[dpdk-dev] [PATCH v4 1/2] eal: make base address hint OS-specific

[Anatoly Burakov <anatoly.burakov@intel.com>]

Not all OS's follow Linux's memory layout, which may lead to
problems following the suggested common address hint absent
of a base-virtaddr flag. Make this address hint OS-specific.

Cc: stable@dpdk.org

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
---
 lib/librte_eal/common/eal_common_memory.c | 19 +------------------
 lib/librte_eal/common/eal_private.h       |  6 ++++++
 lib/librte_eal/freebsd/eal/eal_memory.c   | 10 ++++++++++
 lib/librte_eal/linux/eal/eal_memory.c     | 20 ++++++++++++++++++++
 4 files changed, 37 insertions(+), 18 deletions(-)

diff --git a/lib/librte_eal/common/eal_common_memory.c b/lib/librte_eal/common/eal_common_memory.c
index 19ea47570..4a9cc1f19 100644
--- a/lib/librte_eal/common/eal_common_memory.c
+++ b/lib/librte_eal/common/eal_common_memory.c
@@ -40,23 +40,6 @@
 static void *next_baseaddr;
 static uint64_t system_page_sz;
 
-#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_mem_check_dma_mask for ensuring all
- * memory is within supported range.
- */
-static uint64_t baseaddr = 0x100000000;
-#endif
-
 #define MAX_MMAP_WITH_DEFINED_ADDR_TRIES 5
 void *
 eal_get_virtual_area(void *requested_addr, size_t *size,
@@ -85,7 +68,7 @@ eal_get_virtual_area(void *requested_addr, size_t *size,
 #ifdef RTE_ARCH_64
 	if (next_baseaddr == NULL && internal_config.base_virtaddr == 0 &&
 			rte_eal_process_type() == RTE_PROC_PRIMARY)
-		next_baseaddr = (void *) baseaddr;
+		next_baseaddr = (void *) eal_get_baseaddr();
 #endif
 	if (requested_addr == NULL && next_baseaddr != NULL) {
 		requested_addr = next_baseaddr;
diff --git a/lib/librte_eal/common/eal_private.h b/lib/librte_eal/common/eal_private.h
index 798ede553..31eae2278 100644
--- a/lib/librte_eal/common/eal_private.h
+++ b/lib/librte_eal/common/eal_private.h
@@ -381,4 +381,10 @@ rte_option_init(void);
 void
 rte_option_usage(void);
 
+/**
+ * Get OS-specific EAL mapping base address.
+ */
+uint64_t
+eal_get_baseaddr(void);
+
 #endif /* _EAL_PRIVATE_H_ */
diff --git a/lib/librte_eal/freebsd/eal/eal_memory.c b/lib/librte_eal/freebsd/eal/eal_memory.c
index 9b9a0577a..1bfdb52fb 100644
--- a/lib/librte_eal/freebsd/eal/eal_memory.c
+++ b/lib/librte_eal/freebsd/eal/eal_memory.c
@@ -22,6 +22,16 @@
 
 #define EAL_PAGE_SIZE (sysconf(_SC_PAGESIZE))
 
+uint64_t eal_get_baseaddr(void)
+{
+	/*
+	 * FreeBSD may allocate something in the space we will be mapping things
+	 * before we get a chance to do that, so use a base address that's far
+	 * away from where malloc() et al usually map things.
+	 */
+	return 0x1000000000;
+}
+
 /*
  * Get physical address of any mapped virtual address in the current process.
  */
diff --git a/lib/librte_eal/linux/eal/eal_memory.c b/lib/librte_eal/linux/eal/eal_memory.c
index 1c089a1ef..8516f0d35 100644
--- a/lib/librte_eal/linux/eal/eal_memory.c
+++ b/lib/librte_eal/linux/eal/eal_memory.c
@@ -70,6 +70,26 @@ static int phys_addrs_available = -1;
 
 #define RANDOMIZE_VA_SPACE_FILE "/proc/sys/kernel/randomize_va_space"
 
+uint64_t eal_get_baseaddr(void)
+{
+	/*
+	 * 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_mem_check_dma_mask for ensuring all memory is within supported
+	 * range.
+	 */
+	return 0x100000000;
+}
+
 /*
  * Get physical address of any mapped virtual address in the current process.
  */
-- 
2.17.1