[PATCH] x86: break mtrr_cleanup() to several small functions.

From: Yinghai Lu
Date: Mon Oct 13 2008 - 21:07:38 EST


Ingo said mtrr_cleanup() is some big and ugly.

so break it into more functions and make it more readable.

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>

---
arch/x86/kernel/cpu/mtrr/main.c | 346 +++++++++++++++++++---------------------
1 file changed, 171 insertions(+), 175 deletions(-)

Index: linux-2.6/arch/x86/kernel/cpu/mtrr/main.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/mtrr/main.c
+++ linux-2.6/arch/x86/kernel/cpu/mtrr/main.c
@@ -803,6 +803,7 @@ x86_get_mtrr_mem_range(struct res_range
}

static struct res_range __initdata range[RANGE_NUM];
+static int __initdata nr_range;

#ifdef CONFIG_MTRR_SANITIZER

@@ -1206,39 +1207,43 @@ struct mtrr_cleanup_result {
#define PSHIFT (PAGE_SHIFT - 10)

static struct mtrr_cleanup_result __initdata result[NUM_RESULT];
-static struct res_range __initdata range_new[RANGE_NUM];
static unsigned long __initdata min_loss_pfn[RANGE_NUM];

-static int __init mtrr_cleanup(unsigned address_bits)
+static void __init print_out_mtrr_range_state(void)
{
- unsigned long extra_remove_base, extra_remove_size;
- unsigned long base, size, def, dummy;
- mtrr_type type;
- int nr_range, nr_range_new;
- u64 chunk_size, gran_size;
- unsigned long range_sums, range_sums_new;
- int index_good;
- int num_reg_good;
int i;
+ char start_factor = 'K', size_factor = 'K';
+ unsigned long start_base, size_base;
+ mtrr_type type;

- /* extra one for all 0 */
- int num[MTRR_NUM_TYPES + 1];
+ for (i = 0; i < num_var_ranges; i++) {

- if (!is_cpu(INTEL) || enable_mtrr_cleanup < 1)
- return 0;
- rdmsr(MTRRdefType_MSR, def, dummy);
- def &= 0xff;
- if (def != MTRR_TYPE_UNCACHABLE)
- return 0;
+ size_base = range_state[i].size_pfn << (PAGE_SHIFT - 10);
+ if (!size_base)
+ continue;

- /* get it and store it aside */
- memset(range_state, 0, sizeof(range_state));
- for (i = 0; i < num_var_ranges; i++) {
- mtrr_if->get(i, &base, &size, &type);
- range_state[i].base_pfn = base;
- range_state[i].size_pfn = size;
- range_state[i].type = type;
+ size_base = to_size_factor(size_base, &size_factor),
+ start_base = range_state[i].base_pfn << (PAGE_SHIFT - 10);
+ start_base = to_size_factor(start_base, &start_factor),
+ type = range_state[i].type;
+
+ printk(KERN_DEBUG "reg %d, base: %ld%cB, range: %ld%cB, type %s\n",
+ i, start_base, start_factor,
+ size_base, size_factor,
+ (type == MTRR_TYPE_UNCACHABLE) ? "UC" :
+ ((type == MTRR_TYPE_WRPROT) ? "WP" :
+ ((type == MTRR_TYPE_WRBACK) ? "WB" : "Other"))
+ );
}
+}
+
+static int __init mtrr_need_cleanup(void)
+{
+ int i;
+ mtrr_type type;
+ unsigned long size;
+ /* extra one for all 0 */
+ int num[MTRR_NUM_TYPES + 1];

/* check entries number */
memset(num, 0, sizeof(num));
@@ -1263,30 +1268,134 @@ static int __init mtrr_cleanup(unsigned
num_var_ranges - num[MTRR_NUM_TYPES])
return 0;

- /* print original var MTRRs at first, for debugging: */
- printk(KERN_DEBUG "original variable MTRRs\n");
- for (i = 0; i < num_var_ranges; i++) {
- char start_factor = 'K', size_factor = 'K';
- unsigned long start_base, size_base;
+ return 1;
+}

