Add better error handling for RTAS calls. These can potentially cause

machine checks (e.g. invalid PCI configuration cycles), but these can
be caught and recovered from. This change also the RTAS PCI driver to
work without modification as a replacement for the Grackle driver on
Grackle-based Powermacs.

1 files changed, 18 insertions, 1 deletions

diff --git a/sys/powerpc/ofw/rtas.c b/sys/powerpc/ofw/rtas.c
index 59692c9..66ce12f 100644
--- a/sys/powerpc/ofw/rtas.c
+++ b/sys/powerpc/ofw/rtas.c
@@ -32,6 +32,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/lock.h>
 #include <sys/mutex.h>
 #include <sys/systm.h>
+#include <sys/proc.h>
 
 #include <vm/vm.h>
 #include <vm/vm_page.h>
@@ -39,6 +40,7 @@ __FBSDID("$FreeBSD$");
 
 #include <machine/bus.h>
 #include <machine/md_var.h>
+#include <machine/pcb.h>
 #include <machine/pmap.h>
 #include <machine/rtas.h>
 #include <machine/stdarg.h>
@@ -60,6 +62,8 @@ int rtascall(vm_offset_t callbuffer, uintptr_t rtas_privdat);
 extern uintptr_t	rtas_entry;
 extern register_t	rtasmsr;
 
+int setfault(faultbuf);             /* defined in locore.S */
+
 /*
  * After the VM is up, allocate RTAS memory and instantiate it
  */
@@ -188,6 +192,7 @@ int
 rtas_call_method(cell_t token, int nargs, int nreturns, ...)
 {
 	vm_offset_t argsptr;
+	faultbuf env;
 	va_list ap;
 	struct {
 		cell_t token;
@@ -213,7 +218,19 @@ rtas_call_method(cell_t token, int nargs, int nreturns, ...)
 		args.args_n_results[n] = va_arg(ap, cell_t);
 
 	argsptr = rtas_real_map(&args, sizeof(args));
-	result = rtascall(argsptr, rtas_private_data);
+
+	/* Get rid of any stale machine checks that have been waiting.  */
+	__asm __volatile ("sync; isync");
+        if (!setfault(env)) {
+		__asm __volatile ("sync");
+		result = rtascall(argsptr, rtas_private_data);
+		__asm __volatile ("sync; isync");
+	} else {
+		result = RTAS_HW_ERROR;
+	}
+	curthread->td_pcb->pcb_onfault = 0;
+	__asm __volatile ("sync");
+
 	rtas_real_unmap(argsptr, &args, sizeof(args));
 	mtx_unlock(&rtas_mtx);