Commit f8bd9f25 authored by Juergen Gross's avatar Juergen Gross Committed by Borislav Petkov
Browse files

x86/mtrr: Simplify mtrr_ops initialization 



The way mtrr_if is initialized with the correct mtrr_ops structure is
quite weird.

Simplify that by dropping the vendor specific init functions and the
mtrr_ops[] array. Replace those with direct assignments of the related
vendor specific ops array to mtrr_if.

Note that a direct assignment is okay even for 64-bit builds, where the
symbol isn't present, as the related code will be subject to "dead code
elimination" due to how cpu_feature_enabled() is implemented.

Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20221102074713.21493-17-jgross@suse.com


Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
parent 30f89e52

arch/x86/kernel/cpu/mtrr/amd.c

+1 −7
Original line number Diff line number Diff line
@@ -109,7 +109,7 @@ amd_validate_add_page(unsigned long base, unsigned long size, unsigned int type) 
	return 0;

}



static const struct mtrr_ops amd_mtrr_ops = {

const struct mtrr_ops amd_mtrr_ops = {

	.vendor            = X86_VENDOR_AMD,

	.set               = amd_set_mtrr,

	.get               = amd_get_mtrr,
@@ -117,9 +117,3 @@ static const struct mtrr_ops amd_mtrr_ops = { 
	.validate_add_page = amd_validate_add_page,

	.have_wrcomb       = positive_have_wrcomb,

};
 


int __init amd_init_mtrr(void)

{

	set_mtrr_ops(&amd_mtrr_ops);

	return 0;

}

arch/x86/kernel/cpu/mtrr/centaur.c

+1 −7
Original line number Diff line number Diff line
@@ -111,7 +111,7 @@ centaur_validate_add_page(unsigned long base, unsigned long size, unsigned int t 
	return 0;

}



static const struct mtrr_ops centaur_mtrr_ops = {

const struct mtrr_ops centaur_mtrr_ops = {

	.vendor            = X86_VENDOR_CENTAUR,

	.set               = centaur_set_mcr,

	.get               = centaur_get_mcr,
@@ -119,9 +119,3 @@ static const struct mtrr_ops centaur_mtrr_ops = { 
	.validate_add_page = centaur_validate_add_page,

	.have_wrcomb       = positive_have_wrcomb,

};
 


int __init centaur_init_mtrr(void)

{

	set_mtrr_ops(&centaur_mtrr_ops);

	return 0;

}

arch/x86/kernel/cpu/mtrr/cyrix.c

+1 −7
Original line number Diff line number Diff line
@@ -234,7 +234,7 @@ static void cyrix_set_arr(unsigned int reg, unsigned long base, 
	post_set();

}



static const struct mtrr_ops cyrix_mtrr_ops = {

const struct mtrr_ops cyrix_mtrr_ops = {

	.vendor            = X86_VENDOR_CYRIX,

	.set               = cyrix_set_arr,

	.get               = cyrix_get_arr,
@@ -242,9 +242,3 @@ static const struct mtrr_ops cyrix_mtrr_ops = { 
	.validate_add_page = generic_validate_add_page,

	.have_wrcomb       = positive_have_wrcomb,

};
 


int __init cyrix_init_mtrr(void)

{

	set_mtrr_ops(&cyrix_mtrr_ops);

	return 0;

}

arch/x86/kernel/cpu/mtrr/mtrr.c

+3 −27
Original line number Diff line number Diff line
@@ -69,16 +69,8 @@ static DEFINE_MUTEX(mtrr_mutex); 


u64 size_or_mask, size_and_mask;



static const struct mtrr_ops *mtrr_ops[X86_VENDOR_NUM] __ro_after_init;



const struct mtrr_ops *mtrr_if;



void __init set_mtrr_ops(const struct mtrr_ops *ops)

{

	if (ops->vendor && ops->vendor < X86_VENDOR_NUM)

		mtrr_ops[ops->vendor] = ops;

}



/*  Returns non-zero if we have the write-combining memory type  */

static int have_wrcomb(void)

{
@@ -582,20 +574,6 @@ int arch_phys_wc_index(int handle) 
}

EXPORT_SYMBOL_GPL(arch_phys_wc_index);



/*

 * HACK ALERT!

 * These should be called implicitly, but we can't yet until all the initcall

 * stuff is done...

 */

static void __init init_ifs(void)

{

#ifndef CONFIG_X86_64

	amd_init_mtrr();

	cyrix_init_mtrr();

	centaur_init_mtrr();

#endif

}



/* The suspend/resume methods are only for CPU without MTRR. CPU using generic

 * MTRR driver doesn't require this

 */
@@ -653,8 +631,6 @@ void __init mtrr_bp_init(void) 
{

	u32 phys_addr;



	init_ifs();



	phys_addr = 32;



	if (boot_cpu_has(X86_FEATURE_MTRR)) {
@@ -695,21 +671,21 @@ void __init mtrr_bp_init(void) 
		case X86_VENDOR_AMD:

			if (cpu_feature_enabled(X86_FEATURE_K6_MTRR)) {

				/* Pre-Athlon (K6) AMD CPU MTRRs */

				mtrr_if = mtrr_ops[X86_VENDOR_AMD];

				mtrr_if = &amd_mtrr_ops;

				size_or_mask = SIZE_OR_MASK_BITS(32);

				size_and_mask = 0;

			}

			break;

		case X86_VENDOR_CENTAUR:

			if (cpu_feature_enabled(X86_FEATURE_CENTAUR_MCR)) {

				mtrr_if = mtrr_ops[X86_VENDOR_CENTAUR];

				mtrr_if = &centaur_mtrr_ops;

				size_or_mask = SIZE_OR_MASK_BITS(32);

				size_and_mask = 0;

			}

			break;

		case X86_VENDOR_CYRIX:

			if (cpu_feature_enabled(X86_FEATURE_CYRIX_ARR)) {

				mtrr_if = mtrr_ops[X86_VENDOR_CYRIX];

				mtrr_if = &cyrix_mtrr_ops;

				size_or_mask = SIZE_OR_MASK_BITS(32);

				size_and_mask = 0;

			}

arch/x86/kernel/cpu/mtrr/mtrr.h

+4 −6
Original line number Diff line number Diff line
@@ -51,8 +51,6 @@ void fill_mtrr_var_range(unsigned int index, 
		u32 base_lo, u32 base_hi, u32 mask_lo, u32 mask_hi);

bool get_mtrr_state(void);



extern void __init set_mtrr_ops(const struct mtrr_ops *ops);



extern u64 size_or_mask, size_and_mask;

extern const struct mtrr_ops *mtrr_if;
@@ -66,10 +64,10 @@ void mtrr_state_warn(void); 
const char *mtrr_attrib_to_str(int x);

void mtrr_wrmsr(unsigned, unsigned, unsigned);



/* CPU specific mtrr init functions */

int amd_init_mtrr(void);

int cyrix_init_mtrr(void);

int centaur_init_mtrr(void);

/* CPU specific mtrr_ops vectors. */

extern const struct mtrr_ops amd_mtrr_ops;

extern const struct mtrr_ops cyrix_mtrr_ops;

extern const struct mtrr_ops centaur_mtrr_ops;



extern int changed_by_mtrr_cleanup;

extern int mtrr_cleanup(unsigned address_bits);