tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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]
+12
-9
+12
-9
arch/powerpc/platforms/powernv/opal-xscom.c
+12
-9
arch/powerpc/platforms/powernv/opal-xscom.c
···
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}
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}
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-
static u64 opal_scom_unmangle(u64 reg)
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+
static u64 opal_scom_unmangle(u64 addr)
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{
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/*
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* XSCOM indirect addresses have the top bit set. Additionally
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-
* the reset of the top 3 nibbles is always 0.
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+
* the rest of the top 3 nibbles is always 0.
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*
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* Because the debugfs interface uses signed offsets and shifts
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* the address left by 3, we basically cannot use the top 4 bits
···
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* conversion here. To leave room for further xscom address
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* expansion, we only clear out the top byte
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*
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* For in-kernel use, we also support the real indirect bit, so
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* we test for any of the top 5 bits
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*
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*/
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-
if (reg & (1ull << 59))
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-
reg = (reg & ~(0xffull << 56)) | (1ull << 63);
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-
return reg;
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+
if (addr & (0x1full << 59))
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+
addr = (addr & ~(0xffull << 56)) | (1ull << 63);
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return addr;
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}
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static int opal_scom_read(scom_map_t map, u64 reg, u64 *value)
···
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int64_t rc;
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__be64 v;
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-
reg = opal_scom_unmangle(reg);
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-
rc = opal_xscom_read(m->chip, m->addr + reg, (__be64 *)__pa(&v));
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+
reg = opal_scom_unmangle(m->addr + reg);
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rc = opal_xscom_read(m->chip, reg, (__be64 *)__pa(&v));
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*value = be64_to_cpu(v);
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return opal_xscom_err_xlate(rc);
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}
···
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struct opal_scom_map *m = map;
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int64_t rc;
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-
reg = opal_scom_unmangle(reg);
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-
rc = opal_xscom_write(m->chip, m->addr + reg, value);
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+
reg = opal_scom_unmangle(m->addr + reg);
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+
rc = opal_xscom_write(m->chip, reg, value);
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return opal_xscom_err_xlate(rc);
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}
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