microblaze: linux-user support.
[qemu] / hw / etraxfs_dma.c
index 0a5562b..ba44e0d 100644 (file)
 #include <stdio.h>
 #include <sys/time.h>
 #include "hw.h"
+#include "qemu-common.h"
+#include "sysemu.h"
 
 #include "etraxfs_dma.h"
 
 #define D(x)
 
-#define RW_DATA           0x0
-#define RW_SAVED_DATA     0x58
-#define RW_SAVED_DATA_BUF 0x5c
-#define RW_GROUP          0x60
-#define RW_GROUP_DOWN     0x7c
-#define RW_CMD            0x80
-#define RW_CFG            0x84
-#define RW_STAT           0x88
-#define RW_INTR_MASK      0x8c
-#define RW_ACK_INTR       0x90
-#define R_INTR            0x94
-#define R_MASKED_INTR     0x98
-#define RW_STREAM_CMD     0x9c
-
-#define DMA_REG_MAX   0x100
+#define RW_DATA           (0x0 / 4)
+#define RW_SAVED_DATA     (0x58 / 4)
+#define RW_SAVED_DATA_BUF (0x5c / 4)
+#define RW_GROUP          (0x60 / 4)
+#define RW_GROUP_DOWN     (0x7c / 4)
+#define RW_CMD            (0x80 / 4)
+#define RW_CFG            (0x84 / 4)
+#define RW_STAT           (0x88 / 4)
+#define RW_INTR_MASK      (0x8c / 4)
+#define RW_ACK_INTR       (0x90 / 4)
+#define R_INTR            (0x94 / 4)
+#define R_MASKED_INTR     (0x98 / 4)
+#define RW_STREAM_CMD     (0x9c / 4)
+
+#define DMA_REG_MAX       (0x100 / 4)
 
 /* descriptors */
 
@@ -156,18 +158,16 @@ enum {
 
 enum dma_ch_state
 {
-       RST = 0,
+       RST = 1,
        STOPPED = 2,
        RUNNING = 4
 };
 
 struct fs_dma_channel
 {
-       int regmap;
-       qemu_irq *irq;
+       qemu_irq irq;
        struct etraxfs_dma_client *client;
 
-
        /* Internal status.  */
        int stream_cmd_src;
        enum dma_ch_state state;
@@ -185,13 +185,18 @@ struct fs_dma_channel
 
 struct fs_dma_ctrl
 {
+       int map;
        CPUState *env;
-       target_phys_addr_t base;
 
        int nr_channels;
        struct fs_dma_channel *channels;
+
+        QEMUBH *bh;
 };
 
+static void DMA_run(void *opaque);
+static int channel_out_run(struct fs_dma_ctrl *ctrl, int c);
+
 static inline uint32_t channel_reg(struct fs_dma_ctrl *ctrl, int c, int reg)
 {
        return ctrl->channels[c].regs[reg];
@@ -208,12 +213,13 @@ static inline int channel_en(struct fs_dma_ctrl *ctrl, int c)
                && ctrl->channels[c].client;
 }
 
-static inline int fs_channel(target_phys_addr_t base, target_phys_addr_t addr)
+static inline int fs_channel(target_phys_addr_t addr)
 {
        /* Every channel has a 0x2000 ctrl register map.  */
-       return (addr - base) >> 13;
+       return addr >> 13;
 }
 
