[PATCH] e100: re-enable microcode with more useful defaults

For the four versions of hardware that we (currently) support microcode
download on, the default configuration of our receive interrupt mitigation
microcode was too aggressive, and caused unnecessary delays when pinging,
and low(er) throughput on single connection latency sensitive performance
tests.

This code adds microcode support, and sets the defaults to more reasonable
settings. It also explains the functionality in the code in more detail.
Compile and load tested, shows expected behavior for slight delay of ping
packets (1-2ms) when ucode is loaded, and decent interrupt moderation for
small packets, while maintaining good throughput.

Signed-off-by: Jesse Brandeburg <[e-mail]>
Signed-off-by: Jeff Garzik <[e-mail]>

drivers/net/e100.c

···
 
 #define DRV_NAME		"e100"
 #define DRV_EXT		"-NAPI"
-#define DRV_VERSION		"3.4.14-k2"DRV_EXT
+#define DRV_VERSION		"3.4.14-k4"DRV_EXT
 #define DRV_DESCRIPTION		"Intel(R) PRO/100 Network Driver"
 #define DRV_COPYRIGHT		"Copyright(c) 1999-2005 Intel Corporation"
 #define PFX			DRV_NAME ": "
···
 
 static void e100_get_defaults(struct nic *nic)
 {
-	struct param_range rfds = { .min = 16, .max = 256, .count = 64 };
-	struct param_range cbs  = { .min = 64, .max = 256, .count = 64 };
+	struct param_range rfds = { .min = 16, .max = 256, .count = 256 };
+	struct param_range cbs  = { .min = 64, .max = 256, .count = 128 };
 
 	pci_read_config_byte(nic->pdev, PCI_REVISION_ID, &nic->rev_id);
 	/* MAC type is encoded as rev ID; exception: ICH is treated as 82559 */
···
 		c[16], c[17], c[18], c[19], c[20], c[21], c[22], c[23]);
 }
 
