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authorRussell Currey <ruscur@russell.cc>2016-07-20 19:09:20 +0530
committerStewart Smith <stewart@linux.vnet.ibm.com>2016-07-21 11:51:21 +1000
commit4ae024ed5b9b5e475783c9f930183506ab32a0d9 (patch)
tree93019881b9028df932a43674250d0fb91fcfb814
parenta7ba9f22c48a7051a71301bf19b5b358d3fc4ceb (diff)
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xscom: Return OPAL_WRONG_STATE on XSCOM ops if CPU is asleep
xscom_read and xscom_write return OPAL_SUCCESS if they worked, and OPAL_HARDWARE if they didn't. This doesn't provide information about why the operation failed, such as if the CPU happens to be asleep. This is specifically useful in error scanning, so if every CPU is being scanned for errors, sleeping CPUs likely aren't the cause of failures. So, return OPAL_WRONG_STATE in xscom_read and xscom_write if the CPU is sleeping. Signed-off-by: Russell Currey <ruscur@russell.cc> Reviewed-by: Alistair Popple <alistair@popple.id.au> Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com> (cherry picked from commit 9c2d82394fd2303847cac4a665dee62556ca528a) Signed-off-by: Vipin K Parashar <vipin@linux.vnet.ibm.com> Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
-rw-r--r--doc/opal-api/opal-xscom-read-write-65-66.txt5
-rw-r--r--hw/xscom.c29
2 files changed, 23 insertions, 11 deletions
diff --git a/doc/opal-api/opal-xscom-read-write-65-66.txt b/doc/opal-api/opal-xscom-read-write-65-66.txt
index 92916df..4ed0134 100644
--- a/doc/opal-api/opal-xscom-read-write-65-66.txt
+++ b/doc/opal-api/opal-xscom-read-write-65-66.txt
@@ -10,3 +10,8 @@ each takes three parameters:
int xscom_read(uint32_t partid, uint64_t pcb_addr, uint64_t *val)
int xscom_write(uint32_t partid, uint64_t pcb_addr, uint64_t val)
+
+Returns:
+ OPAL_SUCCESS
+ OPAL_HARDWARE if operation failed
+ OPAL_WRONG_STATE if CPU is asleep
diff --git a/hw/xscom.c b/hw/xscom.c
index c8e13be..84f72f5 100644
--- a/hw/xscom.c
+++ b/hw/xscom.c
@@ -118,7 +118,7 @@ static void xscom_reset(uint32_t gcid)
*/
}
-static bool xscom_handle_error(uint64_t hmer, uint32_t gcid, uint32_t pcb_addr,
+static int xscom_handle_error(uint64_t hmer, uint32_t gcid, uint32_t pcb_addr,
bool is_write)
{
unsigned int stat = GETFIELD(SPR_HMER_XSCOM_STATUS, hmer);
@@ -129,7 +129,10 @@ static bool xscom_handle_error(uint64_t hmer, uint32_t gcid, uint32_t pcb_addr,
switch(stat) {
/* XSCOM blocked, just retry */
case 1:
- return true;
+ return OPAL_BUSY;
+ /* CPU is asleep, don't retry */
+ case 2:
+ return OPAL_WRONG_STATE;
}
/* XXX: Create error log entry ? */
@@ -141,7 +144,7 @@ static bool xscom_handle_error(uint64_t hmer, uint32_t gcid, uint32_t pcb_addr,
xscom_reset(gcid);
/* Non recovered ... just fail */
- return false;
+ return OPAL_HARDWARE;
}
static void xscom_handle_ind_error(uint64_t data, uint32_t gcid,
@@ -175,6 +178,7 @@ static bool xscom_gcid_ok(uint32_t gcid)
static int __xscom_read(uint32_t gcid, uint32_t pcb_addr, uint64_t *val)
{
uint64_t hmer;
+ int64_t ret;
if (!xscom_gcid_ok(gcid)) {
prerror("%s: invalid XSCOM gcid 0x%x\n", __func__, gcid);
@@ -197,16 +201,18 @@ static int __xscom_read(uint32_t gcid, uint32_t pcb_addr, uint64_t *val)
if (!(hmer & SPR_HMER_XSCOM_FAIL))
break;
- /* Handle error and eventually retry */
- if (!xscom_handle_error(hmer, gcid, pcb_addr, false))
- return OPAL_HARDWARE;
+ /* Handle error and possibly eventually retry */
+ ret = xscom_handle_error(hmer, gcid, pcb_addr, false);
+ if (ret == OPAL_HARDWARE || ret == OPAL_WRONG_STATE)
+ return ret;
}
- return 0;
+ return OPAL_SUCCESS;
}
static int __xscom_write(uint32_t gcid, uint32_t pcb_addr, uint64_t val)
{
uint64_t hmer;
+ int64_t ret;
if (!xscom_gcid_ok(gcid)) {
prerror("%s: invalid XSCOM gcid 0x%x\n", __func__, gcid);
@@ -229,11 +235,12 @@ static int __xscom_write(uint32_t gcid, uint32_t pcb_addr, uint64_t val)
if (!(hmer & SPR_HMER_XSCOM_FAIL))
break;
- /* Handle error and eventually retry */
- if (!xscom_handle_error(hmer, gcid, pcb_addr, true))
- return OPAL_HARDWARE;
+ /* Handle error and possibly eventually retry */
+ ret = xscom_handle_error(hmer, gcid, pcb_addr, true);
+ if (ret == OPAL_HARDWARE || ret == OPAL_WRONG_STATE)
+ return ret;
}
- return 0;
+ return OPAL_SUCCESS;
}
/*