[PATCH v4 16/16] x86/mtrr: simplify mtrr_ops initialization

From: Juergen Gross
Date: Tue Oct 04 2022 - 04:13:28 EST

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.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
V4:
- new patch
---
arch/x86/kernel/cpu/mtrr/amd.c | 8 +-------
arch/x86/kernel/cpu/mtrr/centaur.c | 8 +-------
arch/x86/kernel/cpu/mtrr/cyrix.c | 8 +-------
arch/x86/kernel/cpu/mtrr/mtrr.c | 30 +++---------------------------
arch/x86/kernel/cpu/mtrr/mtrr.h | 15 +++++++++------
5 files changed, 15 insertions(+), 54 deletions(-)

diff --git a/arch/x86/kernel/cpu/mtrr/amd.c b/arch/x86/kernel/cpu/mtrr/amd.c
index a65a0272096d..eff6ac62c0ff 100644
--- a/arch/x86/kernel/cpu/mtrr/amd.c
+++ b/arch/x86/kernel/cpu/mtrr/amd.c
@@ -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;
-}
diff --git a/arch/x86/kernel/cpu/mtrr/centaur.c b/arch/x86/kernel/cpu/mtrr/centaur.c
index f27177816569..b8a74eddde83 100644
--- a/arch/x86/kernel/cpu/mtrr/centaur.c
+++ b/arch/x86/kernel/cpu/mtrr/centaur.c
@@ -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;
-}
diff --git a/arch/x86/kernel/cpu/mtrr/cyrix.c b/arch/x86/kernel/cpu/mtrr/cyrix.c
index c77d3b0a5bf2..173b9e01e623 100644
--- a/arch/x86/kernel/cpu/mtrr/cyrix.c
+++ b/arch/x86/kernel/cpu/mtrr/cyrix.c
@@ -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;
-}
diff --git a/arch/x86/kernel/cpu/mtrr/mtrr.c b/arch/x86/kernel/cpu/mtrr/mtrr.c
index 1b652fa768a6..7ba68356c0ff 100644
--- a/arch/x86/kernel/cpu/mtrr/mtrr.c
+++ b/arch/x86/kernel/cpu/mtrr/mtrr.c
@@ -65,16 +65,8 @@ 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)
{
@@ -578,20 +570,6 @@ 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
*/
@@ -649,8 +627,6 @@ void __init mtrr_bp_init(void)
{
u32 phys_addr;

- init_ifs();
-
phys_addr = 32;

if (boot_cpu_has(X86_FEATURE_MTRR)) {
@@ -691,21 +667,21 @@ 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 = vendor_mtrr_ops(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 = vendor_mtrr_ops(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 = vendor_mtrr_ops(cyrix_mtrr_ops);
size_or_mask = SIZE_OR_MASK_BITS(32);
size_and_mask = 0;
}
diff --git a/arch/x86/kernel/cpu/mtrr/mtrr.h b/arch/x86/kernel/cpu/mtrr/mtrr.h
index c98928ceee6a..7a7387356192 100644
--- a/arch/x86/kernel/cpu/mtrr/mtrr.h
+++ b/arch/x86/kernel/cpu/mtrr/mtrr.h
@@ -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 +64,15 @@ 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;
+#ifdef CONFIG_X86_64
+#define vendor_mtrr_ops(x) NULL
+#else
+#define vendor_mtrr_ops(x) &(x)
+#endif

extern int changed_by_mtrr_cleanup;
extern int mtrr_cleanup(unsigned address_bits);
--
2.35.3