v4.19.13 snapshot.
diff --git a/arch/arm/kernel/dma.c b/arch/arm/kernel/dma.c
new file mode 100644
index 0000000..6739d37
--- /dev/null
+++ b/arch/arm/kernel/dma.c
@@ -0,0 +1,286 @@
+/*
+ * linux/arch/arm/kernel/dma.c
+ *
+ * Copyright (C) 1995-2000 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Front-end to the DMA handling. This handles the allocation/freeing
+ * of DMA channels, and provides a unified interface to the machines
+ * DMA facilities.
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/errno.h>
+#include <linux/scatterlist.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+
+#include <asm/dma.h>
+
+#include <asm/mach/dma.h>
+
+DEFINE_RAW_SPINLOCK(dma_spin_lock);
+EXPORT_SYMBOL(dma_spin_lock);
+
+static dma_t *dma_chan[MAX_DMA_CHANNELS];
+
+static inline dma_t *dma_channel(unsigned int chan)
+{
+ if (chan >= MAX_DMA_CHANNELS)
+ return NULL;
+
+ return dma_chan[chan];
+}
+
+int __init isa_dma_add(unsigned int chan, dma_t *dma)
+{
+ if (!dma->d_ops)
+ return -EINVAL;
+
+ sg_init_table(&dma->buf, 1);
+
+ if (dma_chan[chan])
+ return -EBUSY;
+ dma_chan[chan] = dma;
+ return 0;
+}
+
+/*
+ * Request DMA channel
+ *
+ * On certain platforms, we have to allocate an interrupt as well...
+ */
+int request_dma(unsigned int chan, const char *device_id)
+{
+ dma_t *dma = dma_channel(chan);
+ int ret;
+
+ if (!dma)
+ goto bad_dma;
+
+ if (xchg(&dma->lock, 1) != 0)
+ goto busy;
+
+ dma->device_id = device_id;
+ dma->active = 0;
+ dma->invalid = 1;
+
+ ret = 0;
+ if (dma->d_ops->request)
+ ret = dma->d_ops->request(chan, dma);
+
+ if (ret)
+ xchg(&dma->lock, 0);
+
+ return ret;
+
+bad_dma:
+ pr_err("dma: trying to allocate DMA%d\n", chan);
+ return -EINVAL;
+
+busy:
+ return -EBUSY;
+}
+EXPORT_SYMBOL(request_dma);
+
+/*
+ * Free DMA channel
+ *
+ * On certain platforms, we have to free interrupt as well...
+ */
+void free_dma(unsigned int chan)
+{
+ dma_t *dma = dma_channel(chan);
+
+ if (!dma)
+ goto bad_dma;
+
+ if (dma->active) {
+ pr_err("dma%d: freeing active DMA\n", chan);
+ dma->d_ops->disable(chan, dma);
+ dma->active = 0;
+ }
+
+ if (xchg(&dma->lock, 0) != 0) {
+ if (dma->d_ops->free)
+ dma->d_ops->free(chan, dma);
+ return;
+ }
+
+ pr_err("dma%d: trying to free free DMA\n", chan);
+ return;
+
+bad_dma:
+ pr_err("dma: trying to free DMA%d\n", chan);
+}
+EXPORT_SYMBOL(free_dma);
+
+/* Set DMA Scatter-Gather list
+ */
+void set_dma_sg (unsigned int chan, struct scatterlist *sg, int nr_sg)
+{
+ dma_t *dma = dma_channel(chan);
+
+ if (dma->active)
+ pr_err("dma%d: altering DMA SG while DMA active\n", chan);
+
+ dma->sg = sg;
+ dma->sgcount = nr_sg;
+ dma->invalid = 1;
+}
+EXPORT_SYMBOL(set_dma_sg);
+
+/* Set DMA address
+ *
+ * Copy address to the structure, and set the invalid bit
+ */
+void __set_dma_addr (unsigned int chan, void *addr)
