linux/arch/mips/include/asm/processor.h
David Daney 949e51bea3 MIPS: Make TASK_SIZE reflect proper size for both 32 and 64 bit processes.
The TASK_SIZE macro should reflect the size of a user process virtual
address space.  Previously for 64-bit kernels, this was not the case.
The immediate cause of pain was in
hugetlbfs/inode.c:hugetlb_get_unmapped_area() where 32-bit processes
trying to mmap a huge page would be served a page with an address
outside of the 32-bit address range.  But there are other uses of
TASK_SIZE in the kernel as well that would like an accurate value.

The new definition is nice because it now makes TASK_SIZE and
TASK_SIZE_OF() yield the same value for any given process.

For 32-bit kernels there should be no change, although I did factor
out some code in asm/processor.h that became identical for the 32-bit and
64-bit cases.

__UA_LIMIT is now set to ~((1 << SEGBITS) - 1) for 64-bit kernels.
This should eliminate the possibility of getting a
AddressErrorException in the kernel for addresses that pass the
access_ok() test.

With the patch applied, I can still run o32, n32 and n64 processes,
and have an o32 shell fork/exec both n32 and n64 processes.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1701/
2010-10-29 19:08:53 +01:00

362 lines
9.7 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1994 Waldorf GMBH
* Copyright (C) 1995, 1996, 1997, 1998, 1999, 2001, 2002, 2003 Ralf Baechle
* Copyright (C) 1996 Paul M. Antoine
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
*/
#ifndef _ASM_PROCESSOR_H
#define _ASM_PROCESSOR_H
#include <linux/cpumask.h>
#include <linux/threads.h>
#include <asm/cachectl.h>
#include <asm/cpu.h>
#include <asm/cpu-info.h>
#include <asm/mipsregs.h>
#include <asm/prefetch.h>
#include <asm/system.h>
/*
* Return current * instruction pointer ("program counter").
*/
#define current_text_addr() ({ __label__ _l; _l: &&_l;})
/*
* System setup and hardware flags..
*/
extern void (*cpu_wait)(void);
extern unsigned int vced_count, vcei_count;
/*
* MIPS does have an arch_pick_mmap_layout()
*/
#define HAVE_ARCH_PICK_MMAP_LAYOUT 1
/*
* A special page (the vdso) is mapped into all processes at the very
* top of the virtual memory space.
*/
#define SPECIAL_PAGES_SIZE PAGE_SIZE
#ifdef CONFIG_32BIT
/*
* User space process size: 2GB. This is hardcoded into a few places,
* so don't change it unless you know what you are doing.
*/
#define TASK_SIZE 0x7fff8000UL
#ifdef __KERNEL__
#define STACK_TOP_MAX TASK_SIZE
#endif
#define TASK_IS_32BIT_ADDR 1
#endif
#ifdef CONFIG_64BIT
/*
* User space process size: 1TB. This is hardcoded into a few places,
* so don't change it unless you know what you are doing. TASK_SIZE
* is limited to 1TB by the R4000 architecture; R10000 and better can
* support 16TB; the architectural reserve for future expansion is
* 8192EB ...
*/
#define TASK_SIZE32 0x7fff8000UL
#define TASK_SIZE64 0x10000000000UL
#define TASK_SIZE (test_thread_flag(TIF_32BIT_ADDR) ? TASK_SIZE32 : TASK_SIZE64)
#ifdef __KERNEL__
#define STACK_TOP_MAX TASK_SIZE64
#endif
#define TASK_SIZE_OF(tsk) \
(test_tsk_thread_flag(tsk, TIF_32BIT_ADDR) ? TASK_SIZE32 : TASK_SIZE64)
#define TASK_IS_32BIT_ADDR test_thread_flag(TIF_32BIT_ADDR)
#endif
#define STACK_TOP ((TASK_SIZE & PAGE_MASK) - SPECIAL_PAGES_SIZE)
/*
* This decides where the kernel will search for a free chunk of vm
* space during mmap's.
*/
#define TASK_UNMAPPED_BASE PAGE_ALIGN(TASK_SIZE / 3)
#define NUM_FPU_REGS 32
typedef __u64 fpureg_t;
