amd64_edac: add DRAM error injection logic using sysfs

Borislav:
- rename sysfs attrs to more conform names
- cleanup/fix comments according to BKDG text
- fix function return value patterns
- cleanup debug calls

Reviewed-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Doug Thompson <dougthompson@xmission.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>

drivers/edac/amd64_edac_inj.c

@@ -0,0 +1,185 @@
+#include "amd64_edac.h"
+
+/*
+ * store error injection section value which refers to one of 4 16-byte sections
+ * within a 64-byte cacheline
+ *
+ * range: 0..3
+ */
+static ssize_t amd64_inject_section_store(struct mem_ctl_info *mci,
+					  const char *data, size_t count)
+{
+	struct amd64_pvt *pvt = mci->pvt_info;
+	unsigned long value;
+	int ret = 0;
+
+	ret = strict_strtoul(data, 10, &value);
+	if (ret != -EINVAL) {
+		pvt->injection.section = (u32) value;
+		return count;
+	}
+	return ret;
+}
+
+/*
+ * store error injection word value which refers to one of 9 16-bit word of the
+ * 16-byte (128-bit + ECC bits) section
+ *
+ * range: 0..8
+ */
+static ssize_t amd64_inject_word_store(struct mem_ctl_info *mci,
+					const char *data, size_t count)
+{
+	struct amd64_pvt *pvt = mci->pvt_info;
+	unsigned long value;
+	int ret = 0;
+
+	ret = strict_strtoul(data, 10, &value);
+	if (ret != -EINVAL) {
+
+		value = (value <= 8) ? value : 0;
+		pvt->injection.word = (u32) value;
+
+		return count;
+	}
+	return ret;
+}
+
+/*
+ * store 16 bit error injection vector which enables injecting errors to the
+ * corresponding bit within the error injection word above. When used during a
+ * DRAM ECC read, it holds the contents of the of the DRAM ECC bits.
+ */
+static ssize_t amd64_inject_ecc_vector_store(struct mem_ctl_info *mci,
+					     const char *data, size_t count)
+{
+	struct amd64_pvt *pvt = mci->pvt_info;
+	unsigned long value;
+	int ret = 0;
+
+	ret = strict_strtoul(data, 16, &value);
+	if (ret != -EINVAL) {
+
+		pvt->injection.bit_map = (u32) value & 0xFFFF;
+
+		return count;
+	}
+	return ret;
+}
+
+/*
+ * Do a DRAM ECC read. Assemble staged values in the pvt area, format into
+ * fields needed by the injection registers and read the NB Array Data Port.
+ */
+static ssize_t amd64_inject_read_store(struct mem_ctl_info *mci,
+					const char *data, size_t count)
+{
+	struct amd64_pvt *pvt = mci->pvt_info;
+	unsigned long value;
+	u32 section, word_bits;
+	int ret = 0;
+
+	ret = strict_strtoul(data, 10, &value);
+	if (ret != -EINVAL) {
+
+		/* Form value to choose 16-byte section of cacheline */
+		section = F10_NB_ARRAY_DRAM_ECC |
+				SET_NB_ARRAY_ADDRESS(pvt->injection.section);
+		pci_write_config_dword(pvt->misc_f3_ctl,
+					F10_NB_ARRAY_ADDR, section);
+
+		word_bits = SET_NB_DRAM_INJECTION_READ(pvt->injection.word,
+						pvt->injection.bit_map);
+
+		/* Issue 'word' and 'bit' along with the READ request */
+		pci_write_config_dword(pvt->misc_f3_ctl,
+					F10_NB_ARRAY_DATA, word_bits);
+
+		debugf0("section=0x%x word_bits=0x%x\n", section, word_bits);
+
+		return count;
+	}
+	return ret;
+}
+
+/*
+ * Do a DRAM ECC write. Assemble staged values in the pvt area and format into
+ * fields needed by the injection registers.
+ */
+static ssize_t amd64_inject_write_store(struct mem_ctl_info *mci,
+					const char *data, size_t count)
+{
+	struct amd64_pvt *pvt = mci->pvt_info;
+	unsigned long value;
+	u32 section, word_bits;
+	int ret = 0;
+
+	ret = strict_strtoul(data, 10, &value);
+	if (ret != -EINVAL) {
+
+		/* Form value to choose 16-byte section of cacheline */
+		section = F10_NB_ARRAY_DRAM_ECC |
+				SET_NB_ARRAY_ADDRESS(pvt->injection.section);
+		pci_write_config_dword(pvt->misc_f3_ctl,
+					F10_NB_ARRAY_ADDR, section);
+
+		word_bits = SET_NB_DRAM_INJECTION_WRITE(pvt->injection.word,
+						pvt->injection.bit_map);
+
+		/* Issue 'word' and 'bit' along with the READ request */
+		pci_write_config_dword(pvt->misc_f3_ctl,
+					F10_NB_ARRAY_DATA, word_bits);
+
+		debugf0("section=0x%x word_bits=0x%x\n", section, word_bits);
+
+		return count;
+	}
+	return ret;
+}
+
+/*
+ * update NUM_INJ_ATTRS in case you add new members
+ */
+struct mcidev_sysfs_attribute amd64_inj_attrs[] = {
+
+	{
+		.attr = {
+			.name = "inject_section",
+			.mode = (S_IRUGO | S_IWUSR)
+		},
+		.show = NULL,
+		.store = amd64_inject_section_store,
+	},
+	{
+		.attr = {
+			.name = "inject_word",
+			.mode = (S_IRUGO | S_IWUSR)
+		},
+		.show = NULL,
+		.store = amd64_inject_word_store,
+	},
+	{
+		.attr = {
+			.name = "inject_ecc_vector",
+			.mode = (S_IRUGO | S_IWUSR)
+		},
+		.show = NULL,
+		.store = amd64_inject_ecc_vector_store,
+	},
+	{
+		.attr = {
+			.name = "inject_write",
+			.mode = (S_IRUGO | S_IWUSR)
+		},
+		.show = NULL,
+		.store = amd64_inject_write_store,
+	},
+	{
+		.attr = {
+			.name = "inject_read",
+			.mode = (S_IRUGO | S_IWUSR)
+		},
+		.show = NULL,
+		.store = amd64_inject_read_store,
+	},
+};