ide: Split out BMDMA code from ATA core

The ATA core is currently heavily intertwined with BMDMA code. Let's loosen
that a bit, so we can happily replace the DMA backend with different
implementations.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 277 insertions, 3 deletions

diff --git a/hw/ide/pci.c b/hw/ide/pci.c
index ad406ee..510b2de 100644
--- a/hw/ide/pci.c
+++ b/hw/ide/pci.c
@@ -33,6 +33,253 @@
 
 #include <hw/ide/pci.h>
 
+#define BMDMA_PAGE_SIZE 4096
+
+static void bmdma_start_dma(IDEDMA *dma, IDEState *s,
+                            BlockDriverCompletionFunc *dma_cb)
+{
+    BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);
+
+    bm->unit = s->unit;
+    bm->dma_cb = dma_cb;
+    bm->cur_prd_last = 0;
+    bm->cur_prd_addr = 0;
+    bm->cur_prd_len = 0;
+    bm->sector_num = ide_get_sector(s);
+    bm->nsector = s->nsector;
+
+    if (bm->status & BM_STATUS_DMAING) {
+        bm->dma_cb(bmdma_active_if(bm), 0);
+    }
+}
+
+/* return 0 if buffer completed */
+static int bmdma_prepare_buf(IDEDMA *dma, int is_write)
+{
+    BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);
+    IDEState *s = bmdma_active_if(bm);
+    struct {
+        uint32_t addr;
+        uint32_t size;
+    } prd;
+    int l, len;
+
+    qemu_sglist_init(&s->sg, s->nsector / (BMDMA_PAGE_SIZE / 512) + 1);
+    s->io_buffer_size = 0;
+    for(;;) {
+        if (bm->cur_prd_len == 0) {
+            /* end of table (with a fail safe of one page) */
+            if (bm->cur_prd_last ||
+                (bm->cur_addr - bm->addr) >= BMDMA_PAGE_SIZE)
+                return s->io_buffer_size != 0;
+            cpu_physical_memory_read(bm->cur_addr, (uint8_t *)&prd, 8);
+            bm->cur_addr += 8;
+            prd.addr = le32_to_cpu(prd.addr);
+            prd.size = le32_to_cpu(prd.size);
+            len = prd.size & 0xfffe;
+            if (len == 0)
+                len = 0x10000;
+            bm->cur_prd_len = len;
+            bm->cur_prd_addr = prd.addr;
+            bm->cur_prd_last = (prd.size & 0x80000000);
+        }
+        l = bm->cur_prd_len;
+        if (l > 0) {
+            qemu_sglist_add(&s->sg, bm->cur_prd_addr, l);
+            bm->cur_prd_addr += l;
+            bm->cur_prd_len -= l;
+            s->io_buffer_size += l;
+        }
+    }
+    return 1;
+}
+
+/* return 0 if buffer completed */
+static int bmdma_rw_buf(IDEDMA *dma, int is_write)
+{
+    BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);
+    IDEState *s = bmdma_active_if(bm);
+    struct {
+        uint32_t addr;
+        uint32_t size;
+    } prd;
+    int l, len;
+
+    for(;;) {
+        l = s->io_buffer_size - s->io_buffer_index;
+        if (l <= 0)
+            break;
+        if (bm->cur_prd_len == 0) {
+            /* end of table (with a fail safe of one page) */
+            if (bm->cur_prd_last ||
+                (bm->cur_addr - bm->addr) >= BMDMA_PAGE_SIZE)
+                return 0;
+            cpu_physical_memory_read(bm->cur_addr, (uint8_t *)&prd, 8);
+            bm->cur_addr += 8;
+            prd.addr = le32_to_cpu(prd.addr);
+            prd.size = le32_to_cpu(prd.size);
+            len = prd.size & 0xfffe;
+            if (len == 0)
+                len = 0x10000;
+            bm->cur_prd_len = len;
+            bm->cur_prd_addr = prd.addr;
+            bm->cur_prd_last = (prd.size & 0x80000000);
+        }
+        if (l > bm->cur_prd_len)
+            l = bm->cur_prd_len;
+        if (l > 0) {
+            if (is_write) {
+                cpu_physical_memory_write(bm->cur_prd_addr,
+                                          s->io_buffer + s->io_buffer_index, l);
+            } else {
+                cpu_physical_memory_read(bm->cur_prd_addr,
+                                          s->io_buffer + s->io_buffer_index, l);
+            }
+            bm->cur_prd_addr += l;
+            bm->cur_prd_len -= l;
+            s->io_buffer_index += l;
+        }
+    }
+    return 1;
+}
+
+static int bmdma_set_unit(IDEDMA *dma, int unit)
+{
+    BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);
+    bm->unit = unit;
+
+    return 0;
+}
+
+static int bmdma_add_status(IDEDMA *dma, int status)
+{
+    BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);
+    bm->status |= status;
+
+    return 0;
+}
+
+static int bmdma_set_inactive(IDEDMA *dma)
+{
+    BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);
+
+    bm->status &= ~BM_STATUS_DMAING;
+    bm->dma_cb = NULL;
