[Qemu-devel] [PATCH 26/30] dma: eliminate old-style IOMMU support

[Paolo Bonzini <pbonzini@redhat.com>]

The translate function in the DMAContext is now always NULL.
Remove every reference to it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 dma-helpers.c        | 178 +++------------------------------------------------
 exec.c               |   3 +-
 hw/pci/pci.c         |   3 +-
 hw/ppc/spapr_iommu.c |   2 +-
 include/sysemu/dma.h |  79 ++++-------------------
 5 files changed, 26 insertions(+), 239 deletions(-)

diff --git a/dma-helpers.c b/dma-helpers.c
index 2962b69..c53705a 100644
--- a/dma-helpers.c
+++ b/dma-helpers.c
@@ -14,32 +14,26 @@
 
 /* #define DEBUG_IOMMU */
 
-static void do_dma_memory_set(AddressSpace *as,
-                              dma_addr_t addr, uint8_t c, dma_addr_t len)
+int dma_memory_set(DMAContext *dma, dma_addr_t addr, uint8_t c, dma_addr_t len)
 {
+    AddressSpace *as = dma->as;
+
+    dma_barrier(dma, DMA_DIRECTION_FROM_DEVICE);
+
 #define FILLBUF_SIZE 512
     uint8_t fillbuf[FILLBUF_SIZE];
     int l;
+    bool error = false;
 
     memset(fillbuf, c, FILLBUF_SIZE);
     while (len > 0) {
         l = len < FILLBUF_SIZE ? len : FILLBUF_SIZE;
-        address_space_rw(as, addr, fillbuf, l, true);
+        error |= address_space_rw(as, addr, fillbuf, l, true);
         len -= l;
         addr += l;
     }
-}
 
-int dma_memory_set(DMAContext *dma, dma_addr_t addr, uint8_t c, dma_addr_t len)
-{
-    dma_barrier(dma, DMA_DIRECTION_FROM_DEVICE);
-
-    if (dma_has_iommu(dma)) {
-        return iommu_dma_memory_set(dma, addr, c, len);
-    }
-    do_dma_memory_set(dma->as, addr, c, len);
-
-    return 0;
+    return error;
 }
 
 void qemu_sglist_init(QEMUSGList *qsg, int alloc_hint, DMAContext *dma)
@@ -278,162 +272,10 @@ void dma_acct_start(BlockDriverState *bs, BlockAcctCookie *cookie,
     bdrv_acct_start(bs, cookie, sg->size, type);
 }
 
