gpu: nvgpu: Support multiple types of allocators

Support multiple types of allocation backends. Currently there is
only one allocator implementation available: a buddy allocator.
Buddy allocators have certain limitations though. For one the
allocator requires metadata to be allocated from the kernel's
system memory. This causes a given buddy allocation to potentially
sleep on a kmalloc() call.

This patch has been created so that a new backend can be created
which will avoid any dynamic system memory management routines
from being called.

Bug 1781897

Change-Id: I98d6c8402c049942f13fee69c6901a166f177f65
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: http://git-master/r/1172115
GVS: Gerrit_Virtual_Submit
Reviewed-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-by: Yu-Huan Hsu <yhsu@nvidia.com>

1 files changed, 134 insertions, 35 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/gk20a_allocator.h b/drivers/gpu/nvgpu/gk20a/gk20a_allocator.h
index e86e053b..74e23e6c 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a_allocator.h
+++ b/drivers/gpu/nvgpu/gk20a/gk20a_allocator.h
@@ -20,10 +20,49 @@
 #include <linux/list.h>
 #include <linux/rbtree.h>
 #include <linux/debugfs.h>
+#include <linux/seq_file.h>
 #include <linux/platform_device.h>
 
 /* #define ALLOCATOR_DEBUG */
 
+struct gk20a_allocator;
+struct vm_gk20a;
+
+/*
+ * Operations for an allocator to implement.
+ */
+struct gk20a_allocator_ops {
+        u64  (*alloc)(struct gk20a_allocator *allocator, u64 len);
+        void (*free)(struct gk20a_allocator *allocator, u64 addr);
+
+        /*
+         * Special interface to allocate a memory region with a specific
+         * starting address. Yikes. Note: if free() works for freeing both
+         * regular and fixed allocations then free_fixed() does not need to
+         * be implemented. This behavior exists for legacy reasons and should
+         * not be propagated to new allocators.
+         */
+        u64  (*alloc_fixed)(struct gk20a_allocator *allocator,
+                             u64 base, u64 len);
+        void (*free_fixed)(struct gk20a_allocator *allocator,
+                            u64 base, u64 len);
+
+        /*
+         * Returns info about the allocator.
+         */
+        u64  (*base)(struct gk20a_allocator *allocator);
+        u64  (*length)(struct gk20a_allocator *allocator);
+        u64  (*end)(struct gk20a_allocator *allocator);
+        int  (*inited)(struct gk20a_allocator *allocator);
+
+        /* Destructor. */
+        void (*fini)(struct gk20a_allocator *allocator);
+
+        /* Debugging. */
+        void (*print_stats)(struct gk20a_allocator *allocator,
+                            struct seq_file *s, int lock);
+};
+
 /*
  * Each buddy is an element in a binary tree.
  */
@@ -97,8 +136,6 @@ struct gk20a_fixed_alloc {
         u64 end;                        /* End address. */
 };
 
-struct vm_gk20a;
-
 /*
  * GPU buddy allocator for the various GPU address spaces. Each addressable unit
  * doesn't have to correspond to a byte. In some cases each unit is a more
@@ -109,12 +146,10 @@ struct vm_gk20a;
  *
  * order_size is the size of an order 0 buddy.
  */
-struct gk20a_allocator {
-
+struct gk20a_buddy_allocator {
+        struct gk20a_allocator *owner;  /* Owner of this buddy allocator. */
         struct vm_gk20a *vm;            /* Parent VM - can be NULL. */
 
-        char name[32];                  /* Name of allocator. */
-
         u64 base;                       /* Base address of the space. */
         u64 length;                     /* Length of the space. */
         u64 blk_size;                   /* Size of order 0 allocation. */
@@ -132,11 +167,6 @@ struct gk20a_allocator {
         struct rb_root alloced_buddies; /* Outstanding allocations. */
         struct rb_root fixed_allocs;    /* Outstanding fixed allocations. */
 
-        struct mutex lock;              /* Protects buddy access. */
-
-#define GPU_BALLOC_GVA_SPACE            0x1
-        u64 flags;
-
         /*
          * Impose an upper bound on the maximum order.
          */
@@ -155,52 +185,121 @@ struct gk20a_allocator {
          */
         u64 pte_blk_order;
 
-        struct dentry *debugfs_entry;
+        int inited;
+
+#define GPU_BALLOC_GVA_SPACE            0x1
+        u64 flags;
 
         u64 bytes_alloced;
         u64 bytes_alloced_real;
         u64 bytes_freed;
 };
 
-#define balloc_lock(a)          mutex_lock(&(a)->lock)
-#define balloc_unlock(a)        mutex_unlock(&(a)->lock)
+struct gk20a_allocator {
+        char name[32];
+        struct mutex lock;
 
