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authorChristophe Lombard <clombard@linux.vnet.ibm.com>2018-02-20 16:48:56 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2018-03-14 12:01:18 +0300
commitc2be663d5307fb9751a562ac664fa78cd7a00e2b (patch)
treebda7db5d90520ac164fb3948d49677180201d29c /drivers/misc
parent014a32b30e9d81b47ef82b9995b52c3a0c8b4082 (diff)
downloadlinux-c2be663d5307fb9751a562ac664fa78cd7a00e2b.tar.xz
cxl: Fix timebase synchronization status on P9
The PSL Timebase register is updated by the PSL to maintain the timebase. On P9, the Timebase value is only provided by the CAPP as received the last time a timebase request was performed. The timebase requests are initiated through the adapter configuration or application registers. The specific sysfs entry "/sys/class/cxl/cardxx/psl_timebase_synced" is now dynamically updated according the content of the PSL Timebase register. Fixes: f24be42aab37 ("cxl: Add psl9 specific code") Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Reviewed-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'drivers/misc')
-rw-r--r--drivers/misc/cxl/pci.c17
-rw-r--r--drivers/misc/cxl/sysfs.c12
2 files changed, 12 insertions, 17 deletions
diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index e7ac78e85494..83f1d08058fc 100644
--- a/drivers/misc/cxl/pci.c
+++ b/drivers/misc/cxl/pci.c
@@ -659,9 +659,6 @@ static u64 timebase_read_xsl(struct cxl *adapter)
static void cxl_setup_psl_timebase(struct cxl *adapter, struct pci_dev *dev)
{
- u64 psl_tb;
- int delta;
- unsigned int retry = 0;
struct device_node *np;
adapter->psl_timebase_synced = false;
@@ -689,20 +686,6 @@ static void cxl_setup_psl_timebase(struct cxl *adapter, struct pci_dev *dev)
cxl_p1_write(adapter, CXL_PSL_Control, 0x0000000000000000);
cxl_p1_write(adapter, CXL_PSL_Control, CXL_PSL_Control_tb);
- /* Wait until CORE TB and PSL TB difference <= 16usecs */
- do {
- msleep(1);
- if (retry++ > 5) {
- dev_info(&dev->dev, "PSL timebase can't synchronize\n");
- return;
- }
- psl_tb = adapter->native->sl_ops->timebase_read(adapter);
- delta = mftb() - psl_tb;
- if (delta < 0)
- delta = -delta;
- } while (tb_to_ns(delta) > 16000);
-
- adapter->psl_timebase_synced = true;
return;
}
diff --git a/drivers/misc/cxl/sysfs.c b/drivers/misc/cxl/sysfs.c
index a8b6d6a635e9..95285b7f636f 100644
--- a/drivers/misc/cxl/sysfs.c
+++ b/drivers/misc/cxl/sysfs.c
@@ -62,7 +62,19 @@ static ssize_t psl_timebase_synced_show(struct device *device,
char *buf)
{
struct cxl *adapter = to_cxl_adapter(device);
+ u64 psl_tb, delta;
+ /* Recompute the status only in native mode */
+ if (cpu_has_feature(CPU_FTR_HVMODE)) {
+ psl_tb = adapter->native->sl_ops->timebase_read(adapter);
+ delta = abs(mftb() - psl_tb);
+
+ /* CORE TB and PSL TB difference <= 16usecs ? */
+ adapter->psl_timebase_synced = (tb_to_ns(delta) < 16000) ? true : false;
+ pr_devel("PSL timebase %s - delta: 0x%016llx\n",
+ (tb_to_ns(delta) < 16000) ? "synchronized" :
+ "not synchronized", tb_to_ns(delta));
+ }
return scnprintf(buf, PAGE_SIZE, "%i\n", adapter->psl_timebase_synced);
}