i5100_edac: add fault injection code

Add fault injection based on information datasheet for i5100, see 1. In
addition to the i5100 datasheet some missing information on injection
functions where found through experimentation and the i7300 datasheet,
see 2.

[1] Intel 5100 Memory Controller Hub Chipset
    Doc.Nr: 318378
    http://www.intel.com/content/dam/doc/datasheet/5100-
    memory-controller-hub-chipset-datasheet.pdf

[2] Intel 7300 Chipset MemoryController Hub (MCH)
    Doc.Nr: 318082
	http://www.intel.com/assets/pdf/datasheet/318082.pdf

Signed-off-by: Niklas Söderlund <niklas.soderlund@ericsson.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/edac/i5100_edac.c

@@ -68,6 +68,14 @@
 			I5100_FERR_NF_MEM_M1ERR_MASK)
 #define	I5100_NERR_NF_MEM	0xa4	/* MC Next Non-Fatal Errors */
 #define I5100_EMASK_MEM		0xa8	/* MC Error Mask Register */
+#define I5100_MEM0EINJMSK0	0x200	/* Injection Mask0 Register Channel 0 */
+#define I5100_MEM1EINJMSK0	0x208	/* Injection Mask0 Register Channel 1 */
+#define		I5100_MEMXEINJMSK0_EINJEN	(1 << 27)
+#define I5100_MEM0EINJMSK1	0x204	/* Injection Mask1 Register Channel 0 */
+#define I5100_MEM1EINJMSK1	0x206	/* Injection Mask1 Register Channel 1 */
+
+/* Device 19, Function 0 */
+#define I5100_DINJ0 0x9a
 
 /* device 21 and 22, func 0 */
 #define I5100_MTR_0	0x154	/* Memory Technology Registers 0-3 */
@@ -344,6 +352,14 @@ struct i5100_priv {
 
 	struct delayed_work i5100_scrubbing;
 	int scrub_enable;
+
+	/* Error injection */
+	u8 inject_channel;
+	u8 inject_hlinesel;
+	u8 inject_deviceptr1;
+	u8 inject_deviceptr2;
+	u16 inject_eccmask1;
+	u16 inject_eccmask2;
 };
 
 /* map a rank/chan to a slot number on the mainboard */
@@ -864,6 +880,70 @@ static void i5100_init_csrows(struct mem_ctl_info *mci)
 	}
 }
 
+/****************************************************************************
+ *                       Error injection routines
+ ****************************************************************************/
+
+static void i5100_do_inject(struct mem_ctl_info *mci)
+{
+	struct i5100_priv *priv = mci->pvt_info;
+	u32 mask0;
+	u16 mask1;
+
+	/* MEM[1:0]EINJMSK0
+	 * 31    - ADDRMATCHEN
+	 * 29:28 - HLINESEL
+	 *         00 Reserved
+	 *         01 Lower half of cache line
+	 *         10 Upper half of cache line
+	 *         11 Both upper and lower parts of cache line
+	 * 27    - EINJEN
+	 * 25:19 - XORMASK1 for deviceptr1
+	 * 9:5   - SEC2RAM for deviceptr2
+	 * 4:0   - FIR2RAM for deviceptr1
+	 */
+	mask0 = ((priv->inject_hlinesel & 0x3) << 28) |
+		I5100_MEMXEINJMSK0_EINJEN |
+		((priv->inject_eccmask1 & 0xffff) << 10) |
+		((priv->inject_deviceptr2 & 0x1f) << 5) |
+		(priv->inject_deviceptr1 & 0x1f);
+
+	/* MEM[1:0]EINJMSK1
+	 * 15:0  - XORMASK2 for deviceptr2
+	 */
+	mask1 = priv->inject_eccmask2;
+
+	if (priv->inject_channel == 0) {
+		pci_write_config_dword(priv->mc, I5100_MEM0EINJMSK0, mask0);
+		pci_write_config_word(priv->mc, I5100_MEM0EINJMSK1, mask1);
+	} else {
+		pci_write_config_dword(priv->mc, I5100_MEM1EINJMSK0, mask0);
+		pci_write_config_word(priv->mc, I5100_MEM1EINJMSK1, mask1);
+	}
+
+	/* Error Injection Response Function
+	 * Intel 5100 Memory Controller Hub Chipset (318378) datasheet
+	 * hints about this register but carry no data about them. All
+	 * data regarding device 19 is based on experimentation and the
+	 * Intel 7300 Chipset Memory Controller Hub (318082) datasheet
+	 * which appears to be accurate for the i5100 in this area.
+	 *
+	 * The injection code don't work without setting this register.
+	 * The register needs to be flipped off then on else the hardware
+	 * will only preform the first injection.
+	 *
+	 * Stop condition bits 7:4
+	 * 1010 - Stop after one injection
+	 * 1011 - Never stop injecting faults
+	 *
+	 * Start condition bits 3:0
+	 * 1010 - Never start
+	 * 1011 - Start immediately
+	 */
+	pci_write_config_byte(priv->einj, I5100_DINJ0, 0xaa);
+	pci_write_config_byte(priv->einj, I5100_DINJ0, 0xab);
+}
+
 static int i5100_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	int rc;
@@ -993,6 +1073,13 @@ static int i5100_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
 	mci->set_sdram_scrub_rate = i5100_set_scrub_rate;
 	mci->get_sdram_scrub_rate = i5100_get_scrub_rate;
 
+	priv->inject_channel = 0;
+	priv->inject_hlinesel = 0;
+	priv->inject_deviceptr1 = 0;
+	priv->inject_deviceptr2 = 0;
+	priv->inject_eccmask1 = 0;
+	priv->inject_eccmask2 = 0;
+
 	i5100_init_csrows(mci);
 
 	/* this strange construction seems to be in every driver, dunno why */