[PATCH 04/10] xen/arm: static memory initialization

[Penny Zheng <penny.zheng@xxxxxxx>]

This patch introduces static memory initialization, during system RAM boot up.

New func init_staticmem_pages is the equivalent of init_heap_pages, responsible
for static memory initialization.

Helper func free_staticmem_pages is the equivalent of free_heap_pages, to free
nr_pfns pages of static memory.
For each page, it includes the following steps:
1. change page state from in-use(also initialization state) to free state and
grant PGC_reserved.
2. set its owner NULL and make sure this page is not a guest frame any more
3. follow the same cache coherency policy in free_heap_pages
4. scrub the page in need

Signed-off-by: Penny Zheng <penny.zheng@xxxxxxx>
---
 xen/arch/arm/setup.c    |  2 ++
 xen/common/page_alloc.c | 70 +++++++++++++++++++++++++++++++++++++++++
 xen/include/xen/mm.h    |  3 ++
 3 files changed, 75 insertions(+)

diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index 444dbbd676..f80162c478 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -818,6 +818,8 @@ static void __init setup_mm(void)
 
     setup_frametable_mappings(ram_start, ram_end);
     max_page = PFN_DOWN(ram_end);
+
+    init_staticmem_pages();
 }
 #endif
 
diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c
index ace6333c18..58b53c6ac2 100644
--- a/xen/common/page_alloc.c
+++ b/xen/common/page_alloc.c
@@ -150,6 +150,9 @@
 #define p2m_pod_offline_or_broken_hit(pg) 0
 #define p2m_pod_offline_or_broken_replace(pg) BUG_ON(pg != NULL)
 #endif
+#ifdef CONFIG_ARM_64
+#include <asm/setup.h>
+#endif
 
 /*
  * Comma-separated list of hexadecimal page numbers containing bad bytes.
@@ -1512,6 +1515,49 @@ static void free_heap_pages(
     spin_unlock(&heap_lock);
 }
 
+/* Equivalent of free_heap_pages to free nr_pfns pages of static memory. */
+static void free_staticmem_pages(struct page_info *pg, unsigned long nr_pfns,
+                                 bool need_scrub)
+{
+    mfn_t mfn = page_to_mfn(pg);
+    int i;
+
+    for ( i = 0; i < nr_pfns; i++ )
+    {
+        switch ( pg[i].count_info & PGC_state )
+        {
+        case PGC_state_inuse:
+            BUG_ON(pg[i].count_info & PGC_broken);
+            /* Make it free and reserved. */
+            pg[i].count_info = PGC_state_free | PGC_reserved;
+            break;
+
+        default:
+            printk(XENLOG_ERR
+                   "Page state shall be only in PGC_state_inuse. "
+                   "pg[%u] MFN %"PRI_mfn" count_info=%#lx 
tlbflush_timestamp=%#x.\n",
+                   i, mfn_x(mfn) + i,
+                   pg[i].count_info,
+                   pg[i].tlbflush_timestamp);
+            BUG();
+        }
+
+        /*
+         * Follow the same cache coherence scheme in free_heap_pages.
+         * If a page has no owner it will need no safety TLB flush.
+         */
+        pg[i].u.free.need_tlbflush = (page_get_owner(&pg[i]) != NULL);
+        if ( pg[i].u.free.need_tlbflush )
+            page_set_tlbflush_timestamp(&pg[i]);
+
+        /* This page is not a guest frame any more. */
+        page_set_owner(&pg[i], NULL);
+        set_gpfn_from_mfn(mfn_x(mfn) + i, INVALID_M2P_ENTRY);
+
+        if ( need_scrub )
+            scrub_one_page(&pg[i]);
+    }
+}
 
 /*
  * Following rules applied for page offline:
@@ -1828,6 +1874,30 @@ static void init_heap_pages(
     }
 }
 
+/* Equivalent of init_heap_pages to do static memory initialization */
+void __init init_staticmem_pages(void)
+{
+    int bank;
+
+    /*
+     * TODO: Considering NUMA-support scenario.
+     */
+    for ( bank = 0 ; bank < bootinfo.static_mem.nr_banks; bank++ )
+    {
+        paddr_t bank_start = bootinfo.static_mem.bank[bank].start;
+        paddr_t bank_size = bootinfo.static_mem.bank[bank].size;
+        paddr_t bank_end = bank_start + bank_size;
+
+        bank_start = round_pgup(bank_start);
+        bank_end = round_pgdown(bank_end);
+        if ( bank_end <= bank_start )
+            return;
+
+        free_staticmem_pages(maddr_to_page(bank_start),
+                            (bank_end - bank_start) >> PAGE_SHIFT, false);
+    }
+}
+
 static unsigned long avail_heap_pages(
     unsigned int zone_lo, unsigned int zone_hi, unsigned int node)
 {
diff --git a/xen/include/xen/mm.h b/xen/include/xen/mm.h
index 667f9dac83..8b1a2207b2 100644
--- a/xen/include/xen/mm.h
+++ b/xen/include/xen/mm.h
@@ -85,6 +85,9 @@ bool scrub_free_pages(void);
 } while ( false )
 #define FREE_XENHEAP_PAGE(p) FREE_XENHEAP_PAGES(p, 0)
 
+/* Static Memory */
+void init_staticmem_pages(void);
+
 /* Map machine page range in Xen virtual address space. */
 int map_pages_to_xen(
     unsigned long virt,
-- 
2.25.1