3895cb9872 100644 --- a/mm/pkram.c +++ b/mm/pkram.c @@ -6,9 +6,14 @@ #include <linux/mm.h> #include <linux/mutex.h> #include <linux/pkram.h> +#include <linux/sched.h> #include <linux/string.h> #include <linux/types.h> +struct pkram_obj { + __u64 obj_pfn; /* points to the next object in the list */ +}; + /* * Preserved memory is divided into nodes that can be saved or loaded * independently of each other. The nodes are identified by unique name @@ -18,6 +23,7 @@ */ struct pkram_node { __u32 flags; + __u64 obj_pfn; /* points to the first obj of the node */ __u8 name[PKRAM_NAME_MAX]; }; @@ -62,6 +68,21 @@ static struct pkram_node *pkram_find_node(const char *name) return NULL; } +static void pkram_truncate_node(struct pkram_node *node) +{ + unsigned long obj_pfn; + struct pkram_obj *obj; + + obj_pfn = node->obj_pfn; + while (obj_pfn) { + obj = pfn_to_kaddr(obj_pfn); + obj_pfn = obj->obj_pfn; + pkram_free_page(obj); + cond_resched(); + } + node->obj_pfn = 0; +} + static void pkram_stream_init(struct pkram_stream *ps, struct pkram_node *node, gfp_t gfp_mask) { @@ -124,12 +145,31 @@ int pkram_prepare_save(struct pkram_stream *ps, const char *name, gfp_t gfp_mask * * Returns 0 on success, -errno on failure. * + * Error values: + * %ENOMEM: insufficient memory available + * * After the save has finished, pkram_finish_save_obj() (or pkram_discard_save() * in case of failure) is to be called. */ int pkram_prepare_save_obj(struct pkram_stream *ps, enum pkram_data_flags flags) { - return -EINVAL; + struct pkram_node *node = ps->node; + struct pkram_obj *obj; + struct page *page; + + BUG_ON((node->flags & PKRAM_ACCMODE_MASK) != PKRAM_SAVE); + + page = pkram_alloc_page(ps->gfp_mask | __GFP_ZERO); + if (!page) + return -ENOMEM; + obj = page_address(page); + + if (node->obj_pfn) + obj->obj_pfn = node->obj_pfn; + node->obj_pfn = page_to_pfn(page); + + ps->obj = obj; + return 0; } /** @@ -137,7 +177,9 @@ int pkram_prepare_save_obj(struct pkram_stream *ps, enum pkram_data_flags flags) */ void pkram_finish_save_obj(struct pkram_stream *ps) { - WARN_ON_ONCE(1); + struct pkram_node *node = ps->node; + + BUG_ON((node->flags & PKRAM_ACCMODE_MASK) != PKRAM_SAVE); } /** @@ -168,6 +210,7 @@ void pkram_discard_save(struct pkram_stream *ps) pkram_delete_node(node); mutex_unlock(&pkram_mutex); + pkram_truncate_node(node); pkram_free_page(node); } @@ -215,11 +258,26 @@ int pkram_prepare_load(struct pkram_stream *ps, const char *name) * * Returns 0 on success, -errno on failure. * + * Error values: + * %ENODATA: Stream @ps has no preserved memory objects + * * After the load has finished, pkram_finish_load_obj() is to be called. */ int pkram_prepare_load_obj(struct pkram_stream *ps) { - return -EINVAL; + struct pkram_node *node = ps->node; + struct pkram_obj *obj; + + BUG_ON((node->flags & PKRAM_ACCMODE_MASK) != PKRAM_LOAD); + + if (!node->obj_pfn) + return -ENODATA; + + obj = pfn_to_kaddr(node->obj_pfn); + node->obj_pfn = obj->obj_pfn; + + ps->obj = obj; + return 0; } /** @@ -229,7 +287,12 @@ int pkram_prepare_load_obj(struct pkram_stream *ps) */ void pkram_finish_load_obj(struct pkram_stream *ps) { - WARN_ON_ONCE(1); + struct pkram_node *node = ps->node; + struct pkram_obj *obj = ps->obj; + + BUG_ON((node->flags & PKRAM_ACCMODE_MASK) != PKRAM_LOAD); + + pkram_free_page(obj); } /** @@ -243,6 +306,7 @@ void pkram_finish_load(struct pkram_stream *ps) BUG_ON((node->flags & PKRAM_ACCMODE_MASK) != PKRAM_LOAD); + pkram_truncate_node(node); pkram_free_page(node); } -- 1.9.4 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
next prev parent reply other threads:[~2023-04-27 0:10 UTC|newest] Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-04-27 0:08 [RFC v3 00/21] Preserved-over-Kexec RAM Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 01/21] mm: add PKRAM API stubs and Kconfig Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 02/21] mm: PKRAM: implement node load and save functions Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga [this message] 2023-04-27 0:08 ` [RFC v3 03/21] mm: PKRAM: implement object " Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 04/21] mm: PKRAM: implement folio stream operations Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 05/21] mm: PKRAM: implement byte " Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 06/21] mm: PKRAM: link nodes by pfn before reboot Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 07/21] mm: PKRAM: introduce super block Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-06-05 2:40 ` Coiby Xu 2023-06-05 2:40 ` Coiby Xu 2023-06-06 2:01 ` Anthony Yznaga 2023-06-06 2:01 ` Anthony Yznaga 2023-06-06 2:55 ` Coiby Xu 2023-06-06 2:55 ` Coiby Xu 2023-06-06 3:12 ` Anthony Yznaga 2023-06-06 3:12 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 08/21] PKRAM: track preserved pages in a physical mapping pagetable Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 09/21] PKRAM: pass a list of preserved ranges to the next kernel Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 10/21] PKRAM: prepare for adding preserved ranges to memblock reserved Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 11/21] mm: PKRAM: reserve preserved memory at boot Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 12/21] PKRAM: free the preserved ranges list Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 13/21] PKRAM: prevent inadvertent use of a stale superblock Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 14/21] PKRAM: provide a way to ban pages from use by PKRAM Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 15/21] kexec: PKRAM: prevent kexec clobbering preserved pages in some cases Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 16/21] PKRAM: provide a way to check if a memory range has preserved pages Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 17/21] kexec: PKRAM: avoid clobbering already " Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 18/21] mm: PKRAM: allow preserved memory to be freed from userspace Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 19/21] PKRAM: disable feature when running the kdump kernel Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 20/21] x86/KASLR: PKRAM: support physical kaslr Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 21/21] x86/boot/compressed/64: use 1GB pages for mappings Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 18:40 ` H. Peter Anvin 2023-04-27 18:40 ` H. Peter Anvin 2023-04-27 22:38 ` Anthony Yznaga 2023-04-27 22:38 ` Anthony Yznaga 2023-05-26 13:57 ` [RFC v3 00/21] Preserved-over-Kexec RAM Gowans, James 2023-05-26 13:57 ` Gowans, James 2023-05-31 23:14 ` Anthony Yznaga 2023-05-31 23:14 ` Anthony Yznaga 2023-06-01 2:15 ` Baoquan He 2023-06-01 2:15 ` Baoquan He 2023-06-01 23:58 ` Anthony Yznaga 2023-06-01 23:58 ` Anthony Yznaga
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