-bool iommu_dma_memory_valid(DMAContext *dma, dma_addr_t addr, dma_addr_t len,
-                            DMADirection dir)
+void dma_context_init(DMAContext *dma, AddressSpace *as)
 {
-    hwaddr paddr, plen;
-
 #ifdef DEBUG_IOMMU
-    fprintf(stderr, "dma_memory_check context=%p addr=0x" DMA_ADDR_FMT
-            " len=0x" DMA_ADDR_FMT " dir=%d\n", dma, addr, len, dir);
-#endif
-
-    while (len) {
-        if (dma->translate(dma, addr, &paddr, &plen, dir) != 0) {
-            return false;
-        }
-
-        /* The translation might be valid for larger regions. */
-        if (plen > len) {
-            plen = len;
-        }
-
-        if (!address_space_valid(dma->as, paddr, len,
-                                 dir == DMA_DIRECTION_FROM_DEVICE)) {
-            return false;
-        }
-
-        len -= plen;
-        addr += plen;
-    }
-
-    return true;
-}
-
-int iommu_dma_memory_rw(DMAContext *dma, dma_addr_t addr,
-                        void *buf, dma_addr_t len, DMADirection dir)
-{
-    hwaddr paddr, plen;
-    int err;
-
-#ifdef DEBUG_IOMMU
-    fprintf(stderr, "dma_memory_rw context=%p addr=0x" DMA_ADDR_FMT " len=0x"
-            DMA_ADDR_FMT " dir=%d\n", dma, addr, len, dir);
-#endif
-
-    while (len) {
-        err = dma->translate(dma, addr, &paddr, &plen, dir);
-        if (err) {
-	    /*
-             * In case of failure on reads from the guest, we clean the
-             * destination buffer so that a device that doesn't test
-             * for errors will not expose qemu internal memory.
-	     */
-	    memset(buf, 0, len);
-            return -1;
-        }
-
-        /* The translation might be valid for larger regions. */
-        if (plen > len) {
-            plen = len;
-        }
-
-        address_space_rw(dma->as, paddr, buf, plen, dir == DMA_DIRECTION_FROM_DEVICE);
-
-        len -= plen;
-        addr += plen;
-        buf += plen;
-    }
-
-    return 0;
-}
-
-int iommu_dma_memory_set(DMAContext *dma, dma_addr_t addr, uint8_t c,
-                         dma_addr_t len)
-{
-    hwaddr paddr, plen;
-    int err;
-
-#ifdef DEBUG_IOMMU
-    fprintf(stderr, "dma_memory_set context=%p addr=0x" DMA_ADDR_FMT
-            " len=0x" DMA_ADDR_FMT "\n", dma, addr, len);
-#endif
-
-    while (len) {
-        err = dma->translate(dma, addr, &paddr, &plen,
-                             DMA_DIRECTION_FROM_DEVICE);
-        if (err) {
-            return err;
-        }
-
-        /* The translation might be valid for larger regions. */
-        if (plen > len) {
-            plen = len;
-        }
-
-        do_dma_memory_set(dma->as, paddr, c, plen);
-
-        len -= plen;
-        addr += plen;
-    }
-
-    return 0;
-}
-
-void dma_context_init(DMAContext *dma, AddressSpace *as, DMATranslateFunc translate,
-                      DMAMapFunc map, DMAUnmapFunc unmap)
-{
-#ifdef DEBUG_IOMMU
-    fprintf(stderr, "dma_context_init(%p, %p, %p, %p)\n",
-            dma, translate, map, unmap);
+    fprintf(stderr, "dma_context_init(%p -> %p)\n", dma, as);
 #endif
     dma->as = as;
-    dma->translate = translate;
-    dma->map = map;
-    dma->unmap = unmap;
-}
-
-void *iommu_dma_memory_map(DMAContext *dma, dma_addr_t addr, dma_addr_t *len,
-                           DMADirection dir)
-{
-    int err;
-    hwaddr paddr, plen;
-    void *buf;
-
-    if (dma->map) {
-        return dma->map(dma, addr, len, dir);
-    }
-
-    plen = *len;
-    err = dma->translate(dma, addr, &paddr, &plen, dir);
-    if (err) {
-        return NULL;
-    }
-
-    /*
-     * If this is true, the virtual region is contiguous,
-     * but the translated physical region isn't. We just
-     * clamp *len, much like address_space_map() does.
-     */
-    if (plen < *len) {
-        *len = plen;
-    }
-
-    buf = address_space_map(dma->as, paddr, &plen, dir == DMA_DIRECTION_FROM_DEVICE);
-    *len = plen;
-
-    return buf;
-}
-
-void iommu_dma_memory_unmap(DMAContext *dma, void *buffer, dma_addr_t len,
-                            DMADirection dir, dma_addr_t access_len)
-{
-    if (dma->unmap) {
-        dma->unmap(dma, buffer, len, dir, access_len);
-        return;
-    }
-
-    address_space_unmap(dma->as, buffer, len, dir == DMA_DIRECTION_FROM_DEVICE,
-                        access_len);
-
 }
diff --git a/exec.c b/exec.c
index b7266c8..4c43fdd 100644
--- a/exec.c
+++ b/exec.c
@@ -1859,8 +1859,7 @@ static void memory_map_init(void)
     memory_listener_register(&io_memory_listener, &address_space_io);
     memory_listener_register(&tcg_memory_listener, &address_space_memory);
 
