* [PATCH 0/3] Make PMD_ORDER generically available
@ 2021-07-15 13:46 Matthew Wilcox (Oracle)
2021-07-15 13:46 ` [PATCH 1/3] arm: Rename PMD_ORDER to PMD_TABLE_ORDER Matthew Wilcox (Oracle)
` (3 more replies)
0 siblings, 4 replies; 10+ messages in thread
From: Matthew Wilcox (Oracle) @ 2021-07-15 13:46 UTC (permalink / raw)
To: linux-arch, linux-parisc, linux-mips, linux-arm-kernel
Cc: Matthew Wilcox (Oracle), linux-kernel
These three architectures each define PMD_ORDER to mean "the order of
an allocation for a PMD table", but logically PMD_ORDER should be the
order of a PMD allocation, ie (PMD_SHIFT - PAGE_SHIFT) as DAX defines it.
Could each architecture maintainer please apply the appropriate patch
to their respective trees?
Matthew Wilcox (Oracle) (3):
arm: Rename PMD_ORDER to PMD_TABLE_ORDER
mips: Rename PMD_ORDER to PMD_TABLE_ORDER
parisc: Rename PMD_ORDER to PMD_TABLE_ORDER
arch/arm/kernel/head.S | 34 +++++++++++++++---------------
arch/mips/include/asm/pgalloc.h | 2 +-
arch/mips/include/asm/pgtable-32.h | 2 +-
arch/mips/include/asm/pgtable-64.h | 18 ++++++++--------
arch/mips/kernel/asm-offsets.c | 2 +-
arch/parisc/include/asm/pgalloc.h | 6 +++---
arch/parisc/include/asm/pgtable.h | 4 ++--
arch/parisc/mm/init.c | 4 ++--
8 files changed, 36 insertions(+), 36 deletions(-)
--
2.30.2
^ permalink raw reply [flat|nested] 10+ messages in thread* [PATCH 1/3] arm: Rename PMD_ORDER to PMD_TABLE_ORDER 2021-07-15 13:46 [PATCH 0/3] Make PMD_ORDER generically available Matthew Wilcox (Oracle) @ 2021-07-15 13:46 ` Matthew Wilcox (Oracle) 2021-07-15 16:47 ` Russell King (Oracle) 2021-07-15 13:46 ` [PATCH 2/3] mips: " Matthew Wilcox (Oracle) ` (2 subsequent siblings) 3 siblings, 1 reply; 10+ messages in thread From: Matthew Wilcox (Oracle) @ 2021-07-15 13:46 UTC (permalink / raw) To: linux-arch, linux-parisc, linux-mips, linux-arm-kernel Cc: Matthew Wilcox (Oracle), linux-kernel This is the order of the page table allocation, not the order of a PMD. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- arch/arm/kernel/head.S | 34 +++++++++++++++++----------------- 1 file changed, 17 insertions(+), 17 deletions(-) diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 9eb0b4dbcc12..6da39a1d70ba 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -38,10 +38,10 @@ #ifdef CONFIG_ARM_LPAE /* LPAE requires an additional page for the PGD */ #define PG_DIR_SIZE 0x5000 -#define PMD_ORDER 3 +#define PMD_TABLE_ORDER 3 #else #define PG_DIR_SIZE 0x4000 -#define PMD_ORDER 2 +#define PMD_TABLE_ORDER 2 #endif .globl swapper_pg_dir @@ -237,7 +237,7 @@ __create_page_tables: mov r6, r6, lsr #SECTION_SHIFT 1: orr r3, r7, r5, lsl #SECTION_SHIFT @ flags + kernel base - str r3, [r4, r5, lsl #PMD_ORDER] @ identity mapping + str r3, [r4, r5, lsl #PMD_TABLE_ORDER] @ identity mapping cmp r5, r6 addlo r5, r5, #1 @ next section blo 1b @@ -247,13 +247,13 @@ __create_page_tables: * set two variables to indicate the physical start and end of the * kernel. */ - add r0, r4, #KERNEL_OFFSET >> (SECTION_SHIFT - PMD_ORDER) + add r0, r4, #KERNEL_OFFSET >> (SECTION_SHIFT - PMD_TABLE_ORDER) ldr r6, =(_end - 1) adr_l r5, kernel_sec_start @ _pa(kernel_sec_start) str r8, [r5] @ Save