diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index 5e9b4ef..41e0f17 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -14,6 +14,7 @@
 #define _ASM_POWERPC_PACA_H
 #ifdef __KERNEL__
 
+#include <linux/init.h>
 #include <asm/types.h>
 #include <asm/lppaca.h>
 #include <asm/mmu.h>
@@ -140,8 +141,11 @@ struct paca_struct {
 #endif
 };
 
-extern struct paca_struct paca[];
-extern void initialise_pacas(void);
+extern struct paca_struct *paca;
+extern __initdata struct paca_struct boot_paca;
+extern void allocate_pacas(void);
+extern void initialise_paca(struct paca_struct *new_paca, int cpu);
+extern void free_unused_pacas(void);
 
 #endif /* __KERNEL__ */
 #endif /* _ASM_POWERPC_PACA_H */
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 9258074..b24b700 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -219,7 +219,8 @@ generic_secondary_common_init:
 	 * physical cpu id in r24, we need to search the pacas to find
 	 * which logical id maps to our physical one.
 	 */
-	LOAD_REG_ADDR(r13, paca)	/* Get base vaddr of paca array	 */
+	LOAD_REG_ADDR(r13, paca)	/* Load paca pointer		 */
+	ld	r13,0(r13)		/* Get base vaddr of paca array	 */
 	li	r5,0			/* logical cpu id                */
 1:	lhz	r6,PACAHWCPUID(r13)	/* Load HW procid from paca      */
 	cmpw	r6,r24			/* Compare to our id             */
@@ -536,7 +537,8 @@ _GLOBAL(pmac_secondary_start)
 	mtmsrd	r3			/* RI on */
 
 	/* Set up a paca value for this processor. */
-	LOAD_REG_ADDR(r4,paca)		/* Get base vaddr of paca array	*/
+	LOAD_REG_ADDR(r4,paca)		/* Load paca pointer		*/
+	ld	r4,0(r4)		/* Get base vaddr of paca array	*/
 	mulli	r13,r24,PACA_SIZE	/* Calculate vaddr of right paca */
 	add	r13,r13,r4		/* for this processor.		*/
 	mtspr	SPRN_SPRG_PACA,r13	/* Save vaddr of paca in an SPRG*/
diff --git a/arch/powerpc/kernel/paca.c b/arch/powerpc/kernel/paca.c
index d16b1ea..0c40c6f 100644
--- a/arch/powerpc/kernel/paca.c
+++ b/arch/powerpc/kernel/paca.c
@@ -9,11 +9,15 @@
 
 #include <linux/threads.h>
 #include <linux/module.h>
+#include <linux/lmb.h>
 
+#include <asm/firmware.h>
 #include <asm/lppaca.h>
 #include <asm/paca.h>
 #include <asm/sections.h>
 #include <asm/pgtable.h>
+#include <asm/iseries/lpar_map.h>
+#include <asm/iseries/hv_types.h>
 
 /* This symbol is provided by the linker - let it fill in the paca
  * field correctly */
@@ -70,37 +74,82 @@ struct slb_shadow slb_shadow[] __cacheline_aligned = {
  * processors.  The processor VPD array needs one entry per physical
  * processor (not thread).
  */
-struct paca_struct paca[NR_CPUS];
+struct paca_struct *paca;
 EXPORT_SYMBOL(paca);
 
-void __init initialise_pacas(void)
-{
-	int cpu;
+struct paca_struct boot_paca;
 
-	/* The TOC register (GPR2) points 32kB into the TOC, so that 64kB
-	 * of the TOC can be addressed using a single machine instruction.
-	 */
+void __init initialise_paca(struct paca_struct *new_paca, int cpu)
+{
+       /* The TOC register (GPR2) points 32kB into the TOC, so that 64kB
+	* of the TOC can be addressed using a single machine instruction.
+	*/
 	unsigned long kernel_toc = (unsigned long)(&__toc_start) + 0x8000UL;
 
