From 441ac2f33dd7860295cf1d225358ec01d38408b2 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 30 Jan 2017 09:24:39 +0100 Subject: [PATCH] x86/boot/e820: Simplify e820__update_table() - Remove the now unnecessary __e820__update_table() wrappery - Move statics out from function scope, to make the logic clearer - Rename local variables to be more in line with the rest of 820.c - Remove unnecessary local variables: old_nr, *nr_entries No change in functionality. Cc: Alex Thorlton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Dan Williams Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Huang, Ying Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Linus Torvalds Cc: Paul Jackson Cc: Peter Zijlstra Cc: Rafael J. Wysocki Cc: Tejun Heo Cc: Thomas Gleixner Cc: Wei Yang Cc: Yinghai Lu Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar --- arch/x86/kernel/e820.c | 70 +++++++++++++++++++----------------------- 1 file changed, 31 insertions(+), 39 deletions(-) diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index 2da2f7238a72..e2fb20ac5135 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -235,6 +235,11 @@ struct change_member { unsigned long long addr; }; +static struct change_member change_point_list[2*E820_MAX_ENTRIES] __initdata; +static struct change_member *change_point[2*E820_MAX_ENTRIES] __initdata; +static struct e820_entry *overlap_list[E820_MAX_ENTRIES] __initdata; +static struct e820_entry new_entries[E820_MAX_ENTRIES] __initdata; + static int __init cpcompare(const void *a, const void *b) { struct change_member * const *app = a, * const *bpp = b; @@ -252,51 +257,46 @@ static int __init cpcompare(const void *a, const void *b) return (ap->addr != ap->entry->addr) - (bp->addr != bp->entry->addr); } -static int __init __e820__update_table(struct e820_entry *entries, u32 max_nr_entries, u32 *nr_entries) +int __init e820__update_table(struct e820_table *table) { - static struct change_member change_point_list[2*E820_MAX_ENTRIES] __initdata; - static struct change_member *change_point[2*E820_MAX_ENTRIES] __initdata; - static struct e820_entry *overlap_list[E820_MAX_ENTRIES] __initdata; - static struct e820_entry new_entries[E820_MAX_ENTRIES] __initdata; + struct e820_entry *entries = table->entries; + u32 max_nr_entries = ARRAY_SIZE(table->entries); enum e820_type current_type, last_type; unsigned long long last_addr; - u32 chgidx; - u32 overlap_entries; - u32 new_nr_entries; - u32 old_nr, new_nr, chg_nr; - u32 i; + u32 new_nr_entries, overlap_entries; + u32 i, chg_idx, chg_nr; /* If there's only one memory region, don't bother: */ - if (*nr_entries < 2) + if (table->nr_entries < 2) return -1; - old_nr = *nr_entries; - BUG_ON(old_nr > max_nr_entries); + table->nr_entries = table->nr_entries; + BUG_ON(table->nr_entries > max_nr_entries); /* Bail out if we find any unreasonable addresses in the map: */ - for (i = 0; i < old_nr; i++) { + for (i = 0; i < table->nr_entries; i++) { if (entries[i].addr + entries[i].size < entries[i].addr) return -1; } /* Create pointers for initial change-point information (for sorting): */ - for (i = 0; i < 2 * old_nr; i++) + for (i = 0; i < 2 * table->nr_entries; i++) change_point[i] = &change_point_list[i]; /* * Record all known change-points (starting and ending addresses), * omitting empty memory regions: */ - chgidx = 0; - for (i = 0; i < old_nr; i++) { + chg_idx = 0; + for (i = 0; i < table->nr_entries; i++) { if (entries[i].size != 0) { - change_point[chgidx]->addr = entries[i].addr; - change_point[chgidx++]->entry = &entries[i]; - change_point[chgidx]->addr = entries[i].addr + entries[i].size; - change_point[chgidx++]->entry = &entries[i]; + change_point[chg_idx]->addr = entries[i].addr; + change_point[chg_idx++]->entry = &entries[i]; + change_point[chg_idx]->addr = entries[i].addr + entries[i].size; + change_point[chg_idx++]->entry = &entries[i]; } } - chg_nr = chgidx; + chg_nr = chg_idx; /* Sort change-point list by memory addresses (low -> high): */ sort(change_point, chg_nr, sizeof(*change_point), cpcompare, NULL); @@ -308,15 +308,15 @@ static int __init __e820__update_table(struct e820_entry *entries, u32 max_nr_en last_addr = 0; /* Start with 0 as last starting address */ /* Loop through change-points, determining effect on the new map: */ - for (chgidx = 0; chgidx < chg_nr; chgidx++) { + for (chg_idx = 0; chg_idx < chg_nr; chg_idx++) { /* Keep track of all overlapping entries */ - if (change_point[chgidx]->addr == change_point[chgidx]->entry->addr) { + if (change_point[chg_idx]->addr == change_point[chg_idx]->entry->addr) { /* Add map entry to overlap list (> 1 entry implies an overlap) */ - overlap_list[overlap_entries++] = change_point[chgidx]->entry; + overlap_list[overlap_entries++] = change_point[chg_idx]->entry; } else { /* Remove entry from list (order independent, so swap with last): */ for (i = 0; i < overlap_entries; i++) { - if (overlap_list[i] == change_point[chgidx]->entry) + if (overlap_list[i] == change_point[chg_idx]->entry) overlap_list[i] = overlap_list[overlap_entries-1]; } overlap_entries--; @@ -335,7 +335,7 @@ static int __init __e820__update_table(struct e820_entry *entries, u32 max_nr_en /* Continue building up new map based on this information: */ if (current_type != last_type || current_type == E820_TYPE_PRAM) { if (last_type != 0) { - new_entries[new_nr_entries].size = change_point[chgidx]->addr - last_addr; + new_entries[new_nr_entries].size = change_point[chg_idx]->addr - last_addr; /* Move forward only if the new size was non-zero: */ if (new_entries[new_nr_entries].size != 0) /* No more space left for new entries? */ @@ -343,29 +343,21 @@ static int __init __e820__update_table(struct e820_entry *entries, u32 max_nr_en break; } if (current_type != 0) { - new_entries[new_nr_entries].addr = change_point[chgidx]->addr; + new_entries[new_nr_entries].addr = change_point[chg_idx]->addr; new_entries[new_nr_entries].type = current_type; - last_addr = change_point[chgidx]->addr; + last_addr = change_point[chg_idx]->addr; } last_type = current_type; } } - /* Retain count for the new entries: */ - new_nr = new_nr_entries; - /* Copy the new entries into the original location: */ - memcpy(entries, new_entries, new_nr*sizeof(*entries)); - *nr_entries = new_nr; + memcpy(entries, new_entries, new_nr_entries*sizeof(*entries)); + table->nr_entries = new_nr_entries; return 0; } -int __init e820__update_table(struct e820_table *table) -{ - return __e820__update_table(table->entries, ARRAY_SIZE(table->entries), &table->nr_entries); -} - static int __init __append_e820_table(struct boot_e820_entry *entries, u32 nr_entries) { struct boot_e820_entry *entry = entries; -- 2.20.1