physical start of kernel orr r3, r8, r7 @ Add the MMU flags - add r6, r4, r6, lsr #(SECTION_SHIFT - PMD_ORDER) -1: str r3, [r0], #1 << PMD_ORDER + add r6, r4, r6, lsr #(SECTION_SHIFT - PMD_TABLE_ORDER) +1: str r3, [r0], #1 << PMD_TABLE_ORDER add r3, r3, #1 << SECTION_SHIFT cmp r0, r6 bls 1b @@ -269,14 +269,14 @@ __create_page_tables: mov r3, pc mov r3, r3, lsr #SECTION_SHIFT orr r3, r7, r3, lsl #SECTION_SHIFT - add r0, r4, #(XIP_START & 0xff000000) >> (SECTION_SHIFT - PMD_ORDER) - str r3, [r0, #((XIP_START & 0x00f00000) >> SECTION_SHIFT) << PMD_ORDER]! + add r0, r4, #(XIP_START & 0xff000000) >> (SECTION_SHIFT - PMD_TABLE_ORDER) + str r3, [r0, #((XIP_START & 0x00f00000) >> SECTION_SHIFT) << PMD_TABLE_ORDER]! ldr r6, =(_edata_loc - 1) - add r0, r0, #1 << PMD_ORDER - add r6, r4, r6, lsr #(SECTION_SHIFT - PMD_ORDER) + add r0, r0, #1 << PMD_TABLE_ORDER + add r6, r4, r6, lsr #(SECTION_SHIFT - PMD_TABLE_ORDER) 1: cmp r0, r6 add r3, r3, #1 << SECTION_SHIFT - strls r3, [r0], #1 << PMD_ORDER + strls r3, [r0], #1 << PMD_TABLE_ORDER bls 1b #endif @@ -286,10 +286,10 @@ __create_page_tables: */ mov r0, r2, lsr #SECTION_SHIFT cmp r2, #0 - ldrne r3, =FDT_FIXED_BASE >> (SECTION_SHIFT - PMD_ORDER) + ldrne r3, =FDT_FIXED_BASE >> (SECTION_SHIFT - PMD_TABLE_ORDER) addne r3, r3, r4 orrne r6, r7, r0, lsl #SECTION_SHIFT - strne r6, [r3], #1 << PMD_ORDER + strne r6, [r3], #1 << PMD_TABLE_ORDER addne r6, r6, #1 << SECTION_SHIFT strne r6, [r3] @@ -308,7 +308,7 @@ __create_page_tables: addruart r7, r3, r0 mov r3, r3, lsr #SECTION_SHIFT - mov r3, r3, lsl #PMD_ORDER + mov r3, r3, lsl #PMD_TABLE_ORDER add r0, r4, r3 mov r3, r7, lsr #SECTION_SHIFT @@ -338,7 +338,7 @@ __create_page_tables: * If we're using the NetWinder or CATS, we also need to map * in the 16550-type serial port for the debug messages */ - add r0, r4, #0xff000000 >> (SECTION_SHIFT - PMD_ORDER) + add r0, r4, #0xff000000 >> (SECTION_SHIFT - PMD_TABLE_ORDER) orr r3, r7, #0x7c000000 str r3, [r0] #endif @@ -348,10 +348,10 @@ __create_page_tables: * Similar reasons here - for debug. This is * only for Acorn RiscPC architectures. */ - add r0, r4, #0x02000000 >> (SECTION_SHIFT - PMD_ORDER) + add r0, r4, #0x02000000 >> (SECTION_SHIFT - PMD_TABLE_ORDER) orr r3, r7, #0x02000000 str r3, [r0] - add r0, r4, #0xd8000000 >> (SECTION_SHIFT - PMD_ORDER) + add r0, r4, #0xd8000000 >> (SECTION_SHIFT - PMD_TABLE_ORDER) str r3, [r0] #endif #endif -- 2.30.2 ^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH 1/3] arm: Rename PMD_ORDER to PMD_TABLE_ORDER 2021-07-15 13:46 ` [PATCH 1/3] arm: Rename PMD_ORDER to PMD_TABLE_ORDER Matthew Wilcox (Oracle) @ 2021-07-15 16:47 ` Russell King (Oracle) 2021-07-15 18:10 ` Matthew Wilcox 0 siblings, 1 reply; 10+ messages in thread From: Russell King (Oracle) @ 2021-07-15 16:47 UTC (permalink / raw) To: Matthew Wilcox (Oracle) Cc: linux-arch, linux-parisc, linux-mips, linux-arm-kernel, linux-kernel On Thu, Jul 15, 2021 at 02:46:10PM +0100, Matthew Wilcox (Oracle) wrote: > This is the order of the page table allocation, not the order of a PMD. > > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> > --- > arch/arm/kernel/head.S | 34 +++++++++++++++++----------------- > 1 file changed, 