- size_base = range_state[i].size_pfn << (PAGE_SHIFT - 10);
- if (!size_base)
- continue;
+static unsigned long __initdata range_sums;
+static void __init mtrr_calc_range_state(u64 chunk_size, u64 gran_size,
+ unsigned long extra_remove_base,
+ unsigned long extra_remove_size,
+ int i)
+{
+ int num_reg;
+ static struct res_range range_new[RANGE_NUM];
+ static int nr_range_new;
+ unsigned long range_sums_new;
+
+ /* convert ranges to var ranges state */
+ num_reg = x86_setup_var_mtrrs(range, nr_range,
+ chunk_size, gran_size);
+
+ /* we got new setting in range_state, check it */
+ memset(range_new, 0, sizeof(range_new));
+ nr_range_new = x86_get_mtrr_mem_range(range_new, 0,
+ extra_remove_base, extra_remove_size);
+ range_sums_new = sum_ranges(range_new, nr_range_new);
+
+ result[i].chunk_sizek = chunk_size >> 10;
+ result[i].gran_sizek = gran_size >> 10;
+ result[i].num_reg = num_reg;
+ if (range_sums < range_sums_new) {
+ result[i].lose_cover_sizek =
+ (range_sums_new - range_sums) << PSHIFT;
+ result[i].bad = 1;
+ } else
+ result[i].lose_cover_sizek =
+ (range_sums - range_sums_new) << PSHIFT;
+
+ /* double check it */
+ if (!result[i].bad && !result[i].lose_cover_sizek) {
+ if (nr_range_new != nr_range ||
+ memcmp(range, range_new, sizeof(range)))
+ result[i].bad = 1;
+ }

- size_base = to_size_factor(size_base, &size_factor),
- start_base = range_state[i].base_pfn << (PAGE_SHIFT - 10);
- start_base = to_size_factor(start_base, &start_factor),
- type = range_state[i].type;
+ if (!result[i].bad && (range_sums - range_sums_new <
+ min_loss_pfn[num_reg])) {
+ min_loss_pfn[num_reg] =
+ range_sums - range_sums_new;
+ }
+}

- printk(KERN_DEBUG "reg %d, base: %ld%cB, range: %ld%cB, type %s\n",
- i, start_base, start_factor,
- size_base, size_factor,
- (type == MTRR_TYPE_UNCACHABLE) ? "UC" :
- ((type == MTRR_TYPE_WRPROT) ? "WP" :
- ((type == MTRR_TYPE_WRBACK) ? "WB" : "Other"))
- );
+static void __init mtrr_print_out_one_result(int i)
+{
+ char gran_factor, chunk_factor, lose_factor;
+ unsigned long gran_base, chunk_base, lose_base;
+
+ gran_base = to_size_factor(result[i].gran_sizek, &gran_factor),
+ chunk_base = to_size_factor(result[i].chunk_sizek, &chunk_factor),
+ lose_base = to_size_factor(result[i].lose_cover_sizek, &lose_factor),
+ printk(KERN_INFO "%sgran_size: %ld%c \tchunk_size: %ld%c \t",
+ result[i].bad ? "*BAD*" : " ",
+ gran_base, gran_factor, chunk_base, chunk_factor);
+ printk(KERN_CONT "num_reg: %d \tlose cover RAM: %s%ld%c\n",
+ result[i].num_reg, result[i].bad ? "-" : "",
+ lose_base, lose_factor);
+}
+
+static int __init mtrr_search_optimal_index(void)
+{
+ int i;
+ int num_reg_good;
+ int index_good;
+
+ if (nr_mtrr_spare_reg >= num_var_ranges)
+ nr_mtrr_spare_reg = num_var_ranges - 1;
+ num_reg_good = -1;
+ for (i = num_var_ranges - nr_mtrr_spare_reg; i > 0; i--) {
+ if (!min_loss_pfn[i])
+ num_reg_good = i;
+ }
+
+ index_good = -1;
+ if (num_reg_good != -1) {
+ for (i = 0; i < NUM_RESULT; i++) {
+ if (!result[i].bad &&
+ result[i].num_reg == num_reg_good &&
+ !result[i].lose_cover_sizek) {
+ index_good = i;
+ break;
+ }
+ }
+ }
+
+ return index_good;
+}
+
+
+static int __init mtrr_cleanup(unsigned address_bits)
+{
+ unsigned long extra_remove_base, extra_remove_size;
+ unsigned long base, size, def, dummy;
+ mtrr_type type;
+ u64 chunk_size, gran_size;
+ int index_good;
+ int i;
+
+ if (!is_cpu(INTEL) || enable_mtrr_cleanup < 1)
+ return 0;
+ rdmsr(MTRRdefType_MSR, def, dummy);
+ def &= 0xff;
+ if (def != MTRR_TYPE_UNCACHABLE)
+ return 0;
+
+ /* get it and store it aside */
+ memset(range_state, 0, sizeof(range_state));
+ for (i = 0; i < num_var_ranges; i++) {
+ mtrr_if->get(i, &base, &size, &type);
+ range_state[i].base_pfn = base;
+ range_state[i].size_pfn = size;
+ range_state[i].type = type;
}