+#ifdef USE_THIS_DEAD_CODE
 static void channel_load_g(struct fs_dma_ctrl *ctrl, int c)
 {
        target_phys_addr_t addr = channel_reg(ctrl, c, RW_GROUP);
@@ -227,23 +233,24 @@ static void channel_load_g(struct fs_dma_ctrl *ctrl, int c)
 static void dump_c(int ch, struct dma_descr_context *c)
 {
        printf("%s ch=%d\n", __func__, ch);
-       printf("next=%x\n", (uint32_t) c->next);
-       printf("saved_data=%x\n", (uint32_t) c->saved_data);
-       printf("saved_data_buf=%x\n", (uint32_t) c->saved_data_buf);
+       printf("next=%p\n", c->next);
+       printf("saved_data=%p\n", c->saved_data);
+       printf("saved_data_buf=%p\n", c->saved_data_buf);
        printf("eol=%x\n", (uint32_t) c->eol);
 }
 
 static void dump_d(int ch, struct dma_descr_data *d)
 {
        printf("%s ch=%d\n", __func__, ch);
-       printf("next=%x\n", (uint32_t) d->next);
-       printf("buf=%x\n", (uint32_t) d->buf);
-       printf("after=%x\n", (uint32_t) d->after);
+       printf("next=%p\n", d->next);
+       printf("buf=%p\n", d->buf);
+       printf("after=%p\n", d->after);
        printf("intr=%x\n", (uint32_t) d->intr);
        printf("out_eop=%x\n", (uint32_t) d->out_eop);
        printf("in_eop=%x\n", (uint32_t) d->in_eop);
        printf("eol=%x\n", (uint32_t) d->eol);
 }
+#endif
 
 static void channel_load_c(struct fs_dma_ctrl *ctrl, int c)
 {
@@ -256,10 +263,10 @@ static void channel_load_c(struct fs_dma_ctrl *ctrl, int c)
 
        D(dump_c(c, &ctrl->channels[c].current_c));
        /* I guess this should update the current pos.  */
-       ctrl->channels[c].regs[RW_SAVED_DATA] = 
-               (uint32_t)ctrl->channels[c].current_c.saved_data;
+       ctrl->channels[c].regs[RW_SAVED_DATA] =
+               (uint32_t)(unsigned long)ctrl->channels[c].current_c.saved_data;
        ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
-               (uint32_t)ctrl->channels[c].current_c.saved_data_buf;
+               (uint32_t)(unsigned long)ctrl->channels[c].current_c.saved_data_buf;
 }
 
 static void channel_load_d(struct fs_dma_ctrl *ctrl, int c)
@@ -267,23 +274,33 @@ static void channel_load_d(struct fs_dma_ctrl *ctrl, int c)
        target_phys_addr_t addr = channel_reg(ctrl, c, RW_SAVED_DATA);
 
        /* Load and decode. FIXME: handle endianness.  */
-       D(printf("%s addr=%x\n", __func__, addr));
+       D(printf("%s ch=%d addr=%x\n", __func__, c, addr));
        cpu_physical_memory_read (addr,
                                  (void *) &ctrl->channels[c].current_d, 
                                  sizeof ctrl->channels[c].current_d);
 
        D(dump_d(c, &ctrl->channels[c].current_d));
        ctrl->channels[c].regs[RW_DATA] = addr;
-       ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
-               (uint32_t)ctrl->channels[c].current_d.buf;
+}
+
+static void channel_store_c(struct fs_dma_ctrl *ctrl, int c)
+{
+       target_phys_addr_t addr = channel_reg(ctrl, c, RW_GROUP_DOWN);
+
+       /* Encode and store. FIXME: handle endianness.  */
+       D(printf("%s ch=%d addr=%x\n", __func__, c, addr));
+       D(dump_d(c, &ctrl->channels[c].current_d));
+       cpu_physical_memory_write (addr,
+                                 (void *) &ctrl->channels[c].current_c,
+                                 sizeof ctrl->channels[c].current_c);
 }
 
 static void channel_store_d(struct fs_dma_ctrl *ctrl, int c)
 {
        target_phys_addr_t addr = channel_reg(ctrl, c, RW_SAVED_DATA);
 
