[Xen-devel] [PATCH 04/15] xen: mm: add ioremap_cache

[Kai Huang <kaih.linux@xxxxxxxxx>]

Currently Xen only has non-cacheable version of ioremap. Although EPC is
reported as reserved memory in e820 but it can be mapped as cacheable. This
patch adds ioremap_cache (cacheable version of ioremap).

Signed-off-by: Kai Huang <kai.huang@xxxxxxxxxxxxxxx>
---
 xen/arch/x86/mm.c      | 15 +++++++++++++--
 xen/include/xen/vmap.h |  1 +
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 101ab33193..d0b6b3a247 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -6284,9 +6284,10 @@ void *__init arch_vmap_virt_end(void)
     return (void *)fix_to_virt(__end_of_fixed_addresses);
 }
 
-void __iomem *ioremap(paddr_t pa, size_t len)
+static void __iomem *__ioremap(paddr_t pa, size_t len, bool_t cache)
 {
     mfn_t mfn = _mfn(PFN_DOWN(pa));
+    unsigned int flags = cache ? PAGE_HYPERVISOR : PAGE_HYPERVISOR_NOCACHE;
     void *va;
 
     WARN_ON(page_is_ram_type(mfn_x(mfn), RAM_TYPE_CONVENTIONAL));
@@ -6299,12 +6300,22 @@ void __iomem *ioremap(paddr_t pa, size_t len)
         unsigned int offs = pa & (PAGE_SIZE - 1);
         unsigned int nr = PFN_UP(offs + len);
 
-        va = __vmap(&mfn, nr, 1, 1, PAGE_HYPERVISOR_NOCACHE, VMAP_DEFAULT) + 
offs;
+        va = __vmap(&mfn, nr, 1, 1, flags, VMAP_DEFAULT) + offs;
     }
 
     return (void __force __iomem *)va;
 }
 
+void __iomem *ioremap(paddr_t pa, size_t len)
+{
+    return __ioremap(pa, len, false);
+}
+
+void __iomem *ioremap_cache(paddr_t pa, size_t len)
+{
+    return __ioremap(pa, len, true);
+}
+
 int create_perdomain_mapping(struct domain *d, unsigned long va,
                              unsigned int nr, l1_pgentry_t **pl1tab,
                              struct page_info **ppg)
diff --git a/xen/include/xen/vmap.h b/xen/include/xen/vmap.h
index 369560e620..f6037e368c 100644
--- a/xen/include/xen/vmap.h
+++ b/xen/include/xen/vmap.h
@@ -24,6 +24,7 @@ void *vzalloc(size_t size);
 void vfree(void *va);
 
 void __iomem *ioremap(paddr_t, size_t);
+void __iomem *ioremap_cache(paddr_t, size_t);
 
 static inline void iounmap(void __iomem *va)
 {
-- 
2.11.0


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