[PATCH 15/16] EDAC: Fixup scrubrate manipulation

From: Borislav Petkov
Date: Fri Nov 26 2010 - 14:05:51 EST


From: Borislav Petkov <borislav.petkov@xxxxxxx>

Make the ->{get|set}_sdram_scrub_rate return the actual scrub rate
bandwidth it succeded setting and remove superfluous arg pointer used
for that. A negative value returned still means that an error occurred
while setting the scrubrate. Document this for future reference.

Signed-off-by: Borislav Petkov <borislav.petkov@xxxxxxx>
---
drivers/edac/amd64_edac.c | 24 +++++++++---------
drivers/edac/amd64_edac.h | 6 ----
drivers/edac/cpc925_edac.c | 9 +++---
drivers/edac/e752x_edac.c | 8 ++---
drivers/edac/edac_core.h | 2 +-
drivers/edac/edac_mc_sysfs.c | 57 ++++++++++++++++++++---------------------
drivers/edac/i5100_edac.c | 9 ++----
7 files changed, 52 insertions(+), 63 deletions(-)

diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index 4dcad97..f19c34e 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -77,7 +77,11 @@ static int ddr3_dbam[] = { [0] = -1,
*FIXME: Produce a better mapping/linearisation.
*/

-struct scrubrate scrubrates[] = {
+
+struct scrubrate {
+ u32 scrubval; /* bit pattern for scrub rate */
+ u32 bandwidth; /* bandwidth consumed (bytes/sec) */
+} scrubrates[] = {
{ 0x01, 1600000000UL},
{ 0x02, 800000000UL},
{ 0x03, 400000000UL},
@@ -151,14 +155,12 @@ static int __amd64_set_scrub_rate(struct pci_dev *ctl, u32 new_bw, u32 min_rate)
}

scrubval = scrubrates[i].scrubval;
- if (scrubval)
- amd64_info("Setting scrub rate bandwidth: %u\n",
- scrubrates[i].bandwidth);
- else
- amd64_info("Turning scrubbing off.\n");

pci_write_bits32(ctl, K8_SCRCTRL, scrubval, 0x001F);

+ if (scrubval)
+ return scrubrates[i].bandwidth;
+
return 0;
}

@@ -169,11 +171,11 @@ static int amd64_set_scrub_rate(struct mem_ctl_info *mci, u32 bw)
return __amd64_set_scrub_rate(pvt->F3, bw, pvt->min_scrubrate);
}

-static int amd64_get_scrub_rate(struct mem_ctl_info *mci, u32 *bw)
+static int amd64_get_scrub_rate(struct mem_ctl_info *mci)
{
struct amd64_pvt *pvt = mci->pvt_info;
u32 scrubval = 0;
- int status = -1, i;
+ int i, retval = -EINVAL;

amd64_read_pci_cfg(pvt->F3, K8_SCRCTRL, &scrubval);

@@ -183,13 +185,11 @@ static int amd64_get_scrub_rate(struct mem_ctl_info *mci, u32 *bw)

for (i = 0; i < ARRAY_SIZE(scrubrates); i++) {
if (scrubrates[i].scrubval == scrubval) {
- *bw = scrubrates[i].bandwidth;
- status = 0;
+ retval = scrubrates[i].bandwidth;
break;
}
}
-
- return status;
+ return retval;
}

/* Map from a CSROW entry to the mask entry that operates on it */
diff --git a/drivers/edac/amd64_edac.h b/drivers/edac/amd64_edac.h
index b76dce9..613ec72 100644
--- a/drivers/edac/amd64_edac.h
+++ b/drivers/edac/amd64_edac.h
@@ -482,12 +482,6 @@ struct ecc_settings {
} flags;
};