-       /* Load and decode. FIXME: handle endianness.  */
-       D(printf("%s addr=%x\n", __func__, addr));
+       /* Encode and store. FIXME: handle endianness.  */
+       D(printf("%s ch=%d addr=%x\n", __func__, c, addr));
        cpu_physical_memory_write (addr,
                                  (void *) &ctrl->channels[c].current_d, 
                                  sizeof ctrl->channels[c].current_d);
@@ -300,8 +317,12 @@ static inline void channel_start(struct fs_dma_ctrl *ctrl, int c)
        {
                ctrl->channels[c].eol = 0;
                ctrl->channels[c].state = RUNNING;
+               if (!ctrl->channels[c].input)
+                       channel_out_run(ctrl, c);
        } else
                printf("WARNING: starting DMA ch %d with no client\n", c);
+
+        qemu_bh_schedule_idle(ctrl->bh);
 }
 
 static void channel_continue(struct fs_dma_ctrl *ctrl, int c)
@@ -326,20 +347,26 @@ static void channel_continue(struct fs_dma_ctrl *ctrl, int c)
        /* If the current descriptor cleared the eol flag and we had already
           reached eol state, do the continue.  */
        if (!ctrl->channels[c].current_d.eol && ctrl->channels[c].eol) {
-               D(printf("continue %d ok %x\n", c,
+               D(printf("continue %d ok %p\n", c,
                         ctrl->channels[c].current_d.next));
                ctrl->channels[c].regs[RW_SAVED_DATA] =
-                       (uint32_t) ctrl->channels[c].current_d.next;
+                       (uint32_t)(unsigned long)ctrl->channels[c].current_d.next;
                channel_load_d(ctrl, c);
+               ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
+                       (uint32_t)(unsigned long)ctrl->channels[c].current_d.buf;
+
                channel_start(ctrl, c);
        }
+       ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
+               (uint32_t)(unsigned long)ctrl->channels[c].current_d.buf;
 }
 
 static void channel_stream_cmd(struct fs_dma_ctrl *ctrl, int c, uint32_t v)
 {
        unsigned int cmd = v & ((1 << 10) - 1);
 
-       D(printf("%s cmd=%x\n", __func__, cmd));
+       D(printf("%s ch=%d cmd=%x\n",
+                __func__, c, cmd));
        if (cmd & regk_dma_load_d) {
                channel_load_d(ctrl, c);
                if (cmd & regk_dma_burst)
@@ -365,74 +392,91 @@ static void channel_update_irq(struct fs_dma_ctrl *ctrl, int c)
                 c,
                 ctrl->channels[c].regs[R_MASKED_INTR]));
 
-        if (ctrl->channels[c].regs[R_MASKED_INTR])
-                qemu_irq_raise(ctrl->channels[c].irq[0]);
-        else
-                qemu_irq_lower(ctrl->channels[c].irq[0]);
+        qemu_set_irq(ctrl->channels[c].irq,
+                    !!ctrl->channels[c].regs[R_MASKED_INTR]);
 }
 
-static void channel_out_run(struct fs_dma_ctrl *ctrl, int c)
+static int channel_out_run(struct fs_dma_ctrl *ctrl, int c)
 {
        uint32_t len;
        uint32_t saved_data_buf;
        unsigned char buf[2 * 1024];
 
-       if (ctrl->channels[c].eol == 1)
-               return;
-
-       saved_data_buf = channel_reg(ctrl, c, RW_SAVED_DATA_BUF);
+       if (ctrl->channels[c].eol)
+               return 0;
 
-       D(printf("buf=%x after=%x saved_data_buf=%x\n",
-                (uint32_t)ctrl->channels[c].current_d.buf,
-                (uint32_t)ctrl->channels[c].current_d.after,
-                saved_data_buf));
+       do {
+               D(printf("ch=%d buf=%x after=%x saved_data_buf=%x\n",
+                        c,
+                        (uint32_t)ctrl->channels[c].current_d.buf,
+                        (uint32_t)ctrl->channels[c].current_d.after,
+                        saved_data_buf));
 