+/********************************************************/
+/*  Micro code for 8086:1229 Rev 8                      */
+/********************************************************/
+
+/*  Parameter values for the D101M B-step  */
+#define D101M_CPUSAVER_TIMER_DWORD		78
+#define D101M_CPUSAVER_BUNDLE_DWORD		65
+#define D101M_CPUSAVER_MIN_SIZE_DWORD		126
+
+#define D101M_B_RCVBUNDLE_UCODE \
+{\
+0x00550215, 0xFFFF0437, 0xFFFFFFFF, 0x06A70789, 0xFFFFFFFF, 0x0558FFFF, \
+0x000C0001, 0x00101312, 0x000C0008, 0x00380216, \
+0x0010009C, 0x00204056, 0x002380CC, 0x00380056, \
+0x0010009C, 0x00244C0B, 0x00000800, 0x00124818, \
+0x00380438, 0x00000000, 0x00140000, 0x00380555, \
+0x00308000, 0x00100662, 0x00100561, 0x000E0408, \
+0x00134861, 0x000C0002, 0x00103093, 0x00308000, \
+0x00100624, 0x00100561, 0x000E0408, 0x00100861, \
+0x000C007E, 0x00222C21, 0x000C0002, 0x00103093, \
+0x00380C7A, 0x00080000, 0x00103090, 0x00380C7A, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x0010009C, 0x00244C2D, 0x00010004, 0x00041000, \
+0x003A0437, 0x00044010, 0x0038078A, 0x00000000, \
+0x00100099, 0x00206C7A, 0x0010009C, 0x00244C48, \
+0x00130824, 0x000C0001, 0x00101213, 0x00260C75, \
+0x00041000, 0x00010004, 0x00130826, 0x000C0006, \
+0x002206A8, 0x0013C926, 0x00101313, 0x003806A8, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00080600, 0x00101B10, 0x00050004, 0x00100826, \
+0x00101210, 0x00380C34, 0x00000000, 0x00000000, \
+0x0021155B, 0x00100099, 0x00206559, 0x0010009C, \
+0x00244559, 0x00130836, 0x000C0000, 0x00220C62, \
+0x000C0001, 0x00101B13, 0x00229C0E, 0x00210C0E, \
+0x00226C0E, 0x00216C0E, 0x0022FC0E, 0x00215C0E, \
+0x00214C0E, 0x00380555, 0x00010004, 0x00041000, \
+0x00278C67, 0x00040800, 0x00018100, 0x003A0437, \
+0x00130826, 0x000C0001, 0x00220559, 0x00101313, \
+0x00380559, 0x00000000, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00000000, 0x00130831, 0x0010090B, 0x00124813, \
+0x000CFF80, 0x002606AB, 0x00041000, 0x00010004, \
+0x003806A8, 0x00000000, 0x00000000, 0x00000000, \
+}
+
+/********************************************************/
+/*  Micro code for 8086:1229 Rev 9                      */
+/********************************************************/
+
+/*  Parameter values for the D101S  */
+#define D101S_CPUSAVER_TIMER_DWORD		78
+#define D101S_CPUSAVER_BUNDLE_DWORD		67
+#define D101S_CPUSAVER_MIN_SIZE_DWORD		128
+
+#define D101S_RCVBUNDLE_UCODE \
+{\
+0x00550242, 0xFFFF047E, 0xFFFFFFFF, 0x06FF0818, 0xFFFFFFFF, 0x05A6FFFF, \
+0x000C0001, 0x00101312, 0x000C0008, 0x00380243, \
+0x0010009C, 0x00204056, 0x002380D0, 0x00380056, \
+0x0010009C, 0x00244F8B, 0x00000800, 0x00124818, \
+0x0038047F, 0x00000000, 0x00140000, 0x003805A3, \
+0x00308000, 0x00100610, 0x00100561, 0x000E0408, \
+0x00134861, 0x000C0002, 0x00103093, 0x00308000, \
+0x00100624, 0x00100561, 0x000E0408, 0x00100861, \
+0x000C007E, 0x00222FA1, 0x000C0002, 0x00103093, \
+0x00380F90, 0x00080000, 0x00103090, 0x00380F90, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x0010009C, 0x00244FAD, 0x00010004, 0x00041000, \
+0x003A047E, 0x00044010, 0x00380819, 0x00000000, \
+0x00100099, 0x00206FFD, 0x0010009A, 0x0020AFFD, \
+0x0010009C, 0x00244FC8, 0x00130824, 0x000C0001, \
+0x00101213, 0x00260FF7, 0x00041000, 0x00010004, \
+0x00130826, 0x000C0006, 0x00220700, 0x0013C926, \
