gpu: nvgpu: posix: move the posix dir to os

Since the posix code is supporting a particular OS this code
should belong under os/ not common/.

Change-Id: Idf5f75b8ab9d614c9dd43ea23dab8df3c346c0ef
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1800658
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 216 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/os/posix/bitmap.c b/drivers/gpu/nvgpu/os/posix/bitmap.c
new file mode 100644
index 00000000..f25f6e64
--- /dev/null
+++ b/drivers/gpu/nvgpu/os/posix/bitmap.c
@@ -0,0 +1,216 @@
+/*
+ * Copyright (c) 2018, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <nvgpu/posix/bitops.h>
+#include <nvgpu/posix/atomic.h>
+
+#define BIT_MASK(nr)    (1UL << ((nr) % BITS_PER_LONG))
+#define BIT_WORD(nr)    ((nr) / BITS_PER_LONG)
+
+unsigned long __nvgpu_posix_ffs(unsigned long word)
+{
+        return (__builtin_ffsl(word) - 1) &
+                ((sizeof(unsigned long) * 8UL) - 1UL);
+}
+
+unsigned long __nvgpu_posix_fls(unsigned long word)
+{
+        return ((sizeof(unsigned long) * 8UL) - 1UL) - __builtin_clzl(word);
+}
+
+static unsigned long __find_next_bit(const unsigned long *addr,
+                                     unsigned long n,
+                                     unsigned long start,
+                                     bool invert)
+{
+        unsigned long idx;
+        unsigned long w;
+        unsigned long start_mask;
+
+        /*
+         * We make a mask we can XOR into the word so that we can invert the
+         * word without requiring a branch. I.e instead of doing:
+         *
+         *   w = invert ? ~addr[idx] : addr[idx]
+         *
+         * We can do:
+         *
+         *   w = addr[idx] ^= invert_mask
+         *
+         * This saves us a branch every iteration through the loop. Now we can
+         * always just look for 1s.
+         */
+        unsigned long invert_mask = invert ? ~0UL : 0UL;
+
+        if (start >= n)
+                return n;
+
+        start_mask = ~0UL << (start & (BITS_PER_LONG - 1));
+
+        idx = start / BITS_PER_LONG;
+        w = (addr[idx] ^ invert_mask) & start_mask;
+
+        start = round_up(start, BITS_PER_LONG);
+
+        /*
+         * Find the first non-zero word taking into account start and
+         * invert.
+         */
+        while (!w) {
+                idx++;
+                start += BITS_PER_LONG;
+
+                w = addr[idx] ^ invert_mask;
+        }
+
+        return min(n, ffs(w) + idx * BITS_PER_LONG);
+}
+
+unsigned long find_first_bit(const unsigned long *addr, unsigned long size)
+{
+        return __find_next_bit(addr, size, 0, false);
+}
+
+unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size)
+{
+        return __find_next_bit(addr, size, 0, true);
+}
+
+unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
+                            unsigned long offset)
+{
+        return __find_next_bit(addr, size, offset, false);
+}
+
+static unsigned long find_next_zero_bit(const unsigned long *addr,
+                                        unsigned long size,
+                                        unsigned long offset)
+{
+        return __find_next_bit(addr, size, offset, true);
+}
+
+void bitmap_set(unsigned long *map, unsigned int start, int len)
+{
+        unsigned int end = start + len;
+
+        /*
+         * Super slow naive implementation. But speed isn't what matters here.
+         */
+        while (start < end)
+                set_bit(start++, map);
+}
+
+void bitmap_clear(unsigned long *map, unsigned int start, int len)
+{
+        unsigned int end = start + len;
+
+        while (start < end)
+                clear_bit(start++, map);
+}
+
+/*
+ * This is essentially a find-first-fit allocator: this searches a bitmap for
+ * the first space that is large enough to satisfy the requested size of bits.
+ * That means that this is not a vary smart allocator. But it is fast relative
+ * to an allocator that goes looking for an optimal location.
+ */
+unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
+                                             unsigned long size,
+                                             unsigned long start,
+                                             unsigned int nr,
+                                             unsigned long align_mask,
+                                             unsigned long align_offset)
+{
+        unsigned long offs;
+
+        while (start + nr <= size) {
+                start = find_next_zero_bit(map, size, start);
+
+                start = ALIGN_MASK(start + align_offset, align_mask) -
+                        align_offset;
+
+                /*
+                 * Not enough space left to satisfy the requested area.
+                 */
+                if ((start + nr) > size)
+                        return size;
+
+                offs = find_next_bit(map, size, start);
+
+                if ((offs - start) >= nr)
+                        return start;
+
+                start = offs + 1;
+        }
+
+        return size;
+}
+
+unsigned long bitmap_find_next_zero_area(unsigned long *map,
+                                         unsigned long size,
+                                         unsigned long start,
+                                         unsigned int nr,
+                                         unsigned long align_mask)
+{
+        return bitmap_find_next_zero_area_off(map, size, start, nr,
+                                              align_mask, 0);
+}
+
+bool test_bit(int nr, const volatile unsigned long *addr)
+{
+        return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG-1)));
+}
+
+bool test_and_set_bit(int nr, volatile unsigned long *addr)
+{
+        unsigned long mask = BIT_MASK(nr);
+        volatile unsigned long *p = addr + BIT_WORD(nr);
+
+        return !!(__sync_fetch_and_or(p, mask) & mask);
+}
+
+bool test_and_clear_bit(int nr, volatile unsigned long *addr)
+{
+        unsigned long mask = BIT_MASK(nr);
+        unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
+
+        return !!(__sync_fetch_and_and(p, ~mask) & mask);
+}
+
+void set_bit(int nr, volatile unsigned long *addr)
+{
+        unsigned long mask = BIT_MASK(nr);
+        unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
+
+        __atomic_or(p, mask);
+}
+
+void clear_bit(int nr, volatile unsigned long *addr)
+{
+        unsigned long mask = BIT_MASK(nr);
+        unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
+
+        __atomic_and(p, ~mask);
+}