-       if (saved_data_buf == (uint32_t)ctrl->channels[c].current_d.after) {
-               /* Done. Step to next.  */
-               if (ctrl->channels[c].current_d.out_eop) {
-                       /* TODO: signal eop to the client.  */
-                       D(printf("signal eop\n"));
-               }
-               if (ctrl->channels[c].current_d.intr) {
-                       /* TODO: signal eop to the client.  */
-                       /* data intr.  */
-                       D(printf("signal intr\n"));
-                       ctrl->channels[c].regs[R_INTR] |= (1 << 2);
-                       channel_update_irq(ctrl, c);
-               }
-               if (ctrl->channels[c].current_d.eol) {
-                       D(printf("channel %d EOL\n", c));
-                       ctrl->channels[c].eol = 1;
-                       channel_stop(ctrl, c);
-               } else {
-                       ctrl->channels[c].regs[RW_SAVED_DATA] =
-                               (uint32_t) ctrl->channels[c].current_d.next;
-                       /* Load new descriptor.  */
-                       channel_load_d(ctrl, c);
+               channel_load_d(ctrl, c);
+               saved_data_buf = channel_reg(ctrl, c, RW_SAVED_DATA_BUF);
+               len = (uint32_t)(unsigned long)
+                       ctrl->channels[c].current_d.after;
+               len -= saved_data_buf;
+
+               if (len > sizeof buf)
+                       len = sizeof buf;
+               cpu_physical_memory_read (saved_data_buf, buf, len);
+
+               D(printf("channel %d pushes %x %u bytes\n", c, 
+                        saved_data_buf, len));
+
+               if (ctrl->channels[c].client->client.push)
+                       ctrl->channels[c].client->client.push(
+                               ctrl->channels[c].client->client.opaque,
+                               buf, len);
+               else
+                       printf("WARNING: DMA ch%d dataloss,"
+                              " no attached client.\n", c);
+
+               saved_data_buf += len;
+
+               if (saved_data_buf == (uint32_t)(unsigned long)
+                               ctrl->channels[c].current_d.after) {
+                       /* Done. Step to next.  */
+                       if (ctrl->channels[c].current_d.out_eop) {
+                               /* TODO: signal eop to the client.  */
+                               D(printf("signal eop\n"));
+                       }
+                       if (ctrl->channels[c].current_d.intr) {
+                               /* TODO: signal eop to the client.  */
+                               /* data intr.  */
+                               D(printf("signal intr %d eol=%d\n",
+                                       len, ctrl->channels[c].current_d.eol));
+                               ctrl->channels[c].regs[R_INTR] |= (1 << 2);
+                               channel_update_irq(ctrl, c);
+                       }
+                       channel_store_d(ctrl, c);
+                       if (ctrl->channels[c].current_d.eol) {
+                               D(printf("channel %d EOL\n", c));
+                               ctrl->channels[c].eol = 1;
+
+                               /* Mark the context as disabled.  */
+                               ctrl->channels[c].current_c.dis = 1;
+                               channel_store_c(ctrl, c);
+
+                               channel_stop(ctrl, c);
+                       } else {
+                               ctrl->channels[c].regs[RW_SAVED_DATA] =
+                                       (uint32_t)(unsigned long)ctrl->
+                                               channels[c].current_d.next;
+                               /* Load new descriptor.  */
+                               channel_load_d(ctrl, c);
+                               saved_data_buf = (uint32_t)(unsigned long)
+                                       ctrl->channels[c].current_d.buf;
+                       }
+
+                       ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
+                                                       saved_data_buf;
+                       D(dump_d(c, &ctrl->channels[c].current_d));
                }
-
-               channel_store_d(ctrl, c);
-               D(dump_d(c, &ctrl->channels[c].current_d));
-               return;
-       }
-
-       len = (uint32_t) ctrl->channels[c].current_d.after;
-       len -= saved_data_buf;
-
-       if (len > sizeof buf)
-               len = sizeof buf;
-       cpu_physical_memory_read (saved_data_buf, buf, len);
-
-       D(printf("channel %d pushes %x %u bytes\n", c, 
-                saved_data_buf, len));
-       /* TODO: Push content.  */
-       if (ctrl->channels[c].client->client.push)
-               ctrl->channels[c].client->client.push(
-                       ctrl->channels[c].client->client.opaque, buf, len);
-       else
-               printf("WARNING: DMA ch%d dataloss, no attached client.\n", c);
-
-       ctrl->channels[c].regs[RW_SAVED_DATA_BUF] += len;
+               ctrl->channels[c].regs[RW_SAVED_DATA_BUF] = saved_data_buf;
+       } while (!ctrl->channels[c].eol);
+       return 1;
 }
 
