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Commit 91dfc423 authored by Guenter Roeck's avatar Guenter Roeck Committed by Ralf Baechle
Browse files

MIPS: 64-bit: Detect virtual memory size 



Linux kernel 2.6.32 and later allocate address space from the top of the
kernel virtual memory address space.

This patch implements virtual memory size detection for 64 bit MIPS CPUs
to avoid resulting crashes.

Signed-off-by: default avatarGuenter Roeck <guenter.roeck@ericsson.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/935/


Reviewed-by: default avatarDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent ba284b1f

arch/mips/include/asm/cpu-features.h

+7 −0
Original line number Diff line number Diff line
@@ -191,6 +191,9 @@ 
# ifndef cpu_has_64bit_addresses

# define cpu_has_64bit_addresses	0

# endif

# ifndef cpu_vmbits

# define cpu_vmbits 31

# endif

#endif



#ifdef CONFIG_64BIT
@@ -209,6 +212,10 @@ 
# ifndef cpu_has_64bit_addresses

# define cpu_has_64bit_addresses	1

# endif

# ifndef cpu_vmbits

# define cpu_vmbits cpu_data[0].vmbits

# define __NEED_VMBITS_PROBE

# endif

#endif



#if defined(CONFIG_CPU_MIPSR2_IRQ_VI) && !defined(cpu_has_vint)

arch/mips/include/asm/cpu-info.h

+3 −0
Original line number Diff line number Diff line
@@ -58,6 +58,9 @@ struct cpuinfo_mips { 
	struct cache_desc	tcache;	/* Tertiary/split secondary cache */

	int			srsets;	/* Shadow register sets */

	int			core;	/* physical core number */

#ifdef CONFIG_64BIT

	int			vmbits;	/* Virtual memory size in bits */

#endif

#if defined(CONFIG_MIPS_MT_SMP) || defined(CONFIG_MIPS_MT_SMTC)

	/*

	 * In the MIPS MT "SMTC" model, each TC is considered

arch/mips/include/asm/pgtable-64.h

+3 −1
Original line number Diff line number Diff line
@@ -110,7 +110,9 @@ 
#define VMALLOC_START		MAP_BASE

#define VMALLOC_END	\

	(VMALLOC_START + \

	 PTRS_PER_PGD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE - (1UL << 32))

	 min(PTRS_PER_PGD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE, \

	     (1UL << cpu_vmbits)) - (1UL << 32))



#if defined(CONFIG_MODULES) && defined(KBUILD_64BIT_SYM32) && \

	VMALLOC_START != CKSSEG

/* Load modules into 32bit-compatible segment. */

arch/mips/kernel/cpu-probe.c

+11 −0
Original line number Diff line number Diff line
@@ -284,6 +284,15 @@ static inline int __cpu_has_fpu(void) 
	return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);

}



static inline void cpu_probe_vmbits(struct cpuinfo_mips *c)

{

#ifdef __NEED_VMBITS_PROBE

	write_c0_entryhi(0x3ffffffffffff000ULL);

	back_to_back_c0_hazard();

	c->vmbits = fls64(read_c0_entryhi() & 0x3ffffffffffff000ULL);

#endif

}



#define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \

		| MIPS_CPU_COUNTER)
@@ -969,6 +978,8 @@ __cpuinit void cpu_probe(void) 
		c->srsets = ((read_c0_srsctl() >> 26) & 0x0f) + 1;

	else

		c->srsets = 1;



	cpu_probe_vmbits(c);

}



__cpuinit void cpu_report(void)