-    dma_context_init(&dma_context_memory, &address_space_memory,
-                     NULL, NULL, NULL);
+    dma_context_init(&dma_context_memory, &address_space_memory);
 }
 
 MemoryRegion *get_system_memory(void)
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index bb3879b..c9d585c 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -814,8 +814,9 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, PCIBus *bus,
         memory_region_set_enabled(&pci_dev->bus_master_enable_region, false);
         address_space_init(&pci_dev->bus_master_as, &pci_dev->bus_master_enable_region);
         pci_dev->dma = g_new(DMAContext, 1);
-        dma_context_init(pci_dev->dma, &pci_dev->bus_master_as, NULL, NULL, NULL);
+        dma_context_init(pci_dev->dma, &pci_dev->bus_master_as);
     }
+
     pci_dev->devfn = devfn;
     pstrcpy(pci_dev->name, sizeof(pci_dev->name), name);
     pci_dev->irq_state = 0;
diff --git a/hw/ppc/spapr_iommu.c b/hw/ppc/spapr_iommu.c
index f7b1b18..8971d72 100644
--- a/hw/ppc/spapr_iommu.c
+++ b/hw/ppc/spapr_iommu.c
@@ -157,7 +157,7 @@ sPAPRTCETable *spapr_tce_new_table(uint32_t liobn, size_t window_size)
                              &address_space_memory,
                              "iommu-spapr", INT64_MAX);
     address_space_init(&tcet->as, &tcet->iommu);
-    dma_context_init(&tcet->dma, &tcet->as, NULL, NULL, NULL);
+    dma_context_init(&tcet->dma, &tcet->as);
 
     QLIST_INSERT_HEAD(&spapr_tce_tables, tcet, list);
 
diff --git a/include/sysemu/dma.h b/include/sysemu/dma.h
index 2e239dc..3ed621b 100644
--- a/include/sysemu/dma.h
+++ b/include/sysemu/dma.h
@@ -46,26 +46,8 @@ typedef uint64_t dma_addr_t;
 #define DMA_ADDR_BITS 64
 #define DMA_ADDR_FMT "%" PRIx64
 
-typedef int DMATranslateFunc(DMAContext *dma,
-                             dma_addr_t addr,
-                             hwaddr *paddr,
-                             hwaddr *len,
-                             DMADirection dir);
-typedef void* DMAMapFunc(DMAContext *dma,
-                         dma_addr_t addr,
-                         dma_addr_t *len,
-                         DMADirection dir);
-typedef void DMAUnmapFunc(DMAContext *dma,
-                          void *buffer,
-                          dma_addr_t len,
-                          DMADirection dir,
-                          dma_addr_t access_len);
-
 struct DMAContext {
     AddressSpace *as;
-    DMATranslateFunc *translate;
-    DMAMapFunc *map;
-    DMAUnmapFunc *unmap;
 };
 
 /* A global DMA context corresponding to the address_space_memory
@@ -98,41 +80,22 @@ static inline void dma_barrier(DMAContext *dma, DMADirection dir)
     }
 }
 
-static inline bool dma_has_iommu(DMAContext *dma)
-{
-    return dma && dma->translate;
-}
-
 /* Checks that the given range of addresses is valid for DMA.  This is
  * useful for certain cases, but usually you should just use
  * dma_memory_{read,write}() and check for errors */
-bool iommu_dma_memory_valid(DMAContext *dma, dma_addr_t addr, dma_addr_t len,
-                            DMADirection dir);
 static inline bool dma_memory_valid(DMAContext *dma,
                                     dma_addr_t addr, dma_addr_t len,
                                     DMADirection dir)
 {
-    if (!dma_has_iommu(dma)) {
-        return address_space_valid(dma->as, addr, len,
-                                   dir == DMA_DIRECTION_FROM_DEVICE);
-    } else {
-        return iommu_dma_memory_valid(dma, addr, len, dir);
-    }
+    return address_space_valid(dma->as, addr, len,
+                               dir == DMA_DIRECTION_FROM_DEVICE);
 }
 