+0x00101313, 0x00380700, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00080600, 0x00101B10, 0x00050004, 0x00100826, \
+0x00101210, 0x00380FB6, 0x00000000, 0x00000000, \
+0x002115A9, 0x00100099, 0x002065A7, 0x0010009A, \
+0x0020A5A7, 0x0010009C, 0x002445A7, 0x00130836, \
+0x000C0000, 0x00220FE4, 0x000C0001, 0x00101B13, \
+0x00229F8E, 0x00210F8E, 0x00226F8E, 0x00216F8E, \
+0x0022FF8E, 0x00215F8E, 0x00214F8E, 0x003805A3, \
+0x00010004, 0x00041000, 0x00278FE9, 0x00040800, \
+0x00018100, 0x003A047E, 0x00130826, 0x000C0001, \
+0x002205A7, 0x00101313, 0x003805A7, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00130831, \
+0x0010090B, 0x00124813, 0x000CFF80, 0x00260703, \
+0x00041000, 0x00010004, 0x00380700  \
+}
+
+/********************************************************/
+/*  Micro code for the 8086:1229 Rev F/10               */
+/********************************************************/
+
+/*  Parameter values for the D102 E-step  */
+#define D102_E_CPUSAVER_TIMER_DWORD		42
+#define D102_E_CPUSAVER_BUNDLE_DWORD		54
+#define D102_E_CPUSAVER_MIN_SIZE_DWORD		46
+
+#define     D102_E_RCVBUNDLE_UCODE \
+{\
+0x007D028F, 0x0E4204F9, 0x14ED0C85, 0x14FA14E9, 0x0EF70E36, 0x1FFF1FFF, \
+0x00E014B9, 0x00000000, 0x00000000, 0x00000000, \
+0x00E014BD, 0x00000000, 0x00000000, 0x00000000, \
+0x00E014D5, 0x00000000, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00E014C1, 0x00000000, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00E014C8, 0x00000000, 0x00000000, 0x00000000, \
+0x00200600, 0x00E014EE, 0x00000000, 0x00000000, \
+0x0030FF80, 0x00940E46, 0x00038200, 0x00102000, \
+0x00E00E43, 0x00000000, 0x00000000, 0x00000000, \
+0x00300006, 0x00E014FB, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00906E41, 0x00800E3C, 0x00E00E39, 0x00000000, \
+0x00906EFD, 0x00900EFD, 0x00E00EF8, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+0x00000000, 0x00000000, 0x00000000, 0x00000000, \
+}
+
 static void e100_load_ucode(struct nic *nic, struct cb *cb, struct sk_buff *skb)
 {
-	int i;
-	static const u32 ucode[UCODE_SIZE] = {
-		/* NFS packets are misinterpreted as TCO packets and
-		 * incorrectly routed to the BMC over SMBus.  This
-		 * microcode patch checks the fragmented IP bit in the
-		 * NFS/UDP header to distinguish between NFS and TCO. */
-		0x0EF70E36, 0x1FFF1FFF, 0x1FFF1FFF, 0x1FFF1FFF, 0x1FFF1FFF,
-		0x1FFF1FFF, 0x00906E41, 0x00800E3C, 0x00E00E39, 0x00000000,
-		0x00906EFD, 0x00900EFD,	0x00E00EF8,
-	};
+/* *INDENT-OFF* */
+	static struct {
+		u32 ucode[UCODE_SIZE + 1];
+		u8 mac;
+		u8 timer_dword;
+		u8 bundle_dword;
+		u8 min_size_dword;
+	} ucode_opts[] = {
+		{ D101M_B_RCVBUNDLE_UCODE,
+		  mac_82559_D101M,
+		  D101M_CPUSAVER_TIMER_DWORD,
+		  D101M_CPUSAVER_BUNDLE_DWORD,
+		  D101M_CPUSAVER_MIN_SIZE_DWORD },
+		{ D101S_RCVBUNDLE_UCODE,
+		  mac_82559_D101S,
+		  D101S_CPUSAVER_TIMER_DWORD,
+		  D101S_CPUSAVER_BUNDLE_DWORD,
+		  D101S_CPUSAVER_MIN_SIZE_DWORD },
+		{ D102_E_RCVBUNDLE_UCODE,
+		  mac_82551_F,
+		  D102_E_CPUSAVER_TIMER_DWORD,
+		  D102_E_CPUSAVER_BUNDLE_DWORD,
+		  D102_E_CPUSAVER_MIN_SIZE_DWORD },
+		{ D102_E_RCVBUNDLE_UCODE,
+		  mac_82551_10,
+		  D102_E_CPUSAVER_TIMER_DWORD,
+		  D102_E_CPUSAVER_BUNDLE_DWORD,
+		  D102_E_CPUSAVER_MIN_SIZE_DWORD },
+		{ {0}, 0, 0, 0, 0}
+	}, *opts;
+/* *INDENT-ON* */
 