+ /* check if we need handle it and can handle it */
+ if (!mtrr_need_cleanup())
+ return 0;
+
+ /* print original var MTRRs at first, for debugging: */
+ printk(KERN_DEBUG "original variable MTRRs\n");
+ print_out_mtrr_range_state();
+
memset(range, 0, sizeof(range));
extra_remove_size = 0;
extra_remove_base = 1 << (32 - PAGE_SHIFT);
@@ -1309,176 +1418,64 @@ static int __init mtrr_cleanup(unsigned
range_sums >> (20 - PAGE_SHIFT));

if (mtrr_chunk_size && mtrr_gran_size) {
- int num_reg;
- char gran_factor, chunk_factor, lose_factor;
- unsigned long gran_base, chunk_base, lose_base;
-
- debug_print++;
- /* convert ranges to var ranges state */
- num_reg = x86_setup_var_mtrrs(range, nr_range, mtrr_chunk_size,
- mtrr_gran_size);
+ i = 0;
+ mtrr_calc_range_state(mtrr_chunk_size, mtrr_gran_size,
+ extra_remove_base, extra_remove_size, i);

- /* we got new setting in range_state, check it */
- memset(range_new, 0, sizeof(range_new));
- nr_range_new = x86_get_mtrr_mem_range(range_new, 0,
- extra_remove_base,
- extra_remove_size);
- range_sums_new = sum_ranges(range_new, nr_range_new);
+ mtrr_print_out_one_result(i);

- i = 0;
- result[i].chunk_sizek = mtrr_chunk_size >> 10;
- result[i].gran_sizek = mtrr_gran_size >> 10;
- result[i].num_reg = num_reg;
- if (range_sums < range_sums_new) {
- result[i].lose_cover_sizek =
- (range_sums_new - range_sums) << PSHIFT;
- result[i].bad = 1;
- } else
- result[i].lose_cover_sizek =
- (range_sums - range_sums_new) << PSHIFT;
-
- gran_base = to_size_factor(result[i].gran_sizek, &gran_factor),
- chunk_base = to_size_factor(result[i].chunk_sizek, &chunk_factor),
- lose_base = to_size_factor(result[i].lose_cover_sizek, &lose_factor),
- printk(KERN_INFO "%sgran_size: %ld%c \tchunk_size: %ld%c \t",
- result[i].bad?"*BAD*":" ",
- gran_base, gran_factor, chunk_base, chunk_factor);
- printk(KERN_CONT "num_reg: %d \tlose cover RAM: %s%ld%c\n",
- result[i].num_reg, result[i].bad?"-":"",
- lose_base, lose_factor);
if (!result[i].bad) {
set_var_mtrr_all(address_bits);
return 1;
}
printk(KERN_INFO "invalid mtrr_gran_size or mtrr_chunk_size, "
"will find optimal one\n");
- debug_print--;
- memset(result, 0, sizeof(result[0]));
}

i = 0;
memset(min_loss_pfn, 0xff, sizeof(min_loss_pfn));
memset(result, 0, sizeof(result));
for (gran_size = (1ULL<<16); gran_size < (1ULL<<32); gran_size <<= 1) {
- char gran_factor;
- unsigned long gran_base;
-
- if (debug_print)
- gran_base = to_size_factor(gran_size >> 10, &gran_factor);

for (chunk_size = gran_size; chunk_size < (1ULL<<32);
chunk_size <<= 1) {
- int num_reg;

- if (debug_print) {
- char chunk_factor;
- unsigned long chunk_base;
-
- chunk_base = to_size_factor(chunk_size>>10, &chunk_factor),
- printk(KERN_INFO "\n");
- printk(KERN_INFO "gran_size: %ld%c chunk_size: %ld%c \n",
- gran_base, gran_factor, chunk_base, chunk_factor);
- }
if (i >= NUM_RESULT)
continue;

