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powerpc/powernv: Fix indirect XSCOM unmangling

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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]
This commit is contained in:
Benjamin Herrenschmidt 2014-02-28 16:20:38 +11:00
parent 2f3f38e4d3
commit e0cf957614
1 changed files with 12 additions and 9 deletions
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21
arch/powerpc/platforms/powernv/opal-xscom.c
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@ -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 * 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 * Because the debugfs interface uses signed offsets and shifts
* the address left by 3, we basically cannot use the top 4 bits * 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 * conversion here. To leave room for further xscom address
* expansion, we only clear out the top byte * 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)) if (addr & (0x1full << 59))
reg = (reg & ~(0xffull << 56)) | (1ull << 63); addr = (addr & ~(0xffull << 56)) | (1ull << 63);
return reg; return addr;
} }
static int opal_scom_read(scom_map_t map, u64 reg, u64 *value) 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; int64_t rc;
__be64 v; __be64 v;
reg = opal_scom_unmangle(reg); reg = opal_scom_unmangle(m->addr + reg);
rc = opal_xscom_read(m->chip, m->addr + reg, (__be64 *)__pa(&v)); rc = opal_xscom_read(m->chip, reg, (__be64 *)__pa(&v));
*value = be64_to_cpu(v); *value = be64_to_cpu(v);
return opal_xscom_err_xlate(rc); 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; struct opal_scom_map *m = map;
int64_t rc; int64_t rc;
reg = opal_scom_unmangle(reg); reg = opal_scom_unmangle(m->addr + reg);
rc = opal_xscom_write(m->chip, m->addr + reg, value); rc = opal_xscom_write(m->chip, reg, value);
return opal_xscom_err_xlate(rc); return opal_xscom_err_xlate(rc);
} }