lkml.org 
[lkml]   [2008]   [Apr]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[RFC patch 24/27] Immediate Values Use Arch NMI and MCE Support
Remove the architecture agnostic code now replaced by architecture specific,
atomic instruction updates.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
---
include/linux/immediate.h | 11 ------
kernel/immediate.c | 73 +---------------------------------------------
2 files changed, 3 insertions(+), 81 deletions(-)
Index: linux-2.6-lttng/kernel/immediate.c
===================================================================
--- linux-2.6-lttng.orig/kernel/immediate.c 2008-04-11 09:41:33.000000000 -0400
+++ linux-2.6-lttng/kernel/immediate.c 2008-04-14 18:48:05.000000000 -0400
@@ -19,92 +19,23 @@
#include <linux/mutex.h>
#include <linux/immediate.h>
#include <linux/memory.h>
-#include <linux/cpu.h>
-#include <linux/stop_machine.h>

#include <asm/sections.h>
-#include <asm/cacheflush.h>

/*
* Kernel ready to execute the SMP update that may depend on trap and ipi.
*/
static int imv_early_boot_complete;
-static int wrote_text;

extern struct __imv __start___imv[];
extern struct __imv __stop___imv[];

-static int stop_machine_imv_update(void *imv_ptr)
-{
- struct __imv *imv = imv_ptr;
-
- if (!wrote_text) {
- text_poke((void *)imv->imv, (void *)imv->var, imv->size);
- wrote_text = 1;
- smp_wmb(); /* make sure other cpus see that this has run */
- } else
- sync_core();
-
- flush_icache_range(imv->imv, imv->imv + imv->size);
-
- return 0;
-}
-
/*
* imv_mutex nests inside module_mutex. imv_mutex protects builtin
* immediates and module immediates.
*/
static DEFINE_MUTEX(imv_mutex);

-
-/**
- * apply_imv_update - update one immediate value
- * @imv: pointer of type const struct __imv to update
- *
- * Update one immediate value. Must be called with imv_mutex held.
- * It makes sure all CPUs are not executing the modified code by having them
- * busy looping with interrupts disabled.
- * It does _not_ protect against NMI and MCE (could be a problem with Intel's
- * errata if we use immediate values in their code path).
- */
-static int apply_imv_update(const struct __imv *imv)
-{
- /*
- * If the variable and the instruction have the same value, there is
- * nothing to do.
- */
- switch (imv->size) {
- case 1: if (*(uint8_t *)imv->imv
- == *(uint8_t *)imv->var)
- return 0;
- break;
- case 2: if (*(uint16_t *)imv->imv
- == *(uint16_t *)imv->var)
- return 0;
- break;
- case 4: if (*(uint32_t *)imv->imv
- == *(uint32_t *)imv->var)
- return 0;
- break;
- case 8: if (*(uint64_t *)imv->imv
- == *(uint64_t *)imv->var)
- return 0;
- break;
- default:return -EINVAL;
- }
-
- if (imv_early_boot_complete) {
- kernel_text_lock();
- wrote_text = 0;
- stop_machine_run(stop_machine_imv_update, (void *)imv,
- ALL_CPUS);
- kernel_text_unlock();
- } else
- text_poke_early((void *)imv->imv, (void *)imv->var,
- imv->size);
- return 0;
-}
-
/**
* imv_update_range - Update immediate values in a range
* @begin: pointer to the beginning of the range
@@ -121,7 +52,9 @@ void imv_update_range(const struct __imv
mutex_lock(&imv_mutex);
if (!iter->imv) /* Skip removed __init immediate values */
goto skip;
- ret = apply_imv_update(iter);
+ kernel_text_lock();
+ ret = arch_imv_update(iter, !imv_early_boot_complete);
+ kernel_text_unlock();
if (imv_early_boot_complete && ret)
printk(KERN_WARNING
"Invalid immediate value. "
Index: linux-2.6-lttng/include/linux/immediate.h
===================================================================
--- linux-2.6-lttng.orig/include/linux/immediate.h 2008-04-11 09:36:58.000000000 -0400
+++ linux-2.6-lttng/include/linux/immediate.h 2008-04-14 18:46:47.000000000 -0400
@@ -12,17 +12,6 @@

#ifdef CONFIG_IMMEDIATE

-struct __imv {
- unsigned long var; /* Pointer to the identifier variable of the
- * immediate value
- */
- unsigned long imv; /*
- * Pointer to the memory location of the
- * immediate value within the instruction.
- */
- unsigned char size; /* Type size. */
-} __attribute__ ((packed));
-
#include <asm/immediate.h>

/**
--
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68


\
 
 \ /
  Last update: 2008-04-16 23:39    [from the cache]
©2003-2011 Jasper Spaans