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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2014-02-28 05:20:38 (GMT)
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2014-02-28 08:15:49 (GMT)
commite0cf957614976896111e676e5134ac98ee227d3d (patch)
tree6b82fc343dbf1e65134b8fa1bdf71709042c6e95 /arch/powerpc
parent2f3f38e4d3d03dd4125cc9a1f49ab3cc91d8d670 (diff)
powerpc/powernv: Fix indirect XSCOM unmangling
We need to unmangle the full address, not just the register number, and we also need to support the real indirect bit being set for in-kernel uses. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: <stable@vger.kernel.org> [v3.13]
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/platforms/powernv/opal-xscom.c21
1 files changed, 12 insertions, 9 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-xscom.c b/arch/powerpc/platforms/powernv/opal-xscom.c
index 4fbf276..4cd2ea6 100644
--- a/arch/powerpc/platforms/powernv/opal-xscom.c
+++ b/arch/powerpc/platforms/powernv/opal-xscom.c
@@ -71,11 +71,11 @@ static int opal_xscom_err_xlate(int64_t rc)
}
}
-static u64 opal_scom_unmangle(u64 reg)
+static u64 opal_scom_unmangle(u64 addr)
{
/*
* XSCOM indirect addresses have the top bit set. Additionally
- * the reset of the top 3 nibbles is always 0.
+ * the rest of the top 3 nibbles is always 0.
*
* Because the debugfs interface uses signed offsets and shifts
* the address left by 3, we basically cannot use the top 4 bits
@@ -86,10 +86,13 @@ static u64 opal_scom_unmangle(u64 reg)
* conversion here. To leave room for further xscom address
* expansion, we only clear out the top byte
*
+ * For in-kernel use, we also support the real indirect bit, so
+ * we test for any of the top 5 bits
+ *
*/
- if (reg & (1ull << 59))
- reg = (reg & ~(0xffull << 56)) | (1ull << 63);
- return reg;
+ if (addr & (0x1full << 59))
+ addr = (addr & ~(0xffull << 56)) | (1ull << 63);
+ return addr;
}
static int opal_scom_read(scom_map_t map, u64 reg, u64 *value)
@@ -98,8 +101,8 @@ static int opal_scom_read(scom_map_t map, u64 reg, u64 *value)
int64_t rc;
__be64 v;
- reg = opal_scom_unmangle(reg);
- rc = opal_xscom_read(m->chip, m->addr + reg, (__be64 *)__pa(&v));
+ reg = opal_scom_unmangle(m->addr + reg);
+ rc = opal_xscom_read(m->chip, reg, (__be64 *)__pa(&v));
*value = be64_to_cpu(v);
return opal_xscom_err_xlate(rc);
}
@@ -109,8 +112,8 @@ static int opal_scom_write(scom_map_t map, u64 reg, u64 value)
struct opal_scom_map *m = map;
int64_t rc;
- reg = opal_scom_unmangle(reg);
- rc = opal_xscom_write(m->chip, m->addr + reg, value);
+ reg = opal_scom_unmangle(m->addr + reg);
+ rc = opal_xscom_write(m->chip, reg, value);
return opal_xscom_err_xlate(rc);
}

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