- /* convert ranges to var ranges state */
- num_reg = x86_setup_var_mtrrs(range, nr_range,
- chunk_size, gran_size);
-
- /* we got new setting in range_state, check it */
- memset(range_new, 0, sizeof(range_new));
- nr_range_new = x86_get_mtrr_mem_range(range_new, 0,
- extra_remove_base, extra_remove_size);
- range_sums_new = sum_ranges(range_new, nr_range_new);
-
- result[i].chunk_sizek = chunk_size >> 10;
- result[i].gran_sizek = gran_size >> 10;
- result[i].num_reg = num_reg;
- if (range_sums < range_sums_new) {
- result[i].lose_cover_sizek =
- (range_sums_new - range_sums) << PSHIFT;
- result[i].bad = 1;
- } else
- result[i].lose_cover_sizek =
- (range_sums - range_sums_new) << PSHIFT;
-
- /* double check it */
- if (!result[i].bad && !result[i].lose_cover_sizek) {
- if (nr_range_new != nr_range ||
- memcmp(range, range_new, sizeof(range)))
- result[i].bad = 1;
+ mtrr_calc_range_state(chunk_size, gran_size,
+ extra_remove_base, extra_remove_size, i);
+ if (debug_print) {
+ mtrr_print_out_one_result(i);
+ printk(KERN_INFO "\n");
}

- if (!result[i].bad && (range_sums - range_sums_new <
- min_loss_pfn[num_reg])) {
- min_loss_pfn[num_reg] =
- range_sums - range_sums_new;
- }
i++;
}
}

- /* print out all */
- for (i = 0; i < NUM_RESULT; i++) {
- char gran_factor, chunk_factor, lose_factor;
- unsigned long gran_base, chunk_base, lose_base;
-
- gran_base = to_size_factor(result[i].gran_sizek, &gran_factor),
- chunk_base = to_size_factor(result[i].chunk_sizek, &chunk_factor),
- lose_base = to_size_factor(result[i].lose_cover_sizek, &lose_factor),
- printk(KERN_INFO "%sgran_size: %ld%c \tchunk_size: %ld%c \t",
- result[i].bad?"*BAD*":" ",
- gran_base, gran_factor, chunk_base, chunk_factor);
- printk(KERN_CONT "num_reg: %d \tlose cover RAM: %s%ld%c\n",
- result[i].num_reg, result[i].bad?"-":"",
- lose_base, lose_factor);
- }
-
/* try to find the optimal index */
- if (nr_mtrr_spare_reg >= num_var_ranges)
- nr_mtrr_spare_reg = num_var_ranges - 1;
- num_reg_good = -1;
- for (i = num_var_ranges - nr_mtrr_spare_reg; i > 0; i--) {
- if (!min_loss_pfn[i])
- num_reg_good = i;
- }
-
- index_good = -1;
- if (num_reg_good != -1) {
- for (i = 0; i < NUM_RESULT; i++) {
- if (!result[i].bad &&
- result[i].num_reg == num_reg_good &&
- !result[i].lose_cover_sizek) {
- index_good = i;
- break;
- }
- }
- }
+ index_good = mtrr_search_optimal_index();

if (index_good != -1) {
- char gran_factor, chunk_factor, lose_factor;
- unsigned long gran_base, chunk_base, lose_base;
-
printk(KERN_INFO "Found optimal setting for mtrr clean up\n");
i = index_good;
- gran_base = to_size_factor(result[i].gran_sizek, &gran_factor),
- chunk_base = to_size_factor(result[i].chunk_sizek, &chunk_factor),
- lose_base = to_size_factor(result[i].lose_cover_sizek, &lose_factor),
- printk(KERN_INFO "gran_size: %ld%c \tchunk_size: %ld%c \t",
- gran_base, gran_factor, chunk_base, chunk_factor);
- printk(KERN_CONT "num_reg: %d \tlose RAM: %ld%c\n",
- result[i].num_reg, lose_base, lose_factor);
+ mtrr_print_out_one_result(i);
+
/* convert ranges to var ranges state */
chunk_size = result[i].chunk_sizek;
chunk_size <<= 10;
gran_size = result[i].gran_sizek;
gran_size <<= 10;
- debug_print++;
x86_setup_var_mtrrs(range, nr_range, chunk_size, gran_size);
- debug_print--;
set_var_mtrr_all(address_bits);
+ printk(KERN_DEBUG "New variable MTRRs\n");
+ print_out_mtrr_range_state();
return 1;
+ } else {
+ /* print out all */
+ for (i = 0; i < NUM_RESULT; i++)
+ mtrr_print_out_one_result(i);
}

printk(KERN_INFO "mtrr_cleanup: can not find optimal value\n");
@@ -1562,7 +1559,6 @@ int __init mtrr_trim_uncached_memory(uns
{
unsigned long i, base, size, highest_pfn = 0, def, dummy;
mtrr_type type;
- int nr_range;
u64 total_trim_size;

/* extra one for all 0 */
--
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