17 insertions(+), 17 deletions(-) > > diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S > index 9eb0b4dbcc12..6da39a1d70ba 100644 > --- a/arch/arm/kernel/head.S > +++ b/arch/arm/kernel/head.S > @@ -38,10 +38,10 @@ > #ifdef CONFIG_ARM_LPAE > /* LPAE requires an additional page for the PGD */ > #define PG_DIR_SIZE 0x5000 > -#define PMD_ORDER 3 > +#define PMD_TABLE_ORDER 3 > #else > #define PG_DIR_SIZE 0x4000 > -#define PMD_ORDER 2 > +#define PMD_TABLE_ORDER 2 I think PMD_ENTRY_ORDER would make more sense here - this is the power-of-2 of an individual PMD entry, not of the entire table. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last! ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH 1/3] arm: Rename PMD_ORDER to PMD_TABLE_ORDER 2021-07-15 16:47 ` Russell King (Oracle) @ 2021-07-15 18:10 ` Matthew Wilcox 2021-07-15 18:37 ` Russell King (Oracle) 0 siblings, 1 reply; 10+ messages in thread From: Matthew Wilcox @ 2021-07-15 18:10 UTC (permalink / raw) To: Russell King (Oracle) Cc: linux-arch, linux-parisc, linux-mips, linux-arm-kernel, linux-kernel On Thu, Jul 15, 2021 at 05:47:41PM +0100, Russell King (Oracle) wrote: > On Thu, Jul 15, 2021 at 02:46:10PM +0100, Matthew Wilcox (Oracle) wrote: > > This is the order of the page table allocation, not the order of a PMD. > > -#define PMD_ORDER 3 > > +#define PMD_TABLE_ORDER 3 > > #else > > #define PG_DIR_SIZE 0x4000 > > -#define PMD_ORDER 2 > > +#define PMD_TABLE_ORDER 2 > > I think PMD_ENTRY_ORDER would make more sense here - this is the > power-of-2 of an individual PMD entry, not of the entire table. But ... we have two kinds of PMD entries. We have the direct entry that points to a 1-16MB sized chunk of memory, and we have the table entry that points to a 4k-32k chunk of memory that contains PTEs. So I don't think calling it 'entry' order actually disambiguates anything. That's why I went with 'table' -- I can't think of anything else to call it! PMD_PTE_ARRAY_ORDER doesn't seem like an improvement to me ... ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH 1/3] arm: Rename PMD_ORDER to PMD_TABLE_ORDER 2021-07-15 18:10 ` Matthew Wilcox @ 2021-07-15 18:37 ` Russell King (Oracle) 2021-07-15 19:16 ` Matthew Wilcox 0 siblings, 1 reply; 10+ messages in thread From: Russell King (Oracle) @ 2021-07-15 18:37 UTC (permalink / raw) To: Matthew Wilcox Cc: linux-arch, linux-parisc, linux-mips, linux-arm-kernel, linux-kernel On Thu, Jul 15, 2021 at 07:10:54PM +0100, Matthew Wilcox wrote: > On Thu, Jul 15, 2021 at 05:47:41PM +0100, Russell King (Oracle) wrote: > > On Thu, Jul 15, 2021 at 02:46:10PM +0100, Matthew Wilcox (Oracle) wrote: > > > This is the order of the page table allocation, not the order of a PMD. > > > -#define PMD_ORDER 3 > > > +#define PMD_TABLE_ORDER 3 > > > #else > > > #define PG_DIR_SIZE 0x4000 > > > -#define PMD_ORDER 2 > > > +#define PMD_TABLE_ORDER 2 > > > > I think PMD_ENTRY_ORDER would make more sense here - this is the > > power-of-2 of an individual PMD entry, not of the entire table. > > But ... we have two kinds of PMD entries. We have the direct entry that > points to a 1-16MB sized chunk of memory, and we have the table entry that > points to a 