-#define balloc_get_order_list(a, order) (&(a)->buddy_list[(order)])
-#define balloc_order_to_len(a, order)   ((1 << order) * (a)->blk_size)
-#define balloc_base_shift(a, base)      ((base) - (a)->start)
-#define balloc_base_unshift(a, base)    ((base) + (a)->start)
+        void *priv;
+        const struct gk20a_allocator_ops *ops;
 
-int  gk20a_allocator_init(struct gk20a_allocator *allocator,
-                          const char *name, u64 base, u64 size, u64 order0);
-int  __gk20a_allocator_init(struct gk20a_allocator *allocator,
-                            struct vm_gk20a *vm, const char *name,
-                            u64 base, u64 size, u64 order0,
-                            u64 max_order, u64 flags);
-void gk20a_allocator_destroy(struct gk20a_allocator *allocator);
+        struct dentry *debugfs_entry;
+};
+
+static inline void alloc_lock(struct gk20a_allocator *a)
+{
+        mutex_lock(&a->lock);
+}
+
+static inline void alloc_unlock(struct gk20a_allocator *a)
+{
+        mutex_unlock(&a->lock);
+}
+
+static inline struct gk20a_buddy_allocator *buddy_allocator(
+        struct gk20a_allocator *a)
+{
+        return (struct gk20a_buddy_allocator *)a->priv;
+}
+
+static inline struct list_head *balloc_get_order_list(
+        struct gk20a_buddy_allocator *a, int order)
+{
+        return &a->buddy_list[order];
+}
+
+static inline u64 balloc_order_to_len(struct gk20a_buddy_allocator *a,
+                                      int order)
+{
+        return (1 << order) * a->blk_size;
+}
+
+static inline u64 balloc_base_shift(struct gk20a_buddy_allocator *a,
+                                    u64 base)
+{
+        return base - a->start;
+}
+
+static inline u64 balloc_base_unshift(struct gk20a_buddy_allocator *a,
+                                      u64 base)
+{
+        return base + a->start;
+}
+
+static inline struct gk20a_allocator *balloc_owner(
+        struct gk20a_buddy_allocator *a)
+{
+        return a->owner;
+}
 
 /*
- * Normal alloc/free operations for the buddy allocator.
+ * Buddy allocator specific initializers.
  */
-u64  gk20a_balloc(struct gk20a_allocator *allocator, u64 len);
-void gk20a_bfree(struct gk20a_allocator *allocator, u64 addr);
+int  __gk20a_buddy_allocator_init(struct gk20a_allocator *a,
+                                  struct vm_gk20a *vm, const char *name,
+                                  u64 base, u64 size, u64 blk_size,
+                                  u64 max_order, u64 flags);
+int  gk20a_buddy_allocator_init(struct gk20a_allocator *allocator,
+                                const char *name, u64 base, u64 size,
+                                u64 blk_size, u64 flags);
 
 /*
- * Special interface to allocate a memory regions with a specific starting
- * address. Yikes.
+ * Allocator APIs.
  */
-u64  gk20a_balloc_fixed(struct gk20a_allocator *allocator, u64 base, u64 len);
+u64  gk20a_alloc(struct gk20a_allocator *allocator, u64 len);
+void gk20a_free(struct gk20a_allocator *allocator, u64 addr);
+
+u64  gk20a_alloc_fixed(struct gk20a_allocator *allocator, u64 base, u64 len);
+void gk20a_free_fixed(struct gk20a_allocator *allocator, u64 base, u64 len);
+
+u64  gk20a_alloc_base(struct gk20a_allocator *a);
+u64  gk20a_alloc_length(struct gk20a_allocator *a);
+u64  gk20a_alloc_end(struct gk20a_allocator *a);
+u64  gk20a_alloc_initialized(struct gk20a_allocator *a);
+
+void gk20a_alloc_destroy(struct gk20a_allocator *allocator);
+
+void gk20a_alloc_print_stats(struct gk20a_allocator *a,
+                             struct seq_file *s, int lock);
 
 /*
- * Debugfs init.
+ * Debug stuff.
  */
 void gk20a_alloc_debugfs_init(struct platform_device *pdev);
 
+#define __alloc_pstat(seq, allocator, fmt, arg...)              \
+        do {                                                    \
+                if (s)                                          \
+                        seq_printf(seq, fmt, ##arg);            \
+                else                                            \
+                        alloc_dbg(allocator, fmt, ##arg);       \
+        } while (0)
+
 #if defined(ALLOCATOR_DEBUG)
-#define balloc_dbg(alloctor, format, arg...)            \
+#define alloc_dbg(allocator, format, arg...)            \
         pr_info("%-25s %25s() " format,                 \
-                alloctor->name, __func__, ##arg)
+                allocator->name, __func__, ##arg)
 #else
-#define balloc_dbg(allocator, format, arg...)
+#define alloc_dbg(allocator, format, arg...)
 #endif
 
 #endif /* GK20A_ALLOCATOR_H */