+{
+ dma_t *dma = dma_channel(chan);
+
+ if (dma->active)
+ pr_err("dma%d: altering DMA address while DMA active\n", chan);
+
+ dma->sg = NULL;
+ dma->addr = addr;
+ dma->invalid = 1;
+}
+EXPORT_SYMBOL(__set_dma_addr);
+
+/* Set DMA byte count
+ *
+ * Copy address to the structure, and set the invalid bit
+ */
+void set_dma_count (unsigned int chan, unsigned long count)
+{
+ dma_t *dma = dma_channel(chan);
+
+ if (dma->active)
+ pr_err("dma%d: altering DMA count while DMA active\n", chan);
+
+ dma->sg = NULL;
+ dma->count = count;
+ dma->invalid = 1;
+}
+EXPORT_SYMBOL(set_dma_count);
+
+/* Set DMA direction mode
+ */
+void set_dma_mode (unsigned int chan, unsigned int mode)
+{
+ dma_t *dma = dma_channel(chan);
+
+ if (dma->active)
+ pr_err("dma%d: altering DMA mode while DMA active\n", chan);
+
+ dma->dma_mode = mode;
+ dma->invalid = 1;
+}
+EXPORT_SYMBOL(set_dma_mode);
+
+/* Enable DMA channel
+ */
+void enable_dma (unsigned int chan)
+{
+ dma_t *dma = dma_channel(chan);
+
+ if (!dma->lock)
+ goto free_dma;
+
+ if (dma->active == 0) {
+ dma->active = 1;
+ dma->d_ops->enable(chan, dma);
+ }
+ return;
+
+free_dma:
+ pr_err("dma%d: trying to enable free DMA\n", chan);
+ BUG();
+}
+EXPORT_SYMBOL(enable_dma);
+
+/* Disable DMA channel
+ */
+void disable_dma (unsigned int chan)
+{
+ dma_t *dma = dma_channel(chan);
+
+ if (!dma->lock)
+ goto free_dma;
+
+ if (dma->active == 1) {
+ dma->active = 0;
+ dma->d_ops->disable(chan, dma);
+ }
+ return;
+
+free_dma:
+ pr_err("dma%d: trying to disable free DMA\n", chan);
+ BUG();
+}
+EXPORT_SYMBOL(disable_dma);
+
+/*
+ * Is the specified DMA channel active?
+ */
+int dma_channel_active(unsigned int chan)
+{
+ dma_t *dma = dma_channel(chan);
+ return dma->active;
+}
+EXPORT_SYMBOL(dma_channel_active);
+
+void set_dma_page(unsigned int chan, char pagenr)
+{
+ pr_err("dma%d: trying to set_dma_page\n", chan);
+}
+EXPORT_SYMBOL(set_dma_page);
+
+void set_dma_speed(unsigned int chan, int cycle_ns)
+{
+ dma_t *dma = dma_channel(chan);
+ int ret = 0;
+
+ if (dma->d_ops->setspeed)
+ ret = dma->d_ops->setspeed(chan, dma, cycle_ns);
+ dma->speed = ret;
+}
+EXPORT_SYMBOL(set_dma_speed);
+
+int get_dma_residue(unsigned int chan)
+{
+ dma_t *dma = dma_channel(chan);
+ int ret = 0;
+
+ if (dma->d_ops->residue)
+ ret = dma->d_ops->residue(chan, dma);
+
+ return ret;
+}
+EXPORT_SYMBOL(get_dma_residue);
+
+#ifdef CONFIG_PROC_FS
+static int proc_dma_show(struct seq_file *m, void *v)
+{
+ int i;
+
+ for (i = 0 ; i < MAX_DMA_CHANNELS ; i++) {
+ dma_t *dma = dma_channel(i);
+ if (dma && dma->lock)
+ seq_printf(m, "%2d: %s\n", i, dma->device_id);
+ }
+ return 0;
+}
+
+static int __init proc_dma_init(void)
+{
+ proc_create_single("dma", 0, NULL, proc_dma_show);
+ return 0;
+}
+
+__initcall(proc_dma_init);
+#endif