4k-32k chunk of memory that contains PTEs. So I don't think > calling it 'entry' order actually disambiguates anything. That's why > I went with 'table' -- I can't think of anything else to call it! > PMD_PTE_ARRAY_ORDER doesn't seem like an improvement to me ... There may be two kinds of PMD entries, but that isn't relevant here. Going back to the original terminology, 1 << PMD_ORDER here is the size of each PMD entry. It doesn't have anything to do with how much memory is being mapped by each entry. I think what is confusing you is stuff like: add r0, r4, #KERNEL_OFFSET >> (SECTION_SHIFT - PMD_ORDER) r4 is the base address of the page tables, and r0 is the address of the entry we want to manipulate for "KERNEL_OFFSET" - which is the virtual address. 1 << SECTION_SHIFT is how much memory each entry maps (and this is fixed here - there's no variability as you suggest above.) Effectively, the calculation above is: index = KERNEL_OFFSET >> SECTION_SHIFT; pmd_entry_size = 1 << PMD_ORDER; r0 = base + index * pmd_entry_size; but in a single instruction as we can be sure that KERNEL_OFFSET will have zeros as the low bits after shifting by SECTION_SHIFT - PMD_ORDER. Hope this helps to explain what this PMD_ORDER is actually doing here. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last! ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH 1/3] arm: Rename PMD_ORDER to PMD_TABLE_ORDER 2021-07-15 18:37 ` Russell King (Oracle) @ 2021-07-15 19:16 ` Matthew Wilcox 0 siblings, 0 replies; 10+ messages in thread From: Matthew Wilcox @ 2021-07-15 19:16 UTC (permalink / raw) To: Russell King (Oracle) Cc: linux-arch, linux-parisc, linux-mips, linux-arm-kernel, linux-kernel On Thu, Jul 15, 2021 at 07:37:27PM +0100, Russell King (Oracle) wrote: > On Thu, Jul 15, 2021 at 07:10:54PM +0100, Matthew Wilcox wrote: > > On Thu, Jul 15, 2021 at 05:47:41PM +0100, Russell King (Oracle) wrote: > > > On Thu, Jul 15, 2021 at 02:46:10PM +0100, Matthew Wilcox (Oracle) wrote: > > > > This is the order of the page table allocation, not the order of a PMD. > > > > -#define PMD_ORDER 3 > > > > +#define PMD_TABLE_ORDER 3 > > > > #else > > > > #define PG_DIR_SIZE 0x4000 > > > > -#define PMD_ORDER 2 > > > > +#define PMD_TABLE_ORDER 2 > > > > > > I think PMD_ENTRY_ORDER would make more sense here - this is the > > > power-of-2 of an individual PMD entry, not of the entire table. > > > > But ... we have two kinds of PMD entries. We have the direct entry that > > points to a 1-16MB sized chunk of memory, and we have the table entry that > > points to a 4k-32k chunk of memory that contains PTEs. So I don't think > > calling it 'entry' order actually disambiguates anything. That's why > > I went with 'table' -- I can't think of anything else to call it! > > PMD_PTE_ARRAY_ORDER doesn't seem like an improvement to me ... > > There may be two kinds of PMD entries, but that isn't relevant here. > Going back to the original terminology, 1 << PMD_ORDER here is the > size of each PMD entry. It doesn't have anything to do with how much > memory is being mapped by each entry. Oh. Oh! So, 'order' is usually a shift that is _added on to_ the PAGE_SHIFT in order to find how many bytes are in question. See include/asm-generic/getorder.h. Now, PMD_SHIFT is already in use, but perhaps what is meant here is PMD_ENTRY_SHIFT? > I think what is confusing you is stuff like: > > add r0, r4, #KERNEL_OFFSET >> (SECTION_SHIFT - PMD_ORDER) > > r4 is the base address of the page tables, and r0 is the address of > the entry we want to manipulate for "KERNEL_OFFSET" - which is the > virtual address. 