parisc: Map kernel text and data on huge pages

Adjust the linker script and map_pages() to map kernel text and data on
physical 1MB huge/large pages.
Signed-off-by: Helge Deller <deller@gmx.de>

arch/parisc/kernel/asm-offsets.c

@@ -289,6 +289,14 @@ int main(void)
 	DEFINE(ASM_PTE_ENTRY_SIZE, PTE_ENTRY_SIZE);
 	DEFINE(ASM_PFN_PTE_SHIFT, PFN_PTE_SHIFT);
 	DEFINE(ASM_PT_INITIAL, PT_INITIAL);
+	BLANK();
+	/* HUGEPAGE_SIZE is only used in vmlinux.lds.S to align kernel text
+	 * and kernel data on physical huge pages */
+#ifdef CONFIG_HUGETLB_PAGE
+	DEFINE(HUGEPAGE_SIZE, 1UL << REAL_HPAGE_SHIFT);
+#else
+	DEFINE(HUGEPAGE_SIZE, PAGE_SIZE);
+#endif
 	BLANK();
 	DEFINE(EXCDATA_IP, offsetof(struct exception_data, fault_ip));
 	DEFINE(EXCDATA_SPACE, offsetof(struct exception_data, fault_space));

arch/parisc/kernel/vmlinux.lds.S

@@ -60,7 +60,7 @@ SECTIONS
 		EXIT_DATA
 	}
 	PERCPU_SECTION(8)
-	. = ALIGN(PAGE_SIZE);
+	. = ALIGN(HUGEPAGE_SIZE);
 	__init_end = .;
 	/* freed after init ends here */
 
@@ -116,7 +116,7 @@ SECTIONS
 	 * that we can properly leave these
 	 * as writable
 	 */
-	. = ALIGN(PAGE_SIZE);
+	. = ALIGN(HUGEPAGE_SIZE);
 	data_start = .;
 
 	EXCEPTION_TABLE(8)
@@ -135,8 +135,11 @@ SECTIONS
 	_edata = .;
 
 	/* BSS */
-	BSS_SECTION(PAGE_SIZE, PAGE_SIZE, 8)
+	BSS_SECTION(PAGE_SIZE, PAGE_SIZE, PAGE_SIZE)
+
+	/* bootmap is allocated in setup_bootmem() directly behind bss. */
 
+	. = ALIGN(HUGEPAGE_SIZE);
 	_end = . ;
 
 	STABS_DEBUG

arch/parisc/mm/init.c

@@ -407,15 +407,11 @@ static void __init map_pages(unsigned long start_vaddr,
 	unsigned long vaddr;
 	unsigned long ro_start;
 	unsigned long ro_end;
-	unsigned long fv_addr;
-	unsigned long gw_addr;
-	extern const unsigned long fault_vector_20;
-	extern void * const linux_gateway_page;
+	unsigned long kernel_end;
 
 	ro_start = __pa((unsigned long)_text);
 	ro_end   = __pa((unsigned long)&data_start);
-	fv_addr  = __pa((unsigned long)&fault_vector_20) & PAGE_MASK;
-	gw_addr  = __pa((unsigned long)&linux_gateway_page) & PAGE_MASK;
+	kernel_end  = __pa((unsigned long)&_end);
 
 	end_paddr = start_paddr + size;
 
@@ -473,24 +469,25 @@ static void __init map_pages(unsigned long start_vaddr,
 			for (tmp2 = start_pte; tmp2 < PTRS_PER_PTE; tmp2++, pg_table++) {
 				pte_t pte;
 
-				/*
-				 * Map the fault vector writable so we can
-				 * write the HPMC checksum.
-				 */
 				if (force)
 					pte =  __mk_pte(address, pgprot);
-				else if (parisc_text_address(vaddr) &&
-					 address != fv_addr)
+				else if (parisc_text_address(vaddr)) {
 					pte = __mk_pte(address, PAGE_KERNEL_EXEC);
+					if (address >= ro_start && address < kernel_end)
+						pte = pte_mkhuge(pte);
+				}
 				else
 #if defined(CONFIG_PARISC_PAGE_SIZE_4KB)
-				if (address >= ro_start && address < ro_end
-							&& address != fv_addr
-							&& address != gw_addr)
-					pte = __mk_pte(address, PAGE_KERNEL_RO);
-				else
+				if (address >= ro_start && address < ro_end) {
+					pte = __mk_pte(address, PAGE_KERNEL_EXEC);
+					pte = pte_mkhuge(pte);
+				} else
 #endif
+				{
 					pte = __mk_pte(address, pgprot);
+					if (address >= ro_start && address < kernel_end)
+						pte = pte_mkhuge(pte);
+				}
 
 				if (address >= end_paddr) {
 					if (force)
@@ -534,15 +531,12 @@ void free_initmem(void)
 
 	/* force the kernel to see the new TLB entries */
 	__flush_tlb_range(0, init_begin, init_end);
-	/* Attempt to catch anyone trying to execute code here
-	 * by filling the page with BRK insns.
-	 */
-	memset((void *)init_begin, 0x00, init_end - init_begin);
+
 	/* finally dump all the instructions which were cached, since the
 	 * pages are no-longer executable */
 	flush_icache_range(init_begin, init_end);
 	
-	free_initmem_default(-1);
+	free_initmem_default(POISON_FREE_INITMEM);
 
 	/* set up a new led state on systems shipped LED State panel */
 	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_BCOMPLETE);
@@ -712,8 +706,8 @@ static void __init pagetable_init(void)
 		unsigned long size;
 
 		start_paddr = pmem_ranges[range].start_pfn << PAGE_SHIFT;
-		end_paddr = start_paddr + (pmem_ranges[range].pages << PAGE_SHIFT);
 		size = pmem_ranges[range].pages << PAGE_SHIFT;
+		end_paddr = start_paddr + size;
 
 		map_pages((unsigned long)__va(start_paddr), start_paddr,
 			  size, PAGE_KERNEL, 0);