-	/* Can't use for_each_*_cpu, as they aren't functional yet */
-	for (cpu = 0; cpu < NR_CPUS; cpu++) {
-		struct paca_struct *new_paca = &paca[cpu];
-
 #ifdef CONFIG_PPC_BOOK3S
-		new_paca->lppaca_ptr = &lppaca[cpu];
+	new_paca->lppaca_ptr = &lppaca[cpu];
 #else
-		new_paca->kernel_pgd = swapper_pg_dir;
+	new_paca->kernel_pgd = swapper_pg_dir;
 #endif
-		new_paca->lock_token = 0x8000;
-		new_paca->paca_index = cpu;
-		new_paca->kernel_toc = kernel_toc;
-		new_paca->kernelbase = (unsigned long) _stext;
-		new_paca->kernel_msr = MSR_KERNEL;
-		new_paca->hw_cpu_id = 0xffff;
-		new_paca->__current = &init_task;
+	new_paca->lock_token = 0x8000;
+	new_paca->paca_index = cpu;
+	new_paca->kernel_toc = kernel_toc;
+	new_paca->kernelbase = (unsigned long) _stext;
+	new_paca->kernel_msr = MSR_KERNEL;
+	new_paca->hw_cpu_id = 0xffff;
+	new_paca->__current = &init_task;
 #ifdef CONFIG_PPC_STD_MMU_64
-		new_paca->slb_shadow_ptr = &slb_shadow[cpu];
+	new_paca->slb_shadow_ptr = &slb_shadow[cpu];
 #endif /* CONFIG_PPC_STD_MMU_64 */
+}
+
+static int __initdata paca_size;
+
+void __init allocate_pacas(void)
+{
+	int nr_cpus, cpu, limit;
+
+	/*
+	 * We can't take SLB misses on the paca, and we want to access them
+	 * in real mode, so allocate them within the RMA and also within
+	 * the first segment. On iSeries they must be within the area mapped
+	 * by the HV, which is HvPagesToMap * HVPAGESIZE bytes.
+	 */
+	limit = min(0x10000000ULL, lmb.rmo_size);
+	if (firmware_has_feature(FW_FEATURE_ISERIES))
+		limit = min(limit, HvPagesToMap * HVPAGESIZE);
+
+	nr_cpus = NR_CPUS;
+	/* On iSeries we know we can never have more than 64 cpus */
+	if (firmware_has_feature(FW_FEATURE_ISERIES))
+		nr_cpus = min(64, nr_cpus);
+
+	paca_size = PAGE_ALIGN(sizeof(struct paca_struct) * nr_cpus);
+
+	paca = __va(lmb_alloc_base(paca_size, PAGE_SIZE, limit));
+	memset(paca, 0, paca_size);
+
+	printk(KERN_DEBUG "Allocated %u bytes for %d pacas at %p\n",
+		paca_size, nr_cpus, paca);
+
+	/* Can't use for_each_*_cpu, as they aren't functional yet */
+	for (cpu = 0; cpu < nr_cpus; cpu++)
+		initialise_paca(&paca[cpu], cpu);
+}
+
+void __init free_unused_pacas(void)
+{
+	int new_size;
+
+	new_size = PAGE_ALIGN(sizeof(struct paca_struct) * num_possible_cpus());
+
+	if (new_size >= paca_size)
+		return;
+
+	lmb_free(__pa(paca) + new_size, paca_size - new_size);
+
+	printk(KERN_DEBUG "Freed %u bytes for unused pacas\n",
+		paca_size - new_size);
 
-	}
+	paca_size = new_size;
 }
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 4ec3008..50c3c55 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -1224,6 +1224,8 @@ void __init early_init_devtree(void *params)
 	 * FIXME .. and the initrd too? */
 	move_device_tree();
 
+	allocate_pacas();
+
 	DBG("Scanning CPUs ...\n");
 
 	/* Retreive CPU related informations from the flat tree
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 03dd6a2..5df0f6a 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -493,6 +493,8 @@ void __init smp_setup_cpu_maps(void)
 	 * here will have to be reworked
 	 */
 	cpu_init_thread_core_maps(nthreads);
+
+	free_unused_pacas();
 }
 #endif /* CONFIG_SMP */
 
