From 3f89bc3688137fca1be05ce131c96ca45af1fc07 Mon Sep 17 00:00:00 2001
From: Roger Pau Monne <roger.pau@citrix.com>
Date: Thu, 7 May 2015 12:21:55 +0200
Subject: [PATCH] xen: introduce a helper to allocate non-contiguous memory
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The allocator uses independent calls to alloc_heap_pages in order to get the
desired amount of memory and then maps all the independent physical
addresses into a contiguous virtual address space.

In order to keep track of this regions a red-black tree is used.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Tim Deegan <tim@xen.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
---
 xen/common/xmalloc_tlsf.c  | 63 ++++++++++++++++++++++++++++++++++++++++++++++
 xen/include/asm-arm/mm.h   |  2 ++
 xen/include/asm-x86/page.h |  2 ++
 xen/include/xen/xmalloc.h  |  4 +++
 4 files changed, 71 insertions(+)

diff --git a/xen/common/xmalloc_tlsf.c b/xen/common/xmalloc_tlsf.c
index b13317e..a272240 100644
--- a/xen/common/xmalloc_tlsf.c
+++ b/xen/common/xmalloc_tlsf.c
@@ -613,6 +613,13 @@ void *_xzalloc(unsigned long size, unsigned long align)
     return p ? memset(p, 0, size) : p;
 }
 
+void *vzalloc(unsigned long size)
+{
+    void *p = vmalloc(size);
+
+    return p ? memset(p, 0, size) : p;
+}
+
 void xfree(void *p)
 {
     struct bhdr *b;
@@ -651,3 +658,59 @@ void xfree(void *p)
 
     xmem_pool_free(p, xenpool);
 }
+
+void *vmalloc(unsigned long size)
+{
+    unsigned long *mfn;
+    unsigned long pages, i;
+    struct page_info *pg;
+    void *va = NULL;
+
+    ASSERT(!in_irq());
+
+    if ( size == 0 )
+        return ZERO_BLOCK_PTR;
+
+    pages = DIV_ROUND_UP(size, PAGE_SIZE);
+    mfn = xzalloc_array(unsigned long, pages);
+    if ( mfn == NULL )
+        return NULL;
+
+    for ( i = 0; i < pages; i++ )
+    {
+        pg = alloc_domheap_pages(NULL, 1, 0);
+        if ( pg == NULL )
+            goto error;
+        mfn[i] = page_to_mfn(pg);
+    }
+
+    va = vmap(mfn, pages);
+    if ( va == NULL )
+        goto error;
+
+    xfree(mfn);
+    return va;
+
+ error:
+    vunmap(va);
+    for ( i = 0; i < pages; i++ )
+        if ( mfn[i] != 0 )
+            free_domheap_pages(mfn_to_page(mfn[i]), 1);
+    xfree(mfn);
+    return NULL;
+}
+
+void vfree(void *va, unsigned long size)
+{
+    unsigned long pages, i;
+
+    if ( va == NULL || size == 0 )
+        return;
+
+    pages = DIV_ROUND_UP(size, PAGE_SIZE);
+
+    for ( i = 0; i < pages; i++ )
+        free_domheap_pages(vmap_to_page(va + i * PAGE_SIZE), 1);
+
+    vunmap(va);
+}
diff --git a/xen/include/asm-arm/mm.h b/xen/include/asm-arm/mm.h
index d25e485..c0afcec 100644
--- a/xen/include/asm-arm/mm.h
+++ b/xen/include/asm-arm/mm.h
@@ -208,6 +208,8 @@ static inline void __iomem *ioremap_wc(paddr_t start, size_t len)
 #define pfn_to_paddr(pfn) ((paddr_t)(pfn) << PAGE_SHIFT)
 #define paddr_to_pfn(pa)  ((unsigned long)((pa) >> PAGE_SHIFT))
 #define paddr_to_pdx(pa)    pfn_to_pdx(paddr_to_pfn(pa))
+#define vmap_to_mfn(va)     paddr_to_pfn(virt_to_maddr((vaddr_t)va))
+#define vmap_to_page(va)    mfn_to_page(vmap_to_mfn(va))
 
 /* Page-align address and convert to frame number format */
 #define paddr_to_pfn_aligned(paddr)    paddr_to_pfn(PAGE_ALIGN(paddr))
diff --git a/xen/include/asm-x86/page.h b/xen/include/asm-x86/page.h
index a8bc999..8977a76 100644
--- a/xen/include/asm-x86/page.h
+++ b/xen/include/asm-x86/page.h
@@ -262,6 +262,8 @@ void copy_page_sse2(void *, const void *);
 #define pfn_to_paddr(pfn)   __pfn_to_paddr(pfn)
 #define paddr_to_pfn(pa)    __paddr_to_pfn(pa)
 #define paddr_to_pdx(pa)    pfn_to_pdx(paddr_to_pfn(pa))
+#define vmap_to_mfn(va)     l1e_get_pfn(*virt_to_xen_l1e((unsigned long)(va)))
+#define vmap_to_page(va)    mfn_to_page(vmap_to_mfn(va))
 
 #endif /* !defined(__ASSEMBLY__) */
 
diff --git a/xen/include/xen/xmalloc.h b/xen/include/xen/xmalloc.h
index 24a99ac..33f61c1 100644
--- a/xen/include/xen/xmalloc.h
+++ b/xen/include/xen/xmalloc.h
@@ -30,6 +30,10 @@ extern void xfree(void *);
 extern void *_xmalloc(unsigned long size, unsigned long align);
 extern void *_xzalloc(unsigned long size, unsigned long align);
 
+void *vmalloc(unsigned long size);
+void *vzalloc(unsigned long size);
+void vfree(void *va, unsigned long size);
+
 static inline void *_xmalloc_array(
     unsigned long size, unsigned long align, unsigned long num)
 {
-- 
1.9.5 (Apple Git-50.3)