871b72dd1e
* Solve issues described in 6f66cbc630
in a way that doesn't resort to set_cpus_allowed();
* in fact, only collect_cpu_info and apply_microcode callbacks
must run on a target cpu, others will do just fine on any other.
smp_call_function_single() (as suggested by Ingo) is used to run
these callbacks on a target cpu.
* cleanup of synchronization logic of the 'microcode_core' part
The generic 'microcode_core' part guarantees that only a single cpu
(be it a full-fledged cpu, one of the cores or HT)
is being updated at any particular moment of time.
In general, there is no need for any additional sync. mechanism in
arch-specific parts (the patch removes existing spinlocks).
See also the "Synchronization" section in microcode_core.c.
* return -EINVAL instead of -1 (which is translated into -EPERM) in
microcode_write(), reload_cpu() and mc_sysdev_add(). Other suggestions
for an error code?
* use 'enum ucode_state' as return value of request_microcode_{fw, user}
to gain more flexibility by distinguishing between real error cases
and situations when an appropriate ucode was not found (which is not an
error per-se).
* some minor cleanups
Thanks a lot to Hugh Dickins for review/suggestions/testing!
Reference: http://marc.info/?l=linux-kernel&m=124025889012541&w=2
[ Impact: refactor and clean up microcode driver locking code ]
Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Acked-by: Hugh Dickins <hugh@veritas.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Peter Oruba <peter.oruba@amd.com>
Cc: Arjan van de Ven <arjan@infradead.org>
LKML-Reference: <1242078507.5560.9.camel@earth>
[ did some more cleanups ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/include/asm/microcode.h | 25 ++
arch/x86/kernel/microcode_amd.c | 58 ++----
arch/x86/kernel/microcode_core.c | 326 +++++++++++++++++++++-----------------
arch/x86/kernel/microcode_intel.c | 92 +++-------
4 files changed, 261 insertions(+), 240 deletions(-)
(~20 new comment lines)
59 lines
1.3 KiB
C
59 lines
1.3 KiB
C
#ifndef _ASM_X86_MICROCODE_H
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#define _ASM_X86_MICROCODE_H
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struct cpu_signature {
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unsigned int sig;
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unsigned int pf;
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unsigned int rev;
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};
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struct device;
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enum ucode_state { UCODE_ERROR, UCODE_OK, UCODE_NFOUND };
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struct microcode_ops {
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enum ucode_state (*request_microcode_user) (int cpu,
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const void __user *buf, size_t size);
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enum ucode_state (*request_microcode_fw) (int cpu,
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struct device *device);
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void (*microcode_fini_cpu) (int cpu);
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/*
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* The generic 'microcode_core' part guarantees that
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* the callbacks below run on a target cpu when they
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* are being called.
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* See also the "Synchronization" section in microcode_core.c.
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*/
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int (*apply_microcode) (int cpu);
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int (*collect_cpu_info) (int cpu, struct cpu_signature *csig);
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};
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struct ucode_cpu_info {
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struct cpu_signature cpu_sig;
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int valid;
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void *mc;
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};
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extern struct ucode_cpu_info ucode_cpu_info[];
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#ifdef CONFIG_MICROCODE_INTEL
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extern struct microcode_ops * __init init_intel_microcode(void);
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#else
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static inline struct microcode_ops * __init init_intel_microcode(void)
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{
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return NULL;
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}
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#endif /* CONFIG_MICROCODE_INTEL */
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#ifdef CONFIG_MICROCODE_AMD
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extern struct microcode_ops * __init init_amd_microcode(void);
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#else
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static inline struct microcode_ops * __init init_amd_microcode(void)
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{
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return NULL;
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}
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#endif
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#endif /* _ASM_X86_MICROCODE_H */
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