 static int channel_in_process(struct fs_dma_ctrl *ctrl, int c, 
@@ -444,8 +488,9 @@ static int channel_in_process(struct fs_dma_ctrl *ctrl, int c,
        if (ctrl->channels[c].eol == 1)
                return 0;
 
+       channel_load_d(ctrl, c);
        saved_data_buf = channel_reg(ctrl, c, RW_SAVED_DATA_BUF);
-       len = (uint32_t) ctrl->channels[c].current_d.after;
+       len = (uint32_t)(unsigned long)ctrl->channels[c].current_d.after;
        len -= saved_data_buf;
        
        if (len > buflen)
@@ -454,7 +499,8 @@ static int channel_in_process(struct fs_dma_ctrl *ctrl, int c,
        cpu_physical_memory_write (saved_data_buf, buf, len);
        saved_data_buf += len;
 
-       if (saved_data_buf == (uint32_t)ctrl->channels[c].current_d.after
+       if (saved_data_buf ==
+           (uint32_t)(unsigned long)ctrl->channels[c].current_d.after
            || eop) {
                uint32_t r_intr = ctrl->channels[c].regs[R_INTR];
 
@@ -462,7 +508,7 @@ static int channel_in_process(struct fs_dma_ctrl *ctrl, int c,
                         ctrl->channels[c].current_d.after
                         - ctrl->channels[c].current_d.buf));
                ctrl->channels[c].current_d.after = 
-                       (void *) saved_data_buf;
+                       (void *)(unsigned long) saved_data_buf;
 
                /* Done. Step to next.  */
                if (ctrl->channels[c].current_d.intr) {
@@ -483,14 +529,20 @@ static int channel_in_process(struct fs_dma_ctrl *ctrl, int c,
                if (ctrl->channels[c].current_d.eol) {
                        D(printf("channel %d EOL\n", c));
                        ctrl->channels[c].eol = 1;
+
+                       /* Mark the context as disabled.  */
+                       ctrl->channels[c].current_c.dis = 1;
+                       channel_store_c(ctrl, c);
+
                        channel_stop(ctrl, c);
                } else {
                        ctrl->channels[c].regs[RW_SAVED_DATA] =
-                               (uint32_t) ctrl->channels[c].current_d.next;
+                               (uint32_t)(unsigned long)ctrl->
+                                       channels[c].current_d.next;
                        /* Load new descriptor.  */
                        channel_load_d(ctrl, c);
-                       saved_data_buf =
-                               ctrl->channels[c].regs[RW_SAVED_DATA_BUF];
+                       saved_data_buf = (uint32_t)(unsigned long)
+                               ctrl->channels[c].current_d.buf;
                }
        }
 
@@ -498,19 +550,19 @@ static int channel_in_process(struct fs_dma_ctrl *ctrl, int c,
        return len;
 }
 
-static inline void channel_in_run(struct fs_dma_ctrl *ctrl, int c)
+static inline int channel_in_run(struct fs_dma_ctrl *ctrl, int c)
 {
-       if (ctrl->channels[c].client->client.pull)
+       if (ctrl->channels[c].client->client.pull) {
                ctrl->channels[c].client->client.pull(
                        ctrl->channels[c].client->client.opaque);
+               return 1;
+       } else
+               return 0;
 }
 
 static uint32_t dma_rinvalid (void *opaque, target_phys_addr_t addr)
 {
-        struct fs_dma_ctrl *ctrl = opaque;
-        CPUState *env = ctrl->env;
-        cpu_abort(env, "Unsupported short access. reg=%x pc=%x.\n", 
-                  addr, env->pc);
+        hw_error("Unsupported short access. reg=" TARGET_FMT_plx "\n", addr);
         return 0;
 }
 
