[PATCH] devmem: add 128-bit width

[Aaro Koskinen]

From: Aaro Koskinen <aaro.koskinen at nokia.com>

Add 128-bit width if the compiler provides the needed type.

function                                             old     new   delta
devmem_main                                          412     517    +105
usage_messages                                       247     313     +66
.rodata                                             3553    3571     +18
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 3/0 up/down: 189/0)             Total: 189 bytes

Signed-off-by: Aaro Koskinen <aaro.koskinen at nokia.com>
Signed-off-by: Aaro Koskinen <aaro.koskinen at iki.fi>
---
 miscutils/devmem.c | 113 +++++++++++++++++++++++++++------------------
 1 file changed, 69 insertions(+), 44 deletions(-)

diff --git a/miscutils/devmem.c b/miscutils/devmem.c
index f9f0276bc..a6991886a 100644
--- a/miscutils/devmem.c
+++ b/miscutils/devmem.c
@@ -15,12 +15,15 @@
 //kbuild:lib-$(CONFIG_DEVMEM) += devmem.o
 
 //usage:#define devmem_trivial_usage
-//usage:	"ADDRESS [WIDTH [VALUE]]"
+//usage:	"ADDRESS [WIDTH [VALUE]...]"
 //usage:#define devmem_full_usage "\n\n"
 //usage:       "Read/write from physical address\n"
 //usage:     "\n	ADDRESS	Address to act upon"
 //usage:     "\n	WIDTH	Width (8/16/...)"
 //usage:     "\n	VALUE	Data to be written"
+#ifdef __SIZEOF_INT128__
+//usage:     "\n		For 128-bit data, provide 64-bit values (LOW, or HI and LOW)"
+#endif
 
 #include "libbb.h"
 
@@ -28,7 +31,7 @@ int devmem_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int devmem_main(int argc UNUSED_PARAM, char **argv)
 {
 	void *map_base, *virt_addr;
-	uint64_t read_result;
+	uint64_t read_result = read_result; /* for compiler */
 	uint64_t writeval = writeval; /* for compiler */
 	off_t target;
 	unsigned page_size, mapped_size, offset_in_page;
@@ -96,51 +99,73 @@ int devmem_main(int argc UNUSED_PARAM, char **argv)
 	virt_addr = (char*)map_base + offset_in_page;
 
 	if (!argv[3]) {
-		switch (width) {
-		case 8:
-			read_result = *(volatile uint8_t*)virt_addr;
-			break;
-		case 16:
-			read_result = *(volatile uint16_t*)virt_addr;
-			break;
-		case 32:
-			read_result = *(volatile uint32_t*)virt_addr;
-			break;
-		case 64:
-			read_result = *(volatile uint64_t*)virt_addr;
-			break;
-		default:
-			bb_simple_error_msg_and_die("bad width");
+#ifdef __SIZEOF_INT128__
+		if (width == 128) {
+			unsigned __int128 rd =
+				*(volatile unsigned __int128 *)virt_addr;
+			printf("0x%016llX%016llX\n", (uint64_t)(rd >> 64),
+			       (uint64_t)rd);
+		} else
+#endif
+		{
+			switch (width) {
+			case 8:
+				read_result = *(volatile uint8_t*)virt_addr;
+				break;
+			case 16:
+				read_result = *(volatile uint16_t*)virt_addr;
+				break;
+			case 32:
+				read_result = *(volatile uint32_t*)virt_addr;
+				break;
+			case 64:
+				read_result = *(volatile uint64_t*)virt_addr;
+				break;
+			default:
+				bb_simple_error_msg_and_die("bad width");
+			}
+//			printf("Value at address 0x%"OFF_FMT"X (%p): 0x%llX\n",
+//				target, virt_addr,
+//				(unsigned long long)read_result);
+			/* Zero-padded output shows the width of access just done */
+			printf("0x%0*llX\n", (width >> 2), (unsigned long long)read_result);
 		}
-//		printf("Value at address 0x%"OFF_FMT"X (%p): 0x%llX\n",
-//			target, virt_addr,
-//			(unsigned long long)read_result);
-		/* Zero-padded output shows the width of access just done */
-		printf("0x%0*llX\n", (width >> 2), (unsigned long long)read_result);
 	} else {
-		switch (width) {
-		case 8:
-			*(volatile uint8_t*)virt_addr = writeval;
-//			read_result = *(volatile uint8_t*)virt_addr;
-			break;
-		case 16:
-			*(volatile uint16_t*)virt_addr = writeval;
-//			read_result = *(volatile uint16_t*)virt_addr;
-			break;
-		case 32:
-			*(volatile uint32_t*)virt_addr = writeval;
-//			read_result = *(volatile uint32_t*)virt_addr;
-			break;
-		case 64:
-			*(volatile uint64_t*)virt_addr = writeval;
-//			read_result = *(volatile uint64_t*)virt_addr;
-			break;
-		default:
-			bb_simple_error_msg_and_die("bad width");
+#ifdef __SIZEOF_INT128__
+		if (width == 128) {
+			unsigned __int128 wr;
+
+			wr = writeval;
+			if (argv[4])
+				wr = (wr << 64) | bb_strtoull(argv[4], NULL, 0);
+			*(volatile unsigned __int128 *)virt_addr = wr;
+		} else
+#endif
+		{
+			switch (width) {
+			case 8:
+				*(volatile uint8_t*)virt_addr = writeval;
+//				read_result = *(volatile uint8_t*)virt_addr;
+				break;
+			case 16:
+				*(volatile uint16_t*)virt_addr = writeval;
+//				read_result = *(volatile uint16_t*)virt_addr;
+				break;
+			case 32:
+				*(volatile uint32_t*)virt_addr = writeval;
+//				read_result = *(volatile uint32_t*)virt_addr;
+				break;
+			case 64:
+				*(volatile uint64_t*)virt_addr = writeval;
+//				read_result = *(volatile uint64_t*)virt_addr;
+				break;
+			default:
+				bb_simple_error_msg_and_die("bad width");
+			}
+//			printf("Written 0x%llX; readback 0x%llX\n",
+//					(unsigned long long)writeval,
+//					(unsigned long long)read_result);
 		}
-//		printf("Written 0x%llX; readback 0x%llX\n",
-//				(unsigned long long)writeval,
-//				(unsigned long long)read_result);
 	}
 
 	if (ENABLE_FEATURE_CLEAN_UP) {
-- 
2.17.0