ppc64: Allocate RTAS above OF, from Peter Bergner

arch/ppc64/kernel/head.S

@@ -153,8 +153,9 @@ _GLOBAL(__secondary_hold)
  */
 
 /*
- * We make as much of the exception code common between native Pseries
- * and Iseries LPAR implementations as possible.
+ * We make as much of the exception code common between native
+ * exception handlers (including pSeries LPAR) and iSeries LPAR
+ * implementations as possible.
  */
 
 /*
@@ -1340,17 +1341,10 @@ _STATIC(__after_prom_start)
 					/* executed here.                 */
 
         LOADADDR(r0, 4f)                /* Jump to the copy of this code  */
-	mtctr	r0			/* that we just made              */
+	mtctr	r0			/* that we just made/relocated    */
 	bctr
 
-4:	LOADADDR(r9,rtas)
-	sub	r9,r9,r26
-	ld	r5,RTASBASE(r9)		/* get the value of rtas->base */
-	ld	r9,RTASSIZE(r9)		/* get the value of rtas->size */
-	bl	.copy_and_flush		/* copy upto rtas->base */
-	add     r6,r6,r9		/* then skip over rtas->size bytes */
-
-	LOADADDR(r5,klimit)
+4:	LOADADDR(r5,klimit)
 	sub	r5,r5,r26
 	ld	r5,0(r5)		/* get the value of klimit */
 	sub	r5,r5,r27
@@ -1675,9 +1669,6 @@ _STATIC(start_here_pSeries)
 	addi    r2,r2,0x4000
 	sub	r2,r2,r26
 
-	/* Init naca->debug_switch so it can be used in stab & htab init.  */
-	bl	.ppcdbg_initialize
-
 	/* Get the pointer to the segment table which is used by           */
 	/* stab_initialize                                                 */
 	LOADADDR(r27, boot_cpuid)

arch/ppc64/kernel/lmb.c

@@ -12,6 +12,7 @@
  */
 
 #include <linux/config.h>
+#include <linux/kernel.h>
 #include <asm/types.h>
 #include <asm/page.h>
 #include <asm/prom.h>
@@ -27,7 +28,7 @@ extern unsigned long reloc_offset(void);
 static long lmb_add_region(struct lmb_region *, unsigned long, unsigned long, unsigned long);
 
 struct lmb lmb = {
-	0,
+	0, 0,
 	{0,0,0,0,{{0,0,0}}},
 	{0,0,0,0,{{0,0,0}}}
 };
@@ -150,6 +151,10 @@ lmb_add(unsigned long base, unsigned long size)
 	struct lmb *_lmb = PTRRELOC(&lmb);
 	struct lmb_region *_rgn = &(_lmb->memory);
 
+	/* On pSeries LPAR systems, the first LMB is our RMO region. */
+	if ( base == 0 )
+		_lmb->rmo_size = size;
+
 	return lmb_add_region(_rgn, base, size, LMB_MEMORY_AREA);
 
 }
@@ -257,12 +262,17 @@ lmb_overlaps_region(struct lmb_region *rgn, unsigned long base, unsigned long si
 	return (i < rgn->cnt) ? i : -1;
 }
 
-
 unsigned long
 lmb_alloc(unsigned long size, unsigned long align)
+{
+	return lmb_alloc_base(size, align, LMB_ALLOC_ANYWHERE);
+}
+
+unsigned long
+lmb_alloc_base(unsigned long size, unsigned long align, unsigned long max_addr)
 {
 	long i, j;
-	unsigned long base;
+	unsigned long base = 0;
 	unsigned long offset = reloc_offset();
 	struct lmb *_lmb = PTRRELOC(&lmb);
 	struct lmb_region *_mem = &(_lmb->memory);
@@ -276,7 +286,12 @@ lmb_alloc(unsigned long size, unsigned long align)
 		if ( lmbtype != LMB_MEMORY_AREA )
 			continue;
 