-struct scrubrate {
- u32 scrubval; /* bit pattern for scrub rate */
- u32 bandwidth; /* bandwidth consumed (bytes/sec) */
-};
-
-extern struct scrubrate scrubrates[23];
extern const char *tt_msgs[4];
extern const char *ll_msgs[4];
extern const char *rrrr_msgs[16];
diff --git a/drivers/edac/cpc925_edac.c b/drivers/edac/cpc925_edac.c
index 1609a19..b9a781c 100644
--- a/drivers/edac/cpc925_edac.c
+++ b/drivers/edac/cpc925_edac.c
@@ -818,9 +818,10 @@ static void cpc925_del_edac_devices(void)
}

/* Convert current back-ground scrub rate into byte/sec bandwith */
-static int cpc925_get_sdram_scrub_rate(struct mem_ctl_info *mci, u32 *bw)
+static int cpc925_get_sdram_scrub_rate(struct mem_ctl_info *mci)
{
struct cpc925_mc_pdata *pdata = mci->pvt_info;
+ int bw;
u32 mscr;
u8 si;

@@ -832,11 +833,11 @@ static int cpc925_get_sdram_scrub_rate(struct mem_ctl_info *mci, u32 *bw)
if (((mscr & MSCR_SCRUB_MOD_MASK) != MSCR_BACKGR_SCRUB) ||
(si == 0)) {
cpc925_mc_printk(mci, KERN_INFO, "Scrub mode not enabled\n");
- *bw = 0;
+ bw = 0;
} else
- *bw = CPC925_SCRUB_BLOCK_SIZE * 0xFA67 / si;
+ bw = CPC925_SCRUB_BLOCK_SIZE * 0xFA67 / si;

- return 0;
+ return bw;
}

/* Return 0 for single channel; 1 for dual channel */
diff --git a/drivers/edac/e752x_edac.c b/drivers/edac/e752x_edac.c
index 073f5a0..ec302d4 100644
--- a/drivers/edac/e752x_edac.c
+++ b/drivers/edac/e752x_edac.c
@@ -983,11 +983,11 @@ static int set_sdram_scrub_rate(struct mem_ctl_info *mci, u32 new_bw)

pci_write_config_word(pdev, E752X_MCHSCRB, scrubrates[i].scrubval);

- return 0;
+ return scrubrates[i].bandwidth;
}

/* Convert current scrub rate value into byte/sec bandwidth */
-static int get_sdram_scrub_rate(struct mem_ctl_info *mci, u32 *bw)
+static int get_sdram_scrub_rate(struct mem_ctl_info *mci)
{
const struct scrubrate *scrubrates;
struct e752x_pvt *pvt = (struct e752x_pvt *) mci->pvt_info;
@@ -1013,10 +1013,8 @@ static int get_sdram_scrub_rate(struct mem_ctl_info *mci, u32 *bw)
"Invalid sdram scrub control value: 0x%x\n", scrubval);
return -1;
}
+ return scrubrates[i].bandwidth;

- *bw = scrubrates[i].bandwidth;
-
- return 0;
}

/* Return 1 if dual channel mode is active. Else return 0. */
diff --git a/drivers/edac/edac_core.h b/drivers/edac/edac_core.h
index 050f9ee..25d8f97 100644
--- a/drivers/edac/edac_core.h
+++ b/drivers/edac/edac_core.h
@@ -387,7 +387,7 @@ struct mem_ctl_info {
representation and converts it to the closest matching
bandwith in bytes/sec.
*/
- int (*get_sdram_scrub_rate) (struct mem_ctl_info * mci, u32 * bw);
+ int (*get_sdram_scrub_rate) (struct mem_ctl_info * mci);


/* pointer to edac checking routine */
diff --git a/drivers/edac/edac_mc_sysfs.c b/drivers/edac/edac_mc_sysfs.c
index dce61f7..39d97cf 100644
--- a/drivers/edac/edac_mc_sysfs.c
+++ b/drivers/edac/edac_mc_sysfs.c
@@ -436,56 +436,55 @@ static ssize_t mci_reset_counters_store(struct mem_ctl_info *mci,
return count;
}

