cma: add placement specifier for "cma=" kernel parameter

[firefly-linux-kernel-4.4.55.git] / drivers / base / dma-contiguous.c

diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
index c34ec33642436157a344489ea14cc9657293093d..83969f8c5727e79dcb53da459e15d7d1d8dc3834 100644 (file)
--- a/drivers/base/dma-contiguous.c
+++ b/drivers/base/dma-contiguous.c
@@ -60,11 +60,22 @@ struct cma *dma_contiguous_default_area;
  */
 static const phys_addr_t size_bytes = CMA_SIZE_MBYTES * SZ_1M;
 static phys_addr_t size_cmdline = -1;
+static phys_addr_t base_cmdline;
+static phys_addr_t limit_cmdline;
 
 static int __init early_cma(char *p)
 {
        pr_debug("%s(%s)\n", __func__, p);
        size_cmdline = memparse(p, &p);
+       if (*p != '@')
+               return 0;
+       base_cmdline = memparse(p + 1, &p);
+       if (*p != '-') {
+               limit_cmdline = base_cmdline + size_cmdline;
+               return 0;
+       }
+       limit_cmdline = memparse(p + 1, &p);
+
        return 0;
 }
 early_param("cma", early_cma);
@@ -108,11 +119,18 @@ static inline __maybe_unused phys_addr_t cma_early_percent_memory(void)
 void __init dma_contiguous_reserve(phys_addr_t limit)
 {
        phys_addr_t selected_size = 0;
+       phys_addr_t selected_base = 0;
+       phys_addr_t selected_limit = limit;
+       bool fixed = false;
 
        pr_debug("%s(limit %08lx)\n", __func__, (unsigned long)limit);
 
        if (size_cmdline != -1) {
                selected_size = size_cmdline;
+               selected_base = base_cmdline;
+               selected_limit = min_not_zero(limit_cmdline, limit);
+               if (base_cmdline + size_cmdline == limit_cmdline)
+                       fixed = true;
        } else {
 #ifdef CONFIG_CMA_SIZE_SEL_MBYTES
                selected_size = size_bytes;
@@ -129,10 +147,12 @@ void __init dma_contiguous_reserve(phys_addr_t limit)
                pr_debug("%s: reserving %ld MiB for global area\n", __func__,
                         (unsigned long)selected_size / SZ_1M);
 
-               dma_contiguous_reserve_area(selected_size, 0, limit,
-                                           &dma_contiguous_default_area);
+               dma_contiguous_reserve_area(selected_size, selected_base,
+                                           selected_limit,
+                                           &dma_contiguous_default_area,
+                                           fixed);
        }
-};
+}
 
 static DEFINE_MUTEX(cma_mutex);
 
@@ -189,15 +209,20 @@ core_initcall(cma_init_reserved_areas);
  * @base: Base address of the reserved area optional, use 0 for any
  * @limit: End address of the reserved memory (optional, 0 for any).
  * @res_cma: Pointer to store the created cma region.
+ * @fixed: hint about where to place the reserved area
  *
  * This function reserves memory from early allocator. It should be
  * called by arch specific code once the early allocator (memblock or bootmem)
  * has been activated and all other subsystems have already allocated/reserved
  * memory. This function allows to create custom reserved areas for specific
  * devices.
+ *
+ * If @fixed is true, reserve contiguous area at exactly @base.  If false,
+ * reserve in range from @base to @limit.
  */
 int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base,
-                                      phys_addr_t limit, struct cma **res_cma)
+                                      phys_addr_t limit, struct cma **res_cma,
+                                      bool fixed)
 {
        struct cma *cma = &cma_areas[cma_area_count];
        phys_addr_t alignment;
@@ -223,18 +248,15 @@ int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base,
        limit &= ~(alignment - 1);
 
        /* Reserve memory */
-       if (base) {
+       if (base && fixed) {
                if (memblock_is_region_reserved(base, size) ||
                    memblock_reserve(base, size) < 0) {
                        ret = -EBUSY;
                        goto err;
                }
        } else {
-               /*
-                * Use __memblock_alloc_base() since
-                * memblock_alloc_base() panic()s.
-                */
-               phys_addr_t addr = __memblock_alloc_base(size, alignment, limit);
+               phys_addr_t addr = memblock_alloc_range(size, alignment, base,
+                                                       limit);
                if (!addr) {
                        ret = -ENOMEM;
                        goto err;