1 << SECTION_SHIFT is how much memory each entry > maps (and this is fixed here - there's no variability as you suggest > above.) (the variability I intended above was more to accommodate architectural differences; I hate to use x86-specific numbers like 4KiB and 2MiB) > Effectively, the calculation above is: > > index = KERNEL_OFFSET >> SECTION_SHIFT; > pmd_entry_size = 1 << PMD_ORDER; > r0 = base + index * pmd_entry_size; > > but in a single instruction as we can be sure that KERNEL_OFFSET will > have zeros as the low bits after shifting by SECTION_SHIFT - PMD_ORDER. > > Hope this helps to explain what this PMD_ORDER is actually doing here. Thank you, yes, I was terminally confused. ^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH 2/3] mips: Rename PMD_ORDER to PMD_TABLE_ORDER 2021-07-15 13:46 [PATCH 0/3] Make PMD_ORDER generically available Matthew Wilcox (Oracle) 2021-07-15 13:46 ` [PATCH 1/3] arm: Rename PMD_ORDER to PMD_TABLE_ORDER Matthew Wilcox (Oracle) @ 2021-07-15 13:46 ` Matthew Wilcox (Oracle) 2021-07-15 13:46 ` [PATCH 3/3] parisc: " Matthew Wilcox (Oracle) 2021-07-15 16:28 ` [PATCH 0/3] Make PMD_ORDER generically available Helge Deller 3 siblings, 0 replies; 10+ messages in thread From: Matthew Wilcox (Oracle) @ 2021-07-15 13:46 UTC (permalink / raw) To: linux-arch, linux-parisc, linux-mips, linux-arm-kernel Cc: Matthew Wilcox (Oracle), linux-kernel This is the order of the page table allocation, not the order of a PMD. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- arch/mips/include/asm/pgalloc.h | 2 +- arch/mips/include/asm/pgtable-32.h | 2 +- arch/mips/include/asm/pgtable-64.h | 18 +++++++++--------- arch/mips/kernel/asm-offsets.c | 2 +- 4 files changed, 12 insertions(+), 12 deletions(-) diff --git a/arch/mips/include/asm/pgalloc.h b/arch/mips/include/asm/pgalloc.h index 4b2567d6b2df..795e9e2219c9 100644 --- a/arch/mips/include/asm/pgalloc.h +++ b/arch/mips/include/asm/pgalloc.h @@ -61,7 +61,7 @@ static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address) pmd_t *pmd = NULL; struct page *pg; - pg = alloc_pages(GFP_KERNEL | __GFP_ACCOUNT, PMD_ORDER); + pg = alloc_pages(GFP_KERNEL | __GFP_ACCOUNT, PMD_TABLE_ORDER); if (pg) { pgtable_pmd_page_ctor(pg); pmd = (pmd_t *)page_address(pg); diff --git a/arch/mips/include/asm/pgtable-32.h b/arch/mips/include/asm/pgtable-32.h index 95df9c293d8d..8d57bd5b0b94 100644 --- a/arch/mips/include/asm/pgtable-32.h +++ b/arch/mips/include/asm/pgtable-32.h @@ -82,7 +82,7 @@ extern int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1, #define PGD_ORDER (__PGD_ORDER >= 0 ? __PGD_ORDER : 0) #define PUD_ORDER aieeee_attempt_to_allocate_pud -#define PMD_ORDER aieeee_attempt_to_allocate_pmd +#define PMD_TABLE_ORDER aieeee_attempt_to_allocate_pmd #define PTE_ORDER 0 #define