-int iommu_dma_memory_rw(DMAContext *dma, dma_addr_t addr,
-                        void *buf, dma_addr_t len, DMADirection dir);
 static inline int dma_memory_rw_relaxed(DMAContext *dma, dma_addr_t addr,
                                         void *buf, dma_addr_t len,
                                         DMADirection dir)
 {
-    if (!dma_has_iommu(dma)) {
-        /* Fast-path for no IOMMU */
-        address_space_rw(dma->as, addr, buf, len, dir == DMA_DIRECTION_FROM_DEVICE);
-        return 0;
-    } else {
-        return iommu_dma_memory_rw(dma, addr, buf, len, dir);
-    }
+    return address_space_rw(dma->as, addr, buf, len, dir == DMA_DIRECTION_FROM_DEVICE);
 }
 
 static inline int dma_memory_read_relaxed(DMAContext *dma, dma_addr_t addr,
@@ -170,43 +133,26 @@ static inline int dma_memory_write(DMAContext *dma, dma_addr_t addr,
                          DMA_DIRECTION_FROM_DEVICE);
 }
 
-int iommu_dma_memory_set(DMAContext *dma, dma_addr_t addr, uint8_t c,
-			 dma_addr_t len);
-
 int dma_memory_set(DMAContext *dma, dma_addr_t addr, uint8_t c, dma_addr_t len);
 
-void *iommu_dma_memory_map(DMAContext *dma,
-                           dma_addr_t addr, dma_addr_t *len,
-                           DMADirection dir);
 static inline void *dma_memory_map(DMAContext *dma,
                                    dma_addr_t addr, dma_addr_t *len,
                                    DMADirection dir)
 {
-    if (!dma_has_iommu(dma)) {
-        hwaddr xlen = *len;
-        void *p;
-
-        p = address_space_map(dma->as, addr, &xlen, dir == DMA_DIRECTION_FROM_DEVICE);
-        *len = xlen;
-        return p;
-    } else {
-        return iommu_dma_memory_map(dma, addr, len, dir);
-    }
+    hwaddr xlen = *len;
+    void *p;
+
+    p = address_space_map(dma->as, addr, &xlen, dir == DMA_DIRECTION_FROM_DEVICE);
+    *len = xlen;
+    return p;
 }
 
-void iommu_dma_memory_unmap(DMAContext *dma,
-                            void *buffer, dma_addr_t len,
-                            DMADirection dir, dma_addr_t access_len);
 static inline void dma_memory_unmap(DMAContext *dma,
                                     void *buffer, dma_addr_t len,
                                     DMADirection dir, dma_addr_t access_len)
 {
-    if (!dma_has_iommu(dma)) {
-        address_space_unmap(dma->as, buffer, (hwaddr)len,
-                            dir == DMA_DIRECTION_FROM_DEVICE, access_len);
-    } else {
-        iommu_dma_memory_unmap(dma, buffer, len, dir, access_len);
-    }
+    address_space_unmap(dma->as, buffer, (hwaddr)len,
+                        dir == DMA_DIRECTION_FROM_DEVICE, access_len);
 }
 
 #define DEFINE_LDST_DMA(_lname, _sname, _bits, _end) \
@@ -247,8 +193,7 @@ DEFINE_LDST_DMA(q, q, 64, be);
 
 #undef DEFINE_LDST_DMA
 
-void dma_context_init(DMAContext *dma, AddressSpace *as, DMATranslateFunc translate,
-                      DMAMapFunc map, DMAUnmapFunc unmap);
+void dma_context_init(DMAContext *dma, AddressSpace *as);
 
 struct ScatterGatherEntry {
     dma_addr_t base;
-- 
1.8.1.4