+		if ( max_addr == LMB_ALLOC_ANYWHERE )
 		base = _ALIGN_DOWN(lmbbase+lmbsize-size, align);
+		else if ( lmbbase < max_addr )
+			base = _ALIGN_DOWN(min(lmbbase+lmbsize,max_addr)-size, align);
+		else
+			continue;
 
 		while ( (lmbbase <= base) &&
 			((j = lmb_overlaps_region(_rsv,base,size)) >= 0) ) {

arch/ppc64/kernel/prom.c

@@ -619,8 +619,8 @@ prom_initialize_lmb(unsigned long mem)
 }
 
 
-static unsigned long __init
-prom_instantiate_rtas(unsigned long mem)
+static void __init
+prom_instantiate_rtas(void)
 {
 	unsigned long offset = reloc_offset();
 	struct prom_t *_prom = PTRRELOC(&prom);
@@ -653,16 +653,18 @@ prom_instantiate_rtas(unsigned long mem)
 	        _rtas->size = getprop_rval;
 		prom_print(RELOC("instantiating rtas"));
 		if (_rtas->size != 0) {
-			/*
-			 * Ask OF for some space for RTAS.
-			 * Actually OF has bugs so we just arbitrarily
-			 * use memory at the 6MB point.
+			unsigned long rtas_region = RTAS_INSTANTIATE_MAX;
+
+			/* Grab some space within the first RTAS_INSTANTIATE_MAX bytes
+			 * of physical memory (or within the RMO region) because RTAS
+			 * runs in 32-bit mode and relocate off.
 			 */
-			// The new code...
-			mem = PAGE_ALIGN(mem);
-			_rtas->base = mem + offset - KERNELBASE;
+			if ( _naca->platform == PLATFORM_PSERIES_LPAR ) {
+				struct lmb *_lmb  = PTRRELOC(&lmb);
+				rtas_region = min(_lmb->rmo_size, RTAS_INSTANTIATE_MAX);
+			}
+			_rtas->base = lmb_alloc_base(_rtas->size, PAGE_SIZE, rtas_region);
 
-			mem += _rtas->size;
 			prom_print(RELOC(" at 0x"));
 			prom_print_hex(_rtas->base);
 
@@ -699,8 +701,6 @@ prom_instantiate_rtas(unsigned long mem)
 #ifdef DEBUG_PROM
 	prom_print(RELOC("prom_instantiate_rtas: end...\n"));
 #endif
-
-	return mem;
 }
 
 unsigned long prom_strtoul(const char *cp)
@@ -940,7 +940,7 @@ prom_initialize_tce_table(void)
 		align = (minalign < minsize) ? minsize : minalign;
 
 		/* Carve out storage for the TCE table. */
-		base = lmb_alloc(minsize, align);
+		base = lmb_alloc(8UL << 20, 8UL << 20);
 
 		if ( !base ) {
 			prom_print(RELOC("ERROR, cannot find space for TCE table.\n"));
@@ -1378,7 +1378,7 @@ prom_init(unsigned long r3, unsigned long r4, unsigned long pp,
 
 	mem = prom_bi_rec_reserve(mem);
 
-	mem = prom_instantiate_rtas(mem);
+	prom_instantiate_rtas();
         
         /* Initialize some system info into the Naca early... */
         mem = prom_initialize_naca(mem);

include/asm-ppc64/lmb.h

@@ -28,6 +28,9 @@ union lmb_reg_property {
 #define LMB_MEMORY_AREA	1
 #define LMB_IO_AREA	2
 
+#define LMB_ALLOC_ANYWHERE	0
+#define LMB_ALLOC_FIRST4GBYTE	(1UL<<32)
+
 struct lmb_property {
 	unsigned long base;
 	unsigned long physbase;
@@ -45,6 +48,7 @@ struct lmb_region {
 
 struct lmb {
 	unsigned long debug;
+	unsigned long rmo_size;
 	struct lmb_region memory;
 	struct lmb_region reserved;
 };
@@ -59,6 +63,7 @@ extern long lmb_add_io(unsigned long base, unsigned long size);
 #endif /* CONFIG_MSCHUNKS */
 extern long lmb_reserve(unsigned long, unsigned long);
 extern unsigned long lmb_alloc(unsigned long, unsigned long);
+extern unsigned long lmb_alloc_base(unsigned long, unsigned long, unsigned long);
 extern unsigned long lmb_phys_mem_size(void);
 extern unsigned long lmb_end_of_DRAM(void);
 extern unsigned long lmb_abs_to_phys(unsigned long);

include/asm-ppc64/rtas.h

@@ -17,6 +17,8 @@
  */
 
 #define RTAS_UNKNOWN_SERVICE (-1)
+#define RTAS_INSTANTIATE_MAX (1UL<<30) /* Don't instantiate rtas at/above this value */
+
 /*
  * In general to call RTAS use rtas_token("string") to lookup
  * an RTAS token for the given string (e.g. "event-scan").