Commit 03ae5768 authored by Thomas Petazzoni's avatar Thomas Petazzoni Committed by Ingo Molnar
Browse files

x86: use ELF section to list CPU vendor specific code 



Replace the hardcoded list of initialization functions for each CPU
vendor by a list in an ELF section, which is read at initialization in
arch/x86/kernel/cpu/cpu.c to fill the cpu_devs[] array. The ELF
section, named .x86cpuvendor.init, is reclaimed after boot, and
contains entries of type "struct cpu_vendor_dev" which associates a
vendor number with a pointer to a "struct cpu_dev" structure.

This first modification allows to remove all the VENDOR_init_cpu()
functions.

This patch also removes the hardcoded calls to early_init_amd() and
early_init_intel(). Instead, we add a "c_early_init" member to the
cpu_dev structure, which is then called if not NULL by the generic CPU
initialization code. Unfortunately, in early_cpu_detect(), this_cpu is
not yet set, so we have to use the cpu_devs[] array directly.

This patch is part of the Linux Tiny project, and is needed for
further patch that will allow to disable compilation of unused CPU
support code.

Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent bc7c314d

arch/x86/kernel/cpu/amd.c

+4 −1
Original line number Diff line number Diff line
@@ -63,7 +63,7 @@ static __cpuinit int amd_apic_timer_broken(void) 


int force_mwait __cpuinitdata;



void __cpuinit early_init_amd(struct cpuinfo_x86 *c)

static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)

{

	if (cpuid_eax(0x80000000) >= 0x80000007) {

		c->x86_power = cpuid_edx(0x80000007);
@@ -336,6 +336,7 @@ static struct cpu_dev amd_cpu_dev __cpuinitdata = { 
		  }

		},

	},

	.c_early_init   = early_init_amd,

	.c_init		= init_amd,

	.c_size_cache	= amd_size_cache,

};
@@ -345,3 +346,5 @@ int __init amd_init_cpu(void) 
	cpu_devs[X86_VENDOR_AMD] = &amd_cpu_dev;

	return 0;

}



cpu_vendor_dev_register(X86_VENDOR_AMD, &amd_cpu_dev);

arch/x86/kernel/cpu/centaur.c

+1 −5
Original line number Diff line number Diff line
@@ -464,8 +464,4 @@ static struct cpu_dev centaur_cpu_dev __cpuinitdata = { 
	.c_size_cache	= centaur_size_cache,

};



int __init centaur_init_cpu(void)

{

	cpu_devs[X86_VENDOR_CENTAUR] = &centaur_cpu_dev;

	return 0;

}
 
cpu_vendor_dev_register(X86_VENDOR_CENTAUR, &centaur_cpu_dev);

arch/x86/kernel/cpu/common.c

+10 −23
Original line number Diff line number Diff line
@@ -328,14 +328,9 @@ static void __init early_cpu_detect(void) 


	get_cpu_vendor(c, 1);



	switch (c->x86_vendor) {

	case X86_VENDOR_AMD:

		early_init_amd(c);

		break;

	case X86_VENDOR_INTEL:

		early_init_intel(c);

		break;

	}

	if (c->x86_vendor != X86_VENDOR_UNKNOWN &&

	    cpu_devs[c->x86_vendor]->c_early_init)

		cpu_devs[c->x86_vendor]->c_early_init(c);



	early_get_cap(c);

}
@@ -616,23 +611,15 @@ __setup("clearcpuid=", setup_disablecpuid); 


cpumask_t cpu_initialized __cpuinitdata = CPU_MASK_NONE;



/* This is hacky. :)

 * We're emulating future behavior.

 * In the future, the cpu-specific init functions will be called implicitly

 * via the magic of initcalls.

 * They will insert themselves into the cpu_devs structure.

 * Then, when cpu_init() is called, we can just iterate over that array.

 */

void __init early_cpu_init(void)

{

	intel_cpu_init();

	cyrix_init_cpu();

	nsc_init_cpu();

	amd_init_cpu();

	centaur_init_cpu();

	transmeta_init_cpu();

	nexgen_init_cpu();

	umc_init_cpu();

	struct cpu_vendor_dev *cvdev;



	for (cvdev = __x86cpuvendor_start ;

	     cvdev < __x86cpuvendor_end   ;

	     cvdev++)

		cpu_devs[cvdev->vendor] = cvdev->cpu_dev;



	early_cpu_detect();

}

arch/x86/kernel/cpu/cpu.h

+13 −13
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ struct cpu_dev { 


	struct		cpu_model_info c_models[4];



	void            (*c_early_init)(struct cpuinfo_x86 *c);

	void		(*c_init)(struct cpuinfo_x86 * c);

	void		(*c_identify)(struct cpuinfo_x86 * c);

	unsigned int	(*c_size_cache)(struct cpuinfo_x86 * c, unsigned int size);
@@ -21,18 +22,17 @@ struct cpu_dev { 


extern struct cpu_dev * cpu_devs [X86_VENDOR_NUM];



struct cpu_vendor_dev {

	int vendor;

	struct cpu_dev *cpu_dev;

};



#define cpu_vendor_dev_register(cpu_vendor_id, cpu_dev) \

	static struct cpu_vendor_dev __cpu_vendor_dev_##cpu_vendor_id __used \

	__attribute__((__section__(".x86cpuvendor.init"))) = \

	{ cpu_vendor_id, cpu_dev }



extern struct cpu_vendor_dev __x86cpuvendor_start[], __x86cpuvendor_end[];



extern int get_model_name(struct cpuinfo_x86 *c);

extern void display_cacheinfo(struct cpuinfo_x86 *c);
 


extern void early_init_intel(struct cpuinfo_x86 *c);

extern void early_init_amd(struct cpuinfo_x86 *c);



/* Specific CPU type init functions */

int intel_cpu_init(void);

int amd_init_cpu(void);

int cyrix_init_cpu(void);

int nsc_init_cpu(void);

int centaur_init_cpu(void);

int transmeta_init_cpu(void);

int nexgen_init_cpu(void);

int umc_init_cpu(void);

arch/x86/kernel/cpu/cyrix.c

+2 −11
Original line number Diff line number Diff line
@@ -439,11 +439,7 @@ static struct cpu_dev cyrix_cpu_dev __cpuinitdata = { 
	.c_identify	= cyrix_identify,

};



int __init cyrix_init_cpu(void)

{

	cpu_devs[X86_VENDOR_CYRIX] = &cyrix_cpu_dev;

	return 0;

}

cpu_vendor_dev_register(X86_VENDOR_CYRIX, &cyrix_cpu_dev);



static struct cpu_dev nsc_cpu_dev __cpuinitdata = {

	.c_vendor	= "NSC",
@@ -451,9 +447,4 @@ static struct cpu_dev nsc_cpu_dev __cpuinitdata = { 
	.c_init		= init_nsc,

};



int __init nsc_init_cpu(void)

{

	cpu_devs[X86_VENDOR_NSC] = &nsc_cpu_dev;

	return 0;

}

cpu_vendor_dev_register(X86_VENDOR_NSC, &nsc_cpu_dev);

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