-	if(nic->mac == mac_82551_F || nic->mac == mac_82551_10) {
-		for(i = 0; i < UCODE_SIZE; i++)
+/*************************************************************************
+*  CPUSaver parameters
+*
+*  All CPUSaver parameters are 16-bit literals that are part of a
+*  "move immediate value" instruction.  By changing the value of
+*  the literal in the instruction before the code is loaded, the
+*  driver can change the algorithm.
+*
+*  INTDELAY - This loads the dead-man timer with its inital value.
+*    When this timer expires the interrupt is asserted, and the 
+*    timer is reset each time a new packet is received.  (see
+*    BUNDLEMAX below to set the limit on number of chained packets)
+*    The current default is 0x600 or 1536.  Experiments show that
+*    the value should probably stay within the 0x200 - 0x1000.
+*
+*  BUNDLEMAX - 
+*    This sets the maximum number of frames that will be bundled.  In
+*    some situations, such as the TCP windowing algorithm, it may be
+*    better to limit the growth of the bundle size than let it go as
+*    high as it can, because that could cause too much added latency.
+*    The default is six, because this is the number of packets in the
+*    default TCP window size.  A value of 1 would make CPUSaver indicate
+*    an interrupt for every frame received.  If you do not want to put
+*    a limit on the bundle size, set this value to xFFFF.
+*
+*  BUNDLESMALL - 
+*    This contains a bit-mask describing the minimum size frame that
+*    will be bundled.  The default masks the lower 7 bits, which means
+*    that any frame less than 128 bytes in length will not be bundled,
+*    but will instead immediately generate an interrupt.  This does
+*    not affect the current bundle in any way.  Any frame that is 128
+*    bytes or large will be bundled normally.  This feature is meant
+*    to provide immediate indication of ACK frames in a TCP environment.
+*    Customers were seeing poor performance when a machine with CPUSaver
+*    enabled was sending but not receiving.  The delay introduced when
+*    the ACKs were received was enough to reduce total throughput, because
+*    the sender would sit idle until the ACK was finally seen.
+*
+*    The current default is 0xFF80, which masks out the lower 7 bits.
+*    This means that any frame which is x7F (127) bytes or smaller
+*    will cause an immediate interrupt.  Because this value must be a 
+*    bit mask, there are only a few valid values that can be used.  To
+*    turn this feature off, the driver can write the value xFFFF to the
+*    lower word of this instruction (in the same way that the other
+*    parameters are used).  Likewise, a value of 0xF800 (2047) would
+*    cause an interrupt to be generated for every frame, because all
+*    standard Ethernet frames are <= 2047 bytes in length.
+*************************************************************************/
+
+/* if you wish to disable the ucode functionality, while maintaining the 
+ * workarounds it provides, set the following defines to:
+ * BUNDLESMALL 0
+ * BUNDLEMAX 1
+ * INTDELAY 1
+ */
+#define BUNDLESMALL 1
+#define BUNDLEMAX (u16)6
+#define INTDELAY (u16)1536 /* 0x600 */
+
+	/* do not load u-code for ICH devices */
+	if (nic->flags & ich)
+		goto noloaducode;
+
+	/* Search for ucode match against h/w rev_id */
+	for (opts = ucode_opts; opts->mac; opts++) {
+		int i;
+		u32 *ucode = opts->ucode;
+		if (nic->mac != opts->mac)
+			continue;
+
+		/* Insert user-tunable settings */
+		ucode[opts->timer_dword] &= 0xFFFF0000;
+		ucode[opts->timer_dword] |= INTDELAY;
+		ucode[opts->bundle_dword] &= 0xFFFF0000;
+		ucode[opts->bundle_dword] |= BUNDLEMAX;
+		ucode[opts->min_size_dword] &= 0xFFFF0000;
+		ucode[opts->min_size_dword] |= (BUNDLESMALL) ? 0xFFFF : 0xFF80;
+
+		for (i = 0; i < UCODE_SIZE; i++)
 			cb->u.ucode[i] = cpu_to_le32(ucode[i]);
 		cb->command = cpu_to_le16(cb_ucode);
-	} else
-		cb->command = cpu_to_le16(cb_nop);
+		return;
+	}
+
+noloaducode:
+	cb->command = cpu_to_le16(cb_nop);
 }
 
 static void e100_setup_iaaddr(struct nic *nic, struct cb *cb,