PTRS_PER_PGD (USER_PTRS_PER_PGD * 2) diff --git a/arch/mips/include/asm/pgtable-64.h b/arch/mips/include/asm/pgtable-64.h index 41921acdc9d8..ae0d5a09064d 100644 --- a/arch/mips/include/asm/pgtable-64.h +++ b/arch/mips/include/asm/pgtable-64.h @@ -51,12 +51,12 @@ #define PMD_MASK (~(PMD_SIZE-1)) # ifdef __PAGETABLE_PUD_FOLDED -# define PGDIR_SHIFT (PMD_SHIFT + (PAGE_SHIFT + PMD_ORDER - 3)) +# define PGDIR_SHIFT (PMD_SHIFT + (PAGE_SHIFT + PMD_TABLE_ORDER - 3)) # endif #endif #ifndef __PAGETABLE_PUD_FOLDED -#define PUD_SHIFT (PMD_SHIFT + (PAGE_SHIFT + PMD_ORDER - 3)) +#define PUD_SHIFT (PMD_SHIFT + (PAGE_SHIFT + PMD_TABLE_ORDER - 3)) #define PUD_SIZE (1UL << PUD_SHIFT) #define PUD_MASK (~(PUD_SIZE-1)) #define PGDIR_SHIFT (PUD_SHIFT + (PAGE_SHIFT + PUD_ORDER - 3)) @@ -91,13 +91,13 @@ # define PGD_ORDER 1 # define PUD_ORDER aieeee_attempt_to_allocate_pud # endif -#define PMD_ORDER 0 +#define PMD_TABLE_ORDER 0 #define PTE_ORDER 0 #endif #ifdef CONFIG_PAGE_SIZE_8KB #define PGD_ORDER 0 #define PUD_ORDER aieeee_attempt_to_allocate_pud -#define PMD_ORDER 0 +#define PMD_TABLE_ORDER 0 #define PTE_ORDER 0 #endif #ifdef CONFIG_PAGE_SIZE_16KB @@ -107,22 +107,22 @@ #define PGD_ORDER 0 #endif #define PUD_ORDER aieeee_attempt_to_allocate_pud -#define PMD_ORDER 0 +#define PMD_TABLE_ORDER 0 #define PTE_ORDER 0 #endif #ifdef CONFIG_PAGE_SIZE_32KB #define PGD_ORDER 0 #define PUD_ORDER aieeee_attempt_to_allocate_pud -#define PMD_ORDER 0 +#define PMD_TABLE_ORDER 0 #define PTE_ORDER 0 #endif #ifdef CONFIG_PAGE_SIZE_64KB #define PGD_ORDER 0 #define PUD_ORDER aieeee_attempt_to_allocate_pud #ifdef CONFIG_MIPS_VA_BITS_48 -#define PMD_ORDER 0 +#define PMD_TABLE_ORDER 0 #else -#define PMD_ORDER aieeee_attempt_to_allocate_pmd +#define PMD_TABLE_ORDER aieeee_attempt_to_allocate_pmd #endif #define PTE_ORDER 0 #endif @@ -132,7 +132,7 @@ #define PTRS_PER_PUD ((PAGE_SIZE << PUD_ORDER) / sizeof(pud_t)) #endif #ifndef __PAGETABLE_PMD_FOLDED -#define PTRS_PER_PMD ((PAGE_SIZE << PMD_ORDER) / sizeof(pmd_t)) +#define PTRS_PER_PMD ((PAGE_SIZE << PMD_TABLE_ORDER) / sizeof(pmd_t)) #endif #define PTRS_PER_PTE ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t)) diff --git a/arch/mips/kernel/asm-offsets.c b/arch/mips/kernel/asm-offsets.c index 04ca75278f02..d6b89080d245 100644 --- a/arch/mips/kernel/asm-offsets.c +++ b/arch/mips/kernel/asm-offsets.c @@ -198,7 +198,7 @@ void output_mm_defines(void) BLANK(); DEFINE(_PGD_ORDER, PGD_ORDER); #ifndef __PAGETABLE_PMD_FOLDED - DEFINE(_PMD_ORDER, PMD_ORDER); + DEFINE(_PMD_TABLE_ORDER, PMD_TABLE_ORDER); #endif DEFINE(_PTE_ORDER, PTE_ORDER); BLANK(); -- 2.30.2 ^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH 3/3] parisc: Rename PMD_ORDER to PMD_TABLE_ORDER 2021-07-15 13:46 [PATCH 0/3] Make PMD_ORDER generically available Matthew Wilcox (Oracle) 2021-07-15 13:46 ` [PATCH 1/3] arm: Rename PMD_ORDER to PMD_TABLE_ORDER Matthew Wilcox (Oracle) 2021-07-15 13:46 ` [PATCH 2/3] mips: " Matthew Wilcox (Oracle) @ 2021-07-15 13:46 ` Matthew Wilcox (Oracle) 2021-07-15 16:28 ` [PATCH 0/3] Make PMD_ORDER generically available Helge Deller 3 siblings, 0 replies; 10+ messages in thread From: Matthew Wilcox (Oracle) @ 2021-07-15 13:46 UTC (permalink / raw) To: linux-arch, linux-parisc, linux-mips, linux-arm-kernel Cc: Matthew Wilcox (Oracle), linux-kernel This is the order of the page table allocation, not the order of a PMD. