From: Ingo Molnar <mingo@kernel.org>
To: linux-kernel@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>,
Andy Lutomirski <luto@amacapital.net>,
Borislav Petkov <bp@alien8.de>, "H . Peter Anvin" <hpa@zytor.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Yinghai Lu <yinghai@kernel.org>
Subject: [PATCH 20/50] x86/boot/e820: Rename memblock_x86_fill() to e820__memblock_setup() and improve the explanations
Date: Sat, 28 Jan 2017 23:11:41 +0100 [thread overview]
Message-ID: <1485641531-22124-21-git-send-email-mingo@kernel.org> (raw)
In-Reply-To: <1485641531-22124-1-git-send-email-mingo@kernel.org>
So memblock_x86_fill() is another E820 code misnomer:
- nothing in its name tells us that it's part of the E820 subsystem ...
- The 'fill' wording is ambiguous and doesn't tell us whether it's a single
entry or some process - while the _real_ purpose of the function is hidden,
which is to do a complete setup of the (platform independent) memblock regions.
So rename it accordingly, to e820__memblock_setup().
Also translate this incomprehensible and misleading comment:
/*
* EFI may have more than 128 entries
* We are safe to enable resizing, beause memblock_x86_fill()
* is rather later for x86
*/
memblock_allow_resize();
The worst aspect of this comment isn't even the sloppy typos, but that it
casually mentions a '128' number with no explanation, which makes one lead
to the assumption that this is related to the well-known limit of a maximum
of 128 E820 entries passed via legacy bootloaders.
But no, the _real_ meaning of 128 here is that of the memblock subsystem,
which too happens to have a 128 entries limit for very early memblock
regions (which is unrelated to E820), via INIT_MEMBLOCK_REGIONS ...
So change the comment to a more comprehensible version:
/*
* The bootstrap memblock region count maximum is 128 entries
* (INIT_MEMBLOCK_REGIONS), but EFI might pass us more E820 entries
* than that - so allow memblock resizing.
*
* This is safe, because this call happens pretty late during x86 setup,
* so we know about reserved memory regions already. (This is important
* so that memblock resizing does no stomp over reserved areas.)
*/
memblock_allow_resize();
No change in functionality.
Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang, Ying <ying.huang@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Jackson <pj@sgi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/include/asm/e820/api.h | 2 +-
arch/x86/kernel/e820.c | 14 +++++++++-----
arch/x86/kernel/setup.c | 4 ++--
3 files changed, 12 insertions(+), 8 deletions(-)
diff --git a/arch/x86/include/asm/e820/api.h b/arch/x86/include/asm/e820/api.h
index 2c336d8a8593..01698548fbc8 100644
--- a/arch/x86/include/asm/e820/api.h
+++ b/arch/x86/include/asm/e820/api.h
@@ -21,7 +21,7 @@ extern void parse_e820_ext(u64 phys_addr, u32 data_len);
extern unsigned long e820_end_of_ram_pfn(void);
extern unsigned long e820_end_of_low_ram_pfn(void);
extern u64 early_reserve_e820(u64 sizet, u64 align);
-extern void memblock_x86_fill(void);
+extern void e820__memblock_setup(void);
extern void memblock_find_dma_reserve(void);
extern void finish_e820_parsing(void);
extern void e820_reserve_resources(void);
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 624190fe86a7..b8e216b3957a 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -1138,15 +1138,19 @@ void __init e820__memory_setup(void)
e820_print_map(who);
}
-void __init memblock_x86_fill(void)
+void __init e820__memblock_setup(void)
{
int i;
u64 end;
/*
- * EFI may have more than 128 entries
- * We are safe to enable resizing, beause memblock_x86_fill()
- * is rather later for x86
+ * The bootstrap memblock region count maximum is 128 entries
+ * (INIT_MEMBLOCK_REGIONS), but EFI might pass us more E820 entries
+ * than that - so allow memblock resizing.
+ *
+ * This is safe, because this call happens pretty late during x86 setup,
+ * so we know about reserved memory regions already. (This is important
+ * so that memblock resizing does no stomp over reserved areas.)
*/
memblock_allow_resize();
@@ -1163,7 +1167,7 @@ void __init memblock_x86_fill(void)
memblock_add(ei->addr, ei->size);
}
- /* throw away partial pages */
+ /* Throw away partial pages: */
memblock_trim_memory(PAGE_SIZE);
memblock_dump_all();
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index f905430d7b04..838e4b5707ae 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1109,7 +1109,7 @@ void __init setup_arch(char **cmdline_p)
early_alloc_pgt_buf();
/*
- * Need to conclude brk, before memblock_x86_fill()
+ * Need to conclude brk, before e820__memblock_setup()
* it could use memblock_find_in_range, could overlap with
* brk area.
