xnu-1699.22.73.tar.gz

[apple/xnu.git] / osfmk / i386 / ucode.c

diff --git a/osfmk/i386/ucode.c b/osfmk/i386/ucode.c
new file mode 100644 (file)
index 0000000..e416cc5
--- /dev/null
+++ b/osfmk/i386/ucode.c
@@ -0,0 +1,201 @@
+/*
+ *  ucode.c
+ *
+ *  Microcode updater interface sysctl
+ */
+
+#include <kern/locks.h>
+#include <i386/ucode.h>
+#include <sys/errno.h>
+#include <i386/proc_reg.h>
+#include <i386/cpuid.h>
+#include <vm/vm_kern.h>
+#include <i386/mp.h>                   // mp_broadcast
+#include <machine/cpu_number.h> // cpu_number
+
+#define IA32_BIOS_UPDT_TRIG (0x79) /* microcode update trigger MSR */
+
+struct intel_ucupdate *global_update = NULL;
+
+/* Exceute the actual update! */
+static void
+update_microcode(void)
+{
+       /* SDM Example 9-8 code shows that we load the
+        * address of the UpdateData within the microcode blob,
+        * not the address of the header.
+        */
+       wrmsr64(IA32_BIOS_UPDT_TRIG, (uint64_t)(uintptr_t)&global_update->data);
+}
+
+/* locks */
+static lck_grp_attr_t *ucode_slock_grp_attr = NULL;
+static lck_grp_t *ucode_slock_grp = NULL;
+static lck_attr_t *ucode_slock_attr = NULL;
+static lck_spin_t *ucode_slock = NULL;
+
+static kern_return_t
+register_locks(void)
+{
+       /* already allocated? */
+       if (ucode_slock_grp_attr && ucode_slock_grp && ucode_slock_attr && ucode_slock)
+               return KERN_SUCCESS;
+
+       /* allocate lock group attribute and group */
+       if (!(ucode_slock_grp_attr = lck_grp_attr_alloc_init()))
+               goto nomem_out;
+
+       lck_grp_attr_setstat(ucode_slock_grp_attr);
+
+       if (!(ucode_slock_grp = lck_grp_alloc_init("uccode_lock", ucode_slock_grp_attr)))
+               goto nomem_out;
+
+       /* Allocate lock attribute */
+       if (!(ucode_slock_attr = lck_attr_alloc_init()))
+               goto nomem_out;
+
+       /* Allocate the spin lock */
+       /* We keep one global spin-lock. We could have one per update
+        * request... but srsly, why would you update microcode like that?
+        */
+       if (!(ucode_slock = lck_spin_alloc_init(ucode_slock_grp, ucode_slock_attr)))
+               goto nomem_out;
+
+       return KERN_SUCCESS;
+
+nomem_out:
+       /* clean up */
+       if (ucode_slock)
+               lck_spin_free(ucode_slock, ucode_slock_grp);
+       if (ucode_slock_attr)
+               lck_attr_free(ucode_slock_attr);
+       if (ucode_slock_grp)
+               lck_grp_free(ucode_slock_grp);
+       if (ucode_slock_grp_attr)
+               lck_grp_attr_free(ucode_slock_grp_attr);
+
+       return KERN_NO_SPACE;
+}
+
+/* Copy in an update */
+static int
+copyin_update(uint64_t inaddr)
+{
+       struct intel_ucupdate update_header;
+       struct intel_ucupdate *update;
+       vm_size_t size;
+       kern_return_t ret;
+       int error;
+
+       /* Copy in enough header to peek at the size */
+       error = copyin((user_addr_t)inaddr, (void *)&update_header, sizeof(update_header));
+       if (error)
+               return error;
+
+       /* Get the actual, alleged size */
+       size = update_header.total_size;
+
+       /* huge bogus piece of data that somehow made it through? */
+       if (size >= 1024 * 1024)
+               return ENOMEM;
+
+       /* Old microcodes? */
+       if (size == 0)
+               size = 2048; /* default update size; see SDM */
+
+       /*
+        * create the buffer for the update
+        * It need only be aligned to 16-bytes, according to the SDM.
+        * This also wires it down
+        */
+       ret = kmem_alloc_kobject(kernel_map, (vm_offset_t *)&update, size);
+       if (ret != KERN_SUCCESS)
+               return ENOMEM;
+
+       /* Copy it in */
+       error = copyin((user_addr_t)inaddr, (void*)update, size);
+       if (error) {
+               kmem_free(kernel_map, (vm_offset_t)update, size);
+               return error;
+       }
+
+       global_update = update;
+       return 0;
+}
+
+/*
+ * This is called once by every CPU on a wake from sleep/hibernate
+ * and is meant to re-apply a microcode update that got lost
+ * by sleeping.
+ */
+void
+ucode_update_wake()
+{
+       if (global_update) {
+               kprintf("ucode: Re-applying update after wake (CPU #%d)\n", cpu_number());
+               update_microcode();
+#ifdef DEBUG
+       } else {
+               kprintf("ucode: No update to apply (CPU #%d)\n", cpu_number());
+#endif
+       }
+}
+
+static void
+cpu_update(__unused void *arg)
+{
+       /* grab the lock */
+       lck_spin_lock(ucode_slock);
+
+       /* execute the update */
+       update_microcode();
+
+       /* if CPU #0, update global CPU information */
+       if (!cpu_number())
+               cpuid_set_info();
+
+       /* release the lock */
+       lck_spin_unlock(ucode_slock);
+}
+
+/* Farm an update out to all CPUs */
+static void
+xcpu_update(void)
+{
+       if (register_locks() != KERN_SUCCESS)
+               return;
+
+       /* Get all CPUs to perform the update */
+       mp_broadcast(cpu_update, NULL);
+}
+
+/*
+ * sysctl function
+ *
+ */
+int
+ucode_interface(uint64_t addr)
+{
+       int error;
+
+#if !DEBUG
+       /*
+        * Userland may only call this once per boot. Anything else
+        * would not make sense (all updates are cumulative), and also
+        * leak memory, because we don't free previous updates.
+        */
+       if (global_update)
+               return EPERM;
+#endif
+
+       /* Get the whole microcode */
+       error = copyin_update(addr);
+
+       if (error)
+               return error;
+
+       /* Farm out the updates */
+       xcpu_update();
+
+       return 0;
+}