From e0cf957614976896111e676e5134ac98ee227d3d Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Fri, 28 Feb 2014 16:20:38 +1100 Subject: [PATCH] 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 CC: [v3.13] --- arch/powerpc/platforms/powernv/opal-xscom.c | 21 ++++++++++++--------- 1 file 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); } -- 2.7.4