ARM: Implement non-cached memory support

[karo-tx-uboot.git] / arch / arm / lib / cache.c

diff --git a/arch/arm/lib/cache.c b/arch/arm/lib/cache.c
index f1c0792ce8da0afcf1b17b68f6cd9b7547b07822..9cedeac6d641eb7b8548fb8571bcd6a261388fdb 100644 (file)
--- a/arch/arm/lib/cache.c
+++ b/arch/arm/lib/cache.c
@@ -8,6 +8,7 @@
 /* for now: just dummy functions to satisfy the linker */
 
 #include <common.h>
+#include <malloc.h>
 
 __weak void flush_cache(unsigned long start, unsigned long size)
 {
@@ -49,3 +50,46 @@ __weak void enable_caches(void)
 {
        puts("WARNING: Caches not enabled\n");
 }
+
+#ifdef CONFIG_SYS_NONCACHED_MEMORY
+/*
+ * Reserve one MMU section worth of address space below the malloc() area that
+ * will be mapped uncached.
+ */
+static unsigned long noncached_start;
+static unsigned long noncached_end;
+static unsigned long noncached_next;
+
+void noncached_init(void)
+{
+       phys_addr_t start, end;
+       size_t size;
+
+       end = ALIGN(mem_malloc_start, MMU_SECTION_SIZE) - MMU_SECTION_SIZE;
+       size = ALIGN(CONFIG_SYS_NONCACHED_MEMORY, MMU_SECTION_SIZE);
+       start = end - size;
+
+       debug("mapping memory %pa-%pa non-cached\n", &start, &end);
+
+       noncached_start = start;
+       noncached_end = end;
+       noncached_next = start;
+
+#ifndef CONFIG_SYS_DCACHE_OFF
+       mmu_set_region_dcache_behaviour(noncached_start, size, DCACHE_OFF);
+#endif
+}
+
+phys_addr_t noncached_alloc(size_t size, size_t align)
+{
+       phys_addr_t next = ALIGN(noncached_next, align);
+
+       if (next >= noncached_end || (noncached_end - next) < size)
+               return 0;
+
+       debug("allocated %zu bytes of uncached memory @%pa\n", size, &next);
+       noncached_next = next + size;
+
+       return next;
+}
+#endif /* CONFIG_SYS_NONCACHED_MEMORY */