From 73d7434279e390505164afd02360eebe4b43c7fa Mon Sep 17 00:00:00 2001
From: Blue Swirl <blauwirbel@gmail.com>
Date: Sat, 11 Sep 2010 16:38:33 +0000
Subject: ESP: fix ESP DMA access when DMA is not enabled

Sending ESP a command caused it to trigger DMA immediately
even if DMA was not enabled at the DMA controller.

Add a signal from DMA controller to ESP to tell ESP about changes in
DMA enable bit. Also use the correct function for setting up GPIO outputs.

This fixes NetBSD 1.6.1 through 3.0 boot.

Thanks to Artyom Tarasenko for extensive debugging of the problem.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
---
 hw/esp.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 51 insertions(+), 2 deletions(-)

(limited to 'hw/esp.c')

diff --git a/hw/esp.c b/hw/esp.c
index 349052a024..910fd31665 100644
--- a/hw/esp.c
+++ b/hw/esp.c
@@ -80,6 +80,8 @@ struct ESPState {
     ESPDMAMemoryReadWriteFunc dma_memory_read;
     ESPDMAMemoryReadWriteFunc dma_memory_write;
     void *dma_opaque;
+    int dma_enabled;
+    void (*dma_cb)(ESPState *s);
 };
 
 #define ESP_TCLO   0x0
@@ -167,6 +169,24 @@ static void esp_lower_irq(ESPState *s)
     }
 }
 
+static void esp_dma_enable(void *opaque, int irq, int level)
+{
+    DeviceState *d = opaque;
+    ESPState *s = container_of(d, ESPState, busdev.qdev);
+
+    if (level) {
+        s->dma_enabled = 1;
+        DPRINTF("Raise enable\n");
+        if (s->dma_cb) {
+            s->dma_cb(s);
+            s->dma_cb = NULL;
+        }
+    } else {
+        DPRINTF("Lower enable\n");
+        s->dma_enabled = 0;
+    }
+}
+
 static uint32_t get_cmd(ESPState *s, uint8_t *buf)
 {
     uint32_t dmalen;
@@ -243,6 +263,10 @@ static void handle_satn(ESPState *s)
     uint8_t buf[32];
     int len;
 
+    if (!s->dma_enabled) {
+        s->dma_cb = handle_satn;
+        return;
+    }
     len = get_cmd(s, buf);
     if (len)
         do_cmd(s, buf);
@@ -253,6 +277,10 @@ static void handle_s_without_atn(ESPState *s)
     uint8_t buf[32];
     int len;
 
+    if (!s->dma_enabled) {
+        s->dma_cb = handle_s_without_atn;
+        return;
+    }
     len = get_cmd(s, buf);
     if (len) {
         do_busid_cmd(s, buf, 0);
@@ -261,6 +289,10 @@ static void handle_s_without_atn(ESPState *s)
 
 static void handle_satn_stop(ESPState *s)
 {
+    if (!s->dma_enabled) {
+        s->dma_cb = handle_satn_stop;
+        return;
+    }
     s->cmdlen = get_cmd(s, s->cmdbuf);
     if (s->cmdlen) {
         DPRINTF("Set ATN & Stop: cmdlen %d\n", s->cmdlen);
@@ -431,6 +463,7 @@ static void esp_hard_reset(DeviceState *d)
     s->ti_wptr = 0;
     s->dma = 0;
     s->do_cmd = 0;
+    s->dma_cb = NULL;
 
     s->rregs[ESP_CFG1] = 7;
 }
@@ -450,6 +483,18 @@ static void parent_esp_reset(void *opaque, int irq, int level)
     }
 }
 
+static void esp_gpio_demux(void *opaque, int irq, int level)
+{
+    switch (irq) {
+    case 0:
+        parent_esp_reset(opaque, irq, level);
+        break;
+    case 1:
+        esp_dma_enable(opaque, irq, level);
+        break;
+    }
+}
+
 static uint32_t esp_mem_readb(void *opaque, target_phys_addr_t addr)
 {
     ESPState *s = opaque;
@@ -646,7 +691,8 @@ static const VMStateDescription vmstate_esp = {
 void esp_init(target_phys_addr_t espaddr, int it_shift,
               ESPDMAMemoryReadWriteFunc dma_memory_read,
               ESPDMAMemoryReadWriteFunc dma_memory_write,
-              void *dma_opaque, qemu_irq irq, qemu_irq *reset)
+              void *dma_opaque, qemu_irq irq, qemu_irq *reset,
+              qemu_irq *dma_enable)
 {
     DeviceState *dev;
     SysBusDevice *s;
@@ -658,11 +704,14 @@ void esp_init(target_phys_addr_t espaddr, int it_shift,
     esp->dma_memory_write = dma_memory_write;
     esp->dma_opaque = dma_opaque;
     esp->it_shift = it_shift;
+    /* XXX for now until rc4030 has been changed to use DMA enable signal */
+    esp->dma_enabled = 1;
     qdev_init_nofail(dev);
     s = sysbus_from_qdev(dev);
     sysbus_connect_irq(s, 0, irq);
     sysbus_mmio_map(s, 0, espaddr);
     *reset = qdev_get_gpio_in(dev, 0);
+    *dma_enable = qdev_get_gpio_in(dev, 1);
 }
 
 static int esp_init1(SysBusDevice *dev)
@@ -676,7 +725,7 @@ static int esp_init1(SysBusDevice *dev)
     esp_io_memory = cpu_register_io_memory(esp_mem_read, esp_mem_write, s);
     sysbus_init_mmio(dev, ESP_REGS << s->it_shift, esp_io_memory);
 
-    qdev_init_gpio_in(&dev->qdev, parent_esp_reset, 1);
+    qdev_init_gpio_in(&dev->qdev, esp_gpio_demux, 2);
 
     scsi_bus_new(&s->bus, &dev->qdev, 0, ESP_MAX_DEVS, esp_command_complete);
     return scsi_bus_legacy_handle_cmdline(&s->bus);
-- 
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