[MIPS] Load modules to CKSEG0 if CONFIG_BUILD_ELF64=n
This is a patch to load 64-bit modules to CKSEG0 so that can be
compiled with -msym32 option. This makes each module ~10% smaller.
* introduce MODULE_START and MODULE_END
* custom module_alloc()
* PGD for modules
* change XTLB refill handler synthesizer
* enable -msym32 for modules again
(revert ca78b1a5c6a6e70e052d3ea253828e49b5d07c8a)
New XTLB refill handler looks like this:
80000080 dmfc0 k0,C0_BADVADDR
80000084 bltz k0,800000e4 # goto l_module_alloc
80000088 lui k1,0x8046 # %high(pgd_current)
8000008c ld k1,24600(k1) # %low(pgd_current)
80000090 dsrl k0,k0,0x1b # l_vmalloc_done:
80000094 andi k0,k0,0x1ff8
80000098 daddu k1,k1,k0
8000009c dmfc0 k0,C0_BADVADDR
800000a0 ld k1,0(k1)
800000a4 dsrl k0,k0,0x12
800000a8 andi k0,k0,0xff8
800000ac daddu k1,k1,k0
800000b0 dmfc0 k0,C0_XCONTEXT
800000b4 ld k1,0(k1)
800000b8 andi k0,k0,0xff0
800000bc daddu k1,k1,k0
800000c0 ld k0,0(k1)
800000c4 ld k1,8(k1)
800000c8 dsrl k0,k0,0x6
800000cc mtc0 k0,C0_ENTRYLO0
800000d0 dsrl k1,k1,0x6
800000d4 mtc0 k1,C0_ENTRYL01
800000d8 nop
800000dc tlbwr
800000e0 eret
800000e4 dsll k1,k0,0x2 # l_module_alloc:
800000e8 bgez k1,80000008 # goto l_vmalloc
800000ec lui k1,0xc000
800000f0 dsubu k0,k0,k1
800000f4 lui k1,0x8046 # %high(module_pg_dir)
800000f8 beq zero,zero,80000000
800000fc nop
80000000 beq zero,zero,80000090 # goto l_vmalloc_done
80000004 daddiu k1,k1,0x4000
80000008 dsll32 k1,k1,0x0 # l_vmalloc:
8000000c dsubu k0,k0,k1
80000010 beq zero,zero,80000090 # goto l_vmalloc_done
80000014 lui k1,0x8046 # %high(swapper_pg_dir)
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index d580d46..641aa30 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -63,9 +63,7 @@
ifdef CONFIG_BUILD_ELF64
cflags-y += $(call cc-option,-mno-explicit-relocs)
else
-# -msym32 can not be used for modules since they are loaded into XKSEG
-CFLAGS_MODULE += $(call cc-option,-mno-explicit-relocs)
-CFLAGS_KERNEL += $(call cc-option,-msym32)
+cflags-y += $(call cc-option,-msym32)
endif
endif
diff --git a/arch/mips/kernel/head.S b/arch/mips/kernel/head.S
index ddc1b71..a2e095a 100644
--- a/arch/mips/kernel/head.S
+++ b/arch/mips/kernel/head.S
@@ -250,6 +250,9 @@
*/
page swapper_pg_dir, _PGD_ORDER
#ifdef CONFIG_64BIT
+#if defined(CONFIG_MODULES) && !defined(CONFIG_BUILD_ELF64)
+ page module_pg_dir, _PGD_ORDER
+#endif
page invalid_pmd_table, _PMD_ORDER
#endif
page invalid_pte_table, _PTE_ORDER
diff --git a/arch/mips/kernel/module.c b/arch/mips/kernel/module.c
index d7bf021..cb08014 100644
--- a/arch/mips/kernel/module.c
+++ b/arch/mips/kernel/module.c
@@ -29,6 +29,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/spinlock.h>
+#include <asm/pgtable.h> /* MODULE_START */
struct mips_hi16 {
struct mips_hi16 *next;
@@ -43,9 +44,23 @@
void *module_alloc(unsigned long size)
{
+#ifdef MODULE_START
+ struct vm_struct *area;
+
+ size = PAGE_ALIGN(size);
+ if (!size)
+ return NULL;
+
+ area = __get_vm_area(size, VM_ALLOC, MODULE_START, MODULE_END);
+ if (!area)
+ return NULL;
+
+ return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL);
+#else
if (size == 0)
return NULL;
return vmalloc(size);
+#endif
}
/* Free memory returned from module_alloc */
diff --git a/arch/mips/mm/fault.c b/arch/mips/mm/fault.c
index 8423d85..6f90e7e 100644
--- a/arch/mips/mm/fault.c
+++ b/arch/mips/mm/fault.c
@@ -60,6 +60,10 @@
*/
if (unlikely(address >= VMALLOC_START && address <= VMALLOC_END))
goto vmalloc_fault;
+#ifdef MODULE_START
+ if (unlikely(address >= MODULE_START && address < MODULE_END))
+ goto vmalloc_fault;
+#endif
/*
* If we're in an interrupt or have no user
diff --git a/arch/mips/mm/pgtable-64.c b/arch/mips/mm/pgtable-64.c
index 8d600d3..c46eb65 100644
--- a/arch/mips/mm/pgtable-64.c
+++ b/arch/mips/mm/pgtable-64.c
@@ -58,6 +58,9 @@
/* Initialize the entire pgd. */
pgd_init((unsigned long)swapper_pg_dir);
+#ifdef MODULE_START
+ pgd_init((unsigned long)module_pg_dir);
+#endif
pmd_init((unsigned long)invalid_pmd_table, (unsigned long)invalid_pte_table);
pgd_base = swapper_pg_dir;
diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index fec318a..492c518 100644
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -423,6 +423,9 @@
label_invalid,
label_second_part,
label_leave,
+#ifdef MODULE_START
+ label_module_alloc,
+#endif
label_vmalloc,
label_vmalloc_done,
label_tlbw_hazard,
@@ -455,6 +458,9 @@
L_LA(_second_part)
L_LA(_leave)
+#ifdef MODULE_START
+L_LA(_module_alloc)
+#endif
L_LA(_vmalloc)
L_LA(_vmalloc_done)
L_LA(_tlbw_hazard)
@@ -686,6 +692,13 @@
i_bgezl(p, reg, 0);
}
+static void __init __attribute__((unused))
+il_bgez(u32 **p, struct reloc **r, unsigned int reg, enum label_id l)
+{
+ r_mips_pc16(r, *p, l);
+ i_bgez(p, reg, 0);
+}
+
/* The only general purpose registers allowed in TLB handlers. */
#define K0 26
#define K1 27
@@ -970,7 +983,11 @@
* The vmalloc handling is not in the hotpath.
