flashrom: Abstract mmap() in physmap.c and only open /dev/mem on the first physmap() call.

Signed-off-by: Stefan Reinauer <stepan@coresystems.de>
Signed-off-by: Peter Stuge <peter@stuge.se>
Acked-by: Peter Stuge <peter@stuge.se>


git-svn-id: svn://svn.coreboot.org/coreboot/trunk@3903 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

1 files changed, 58 insertions, 0 deletions

diff --git a/util/flashrom/physmap.c b/util/flashrom/physmap.c
new file mode 100644
index 0000000000..65d25698c8
--- /dev/null
+++ b/util/flashrom/physmap.c
@@ -0,0 +1,58 @@
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <errno.h>
+#include "flash.h"
+
+#if defined (__sun) && (defined(__i386) || defined(__amd64))
+#  define MEM_DEV "/dev/xsvc"
+#else
+#  define MEM_DEV "/dev/mem"
+#endif
+
+static int fd_mem = -1;
+
+void *sys_physmap(unsigned long phys_addr, size_t len)
+{
+	void *virt_addr;
+
+	if (-1 == fd_mem) {
+		/* Open the memory device UNCACHED. Important for MMIO. */
+		if (-1 == (fd_mem = open(MEM_DEV, O_RDWR|O_SYNC))) {
+			perror("Critical error: open(" MEM_DEV ")");
+			exit(1);
+		}
+	}
+
+	virt_addr = mmap(0, len, PROT_WRITE|PROT_READ, MAP_SHARED, fd_mem, (off_t)phys_addr);
+	return MAP_FAILED == virt_addr ? NULL : virt_addr;
+}
+
+void physunmap(void *virt_addr, size_t len)
+{
+	munmap(virt_addr, len);
+}
+
+void *physmap(const char *descr, unsigned long phys_addr, size_t len)
+{
+	void *virt_addr = sys_physmap(phys_addr, len);
+
+	if (NULL == virt_addr) {
+		if (NULL == descr)
+			descr = "memory";
+		fprintf(stderr, "Error accessing %s, 0x%lx bytes at 0x%08lx\n", descr, (unsigned long)len, phys_addr);
+		perror(MEM_DEV " mmap failed");
+		if (EINVAL == errno) {
+			fprintf(stderr, "In Linux this error can be caused by the CONFIG_NONPROMISC_DEVMEM (<2.6.27),\n");
+			fprintf(stderr, "CONFIG_STRICT_DEVMEM (>=2.6.27) and CONFIG_X86_PAT kernel options.\n");
+			fprintf(stderr, "Please check if either is enabled in your kernel before reporting a failure.\n");
+			fprintf(stderr, "You can override CONFIG_X86_PAT at boot with the nopat kernel parameter but\n");
+			fprintf(stderr, "disabling the other option unfortunately requires a kernel recompile. Sorry!\n");
+		}
+		exit(1);
+	}
+
+	return virt_addr;
+}