/*
* It would be nice to add some more fields for emulator statistics, but there
* are a number of fixed offsets in offset.h and elsewhere that would have to
* be recalculated by hand. So the additional information will be private to
* the FPU emulator for now. See asm-mips/fpu_emulator.h.
*/
struct mips_fpu_struct {
fpureg_t fpr[NUM_FPU_REGS];
unsigned int fcr31;
};
#define NUM_DSP_REGS 6
typedef __u32 dspreg_t;
struct mips_dsp_state {
dspreg_t dspr[NUM_DSP_REGS];
unsigned int dspcontrol;
};
#define INIT_CPUMASK { \
{0,} \
}
struct mips3264_watch_reg_state {
/* The width of watchlo is 32 in a 32 bit kernel and 64 in a
64 bit kernel. We use unsigned long as it has the same
property. */
unsigned long watchlo[NUM_WATCH_REGS];
/* Only the mask and IRW bits from watchhi. */
u16 watchhi[NUM_WATCH_REGS];
};
union mips_watch_reg_state {
struct mips3264_watch_reg_state mips3264;
};
#ifdef CONFIG_CPU_CAVIUM_OCTEON
struct octeon_cop2_state {
/* DMFC2 rt, 0x0201 */
unsigned long cop2_crc_iv;
/* DMFC2 rt, 0x0202 (Set with DMTC2 rt, 0x1202) */
unsigned long cop2_crc_length;
/* DMFC2 rt, 0x0200 (set with DMTC2 rt, 0x4200) */
unsigned long cop2_crc_poly;
/* DMFC2 rt, 0x0402; DMFC2 rt, 0x040A */
unsigned long cop2_llm_dat[2];
/* DMFC2 rt, 0x0084 */
unsigned long cop2_3des_iv;
/* DMFC2 rt, 0x0080; DMFC2 rt, 0x0081; DMFC2 rt, 0x0082 */
unsigned long cop2_3des_key[3];
/* DMFC2 rt, 0x0088 (Set with DMTC2 rt, 0x0098) */
unsigned long cop2_3des_result;
/* DMFC2 rt, 0x0111 (FIXME: Read Pass1 Errata) */
unsigned long cop2_aes_inp0;
/* DMFC2 rt, 0x0102; DMFC2 rt, 0x0103 */
unsigned long cop2_aes_iv[2];
/* DMFC2 rt, 0x0104; DMFC2 rt, 0x0105; DMFC2 rt, 0x0106; DMFC2
* rt, 0x0107 */
unsigned long cop2_aes_key[4];
/* DMFC2 rt, 0x0110 */
unsigned long cop2_aes_keylen;
/* DMFC2 rt, 0x0100; DMFC2 rt, 0x0101 */
unsigned long cop2_aes_result[2];
/* DMFC2 rt, 0x0240; DMFC2 rt, 0x0241; DMFC2 rt, 0x0242; DMFC2
* rt, 0x0243; DMFC2 rt, 0x0244; DMFC2 rt, 0x0245; DMFC2 rt,
* 0x0246; DMFC2 rt, 0x0247; DMFC2 rt, 0x0248; DMFC2 rt,
* 0x0249; DMFC2 rt, 0x024A; DMFC2 rt, 0x024B; DMFC2 rt,
* 0x024C; DMFC2 rt, 0x024D; DMFC2 rt, 0x024E - Pass2 */
unsigned long cop2_hsh_datw[15];
/* DMFC2 rt, 0x0250; DMFC2 rt, 0x0251; DMFC2 rt, 0x0252; DMFC2
* rt, 0x0253; DMFC2 rt, 0x0254; DMFC2 rt, 0x0255; DMFC2 rt,
* 0x0256; DMFC2 rt, 0x0257 - Pass2 */
unsigned long cop2_hsh_ivw[8];
/* DMFC2 rt, 0x0258; DMFC2 rt, 0x0259 - Pass2 */
unsigned long cop2_gfm_mult[2];
/* DMFC2 rt, 0x025E - Pass2 */
unsigned long cop2_gfm_poly;
/* DMFC2 rt, 0x025A; DMFC2 rt, 0x025B - Pass2 */
unsigned long cop2_gfm_result[2];
};
#define INIT_OCTEON_COP2 {0,}
struct octeon_cvmseg_state {
unsigned long cvmseg[CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE]
[cpu_dcache_line_size() / sizeof(unsigned long)];
};
#endif
typedef struct {
unsigned long seg;
} mm_segment_t;
#define ARCH_MIN_TASKALIGN 8
struct mips_abi;
/*
* If you change thread_struct remember to change the #defines below too!
*/
struct thread_struct {
/* Saved main processor registers. */
unsigned long reg16;
unsigned long reg17, reg18, reg19, reg20, reg21, reg22, reg23;
unsigned long reg29, reg30, reg31;
/* Saved cp0 stuff. */
unsigned long cp0_status;
/* Saved fpu/fpu emulator stuff. */
struct mips_fpu_struct fpu;
#ifdef CONFIG_MIPS_MT_FPAFF
/* Emulated instruction count */
unsigned long emulated_fp;
/* Saved per-thread scheduler affinity mask */
cpumask_t user_cpus_allowed;
#endif /* CONFIG_MIPS_MT_FPAFF */