+    bm->unit = -1;
+
+    return 0;
+}
+
+static void bmdma_restart_dma(BMDMAState *bm, int is_read)
+{
+    IDEState *s = bmdma_active_if(bm);
+
+    ide_set_sector(s, bm->sector_num);
+    s->io_buffer_index = 0;
+    s->io_buffer_size = 0;
+    s->nsector = bm->nsector;
+    bm->cur_addr = bm->addr;
+
+    if (is_read) {
+        bm->dma_cb = ide_read_dma_cb;
+    } else {
+        bm->dma_cb = ide_write_dma_cb;
+    }
+
+    bmdma_start_dma(&bm->dma, s, bm->dma_cb);
+}
+
+static void bmdma_restart_bh(void *opaque)
+{
+    BMDMAState *bm = opaque;
+    int is_read;
+
+    qemu_bh_delete(bm->bh);
+    bm->bh = NULL;
+
+    is_read = !!(bm->status & BM_STATUS_RETRY_READ);
+
+    if (bm->status & BM_STATUS_DMA_RETRY) {
+        bm->status &= ~(BM_STATUS_DMA_RETRY | BM_STATUS_RETRY_READ);
+        bmdma_restart_dma(bm, is_read);
+    } else if (bm->status & BM_STATUS_PIO_RETRY) {
+        bm->status &= ~(BM_STATUS_PIO_RETRY | BM_STATUS_RETRY_READ);
+        if (is_read) {
+            ide_sector_read(bmdma_active_if(bm));
+        } else {
+            ide_sector_write(bmdma_active_if(bm));
+        }
+    } else if (bm->status & BM_STATUS_RETRY_FLUSH) {
+        ide_flush_cache(bmdma_active_if(bm));
+    }
+}
+
+static void bmdma_restart_cb(void *opaque, int running, int reason)
+{
+    IDEDMA *dma = opaque;
+    BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);
+
+    if (!running)
+        return;
+
+    if (!bm->bh) {
+        bm->bh = qemu_bh_new(bmdma_restart_bh, &bm->dma);
+        qemu_bh_schedule(bm->bh);
+    }
+}
+
+static void bmdma_cancel(BMDMAState *bm)
+{
+    if (bm->status & BM_STATUS_DMAING) {
+        /* cancel DMA request */
+        bmdma_set_inactive(&bm->dma);
+    }
+}
+
+static int bmdma_reset(IDEDMA *dma)
+{
+    BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);
+
+#ifdef DEBUG_IDE
+    printf("ide: dma_reset\n");
+#endif
+    bmdma_cancel(bm);
+    bm->cmd = 0;
+    bm->status = 0;
+    bm->addr = 0;
+    bm->cur_addr = 0;
+    bm->cur_prd_last = 0;
+    bm->cur_prd_addr = 0;
+    bm->cur_prd_len = 0;
+    bm->sector_num = 0;
+    bm->nsector = 0;
+
+    return 0;
+}
+
+static int bmdma_start_transfer(IDEDMA *dma)
+{
+    return 0;
+}
+
+static void bmdma_irq(void *opaque, int n, int level)
+{
+    BMDMAState *bm = opaque;
+
+    if (!level) {
+        /* pass through lower */
+        qemu_set_irq(bm->irq, level);
+        return;
+    }
+
+    if (bm) {
+        bm->status |= BM_STATUS_INT;
+    }
+
+    /* trigger the real irq */
+    qemu_set_irq(bm->irq, level);
+}
+
 void bmdma_cmd_writeb(void *opaque, uint32_t addr, uint32_t val)
 {
     BMDMAState *bm = opaque;
@@ -55,10 +302,10 @@ void bmdma_cmd_writeb(void *opaque, uint32_t addr, uint32_t val)
              * whole DMA operation will be submitted to disk with a single
              * aio operation with preadv/pwritev.
              */
-            if (bm->aiocb) {
+            if (bm->bus->dma->aiocb) {
                 qemu_aio_flush();
 #ifdef DEBUG_IDE
-                if (bm->aiocb)
+                if (bm->bus->dma->aiocb)
                     printf("ide_dma_cancel: aiocb still pending");
                 if (bm->status & BM_STATUS_DMAING)
                     printf("ide_dma_cancel: BM_STATUS_DMAING still pending");
@@ -70,7 +317,7 @@ void bmdma_cmd_writeb(void *opaque, uint32_t addr, uint32_t val)
                 bm->status |= BM_STATUS_DMAING;
                 /* start dma transfer if possible */
                 if (bm->dma_cb)
-                    bm->dma_cb(bm, 0);
+                    bm->dma_cb(bmdma_active_if(bm), 0);
             }
         }
     }
@@ -198,3 +445,30 @@ void pci_ide_create_devs(PCIDevice *dev, DriveInfo **hd_table)
         ide_create_drive(d->bus+bus[i], unit[i], hd_table[i]);
     }
 }
+
+static const struct IDEDMAOps bmdma_ops = {
+    .start_dma = bmdma_start_dma,
+    .start_transfer = bmdma_start_transfer,
+    .prepare_buf = bmdma_prepare_buf,
+    .rw_buf = bmdma_rw_buf,
+    .set_unit = bmdma_set_unit,
+    .add_status = bmdma_add_status,
+    .set_inactive = bmdma_set_inactive,
+    .restart_cb = bmdma_restart_cb,
+    .reset = bmdma_reset,
+};
+
+void bmdma_init(IDEBus *bus, BMDMAState *bm)
+{
+    qemu_irq *irq;
+
+    if (bus->dma == &bm->dma) {
+        return;
+    }
+
+    bm->dma.ops = &bmdma_ops;
+    bus->dma = &bm->dma;
+    bm->irq = bus->irq;
+    irq = qemu_allocate_irqs(bmdma_irq, bm, 1);
+    bus->irq = *irq;
+}