@@ -521,33 +573,42 @@ dma_readl (void *opaque, target_phys_addr_t addr)
        int c;
        uint32_t r = 0;
 
-       /* Make addr relative to this instances base.  */
-       c = fs_channel(ctrl->base, addr);
-        addr &= 0x1fff;
+       /* Make addr relative to this channel and bounded to nr regs.  */
+       c = fs_channel(addr);
+       addr &= 0xff;
+       addr >>= 2;
        switch (addr)
-        {
+       {
                case RW_STAT:
                        r = ctrl->channels[c].state & 7;
                        r |= ctrl->channels[c].eol << 5;
                        r |= ctrl->channels[c].stream_cmd_src << 8;
                        break;
 
-                default:
+               default:
                        r = ctrl->channels[c].regs[addr];
-                       D(printf ("%s c=%d addr=%x pc=%x\n",
-                                __func__, c, addr, env->pc));
-                        break;
-        }
+                       D(printf ("%s c=%d addr=%x\n",
+                                 __func__, c, addr));
+                       break;
+       }
        return r;
 }
 
 static void
 dma_winvalid (void *opaque, target_phys_addr_t addr, uint32_t value)
 {
-        struct fs_dma_ctrl *ctrl = opaque;
-        CPUState *env = ctrl->env;
-        cpu_abort(env, "Unsupported short access. reg=%x pc=%x.\n", 
-                  addr, env->pc);
+        hw_error("Unsupported short access. reg=" TARGET_FMT_plx "\n", addr);
+}
+
+static void
+dma_update_state(struct fs_dma_ctrl *ctrl, int c)
+{
+       if ((ctrl->channels[c].regs[RW_CFG] & 1) != 3) {
+               if (ctrl->channels[c].regs[RW_CFG] & 2)
+                       ctrl->channels[c].state = STOPPED;
+               if (!(ctrl->channels[c].regs[RW_CFG] & 1))
+                       ctrl->channels[c].state = RST;
+       }
 }
 
 static void
@@ -556,20 +617,25 @@ dma_writel (void *opaque, target_phys_addr_t addr, uint32_t value)
         struct fs_dma_ctrl *ctrl = opaque;
        int c;
 
-        /* Make addr relative to this instances base.  */
-       c = fs_channel(ctrl->base, addr);
-        addr &= 0x1fff;
+        /* Make addr relative to this channel and bounded to nr regs.  */
+       c = fs_channel(addr);
+        addr &= 0xff;
+        addr >>= 2;
         switch (addr)
-        {
+       {
                case RW_DATA:
                        ctrl->channels[c].regs[addr] = value;
                        break;
 
                case RW_CFG:
                        ctrl->channels[c].regs[addr] = value;
+                       dma_update_state(ctrl, c);
                        break;
                case RW_CMD:
                        /* continue.  */
+                       if (value & ~1)
+                               printf("Invalid store to ch=%d RW_CMD %x\n",
+                                      c, value);
                        ctrl->channels[c].regs[addr] = value;
                        channel_continue(ctrl, c);
                        break;
@@ -590,14 +656,18 @@ dma_writel (void *opaque, target_phys_addr_t addr, uint32_t value)
                        break;
 
                case RW_STREAM_CMD:
+                       if (value & ~1023)
+                               printf("Invalid store to ch=%d "
+                                      "RW_STREAMCMD %x\n",
+                                      c, value);
                        ctrl->channels[c].regs[addr] = value;
+                       D(printf("stream_cmd ch=%d\n", c));
                        channel_stream_cmd(ctrl, c, value);
                        break;
 