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- arch/parisc/include/asm/pgalloc.h | 6 +++--- arch/parisc/include/asm/pgtable.h | 4 ++-- arch/parisc/mm/init.c | 4 ++-- 3 files changed, 7 insertions(+), 7 deletions(-) diff --git a/arch/parisc/include/asm/pgalloc.h b/arch/parisc/include/asm/pgalloc.h index 6a7e98e71f1d..54b63374579b 100644 --- a/arch/parisc/include/asm/pgalloc.h +++ b/arch/parisc/include/asm/pgalloc.h @@ -48,15 +48,15 @@ static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address) { pmd_t *pmd; - pmd = (pmd_t *)__get_free_pages(GFP_PGTABLE_KERNEL, PMD_ORDER); + pmd = (pmd_t *)__get_free_pages(GFP_PGTABLE_KERNEL, PMD_TABLE_ORDER); if (likely(pmd)) - memset ((void *)pmd, 0, PAGE_SIZE << PMD_ORDER); + memset ((void *)pmd, 0, PAGE_SIZE << PMD_TABLE_ORDER); return pmd; } static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd) { - free_pages((unsigned long)pmd, PMD_ORDER); + free_pages((unsigned long)pmd, PMD_TABLE_ORDER); } #endif diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h index 43937af127b1..7badd872f05a 100644 --- a/arch/parisc/include/asm/pgtable.h +++ b/arch/parisc/include/asm/pgtable.h @@ -112,7 +112,7 @@ static inline void purge_tlb_entries(struct mm_struct *mm, unsigned long addr) #define KERNEL_INITIAL_SIZE (1 << KERNEL_INITIAL_ORDER) #if CONFIG_PGTABLE_LEVELS == 3 -#define PMD_ORDER 1 +#define PMD_TABLE_ORDER 1 #define PGD_ORDER 0 #else #define PGD_ORDER 1 @@ -131,7 +131,7 @@ static inline void purge_tlb_entries(struct mm_struct *mm, unsigned long addr) #define PMD_SHIFT (PLD_SHIFT + BITS_PER_PTE) #define PMD_SIZE (1UL << PMD_SHIFT) #define PMD_MASK (~(PMD_SIZE-1)) -#define BITS_PER_PMD (PAGE_SHIFT + PMD_ORDER - BITS_PER_PMD_ENTRY) +#define BITS_PER_PMD (PAGE_SHIFT + PMD_TABLE_ORDER - BITS_PER_PMD_ENTRY) #define PTRS_PER_PMD (1UL << BITS_PER_PMD) #else #define BITS_PER_PMD 0 diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c index 591a4e939415..3f7d6d5b56ac 100644 --- a/arch/parisc/mm/init.c +++ b/arch/parisc/mm/init.c @@ -378,8 +378,8 @@ static void __init map_pages(unsigned long start_vaddr, #if CONFIG_PGTABLE_LEVELS == 3 if (pud_none(*pud)) { - pmd = memblock_alloc(PAGE_SIZE << PMD_ORDER, - PAGE_SIZE << PMD_ORDER); + pmd = memblock_alloc(PAGE_SIZE << PMD_TABLE_ORDER, + PAGE_SIZE << PMD_TABLE_ORDER); if (!pmd) panic("pmd allocation failed.\n"); pud_populate(NULL, pud, pmd); -- 2.30.2 ^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH 0/3] Make PMD_ORDER generically available 2021-07-15 13:46 [PATCH 0/3] Make PMD_ORDER generically available Matthew Wilcox (Oracle) ` (2 preceding siblings ...) 