*/
i_dmfc0(p, tmp, C0_BADVADDR);
+#ifdef MODULE_START
+ il_bltz(p, r, tmp, label_module_alloc);
+#else
il_bltz(p, r, tmp, label_vmalloc);
+#endif
/* No i_nop needed here, since the next insn doesn't touch TMP. */
#ifdef CONFIG_SMP
@@ -1023,8 +1040,46 @@
{
long swpd = (long)swapper_pg_dir;
+#ifdef MODULE_START
+ long modd = (long)module_pg_dir;
+
+ l_module_alloc(l, *p);
+ /*
+ * Assumption:
+ * VMALLOC_START >= 0xc000000000000000UL
+ * MODULE_START >= 0xe000000000000000UL
+ */
+ i_SLL(p, ptr, bvaddr, 2);
+ il_bgez(p, r, ptr, label_vmalloc);
+
+ if (in_compat_space_p(MODULE_START) && !rel_lo(MODULE_START)) {
+ i_lui(p, ptr, rel_hi(MODULE_START)); /* delay slot */
+ } else {
+ /* unlikely configuration */
+ i_nop(p); /* delay slot */
+ i_LA(p, ptr, MODULE_START);
+ }
+ i_dsubu(p, bvaddr, bvaddr, ptr);
+
+ if (in_compat_space_p(modd) && !rel_lo(modd)) {
+ il_b(p, r, label_vmalloc_done);
+ i_lui(p, ptr, rel_hi(modd));
+ } else {
+ i_LA_mostly(p, ptr, modd);
+ il_b(p, r, label_vmalloc_done);
+ i_daddiu(p, ptr, ptr, rel_lo(modd));
+ }
+
+ l_vmalloc(l, *p);
+ if (in_compat_space_p(MODULE_START) && !rel_lo(MODULE_START) &&
+ MODULE_START << 32 == VMALLOC_START)
+ i_dsll32(p, ptr, ptr, 0); /* typical case */
+ else
+ i_LA(p, ptr, VMALLOC_START);
+#else
l_vmalloc(l, *p);
i_LA(p, ptr, VMALLOC_START);
+#endif
i_dsubu(p, bvaddr, bvaddr, ptr);
if (in_compat_space_p(swpd) && !rel_lo(swpd)) {
diff --git a/include/asm-mips/pgtable-64.h b/include/asm-mips/pgtable-64.h
index 7e73203..b9b1e86 100644
--- a/include/asm-mips/pgtable-64.h
+++ b/include/asm-mips/pgtable-64.h
@@ -14,6 +14,7 @@
#include <asm/addrspace.h>
#include <asm/page.h>
#include <asm/cachectl.h>
+#include <asm/fixmap.h>
#include <asm-generic/pgtable-nopud.h>
@@ -103,6 +104,13 @@
#define VMALLOC_START MAP_BASE
#define VMALLOC_END \
(VMALLOC_START + PTRS_PER_PGD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE)
+#if defined(CONFIG_MODULES) && !defined(CONFIG_BUILD_ELF64) && \
+ VMALLOC_START != CKSSEG
+/* Load modules into 32bit-compatible segment. */
+#define MODULE_START CKSSEG
+#define MODULE_END (FIXADDR_START-2*PAGE_SIZE)
+extern pgd_t module_pg_dir[PTRS_PER_PGD];
+#endif
#define pte_ERROR(e) \
printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))
@@ -174,7 +182,12 @@
#define __pmd_offset(address) pmd_index(address)
/* to find an entry in a kernel page-table-directory */
+#ifdef MODULE_START
+#define pgd_offset_k(address) \
+ ((address) >= MODULE_START ? module_pg_dir : pgd_offset(&init_mm, 0UL))
+#else
#define pgd_offset_k(address) pgd_offset(&init_mm, 0UL)
+#endif
#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
#define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))