[PATCH 7/8] xtensa: support aliasing cache in kmap

[Max Filippov <jcmvbkbc@gmail.com>]

Define ARCH_PKMAP_COLORING and provide corresponding macro definitions
on cores with aliasing data cache.

Instead of single last_pkmap_nr maintain an array last_pkmap_nr_arr of
pkmap counters for each page color. Make sure that kmap maps physical
page at virtual address with color matching its physical address.

Cc: linux-mm@kvack.org
Cc: linux-arch@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 arch/xtensa/include/asm/highmem.h | 18 ++++++++++++++++--
 arch/xtensa/mm/highmem.c          |  1 +
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/arch/xtensa/include/asm/highmem.h b/arch/xtensa/include/asm/highmem.h
index 2653ef5..a5c3380 100644
--- a/arch/xtensa/include/asm/highmem.h
+++ b/arch/xtensa/include/asm/highmem.h
@@ -17,14 +17,28 @@
 #include <asm/kmap_types.h>
 #include <asm/pgtable.h>
 
-#define PKMAP_BASE		(FIXADDR_START - PMD_SIZE)
-#define LAST_PKMAP		PTRS_PER_PTE
+#define PKMAP_BASE		((FIXADDR_START - \
+				  (LAST_PKMAP + 1) * PAGE_SIZE) & PMD_MASK)
+#define LAST_PKMAP		(PTRS_PER_PTE * DCACHE_N_COLORS)
 #define LAST_PKMAP_MASK		(LAST_PKMAP - 1)
 #define PKMAP_NR(virt)		(((virt) - PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)		(PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
 #define kmap_prot		PAGE_KERNEL
 
+#if DCACHE_WAY_SIZE > PAGE_SIZE
+#define ARCH_PKMAP_COLORING
+#define set_pkmap_color(pg, cl)		((cl) = DCACHE_ALIAS(page_to_phys(pg)))
+#define get_last_pkmap_nr(p, cl)	(last_pkmap_nr_arr[cl] + (cl))
+#define get_next_pkmap_nr(p, cl)	\
+	((last_pkmap_nr_arr[cl] = ((last_pkmap_nr_arr[cl] + DCACHE_N_COLORS) & \
+				   LAST_PKMAP_MASK)) + (cl))
+#define no_more_pkmaps(p, cl)		((p) < DCACHE_N_COLORS)
+#define get_next_pkmap_counter(c, cl)	((c) - DCACHE_N_COLORS)
+
+extern unsigned int last_pkmap_nr_arr[];
+#endif
+
 extern pte_t *pkmap_page_table;
 
 void *kmap_high(struct page *page);
diff --git a/arch/xtensa/mm/highmem.c b/arch/xtensa/mm/highmem.c
index 466abae..3742a37 100644
--- a/arch/xtensa/mm/highmem.c
+++ b/arch/xtensa/mm/highmem.c
@@ -12,6 +12,7 @@
 #include <linux/highmem.h>
 #include <asm/tlbflush.h>
 
+unsigned int last_pkmap_nr_arr[DCACHE_N_COLORS];
 static pte_t *kmap_pte;
 
 static inline enum fixed_addresses kmap_idx(int type, unsigned long color)
-- 
1.8.1.4