-                default:
-                        D(printf ("%s c=%d %x %x pc=%x\n",
-                                 __func__, c, addr, value, env->pc));
-                        break;
+               default:
+                       D(printf ("%s c=%d %x %x\n", __func__, c, addr));
+                       break;
         }
 }
 
@@ -613,7 +683,7 @@ static CPUWriteMemoryFunc *dma_write[] = {
        &dma_writel,
 };
 
-void etraxfs_dmac_run(void *opaque)
+static int etraxfs_dmac_run(void *opaque)
 {
        struct fs_dma_ctrl *ctrl = opaque;
        int i;
@@ -625,13 +695,14 @@ void etraxfs_dmac_run(void *opaque)
        {
                if (ctrl->channels[i].state == RUNNING)
                {
-                       p++;
-                       if (ctrl->channels[i].input)
-                               channel_in_run(ctrl, i);
-                       else
-                               channel_out_run(ctrl, i);
+                       if (ctrl->channels[i].input) {
+                               p += channel_in_run(ctrl, i);
+                       } else {
+                               p += channel_out_run(ctrl, i);
+                       }
                }
        }
+       return p;
 }
 
 int etraxfs_dmac_input(struct etraxfs_dma_client *client, 
@@ -645,7 +716,7 @@ int etraxfs_dmac_input(struct etraxfs_dma_client *client,
 void etraxfs_dmac_connect(void *opaque, int c, qemu_irq *line, int input)
 {
        struct fs_dma_ctrl *ctrl = opaque;
-       ctrl->channels[c].irq = line;
+       ctrl->channels[c].irq = *line;
        ctrl->channels[c].input = input;
 }
 
@@ -659,46 +730,32 @@ void etraxfs_dmac_connect_client(void *opaque, int c,
 }
 
 
-static void *etraxfs_dmac;
-void DMA_run(void)
+static void DMA_run(void *opaque)
 {
-       if (etraxfs_dmac)
-               etraxfs_dmac_run(etraxfs_dmac);
+    struct fs_dma_ctrl *etraxfs_dmac = opaque;
+    int p = 1;
+
+    if (vm_running)
+        p = etraxfs_dmac_run(etraxfs_dmac);
+
+    if (p)
+        qemu_bh_schedule_idle(etraxfs_dmac->bh);
 }
 
 void *etraxfs_dmac_init(CPUState *env, 
                        target_phys_addr_t base, int nr_channels)
 {
        struct fs_dma_ctrl *ctrl = NULL;
-       int i;
 
        ctrl = qemu_mallocz(sizeof *ctrl);
-       if (!ctrl)
-               return NULL;
 
-       ctrl->base = base;
+        ctrl->bh = qemu_bh_new(DMA_run, ctrl);
+
        ctrl->env = env;
        ctrl->nr_channels = nr_channels;
        ctrl->channels = qemu_mallocz(sizeof ctrl->channels[0] * nr_channels);
-       if (!ctrl->channels)
-               goto err;
-
-       for (i = 0; i < nr_channels; i++)
-       {
-               ctrl->channels[i].regmap = cpu_register_io_memory(0,
-                                                                 dma_read, 
-                                                                 dma_write, 
-                                                                 ctrl);
-               cpu_register_physical_memory (base + i * 0x2000,
-                                             sizeof ctrl->channels[i].regs, 
-                                             ctrl->channels[i].regmap);
-       }
 
-       /* Hax, we only support one DMA controller at a time.  */
-       etraxfs_dmac = ctrl;
+       ctrl->map = cpu_register_io_memory(0, dma_read, dma_write, ctrl);
+       cpu_register_physical_memory(base, nr_channels * 0x2000, ctrl->map);
        return ctrl;
-  err:
-       qemu_free(ctrl->channels);
-       qemu_free(ctrl);
-       return NULL;
 }