2.4.19-pre5

 arch

 i386

 kernel

diff -Naur -X /home/marcelo/lib/dontdiff linux.orig/arch/i386/kernel/microcode.c linux/arch/i386/kernel/microcode.c
--- linux.orig/arch/i386/kernel/microcode.c   Tue Oct 30 23:13:17 2001
+++ linux/arch/i386/kernel/microcode.c   Fri Mar 29 20:51:35 2002
@@ -51,6 +51,12 @@
  *      Bugfix for HT (Hyper-Threading) enabled processors
  *      whereby processor resources are shared by all logical processors
  *      in a single CPU package.
+ *   1.10   28 Feb 2002 Asit K Mallick <asit.k.mallick@intel.com> and
+ *      Tigran Aivazian <tigran@veritas.com>,
+ *      Serialize updates as required on HT processors due to speculative
+ *      nature of implementation.
+ *   1.11   22 Mar 2001 Tigran Aivazian <tigran@veritas.com>
+ *      Fix the panic when writing zero-length microcode chunk.
  */
 
 #include <linux/init.h>
@@ -60,12 +66,16 @@
 #include <linux/vmalloc.h>
 #include <linux/miscdevice.h>
 #include <linux/devfs_fs_kernel.h>
+#include <linux/spinlock.h>
 
 #include <asm/msr.h>
 #include <asm/uaccess.h>
 #include <asm/processor.h>
 
-#define MICROCODE_VERSION    "1.09"
+
+static spinlock_t microcode_update_lock = SPIN_LOCK_UNLOCKED;
+
+#define MICROCODE_VERSION    "1.11"
 
 MODULE_DESCRIPTION("Intel CPU (IA-32) microcode update driver");
 MODULE_AUTHOR("Tigran Aivazian <tigran@veritas.com>");
@@ -195,7 +205,8 @@
    struct cpuinfo_x86 *c = cpu_data + cpu_num;
    struct update_req *req = update_req + cpu_num;
    unsigned int pf = 0, val[2], rev, sig;
-   int i,found=0;
+   unsigned long flags;
+   int i;
 
    req->err = 1; /* assume update will fail on this cpu */
 
@@ -216,8 +227,9 @@
    for (i=0; i<microcode_num; i++)
       if (microcode[i].sig == sig && microcode[i].pf == pf &&
           microcode[i].ldrver == 1 && microcode[i].hdrver == 1) {
-
-         found=1;
+         int sum = 0;
+         struct microcode *m = µcode[i];
+         unsigned int *sump = (unsigned int *)(m+1);
 
          printf("Microcode\n");
          printf("   Header Revision %d\n",microcode[i].hdrver);
@@ -234,54 +246,69 @@
          printf("   Loader Revision %x\n",microcode[i].ldrver);
          printf("   Processor Flags %x\n\n",microcode[i].pf);
 
+         req->slot = i;
+
+         /* serialize access to update decision */
+         spin_lock_irqsave(µcode_update_lock, flags);          
+
          /* trick, to work even if there was no prior update by the BIOS */
          wrmsr(MSR_IA32_UCODE_REV, 0, 0);
          __asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx");
 
          /* get current (on-cpu) revision into rev (ignore val[0]) */
          rdmsr(MSR_IA32_UCODE_REV, val[0], rev);
+         
          if (microcode[i].rev < rev) {
+            spin_unlock_irqrestore(µcode_update_lock, flags);
             printk(KERN_ERR 
-               "microcode: CPU%d not 'upgrading' to earlier revision"
+                   "microcode: CPU%d not 'upgrading' to earlier revision"
+                   " %d (current=%d)\n", cpu_num, microcode[i].rev, rev);
+            return;
+         } else if (microcode[i].rev == rev) {
+            /* notify the caller of success on this cpu */
+            req->err = 0;
+            spin_unlock_irqrestore(µcode_update_lock, flags);
+            printk(KERN_ERR 
+               "microcode: CPU%d already at revision"
                " %d (current=%d)\n", cpu_num, microcode[i].rev, rev);
-         } else {
-            int sum = 0;
-            struct microcode *m = µcode[i];
-            unsigned int *sump = (unsigned int *)(m+1);
-
-            while (--sump >= (unsigned int *)m)
-               sum += *sump;
-            if (sum != 0) {
-               printk(KERN_ERR "microcode: CPU%d aborting, "
-                     "bad checksum\n", cpu_num);
-               break;
-            }
-
-            /* write microcode via MSR 0x79 */
-            wrmsr(MSR_IA32_UCODE_WRITE, (unsigned int)(m->bits), 0);
+            return;
+         }
 
-            /* serialize */
-            __asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx");
+         /* Verify the checksum */
+         while (--sump >= (unsigned int *)m)
+            sum += *sump;
+         if (sum != 0) {
+            req->err = 1;
+            spin_unlock_irqrestore(µcode_update_lock, flags);
+            printk(KERN_ERR "microcode: CPU%d aborting, "
+                   "bad checksum\n", cpu_num);
+            return;
+         }
+         
+         /* write microcode via MSR 0x79 */
+         wrmsr(MSR_IA32_UCODE_WRITE, (unsigned int)(m->bits), 0);
 
-            /* get the current revision from MSR 0x8B */
-            rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
+         /* serialize */
+         __asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx");
 
-            /* notify the caller of success on this cpu */
-            req->err = 0;
-            req->slot = i;
+         /* get the current revision from MSR 0x8B */
+         rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
 
-            printk(KERN_INFO "microcode: CPU%d updated from revision "
-                  "%d to %d, date=%08x\n", 
-                  cpu_num, rev, val[1], m->date);
-         }
-         break;
+         /* notify the caller of success on this cpu */
+         req->err = 0;
+         spin_unlock_irqrestore(µcode_update_lock, flags);
+         printk(KERN_INFO "microcode: CPU%d updated from revision "
+                "%d to %d, date=%08x\n", 
+                cpu_num, rev, val[1], microcode[i].date);
+         return;
       }
-
-   if(!found)
-      printk(KERN_ERR "microcode: CPU%d no microcode found! (sig=%x, pflags=%d)\n",
-            cpu_num, sig, pf);
+   
+   printk(KERN_ERR
+          "microcode: CPU%d no microcode found! (sig=%x, pflags=%d)\n", 
+          cpu_num, sig, pf);
 }
 
+
 static ssize_t microcode_read(struct file *file, char *buf, size_t len, loff_t *ppos)
 {
    ssize_t ret = 0;
@@ -305,9 +332,13 @@
 {
    ssize_t ret;
 
-   if (len % sizeof(struct microcode) != 0) {
+   if (!len || len % sizeof(struct microcode) != 0) {
       printk(KERN_ERR "microcode: can only write in N*%d bytes units\n", 
          sizeof(struct microcode));
+      return -EINVAL;
+   }
+   if ((len >> PAGE_SHIFT) > num_physpages) {
+      printk(KERN_ERR "microcode: too much data (max %d pages)\n", num_physpages);
       return -EINVAL;
    }
    down_write(µcode_rwsem);