*/
@@ -1118,7 +1118,7 @@ void __init setup_arch(char **cmdline_p)
cleanup_highmap();
memblock_set_current_limit(ISA_END_ADDRESS);
- memblock_x86_fill();
+ e820__memblock_setup();
reserve_bios_regions();
--
2.7.4
next prev parent reply other threads:[~2017-01-28 22:21 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-28 22:11 [PATCH 00/50] x86: Clean up and reorganize the E820 table handling code Ingo Molnar
2017-01-28 22:11 ` [PATCH 01/50] x86/boot/e820: Introduce arch/x86/include/asm/e820/types.h Ingo Molnar
2017-01-29 17:13 ` Sam Ravnborg
2017-01-30 7:58 ` Ingo Molnar
2017-01-31 5:41 ` Sam Ravnborg
2017-01-31 16:35 ` Ingo Molnar
2017-01-31 17:22 ` Sam Ravnborg
2017-01-31 18:00 ` Ingo Molnar
2017-01-31 18:04 ` Joe Perches
2017-01-31 19:17 ` Sam Ravnborg
2017-02-01 8:56 ` Ingo Molnar
2017-01-28 22:11 ` [PATCH 02/50] x86/boot/e820: Clean up and improve comments in asm/e820/types.h Ingo Molnar
2017-01-28 22:11 ` [PATCH 03/50] x86/boot/e820: Move asm/e820.h to asm/e820/api.h Ingo Molnar
2017-01-28 22:11 ` [PATCH 04/50] x86/boot/e820: Split minimal UAPI types out into uapi/asm/e820/types.h Ingo Molnar
2017-01-28 22:11 ` [PATCH 05/50] x86/boot/e820: Clean up the E820_X_MAX definition Ingo Molnar
2017-01-28 22:11 ` [PATCH 06/50] x86/boot/e820: Remove spurious asm/e820/api.h inclusions Ingo Molnar
2017-01-28 22:11 ` [PATCH 07/50] x86/boot/e820: Remove assembly guard from asm/e820/types.h Ingo Molnar
2017-01-28 22:11 ` [PATCH 08/50] x86/boot/e820: Clean up asm/e820/api.h Ingo Molnar
2017-01-28 22:11 ` [PATCH 09/50] x86/boot/e820: Remove unnecessary __ASSEMBLY__ guard Ingo Molnar
2017-01-28 22:11 ` [PATCH 10/50] x86/boot/e820: Move HIGH_MEMORY define to asm/e820/types.h Ingo Molnar
2017-01-28 22:11 ` [PATCH 11/50] x86/boot/e820: Rename the basic e820 data types to 'struct e820_entry' and 'struct e820_array' Ingo Molnar
2017-01-28 22:11 ` [PATCH 12/50] x86/boot/e820: Remove unnecessary #include <linux/ioport.h> from asm/e820/api.h Ingo Molnar
2017-01-28 22:11 ` [PATCH 13/50] x86/boot/e820: Remove e820_mark_nosave_regions() definition uglies Ingo Molnar
2017-01-28 22:11 ` [PATCH 14/50] x86/boot/e820: Rename 'e820_map' variables to 'e820_array' Ingo Molnar
2017-01-28 22:11 ` [PATCH 15/50] x86/boot/e820: Rename everything to e820_table Ingo Molnar
2017-01-28 22:11 ` [PATCH 16/50] x86/boot/e820: Harmonize the 'struct e820_table' fields Ingo Molnar
2017-01-28 22:11 ` [PATCH 17/50] x86/boot/e820: Rename default_machine_specific_memory_setup() to e820__memory_setup_default() Ingo Molnar
2017-01-28 22:11 ` [PATCH 18/50] x86/boot/e820: Rename e820_table_saved to e820_table_firmware and improve the description Ingo Molnar
2017-01-28 22:11 ` [PATCH 19/50] x86/boot/e820: Basic cleanup of e820.c Ingo Molnar
2017-01-28 22:11 ` Ingo Molnar [this message]
2017-01-28 22:11 ` [PATCH 21/50] x86/boot/e820: Consolidate 'struct e820_entry *entry' local variable names Ingo Molnar
2017-01-28 22:11 ` [PATCH 22/50] x86/boot/e820: Convert printk(KERN_* ...) to pr_*() Ingo Molnar
2017-01-28 22:59 ` Joe Perches
2017-01-28 22:11 ` [PATCH 23/50] x86/boot/e820: Move the memblock_find_dma_reserve() function and rename it to memblock_set_dma_reserve() Ingo Molnar
