[PATCH 15/39] MIPS: add kmap_noncoherent to wire a cached non-coherent TLB entry

[Paul Burton <paul.burton@xxxxxxxxxx>]

This is identical to kmap_coherent apart from the cache coherency
attribute used for the TLB entry, so kmap_coherent is abstracted to
kmap_prot which is then called for both kmap_coherent &
kmap_noncoherent. This will be used by a subsequent patch.

Suggested-by: Leonid Yegoshin <leonid.yegoshin@xxxxxxxxxx>
Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
---
 arch/mips/include/asm/cacheflush.h |  6 ++++++
 arch/mips/include/asm/pgtable.h    |  2 ++
 arch/mips/mm/init.c                | 14 ++++++++++++--
 3 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/arch/mips/include/asm/cacheflush.h b/arch/mips/include/asm/cacheflush.h
index 69468de..e08381a 100644
--- a/arch/mips/include/asm/cacheflush.h
+++ b/arch/mips/include/asm/cacheflush.h
@@ -113,6 +113,12 @@ unsigned long run_uncached(void *func);
 
 extern void *kmap_coherent(struct page *page, unsigned long addr);
 extern void kunmap_coherent(void);
+extern void *kmap_noncoherent(struct page *page, unsigned long addr);
+
+static inline void kunmap_noncoherent(void)
+{
+	kunmap_coherent();
+}
 
 #define ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
 static inline void flush_kernel_dcache_page(struct page *page)
diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
index 008324d..539ddd1 100644
--- a/arch/mips/include/asm/pgtable.h
+++ b/arch/mips/include/asm/pgtable.h
@@ -32,6 +32,8 @@ struct vm_area_struct;
 				 _page_cachable_default)
 #define PAGE_KERNEL	__pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \
 				 _PAGE_GLOBAL | _page_cachable_default)
+#define PAGE_KERNEL_NC	__pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \
+				 _PAGE_GLOBAL | _CACHE_CACHABLE_NONCOHERENT)
 #define PAGE_USERIO	__pgprot(_PAGE_PRESENT | (cpu_has_rixi ? 0 : _PAGE_READ) | _PAGE_WRITE | \
 				 _page_cachable_default)
 #define PAGE_KERNEL_UNCACHED __pgprot(_PAGE_PRESENT | __READABLE | \
diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index 4fc74c7..c40a194 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -114,7 +114,7 @@ static void __init kmap_coherent_init(void)
 static inline void kmap_coherent_init(void) {}
 #endif
 
-void *kmap_coherent(struct page *page, unsigned long addr)
+static void *kmap_prot(struct page *page, unsigned long addr, pgprot_t prot)
 {
 	enum fixed_addresses idx;
 	unsigned long vaddr, flags, entrylo;
@@ -133,7 +133,7 @@ void *kmap_coherent(struct page *page, unsigned long addr)
 	idx += in_interrupt() ? FIX_N_COLOURS : 0;
 #endif
 	vaddr = __fix_to_virt(FIX_CMAP_END - idx);
-	pte = mk_pte(page, PAGE_KERNEL);
+	pte = mk_pte(page, prot);
 #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
 	entrylo = pte.pte_high;
 #else
@@ -171,6 +171,16 @@ void *kmap_coherent(struct page *page, unsigned long addr)
 	return (void*) vaddr;
 }
 
+void *kmap_coherent(struct page *page, unsigned long addr)
+{
+	return kmap_prot(page, addr, PAGE_KERNEL);
+}
+
+void *kmap_noncoherent(struct page *page, unsigned long addr)
+{
+	return kmap_prot(page, addr, PAGE_KERNEL_NC);
+}
+
 void kunmap_coherent(void)
 {
 #ifndef CONFIG_MIPS_MT_SMTC
-- 
1.8.5.3