powerpc: Add PACA fields specific to 64-bit Book3E processors

This adds various fields in the PACA that are for use specifically
by Book3E processors, such as exception save areas, current pgd
pointer, special exceptions kernel stacks etc...
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/include/asm/paca.h

@@ -17,6 +17,8 @@
 #include <asm/types.h>
 #include <asm/lppaca.h>
 #include <asm/mmu.h>
+#include <asm/page.h>
+#include <asm/exception-64e.h>
 
 register struct paca_struct *local_paca asm("r13");
 
@@ -91,6 +93,21 @@ struct paca_struct {
 	u16 slb_cache[SLB_CACHE_ENTRIES];
 #endif /* CONFIG_PPC_STD_MMU_64 */
 
+#ifdef CONFIG_PPC_BOOK3E
+	pgd_t *pgd;			/* Current PGD */
+	pgd_t *kernel_pgd;		/* Kernel PGD */
+	u64 exgen[8] __attribute__((aligned(0x80)));
+	u64 extlb[EX_TLB_SIZE*3] __attribute__((aligned(0x80)));
+	u64 exmc[8];		/* used for machine checks */
+	u64 excrit[8];		/* used for crit interrupts */
+	u64 exdbg[8];		/* used for debug interrupts */
+
+	/* Kernel stack pointers for use by special exceptions */
+	void *mc_kstack;
+	void *crit_kstack;
+	void *dbg_kstack;
+#endif /* CONFIG_PPC_BOOK3E */
+
 	mm_context_t context;
 
 	/*

arch/powerpc/kernel/asm-offsets.c

@@ -140,6 +140,20 @@ int main(void)
 					    context.high_slices_psize));
 	DEFINE(MMUPSIZEDEFSIZE, sizeof(struct mmu_psize_def));
 #endif /* CONFIG_PPC_MM_SLICES */
+
+#ifdef CONFIG_PPC_BOOK3E
+	DEFINE(PACAPGD, offsetof(struct paca_struct, pgd));
+	DEFINE(PACA_KERNELPGD, offsetof(struct paca_struct, kernel_pgd));
+	DEFINE(PACA_EXGEN, offsetof(struct paca_struct, exgen));
+	DEFINE(PACA_EXTLB, offsetof(struct paca_struct, extlb));
+	DEFINE(PACA_EXMC, offsetof(struct paca_struct, exmc));
+	DEFINE(PACA_EXCRIT, offsetof(struct paca_struct, excrit));
+	DEFINE(PACA_EXDBG, offsetof(struct paca_struct, exdbg));
+	DEFINE(PACA_MC_STACK, offsetof(struct paca_struct, mc_kstack));
+	DEFINE(PACA_CRIT_STACK, offsetof(struct paca_struct, crit_kstack));
+	DEFINE(PACA_DBG_STACK, offsetof(struct paca_struct, dbg_kstack));
+#endif /* CONFIG_PPC_BOOK3E */
+
 #ifdef CONFIG_PPC_STD_MMU_64
 	DEFINE(PACASTABREAL, offsetof(struct paca_struct, stab_real));
 	DEFINE(PACASTABVIRT, offsetof(struct paca_struct, stab_addr));

arch/powerpc/kernel/paca.c

@@ -13,6 +13,7 @@
 #include <asm/lppaca.h>
 #include <asm/paca.h>
 #include <asm/sections.h>
+#include <asm/pgtable.h>
 
 /* This symbol is provided by the linker - let it fill in the paca
  * field correctly */
@@ -87,6 +88,8 @@ void __init initialise_pacas(void)
 
 #ifdef CONFIG_PPC_BOOK3S
 		new_paca->lppaca_ptr = &lppaca[cpu];
+#else
+		new_paca->kernel_pgd = swapper_pg_dir;
 #endif
 		new_paca->lock_token = 0x8000;
 		new_paca->paca_index = cpu;