linux-kernel - [RFC 30/43] memblock: add for_each_reserved_mem

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Wed,  6 May 2020 17:41:56 -0700
From:   Anthony Yznaga <anthony.yznaga@...cle.com>
To:     linux-mm@...ck.org, linux-kernel@...r.kernel.org
Cc:     willy@...radead.org, corbet@....net, tglx@...utronix.de,
        mingo@...hat.com, bp@...en8.de, x86@...nel.org, hpa@...or.com,
        dave.hansen@...ux.intel.com, luto@...nel.org, peterz@...radead.org,
        rppt@...ux.ibm.com, akpm@...ux-foundation.org, hughd@...gle.com,
        ebiederm@...ssion.com, masahiroy@...nel.org, ardb@...nel.org,
        ndesaulniers@...gle.com, dima@...ovin.in, daniel.kiper@...cle.com,
        nivedita@...m.mit.edu, rafael.j.wysocki@...el.com,
        dan.j.williams@...el.com, zhenzhong.duan@...cle.com,
        jroedel@...e.de, bhe@...hat.com, guro@...com,
        Thomas.Lendacky@....com, andriy.shevchenko@...ux.intel.com,
        keescook@...omium.org, hannes@...xchg.org, minchan@...nel.org,
        mhocko@...nel.org, ying.huang@...el.com,
        yang.shi@...ux.alibaba.com, gustavo@...eddedor.com,
        ziqian.lzq@...fin.com, vdavydov.dev@...il.com,
        jason.zeng@...el.com, kevin.tian@...el.com, zhiyuan.lv@...el.com,
        lei.l.li@...el.com, paul.c.lai@...el.com, ashok.raj@...el.com,
        linux-fsdevel@...r.kernel.org, linux-doc@...r.kernel.org,
        kexec@...ts.infradead.org
Subject: [RFC 30/43] memblock: add for_each_reserved_mem_range()

To support deferred initialization of page structs for preserved
pages, add an iterator of the memblock reserved list that can select or
exclude ranges based on memblock flags.

Signed-off-by: Anthony Yznaga <anthony.yznaga@...cle.com>
---
 include/linux/memblock.h | 10 ++++++++++
 mm/memblock.c            | 51 +++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 60 insertions(+), 1 deletion(-)

diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 27ab2b30ae1d..f348ebb750c9 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -145,6 +145,11 @@ void __next_mem_range_rev(u64 *idx, int nid, enum memblock_flags flags,
 void __next_reserved_mem_region(u64 *idx, phys_addr_t *out_start,
 				phys_addr_t *out_end);
 
+void __next_reserved_mem_range(u64 *idx, enum memblock_flags flags,
+			       enum memblock_flags exclflags,
+			       phys_addr_t *out_start, phys_addr_t *out_end,
+			       int *out_nid);
+
 void __memblock_free_late(phys_addr_t base, phys_addr_t size);
 
 /**
@@ -202,6 +207,11 @@ void __memblock_free_late(phys_addr_t base, phys_addr_t size);
 	     i != (u64)ULLONG_MAX;					\
 	     __next_reserved_mem_region(&i, p_start, p_end))
 
+#define for_each_reserved_mem_range(i, flags, exclflags, p_start, p_end, p_nid)\
+	for (i = 0UL, __next_reserved_mem_range(&i, flags, exclflags, p_start, p_end, p_nid);	\
+	     i != (u64)ULLONG_MAX;					\
+	     __next_reserved_mem_range(&i, flags, exclflags, p_start, p_end, p_nid))
+
 static inline bool memblock_is_hotpluggable(struct memblock_region *m)
 {
 	return m->flags & MEMBLOCK_HOTPLUG;
diff --git a/mm/memblock.c b/mm/memblock.c
index 1a9a2055ed11..33597f352dc0 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -987,6 +987,55 @@ void __init_memblock __next_reserved_mem_region(u64 *idx,
 	*idx = ULLONG_MAX;
 }
 
+/**
+ * __next_reserved_mem_range - next function for for_each_reserved_range()
+ * @idx: pointer to u64 loop variable
+ * @flags: pick blocks based on memory attributes
+ * @exclflags: exclude blocks based on memory attributes
+ * @out_start: ptr to phys_addr_t for start address of the range, can be %NULL
+ * @out_end: ptr to phys_addr_t for end address of the range, can be %NULL
+ * @out_nid: ptr to int for nid of the range, can be %NULL
+ *
+ * Iterate over all reserved memory ranges.
+ */
+void __init_memblock __next_reserved_mem_range(u64 *idx,
+					   enum memblock_flags flags,
+					   enum memblock_flags exclflags,
+					   phys_addr_t *out_start,
+					   phys_addr_t *out_end, int *out_nid)
+{
+	struct memblock_type *type = &memblock.reserved;
+	int _idx = *idx;
+
+	for (; _idx < type->cnt; _idx++) {
+		struct memblock_region *r = &type->regions[_idx];
+		phys_addr_t base = r->base;
+		phys_addr_t size = r->size;
+
+		/* skip preserved pages */
+		if ((exclflags & MEMBLOCK_PRESERVED) && memblock_is_preserved(r))
+			continue;
+
+		/* skip non-preserved pages */
+		if ((flags & MEMBLOCK_PRESERVED) && !memblock_is_preserved(r))
+			continue;
+
+		if (out_start)
+			*out_start = base;
+		if (out_end)
+			*out_end = base + size - 1;
+		if (out_nid)
+			*out_nid = r->nid;
+
+		_idx++;
+		*idx = (u64)_idx;
+		return;
+	}
+
+	/* signal end of iteration */
+	*idx = ULLONG_MAX;
+}
+
 static bool should_skip_region(struct memblock_region *m, int nid, int flags)
 {
 	int m_nid = memblock_get_region_node(m);
@@ -1011,7 +1060,7 @@ static bool should_skip_region(struct memblock_region *m, int nid, int flags)
 }
 
 /**
- * __next_mem_range - next function for for_each_free_mem_range() etc.
+ * __next__mem_range - next function for for_each_free_mem_range() etc.
  * @idx: pointer to u64 loop variable
  * @nid: node selector, %NUMA_NO_NODE for all nodes
  * @flags: pick from blocks based on memory attributes
-- 
2.13.3