/* Saved state of the DSP ASE, if available. */
struct mips_dsp_state dsp;
/* Saved watch register state, if available. */
union mips_watch_reg_state watch;
/* Other stuff associated with the thread. */
unsigned long cp0_badvaddr; /* Last user fault */
unsigned long cp0_baduaddr; /* Last kernel fault accessing USEG */
unsigned long error_code;
unsigned long irix_trampoline; /* Wheee... */
unsigned long irix_oldctx;
#ifdef CONFIG_CPU_CAVIUM_OCTEON
struct octeon_cop2_state cp2 __attribute__ ((__aligned__(128)));
struct octeon_cvmseg_state cvmseg __attribute__ ((__aligned__(128)));
#endif
struct mips_abi *abi;
};
#ifdef CONFIG_MIPS_MT_FPAFF
#define FPAFF_INIT \
.emulated_fp = 0, \
.user_cpus_allowed = INIT_CPUMASK,
#else
#define FPAFF_INIT
#endif /* CONFIG_MIPS_MT_FPAFF */
#ifdef CONFIG_CPU_CAVIUM_OCTEON
#define OCTEON_INIT \
.cp2 = INIT_OCTEON_COP2,
#else
#define OCTEON_INIT
#endif /* CONFIG_CPU_CAVIUM_OCTEON */
#define INIT_THREAD { \
/* \
* Saved main processor registers \
*/ \
.reg16 = 0, \
.reg17 = 0, \
.reg18 = 0, \
.reg19 = 0, \
.reg20 = 0, \
.reg21 = 0, \
.reg22 = 0, \
.reg23 = 0, \
.reg29 = 0, \
.reg30 = 0, \
.reg31 = 0, \
/* \
* Saved cp0 stuff \
*/ \
.cp0_status = 0, \
/* \
* Saved FPU/FPU emulator stuff \
*/ \
.fpu = { \
.fpr = {0,}, \
.fcr31 = 0, \
}, \
/* \
* FPU affinity state (null if not FPAFF) \
*/ \
FPAFF_INIT \
/* \
* Saved DSP stuff \
*/ \
.dsp = { \
.dspr = {0, }, \
.dspcontrol = 0, \
}, \
/* \
* saved watch register stuff \
*/ \
.watch = {{{0,},},}, \
/* \
* Other stuff associated with the process \
*/ \
.cp0_badvaddr = 0, \
.cp0_baduaddr = 0, \
.error_code = 0, \
.irix_trampoline = 0, \
.irix_oldctx = 0, \
/* \
* Cavium Octeon specifics (null if not Octeon) \
*/ \
OCTEON_INIT \
}
struct task_struct;
/* Free all resources held by a thread. */
#define release_thread(thread) do { } while(0)
/* Prepare to copy thread state - unlazy all lazy status */
#define prepare_to_copy(tsk) do { } while (0)
extern long kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
extern unsigned long thread_saved_pc(struct task_struct *tsk);
/*
* Do necessary setup to start up a newly executed thread.
*/
extern void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp);
unsigned long get_wchan(struct task_struct *p);
#define __KSTK_TOS(tsk) ((unsigned long)task_stack_page(tsk) + \
THREAD_SIZE - 32 - sizeof(struct pt_regs))
#define task_pt_regs(tsk) ((struct pt_regs *)__KSTK_TOS(tsk))
#define KSTK_EIP(tsk) (task_pt_regs(tsk)->cp0_epc)
#define KSTK_ESP(tsk) (task_pt_regs(tsk)->regs[29])
#define KSTK_STATUS(tsk) (task_pt_regs(tsk)->cp0_status)
#define cpu_relax() barrier()
/*
* Return_address is a replacement for __builtin_return_address(count)
* which on certain architectures cannot reasonably be implemented in GCC
* (MIPS, Alpha) or is unuseable with -fomit-frame-pointer (i386).
* Note that __builtin_return_address(x>=1) is forbidden because GCC
* aborts compilation on some CPUs. It's simply not possible to unwind
* some CPU's stackframes.
*
* __builtin_return_address works only for non-leaf functions. We avoid the
* overhead of a function call by forcing the compiler to save the return
* address register on the stack.
*/
#define return_address() ({__asm__ __volatile__("":::"$31");__builtin_return_address(0);})
#ifdef CONFIG_CPU_HAS_PREFETCH
#define ARCH_HAS_PREFETCH
#define prefetch(x) __builtin_prefetch((x), 0, 1)
#define ARCH_HAS_PREFETCHW
#define prefetchw(x) __builtin_prefetch((x), 1, 1)
#endif
#endif /* _ASM_PROCESSOR_H */