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 23/50] x86/boot/e820: Move the memblock_find_dma_reserve() function and rename it to memblock_set_dma_reserve()
Date: Sat, 28 Jan 2017 23:11:44 +0100 [thread overview]
Message-ID: <1485641531-22124-24-git-send-email-mingo@kernel.org> (raw)
In-Reply-To: <1485641531-22124-1-git-send-email-mingo@kernel.org>
We introduced memblock_find_dma_reserve() in this commit:
6f2a75369e75 x86, memblock: Use memblock_memory_size()/memblock_free_memory_size() to get correct dma_reserve
But there's several problems with it:
- The changelog is full of typos and is incomprehensible in general, and
the comments in the code are not much better either.
- The function was inexplicably placed into e820.c, while it has very
little connection to the E820 table: when we call
memblock_find_dma_reserve() then memblock is already set up and we
are not using the E820 table anymore.
- The function is a wrapper around set_dma_reserve(), but changed the 'set'
name to 'find' - actively misleading about its primary purpose, which is
still to set the DMA-reserve value.
- The function is limited to 64-bit systems, but neither the changelog nor
the comments explain why. The change would appear to be relevant to
32-bit systems as well, as the ISA DMA zone is the first 16 MB of RAM.
So address some of these problems:
- Move it into arch/x86/mm/init.c, next to the other zone setup related
functions.
- Clean up the code flow and names of local variables a bit.
- Rename it to memblock_set_dma_reserve()
- Improve the comments.
No change in functionality. Enabling it for 32-bit systems is left
for a separate patch.
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 | 1 -
arch/x86/include/asm/pgtable.h | 1 +
arch/x86/kernel/e820.c | 31 -------------------------------
arch/x86/mm/init.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 48 insertions(+), 32 deletions(-)
diff --git a/arch/x86/include/asm/e820/api.h b/arch/x86/include/asm/e820/api.h
index 01698548fbc8..7c9e4bb84059 100644
--- a/arch/x86/include/asm/e820/api.h
+++ b/arch/x86/include/asm/e820/api.h
@@ -22,7 +22,6 @@ 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 e820__memblock_setup(void);
-extern void memblock_find_dma_reserve(void);
extern void finish_e820_parsing(void);
extern void e820_reserve_resources(void);
extern void e820_reserve_resources_late(void);
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index ffaefb24891c..2d8116136f3e 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -733,6 +733,7 @@ static inline int pgd_none(pgd_t pgd)
extern int direct_gbpages;
void init_mem_mapping(void);
void early_alloc_pgt_buf(void);
+extern void memblock_find_dma_reserve(void);
#ifdef CONFIG_X86_64
/* Realmode trampoline initialization. */
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 4a8d905226c9..5f8ba898e29d 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -1172,34 +1172,3 @@ void __init e820__memblock_setup(void)
memblock_dump_all();
}
-
-void __init memblock_find_dma_reserve(void)
-{
-#ifdef CONFIG_X86_64
- u64 nr_pages = 0, nr_free_pages = 0;
- unsigned long start_pfn, end_pfn;
- phys_addr_t start, end;
- int i;
- u64 u;
-
- /*
- * need to find out used area below MAX_DMA_PFN
- * need to use memblock to get free size in [0, MAX_DMA_PFN]
- * at first, and assume boot_mem will not take below MAX_DMA_PFN
- */
- for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
- start_pfn = min(start_pfn, MAX_DMA_PFN);
- end_pfn = min(end_pfn, MAX_DMA_PFN);
- nr_pages += end_pfn - start_pfn;
- }
-
- for_each_free_mem_range(u, NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end, NULL) {
- start_pfn = min_t(unsigned long, PFN_UP(start), MAX_DMA_PFN);
- end_pfn = min_t(unsigned long, PFN_DOWN(end), MAX_DMA_PFN);
- if (start_pfn < end_pfn)
- nr_free_pages += end_pfn - start_pfn;
- }
-
- set_dma_reserve(nr_pages - nr_free_pages);
-#endif
-}
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index b7b4ad569d13..922671d3af85 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -724,6 +724,53 @@ void __init free_initrd_mem(unsigned long start, unsigned long end)
}
#endif
+/*
+ * Calculate the precise size of the DMA zone (first 16 MB of RAM),
+ * and pass it to the MM layer - to help it set zone watermarks more
+ * accurately.
+ *
+ * Done on 64-bit systems only for the time being, although 32-bit systems
+ * might benefit from this as well.
+ */
+void __init memblock_find_dma_reserve(void)
+{
+#ifdef CONFIG_X86_64
+ u64 nr_pages = 0, nr_free_pages = 0;
+ unsigned long start_pfn, end_pfn;
+ phys_addr_t start_addr, end_addr;
+ int i;
+ u64 u;
+
+ /*
+ * Iterate over all memory ranges (free and reserved ones alike),
+ * to calculate the total number of pages in the first 16 MB of RAM:
+ */
+ nr_pages = 0;
+ for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
+ start_pfn = min(start_pfn, MAX_DMA_PFN);
+ end_pfn = min(end_pfn, MAX_DMA_PFN);
+
+ nr_pages += end_pfn - start_pfn;
+ }
+
+ /*
+ * Iterate over free memory ranges to calculate the number of free
+ * pages in the DMA zone, while not counting potential partial
+ * pages at the beginning or the end of the range:
+ */
+ nr_free_pages = 0;
+ for_each_free_mem_range(u, NUMA_NO_NODE, MEMBLOCK_NONE, &start_addr, &end_addr, NULL) {
+ start_pfn = min_t(unsigned long, PFN_UP(start_addr), MAX_DMA_PFN);
+ end_pfn = min_t(unsigned long, PFN_DOWN(end_addr), MAX_DMA_PFN);
+
+ if (start_pfn < end_pfn)
+ nr_free_pages += end_pfn - start_pfn;
+ }
+
+ set_dma_reserve(nr_pages - nr_free_pages);
+#endif
+}
+
void __init zone_sizes_init(void)
{
unsigned long max_zone_pfns[MAX_NR_ZONES];
--
2.7.4
next prev parent reply other threads:[~2017-01-28 22:22 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 ` [PATCH 20/50] x86/boot/e820: Rename memblock_x86_fill() to e820__memblock_setup() and improve the explanations Ingo Molnar
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 ` Ingo Molnar [this message]
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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