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 6568406..6354739 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -144,9 +144,9 @@ early_param("smt-enabled", early_smt_enabled);
 #endif /* CONFIG_SMP */
 
 /* Put the paca pointer into r13 and SPRG_PACA */
-void __init setup_paca(int cpu)
+static void __init setup_paca(struct paca_struct *new_paca)
 {
-	local_paca = &paca[cpu];
+	local_paca = new_paca;
 	mtspr(SPRN_SPRG_PACA, local_paca);
 #ifdef CONFIG_PPC_BOOK3E
 	mtspr(SPRN_SPRG_TLB_EXFRAME, local_paca->extlb);
@@ -176,14 +176,12 @@ void __init early_setup(unsigned long dt_ptr)
 {
 	/* -------- printk is _NOT_ safe to use here ! ------- */
 
-	/* Fill in any unititialised pacas */
-	initialise_pacas();
-
 	/* Identify CPU type */
 	identify_cpu(0, mfspr(SPRN_PVR));
 
 	/* Assume we're on cpu 0 for now. Don't write to the paca yet! */
-	setup_paca(0);
+	initialise_paca(&boot_paca, 0);
+	setup_paca(&boot_paca);
 
 	/* Initialize lockdep early or else spinlocks will blow */
 	lockdep_init();
@@ -203,7 +201,7 @@ void __init early_setup(unsigned long dt_ptr)
 	early_init_devtree(__va(dt_ptr));
 
 	/* Now we know the logical id of our boot cpu, setup the paca. */
-	setup_paca(boot_cpuid);
+	setup_paca(&paca[boot_cpuid]);
 
 	/* Fix up paca fields required for the boot cpu */
 	get_paca()->cpu_start = 1;
diff --git a/arch/powerpc/platforms/iseries/exception.S b/arch/powerpc/platforms/iseries/exception.S
index 5369653..fba5bf9 100644
--- a/arch/powerpc/platforms/iseries/exception.S
+++ b/arch/powerpc/platforms/iseries/exception.S
@@ -43,17 +43,14 @@ system_reset_iSeries:
 	LOAD_REG_ADDR(r23, alpaca)
 	li	r0,ALPACA_SIZE
 	sub	r23,r13,r23
-	divdu	r23,r23,r0		/* r23 has cpu number */
-	LOAD_REG_ADDR(r13, paca)
-	mulli	r0,r23,PACA_SIZE
-	add	r13,r13,r0
-	mtspr	SPRN_SPRG_PACA,r13	/* Save it away for the future */
-	mfmsr	r24
-	ori	r24,r24,MSR_RI
-	mtmsrd	r24			/* RI on */
-	mr	r24,r23
+	divdu	r24,r23,r0		/* r24 has cpu number */
 	cmpwi	0,r24,0			/* Are we processor 0? */
 	bne	1f
+	LOAD_REG_ADDR(r13, boot_paca)
+	mtspr	SPRN_SPRG_PACA,r13	/* Save it away for the future */
+	mfmsr	r23
+	ori	r23,r23,MSR_RI
+	mtmsrd	r23			/* RI on */
 	b	.__start_initialization_iSeries	/* Start up the first processor */
 1:	mfspr	r4,SPRN_CTRLF
 	li	r5,CTRL_RUNLATCH	/* Turn off the run light */
@@ -86,6 +83,16 @@ system_reset_iSeries:
 #endif
 
 2:
+	/* Load our paca now that it's been allocated */
+	LOAD_REG_ADDR(r13, paca)
+	ld	r13,0(r13)
+	mulli	r0,r24,PACA_SIZE
+	add	r13,r13,r0
+	mtspr	SPRN_SPRG_PACA,r13	/* Save it away for the future */
+	mfmsr	r23
+	ori	r23,r23,MSR_RI
+	mtmsrd	r23			/* RI on */
+
 	HMT_LOW
 #ifdef CONFIG_SMP
 	lbz	r23,PACAPROCSTART(r13)	/* Test if this processor
