Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 129 insertions, 0 deletions

diff --git a/drivers/char/ftape/lowlevel/ftape-buffer.c b/drivers/char/ftape/lowlevel/ftape-buffer.c
new file mode 100644
index 00000000000..54af20cd9a2
--- /dev/null
+++ b/drivers/char/ftape/lowlevel/ftape-buffer.c
@@ -0,0 +1,129 @@
+/*
+ *      Copyright (C) 1997 Claus-Justus Heine
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2, or (at your option)
+ any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; see the file COPYING.  If not, write to
+ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+
+ *
+ * $Source: /homes/cvs/ftape-stacked/ftape/lowlevel/ftape-buffer.c,v $
+ * $Revision: 1.3 $
+ * $Date: 1997/10/16 23:33:11 $
+ *
+ *  This file contains the allocator/dealloctor for ftape's dynamic dma
+ *  buffer.
+ */
+
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <asm/dma.h>
+
+#include <linux/ftape.h>
+#include "../lowlevel/ftape-rw.h"
+#include "../lowlevel/ftape-read.h"
+#include "../lowlevel/ftape-tracing.h"
+
+/*  DMA'able memory allocation stuff.
+ */
+
+static inline void *dmaalloc(size_t size)
+{
+        unsigned long addr;
+
+        if (size == 0) {
+                return NULL;
+        }
+        addr = __get_dma_pages(GFP_KERNEL, get_order(size));
+        if (addr) {
+                struct page *page;
+
+                for (page = virt_to_page(addr); page < virt_to_page(addr+size); page++)
+                        SetPageReserved(page);
+        }
+        return (void *)addr;
+}
+
+static inline void dmafree(void *addr, size_t size)
+{
+        if (size > 0) {
+                struct page *page;
+
+                for (page = virt_to_page((unsigned long)addr);
+                     page < virt_to_page((unsigned long)addr+size); page++)
+                        ClearPageReserved(page);
+                free_pages((unsigned long) addr, get_order(size));
+        }
+}
+
+static int add_one_buffer(void)
+{
+        TRACE_FUN(ft_t_flow);
+        
+        if (ft_nr_buffers >= FT_MAX_NR_BUFFERS) {
+                TRACE_EXIT -ENOMEM;
+        }
+        ft_buffer[ft_nr_buffers] = kmalloc(sizeof(buffer_struct), GFP_KERNEL);
+        if (ft_buffer[ft_nr_buffers] == NULL) {
+                TRACE_EXIT -ENOMEM;
+        }
+        memset(ft_buffer[ft_nr_buffers], 0, sizeof(buffer_struct));
+        ft_buffer[ft_nr_buffers]->address = dmaalloc(FT_BUFF_SIZE);
+        if (ft_buffer[ft_nr_buffers]->address == NULL) {
+                kfree(ft_buffer[ft_nr_buffers]);
+                ft_buffer[ft_nr_buffers] = NULL;
+                TRACE_EXIT -ENOMEM;
+        }
+        ft_nr_buffers ++;
+        TRACE(ft_t_info, "buffer nr #%d @ %p, dma area @ %p",
+              ft_nr_buffers,
+              ft_buffer[ft_nr_buffers-1],
+              ft_buffer[ft_nr_buffers-1]->address);
+        TRACE_EXIT 0;
+}
+
+static void del_one_buffer(void)
+{
+        TRACE_FUN(ft_t_flow);
+        if (ft_nr_buffers > 0) {
+                TRACE(ft_t_info, "releasing buffer nr #%d @ %p, dma area @ %p",
+                      ft_nr_buffers,
+                      ft_buffer[ft_nr_buffers-1],
+                      ft_buffer[ft_nr_buffers-1]->address);
+                ft_nr_buffers --;
+                dmafree(ft_buffer[ft_nr_buffers]->address, FT_BUFF_SIZE);
+                kfree(ft_buffer[ft_nr_buffers]);
+                ft_buffer[ft_nr_buffers] = NULL;
+        }
+        TRACE_EXIT;
+}
+
+int ftape_set_nr_buffers(int cnt)
+{
+        int delta = cnt - ft_nr_buffers;
+        TRACE_FUN(ft_t_flow);
+
+        if (delta > 0) {
+                while (delta--) {
+                        if (add_one_buffer() < 0) {
+                                TRACE_EXIT -ENOMEM;
+                        }
+                }
+        } else if (delta < 0) {
+                while (delta++) {
+                        del_one_buffer();
+                }
+        }
+        ftape_zap_read_buffers();
+        TRACE_EXIT 0;
+}