X-Git-Url: https://gerrit.fd.io/r/gitweb?p=deb_dpdk.git;a=blobdiff_plain;f=lib%2Flibrte_eal%2Flinuxapp%2Feal%2Feal_memory.c;h=bac969a1285a1cb6f51b45a79fb26a9ab2583b02;hp=17c20d4b3e322f4917b8809184185d70952975ce;hb=6e7cbd63706f3435b9d9a2057a37db1da01db9a7;hpb=e4df4d55df003957fc5afd7440e3d3192d7ce218

diff --git a/lib/librte_eal/linuxapp/eal/eal_memory.c b/lib/librte_eal/linuxapp/eal/eal_memory.c
index 17c20d4b..bac969a1 100644
--- a/lib/librte_eal/linuxapp/eal/eal_memory.c
+++ b/lib/librte_eal/linuxapp/eal/eal_memory.c
@@ -88,6 +88,23 @@
 
 static uint64_t baseaddr_offset;
 
+#ifdef RTE_ARCH_64
+/*
+ * Linux kernel uses a really high address as starting address for serving
+ * mmaps calls. If there exists addressing limitations and IOVA mode is VA,
+ * this starting address is likely too high for those devices. However, it
+ * is possible to use a lower address in the process virtual address space
+ * as with 64 bits there is a lot of available space.
+ *
+ * Current known limitations are 39 or 40 bits. Setting the starting address
+ * at 4GB implies there are 508GB or 1020GB for mapping the available
+ * hugepages. This is likely enough for most systems, although a device with
+ * addressing limitations should call rte_dev_check_dma_mask for ensuring all
+ * memory is within supported range.
+ */
+static uint64_t baseaddr = 0x100000000;
+#endif
+
 static bool phys_addrs_available = true;
 
 #define RANDOMIZE_VA_SPACE_FILE "/proc/sys/kernel/randomize_va_space"
@@ -95,7 +112,7 @@ static bool phys_addrs_available = true;
 static void
 test_phys_addrs_available(void)
 {
-	uint64_t tmp;
+	uint64_t tmp = 0;
 	phys_addr_t physaddr;
 
 	if (!rte_eal_has_hugepages()) {
@@ -250,6 +267,23 @@ aslr_enabled(void)
 	}
 }
 
+static void *
+get_addr_hint(void)
+{
+	if (internal_config.base_virtaddr != 0) {
+		return (void *) (uintptr_t)
+			    (internal_config.base_virtaddr +
+			     baseaddr_offset);
+	} else {
+#ifdef RTE_ARCH_64
+		return (void *) (uintptr_t) (baseaddr +
+				baseaddr_offset);
+#else
+		return NULL;
+#endif
+	}
+}
+
 /*
  * Try to mmap *size bytes in /dev/zero. If it is successful, return the
  * pointer to the mmap'd area and keep *size unmodified. Else, retry
@@ -260,16 +294,10 @@ aslr_enabled(void)
 static void *
 get_virtual_area(size_t *size, size_t hugepage_sz)
 {
-	void *addr;
+	void *addr, *addr_hint;
 	int fd;
 	long aligned_addr;
 
-	if (internal_config.base_virtaddr != 0) {
-		addr = (void*) (uintptr_t) (internal_config.base_virtaddr +
-				baseaddr_offset);
-	}
-	else addr = NULL;
-
 	RTE_LOG(DEBUG, EAL, "Ask a virtual area of 0x%zx bytes\n", *size);
 
 	fd = open("/dev/zero", O_RDONLY);
@@ -278,7 +306,9 @@ get_virtual_area(size_t *size, size_t hugepage_sz)
 		return NULL;
 	}
 	do {
-		addr = mmap(addr,
+		addr_hint = get_addr_hint();
+
+		addr = mmap(addr_hint,
 				(*size) + hugepage_sz, PROT_READ,
 #ifdef RTE_ARCH_PPC_64
 				MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB,
@@ -286,8 +316,15 @@ get_virtual_area(size_t *size, size_t hugepage_sz)
 				MAP_PRIVATE,
 #endif
 				fd, 0);
-		if (addr == MAP_FAILED)
+		if (addr == MAP_FAILED) {
+			/* map failed. Let's try with less memory */
 			*size -= hugepage_sz;
+		} else if (addr_hint && addr != addr_hint) {
+			/* hint was not used. Try with another offset */
+			munmap(addr, (*size) + hugepage_sz);
+			addr = MAP_FAILED;
+			baseaddr_offset += 0x100000000;
+		}
 	} while (addr == MAP_FAILED && *size > 0);
 
 	if (addr == MAP_FAILED) {