-/* memory scrubbing */
+/* Memory scrubbing interface:
+ *
+ * A MC driver can limit the scrubbing bandwidth based on the CPU type.
+ * Therefore, ->set_sdram_scrub_rate should be made to return the actual
+ * bandwidth that is accepted or 0 when scrubbing is to be disabled.
+ *
+ * Negative value still means that an error has occurred while setting
+ * the scrub rate.
+ */
static ssize_t mci_sdram_scrub_rate_store(struct mem_ctl_info *mci,
const char *data, size_t count)
{
unsigned long bandwidth = 0;
- int err;
+ int new_bw = 0;

- if (!mci->set_sdram_scrub_rate) {
- edac_printk(KERN_WARNING, EDAC_MC,
- "Memory scrub rate setting not implemented!\n");
+ if (!mci->set_sdram_scrub_rate)
return -EINVAL;
- }

if (strict_strtoul(data, 10, &bandwidth) < 0)
return -EINVAL;

- err = mci->set_sdram_scrub_rate(mci, (u32)bandwidth);
- if (err) {
- edac_printk(KERN_DEBUG, EDAC_MC,
- "Failed setting scrub rate to %lu\n", bandwidth);
- return -EINVAL;
- }
- else {
- edac_printk(KERN_DEBUG, EDAC_MC,
- "Scrub rate set to: %lu\n", bandwidth);
+ new_bw = mci->set_sdram_scrub_rate(mci, bandwidth);
+ if (new_bw >= 0) {
+ edac_printk(KERN_DEBUG, EDAC_MC, "Scrub rate set to %d\n", new_bw);
return count;
}
+
+ edac_printk(KERN_DEBUG, EDAC_MC, "Error setting scrub rate to: %lu\n", bandwidth);
+ return -EINVAL;
}

+/*
+ * ->get_sdram_scrub_rate() return value semantics same as above.
+ */
static ssize_t mci_sdram_scrub_rate_show(struct mem_ctl_info *mci, char *data)
{
- u32 bandwidth = 0;
- int err;
+ int bandwidth = 0;

- if (!mci->get_sdram_scrub_rate) {
- edac_printk(KERN_WARNING, EDAC_MC,
- "Memory scrub rate reading not implemented\n");
+ if (!mci->get_sdram_scrub_rate)
return -EINVAL;
- }

- err = mci->get_sdram_scrub_rate(mci, &bandwidth);
- if (err) {
+ bandwidth = mci->get_sdram_scrub_rate(mci);
+ if (bandwidth < 0) {
edac_printk(KERN_DEBUG, EDAC_MC, "Error reading scrub rate\n");
- return err;
- }
- else {
- edac_printk(KERN_DEBUG, EDAC_MC,
- "Read scrub rate: %d\n", bandwidth);
- return sprintf(data, "%d\n", bandwidth);
+ return bandwidth;
}
+
+ edac_printk(KERN_DEBUG, EDAC_MC, "Read scrub rate: %d\n", bandwidth);
+ return sprintf(data, "%d\n", bandwidth);
}

/* default attribute files for the MCI object */
diff --git a/drivers/edac/i5100_edac.c b/drivers/edac/i5100_edac.c
index f459a6c..0448da0 100644
--- a/drivers/edac/i5100_edac.c
+++ b/drivers/edac/i5100_edac.c
@@ -611,20 +611,17 @@ static int i5100_set_scrub_rate(struct mem_ctl_info *mci, u32 bandwidth)

bandwidth = 5900000 * i5100_mc_scrben(dw);

- return 0;
+ return bandwidth;
}

-static int i5100_get_scrub_rate(struct mem_ctl_info *mci,
- u32 *bandwidth)
+static int i5100_get_scrub_rate(struct mem_ctl_info *mci)
{
struct i5100_priv *priv = mci->pvt_info;
u32 dw;

pci_read_config_dword(priv->mc, I5100_MC, &dw);

- *bandwidth = 5900000 * i5100_mc_scrben(dw);
-
- return 0;
+ return 5900000 * i5100_mc_scrben(dw);
}

static struct pci_dev *pci_get_device_func(unsigned vendor,
--
1.7.3.1.50.g1e633

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