Implement TCE translation for sPAPR VIO

This patch implements the necessary infrastructure and hypercalls for
sPAPR's TCE (Translation Control Entry) IOMMU mechanism.  This is necessary
for all virtual IO devices which do DMA (i.e. nearly all of them).

Signed-off-by: Ben Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 238 insertions, 0 deletions

diff --git a/hw/spapr_vio.c b/hw/spapr_vio.c
index 605079c..39d77ee 100644
--- a/hw/spapr_vio.c
+++ b/hw/spapr_vio.c
@@ -37,6 +37,7 @@
 #endif /* CONFIG_FDT */
 
 /* #define DEBUG_SPAPR */
+/* #define DEBUG_TCE */
 
 #ifdef DEBUG_SPAPR
 #define dprintf(fmt, ...) \
@@ -115,6 +116,28 @@ static int vio_make_devnode(VIOsPAPRDevice *dev,
         }
     }
 
+    if (dev->rtce_window_size) {
+        uint32_t dma_prop[] = {cpu_to_be32(dev->reg),
+                               0, 0,
+                               0, cpu_to_be32(dev->rtce_window_size)};
+
+        ret = fdt_setprop_cell(fdt, node_off, "ibm,#dma-address-cells", 2);
+        if (ret < 0) {
+            return ret;
+        }
+
+        ret = fdt_setprop_cell(fdt, node_off, "ibm,#dma-size-cells", 2);
+        if (ret < 0) {
+            return ret;
+        }
+
+        ret = fdt_setprop(fdt, node_off, "ibm,my-dma-window", dma_prop,
+                          sizeof(dma_prop));
+        if (ret < 0) {
+            return ret;
+        }
+    }
+
     if (info->devnode) {
         ret = (info->devnode)(dev, fdt, node_off);
         if (ret < 0) {
@@ -126,6 +149,216 @@ static int vio_make_devnode(VIOsPAPRDevice *dev,
 }
 #endif /* CONFIG_FDT */
 