2017-01-28 22:11 ` [PATCH 24/50] x86/boot/e820: Rename parse_e820_ext() to e820__memory_setup_extended() Ingo Molnar
2017-01-28 22:11 ` [PATCH 25/50] x86/boot/e820: Move e820_reserve_setup_data() to e820.c Ingo Molnar
2017-01-28 22:11 ` [PATCH 26/50] x86/boot/e820: Clarify the role of finish_e820_parsing() and rename it to e820__finish_early_params() Ingo Molnar
2017-01-28 22:11 ` [PATCH 27/50] x86/boot/e820: Rename early_reserve_e820() to e820__memblock_alloc() and document it Ingo Molnar
2017-01-28 22:11 ` [PATCH 28/50] x86/boot/e820: Rename update_e820() to e820__update_table() Ingo Molnar
2017-01-28 22:11 ` [PATCH 29/50] x86/boot/e820: Rename sanitize_e820_table() " Ingo Molnar
2017-01-28 22:11 ` [PATCH 30/50] x86/boot/e820: Rename e820_any_mapped()/e820_all_mapped() to e820__mapped_any()/e820__mapped_all() Ingo Molnar
2017-01-28 22:11 ` [PATCH 31/50] x86/boot/e820: Rename e820_setup_gap() to e820__setup_pci_gap() Ingo Molnar
2017-01-28 22:11 ` [PATCH 32/50] x86/boot/e820: Create coherent API function names for E820 range operations Ingo Molnar
2017-01-28 22:11 ` [PATCH 33/50] x86/boot/e820: Rename e820_print_map() to e820__print_table() Ingo Molnar
2017-01-28 22:11 ` [PATCH 34/50] x86/boot/e820: Reorder the function prototypes in api.h Ingo Molnar
2017-01-28 22:11 ` [PATCH 35/50] x86/boot/e820: Simplify e820_reserve_resources() Ingo Molnar
2017-01-28 22:11 ` [PATCH 36/50] x86/boot/e820: Introduce 'enum e820_type' Ingo Molnar
2017-01-28 22:11 ` [PATCH 37/50] x86/boot/e820: Use 'enum e820_type' in 'struct e820_entry' Ingo Molnar
2017-01-28 23:07 ` Linus Torvalds
2017-01-29 9:19 ` Ingo Molnar
2017-01-29 12:38 ` [PATCH] x86/boot/e820: Separate the E820 ABI structures from the in-kernel structures Ingo Molnar
2017-01-29 18:53 ` [PATCH 37/50] x86/boot/e820: Use 'enum e820_type' in 'struct e820_entry' Linus Torvalds
2017-01-28 22:11 ` [PATCH 38/50] x86/boot/e820: Use 'enum e820_type' when handling the e820 region type Ingo Molnar
2017-01-28 22:12 ` [PATCH 39/50] x86/boot/e820: Prefix the E820_* type names with "E820_TYPE_" Ingo Molnar
2017-01-28 22:12 ` [PATCH 40/50] x86/boot/e820: Clean up the E820 table size define names Ingo Molnar
2017-01-28 22:12 ` [PATCH 41/50] x86/boot/e820: Clean up and standardize sizeof() uses Ingo Molnar
2017-01-28 22:12 ` [PATCH 42/50] xen, x86/boot/e820: Simplify Xen's xen_e820_table construct Ingo Molnar
2017-01-28 22:12 ` [PATCH 43/50] x86/boot/e820: Simplify the e820__update_table() interface Ingo Molnar
2017-01-28 22:12 ` [PATCH 44/50] x86/boot/e820: Clean up __e820__update_table() et al Ingo Molnar
2017-01-28 22:12 ` [PATCH 45/50] x86/boot/e820: Document e820__reserve_setup_data() Ingo Molnar
2017-01-28 22:12 ` [PATCH 46/50] x86/boot/e820: Use bool in query APIs Ingo Molnar
2017-01-28 22:12 ` [PATCH 47/50] x86/boot/e820: Rename e820_reserve_resources*() to e820__reserve_resources*() Ingo Molnar
2017-01-28 22:12 ` [PATCH 48/50] x86/boot/e820: Rename e820_mark_nosave_regions() to e820__register_nosave_regions() Ingo Molnar
2017-01-28 22:12 ` [PATCH 49/50] x86/boot/e820: Remove unnecessary #include's Ingo Molnar
2017-01-28 22:12 ` [PATCH 50/50] x86/boot/e820: Rename the remaining E820 APIs to the e820__*() prefix Ingo Molnar
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