2021-07-15 13:46 ` [PATCH 3/3] parisc: " Matthew Wilcox (Oracle) @ 2021-07-15 16:28 ` Helge Deller 2021-07-15 16:38 ` Matthew Wilcox 3 siblings, 1 reply; 10+ messages in thread From: Helge Deller @ 2021-07-15 16:28 UTC (permalink / raw) To: Matthew Wilcox (Oracle), linux-arch, linux-parisc, linux-mips, linux-arm-kernel Cc: linux-kernel On 7/15/21 3:46 PM, Matthew Wilcox (Oracle) wrote: > These three architectures each define PMD_ORDER to mean "the order of > an allocation for a PMD table", but logically PMD_ORDER should be the > order of a PMD allocation, ie (PMD_SHIFT - PAGE_SHIFT) as DAX defines it. Some architectures do have PGD_ORDER, PUD_ORDER and PTE_ORDER as well. If you rename PMD_ORDER, IMHO the others should be renamed too. Why not simply rename "PMD_ORDER" in fs/dax.c to e.g. #define DAX_PMD_SHIFT (PMD_SHIFT - PAGE_SHIFT) and use that inside the dax filesystem code? Helge > Could each architecture maintainer please apply the appropriate patch > to their respective trees? > > Matthew Wilcox (Oracle) (3): > arm: Rename PMD_ORDER to PMD_TABLE_ORDER > mips: Rename PMD_ORDER to PMD_TABLE_ORDER > parisc: Rename PMD_ORDER to PMD_TABLE_ORDER > > arch/arm/kernel/head.S | 34 +++++++++++++++--------------- > arch/mips/include/asm/pgalloc.h | 2 +- > arch/mips/include/asm/pgtable-32.h | 2 +- > arch/mips/include/asm/pgtable-64.h | 18 ++++++++-------- > arch/mips/kernel/asm-offsets.c | 2 +- > arch/parisc/include/asm/pgalloc.h | 6 +++--- > arch/parisc/include/asm/pgtable.h | 4 ++-- > arch/parisc/mm/init.c | 4 ++-- > 8 files changed, 36 insertions(+), 36 deletions(-) > ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH 0/3] Make PMD_ORDER generically available 2021-07-15 16:28 ` [PATCH 0/3] Make PMD_ORDER generically available Helge Deller @ 2021-07-15 16:38 ` Matthew Wilcox 0 siblings, 0 replies; 10+ messages in thread From: Matthew Wilcox @ 2021-07-15 16:38 UTC (permalink / raw) To: Helge Deller Cc: linux-arch, linux-parisc, linux-mips, linux-arm-kernel, linux-kernel On Thu, Jul 15, 2021 at 06:28:42PM +0200, Helge Deller wrote: > On 7/15/21 3:46 PM, Matthew Wilcox (Oracle) wrote: > > These three architectures each define PMD_ORDER to mean "the order of > > an allocation for a PMD table", but logically PMD_ORDER should be the > > order of a PMD allocation, ie (PMD_SHIFT - PAGE_SHIFT) as DAX defines it. > > Some architectures do have PGD_ORDER, PUD_ORDER and PTE_ORDER as well. > If you rename PMD_ORDER, IMHO the others should be renamed too. > > Why not simply rename "PMD_ORDER" in fs/dax.c to e.g. > #define DAX_PMD_SHIFT (PMD_SHIFT - PAGE_SHIFT) > and use that inside the dax filesystem code? Because that's wrong. PMD order is clearly the order of a PMD page, not the order of a PMD table. I'm sure the others should also be renamed, but this is the one which is causing me pain today. ^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2021-07-15 19:53 UTC | newest] Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-07-15 13:46 [PATCH 0/3] Make PMD_ORDER generically available Matthew Wilcox (Oracle) 2021-07-15 13:46 ` [PATCH 1/3] arm: Rename PMD_ORDER to PMD_TABLE_ORDER Matthew Wilcox (Oracle) 2021-07-15 16:47 ` Russell King (Oracle) 2021-07-15 18:10 ` Matthew Wilcox 2021-07-15 18:37 ` Russell King (Oracle) 2021-07-15 19:16 ` Matthew Wilcox 2021-07-15 13:46 ` [PATCH 2/3] mips: " Matthew Wilcox (Oracle) 2021-07-15 13:46 ` [PATCH 3/3] parisc: " Matthew Wilcox (Oracle) 2021-07-15 16:28 ` [PATCH 0/3] Make PMD_ORDER generically available Helge Deller 2021-07-15 16:38 ` Matthew Wilcox
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