+/*
+ * RTCE handling
+ */
+
+static void rtce_init(VIOsPAPRDevice *dev)
+{
+    size_t size = (dev->rtce_window_size >> SPAPR_VIO_TCE_PAGE_SHIFT)
+        * sizeof(VIOsPAPR_RTCE);
+
+    if (size) {
+        dev->rtce_table = qemu_mallocz(size);
+    }
+}
+
+static target_ulong h_put_tce(CPUState *env, sPAPREnvironment *spapr,
+                              target_ulong opcode, target_ulong *args)
+{
+    target_ulong liobn = args[0];
+    target_ulong ioba = args[1];
+    target_ulong tce = args[2];
+    VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, liobn);
+    VIOsPAPR_RTCE *rtce;
+
+    if (!dev) {
+        hcall_dprintf("spapr_vio_put_tce on non-existent LIOBN "
+                      TARGET_FMT_lx "\n", liobn);
+        return H_PARAMETER;
+    }
+
+    ioba &= ~(SPAPR_VIO_TCE_PAGE_SIZE - 1);
+
+#ifdef DEBUG_TCE
+    fprintf(stderr, "spapr_vio_put_tce on %s  ioba 0x" TARGET_FMT_lx
+            "  TCE 0x" TARGET_FMT_lx "\n", dev->qdev.id, ioba, tce);
+#endif
+
+    if (ioba >= dev->rtce_window_size) {
+        hcall_dprintf("spapr_vio_put_tce on out-of-boards IOBA 0x"
+                      TARGET_FMT_lx "\n", ioba);
+        return H_PARAMETER;
+    }
+
+    rtce = dev->rtce_table + (ioba >> SPAPR_VIO_TCE_PAGE_SHIFT);
+    rtce->tce = tce;
+
+    return H_SUCCESS;
+}
+
+int spapr_vio_check_tces(VIOsPAPRDevice *dev, target_ulong ioba,
+                         target_ulong len, enum VIOsPAPR_TCEAccess access)
+{
+    int start, end, i;
+
+    start = ioba >> SPAPR_VIO_TCE_PAGE_SHIFT;
+    end = (ioba + len - 1) >> SPAPR_VIO_TCE_PAGE_SHIFT;
+
+    for (i = start; i <= end; i++) {
+        if ((dev->rtce_table[i].tce & access) != access) {
+#ifdef DEBUG_TCE
+            fprintf(stderr, "FAIL on %d\n", i);
+#endif
+            return -1;
+        }
+    }
+
+    return 0;
+}
+
+int spapr_tce_dma_write(VIOsPAPRDevice *dev, uint64_t taddr, const void *buf,
+                        uint32_t size)
+{
+#ifdef DEBUG_TCE
+    fprintf(stderr, "spapr_tce_dma_write taddr=0x%llx size=0x%x\n",
+            (unsigned long long)taddr, size);
+#endif
+
+    while (size) {
+        uint64_t tce;
+        uint32_t lsize;
+        uint64_t txaddr;
+
+        /* Check if we are in bound */
+        if (taddr >= dev->rtce_window_size) {
+#ifdef DEBUG_TCE
+            fprintf(stderr, "spapr_tce_dma_write out of bounds\n");
+#endif
+            return H_DEST_PARM;
+        }
+        tce = dev->rtce_table[taddr >> SPAPR_VIO_TCE_PAGE_SHIFT].tce;
+
+        /* How much til end of page ? */
+        lsize = MIN(size, ((~taddr) & SPAPR_VIO_TCE_PAGE_MASK) + 1);
+
+        /* Check TCE */
+        if (!(tce & 2)) {
+            return H_DEST_PARM;
+        }
+
+        /* Translate */
+        txaddr = (tce & ~SPAPR_VIO_TCE_PAGE_MASK) |
+            (taddr & SPAPR_VIO_TCE_PAGE_MASK);
+
+#ifdef DEBUG_TCE
+        fprintf(stderr, " -> write to txaddr=0x%llx, size=0x%x\n",
+                (unsigned long long)txaddr, lsize);
+#endif
+
+        /* Do it */
+        cpu_physical_memory_write(txaddr, buf, lsize);
+        buf += lsize;
+        taddr += lsize;
+        size -= lsize;
+    }
+    return 0;
+}
+
+int spapr_tce_dma_zero(VIOsPAPRDevice *dev, uint64_t taddr, uint32_t size)
+{
+    /* FIXME: allocating a temp buffer is nasty, but just stepping
+     * through writing zeroes is awkward.  This will do for now. */
+    uint8_t zeroes[size];
+
+#ifdef DEBUG_TCE
+    fprintf(stderr, "spapr_tce_dma_zero taddr=0x%llx size=0x%x\n",
+            (unsigned long long)taddr, size);
+#endif
+
+    memset(zeroes, 0, size);
+    return spapr_tce_dma_write(dev, taddr, zeroes, size);
+}
+
+void stb_tce(VIOsPAPRDevice *dev, uint64_t taddr, uint8_t val)
+{
+    spapr_tce_dma_write(dev, taddr, &val, sizeof(val));
+}
+
+void sth_tce(VIOsPAPRDevice *dev, uint64_t taddr, uint16_t val)
+{
+    val = tswap16(val);
+    spapr_tce_dma_write(dev, taddr, &val, sizeof(val));
+}
+
+
+void stw_tce(VIOsPAPRDevice *dev, uint64_t taddr, uint32_t val)
+{
+    val = tswap32(val);
+    spapr_tce_dma_write(dev, taddr, &val, sizeof(val));
+}
+
+void stq_tce(VIOsPAPRDevice *dev, uint64_t taddr, uint64_t val)
+{
+    val = tswap64(val);
+    spapr_tce_dma_write(dev, taddr, &val, sizeof(val));
+}
+
+int spapr_tce_dma_read(VIOsPAPRDevice *dev, uint64_t taddr, void *buf,
+                       uint32_t size)
+{
+#ifdef DEBUG_TCE
+    fprintf(stderr, "spapr_tce_dma_write taddr=0x%llx size=0x%x\n",
+            (unsigned long long)taddr, size);
+#endif
+
+    while (size) {
+        uint64_t tce;
+        uint32_t lsize;
+        uint64_t txaddr;
+
+        /* Check if we are in bound */
+        if (taddr >= dev->rtce_window_size) {
+#ifdef DEBUG_TCE
+            fprintf(stderr, "spapr_tce_dma_read out of bounds\n");
+#endif
+            return H_DEST_PARM;
+        }
+        tce = dev->rtce_table[taddr >> SPAPR_VIO_TCE_PAGE_SHIFT].tce;
+
+        /* How much til end of page ? */
+        lsize = MIN(size, ((~taddr) & SPAPR_VIO_TCE_PAGE_MASK) + 1);
+
+        /* Check TCE */
+        if (!(tce & 1)) {
+            return H_DEST_PARM;
+        }
+
+        /* Translate */
+        txaddr = (tce & ~SPAPR_VIO_TCE_PAGE_MASK) |
+            (taddr & SPAPR_VIO_TCE_PAGE_MASK);
+
+#ifdef DEBUG_TCE
+        fprintf(stderr, " -> write to txaddr=0x%llx, size=0x%x\n",
+                (unsigned long long)txaddr, lsize);
+#endif
+        /* Do it */
+        cpu_physical_memory_read(txaddr, buf, lsize);
+        buf += lsize;
+        taddr += lsize;
+        size -= lsize;
+    }
+    return H_SUCCESS;
+}
+
+uint64_t ldq_tce(VIOsPAPRDevice *dev, uint64_t taddr)
+{
+    uint64_t val;
+
+    spapr_tce_dma_read(dev, taddr, &val, sizeof(val));
+    return tswap64(val);
+}
+
 static int spapr_vio_busdev_init(DeviceState *qdev, DeviceInfo *qinfo)
 {
     VIOsPAPRDeviceInfo *info = (VIOsPAPRDeviceInfo *)qinfo;
@@ -138,6 +371,8 @@ static int spapr_vio_busdev_init(DeviceState *qdev, DeviceInfo *qinfo)
 
     dev->qdev.id = id;
 
+    rtce_init(dev);
+
     return info->init(dev);
 }
 
@@ -193,6 +428,9 @@ VIOsPAPRBus *spapr_vio_bus_init(void)
     /* hcall-vio */
     spapr_register_hypercall(H_VIO_SIGNAL, h_vio_signal);
 
+    /* hcall-tce */
+    spapr_register_hypercall(H_PUT_TCE, h_put_tce);
+
     for (qinfo = device_info_list; qinfo; qinfo = qinfo->next) {
         VIOsPAPRDeviceInfo *info = (VIOsPAPRDeviceInfo *)qinfo;