* [RFC PATCH] Support for big page sizes on 44x @ 2008-09-10 21:53 Ilya Yanok 2008-09-10 21:53 ` [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for Ilya Yanok 2008-09-10 21:53 ` [PATCH] mm: fix ENTRIES_PER_PAGEPAGE overflow with 256KB pages Ilya Yanok 0 siblings, 2 replies; 25+ messages in thread From: Ilya Yanok @ 2008-09-10 21:53 UTC (permalink / raw) To: linuxppc-dev; +Cc: dzu, wd This adds support for selecting page size on PPC 44x. However there are still number of problems: 1. We can't use default PKMAP_BASE definition with 64KB/256KB pages so we change it. Not sure that it's optimal. Then redefined PKMAP_BASE is not aligned on (1<<PMD_SHIFT), don't know if it is really bad. 2. with 16KB/64KB/256KB pages WARN_ON(!pmd_none(*pmd)) is triggered inside dma_alloc_init() function. Not sure if it is really bad. 3. with 256KB pages ENTRIES_PER_PAGEPAGE in mm/shem.c become zero. Second patch tries to address this issue. 4. Ugly ppc_page_asm.h file. I'd prefer to see these defines calculated instead of being hardcoded but PTE_SHIFT and PMD_SHIFT are declared inside #ifndef __ASSEMBLY__. Don't know why. We would appreciate any comment. ^ permalink raw reply [flat|nested] 25+ messages in thread
* [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for 2008-09-10 21:53 [RFC PATCH] Support for big page sizes on 44x Ilya Yanok @ 2008-09-10 21:53 ` Ilya Yanok 2008-09-11 16:57 ` prodyut hazarika ` (2 more replies) 2008-09-10 21:53 ` [PATCH] mm: fix ENTRIES_PER_PAGEPAGE overflow with 256KB pages Ilya Yanok 1 sibling, 3 replies; 25+ messages in thread From: Ilya Yanok @ 2008-09-10 21:53 UTC (permalink / raw) To: linuxppc-dev; +Cc: Ilya Yanok, dzu, wd This patch adds support for page sizes bigger than 4KB (16KB/64KB/256KB) on PPC 44x. Signed-off-by: Yuri Tikhonov <yur@emcraft.com> Signed-off-by: Ilya Yanok <yanok@emcraft.com> --- arch/powerpc/Kconfig | 23 +++++++++ arch/powerpc/include/asm/highmem.h | 8 +++- arch/powerpc/include/asm/page.h | 26 +++++++++- arch/powerpc/include/asm/page_32.h | 4 ++ arch/powerpc/include/asm/ppc_page_asm.h | 75 +++++++++++++++++++++++++++++++ arch/powerpc/include/asm/thread_info.h | 4 ++ arch/powerpc/kernel/head_44x.S | 21 +++++--- arch/powerpc/kernel/head_booke.h | 7 ++- arch/powerpc/kernel/misc_32.S | 13 +++--- arch/powerpc/mm/pgtable_32.c | 2 +- 10 files changed, 162 insertions(+), 21 deletions(-) create mode 100644 arch/powerpc/include/asm/ppc_page_asm.h diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 587da5e..ca93157 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -413,6 +413,29 @@ config PPC_64K_PAGES while on hardware with such support, it will be used to map normal application pages. +choice + prompt "Page size" + depends on 44x && PPC32 + default PPC32_4K_PAGES + help + The PAGE_SIZE definition. Increasing the page size may + improve the system performance in some dedicated cases. + If unsure, set it to 4 KB. + +config PPC32_4K_PAGES + bool "4k page size" + +config PPC32_16K_PAGES + bool "16k page size" + +config PPC32_64K_PAGES + bool "64k page size" + +config PPC32_256K_PAGES + bool "256k page size" + +endchoice + config FORCE_MAX_ZONEORDER int "Maximum zone order" default "9" if PPC_64K_PAGES diff --git a/arch/powerpc/include/asm/highmem.h b/arch/powerpc/include/asm/highmem.h index 5d99b64..1aec96d 100644 --- a/arch/powerpc/include/asm/highmem.h +++ b/arch/powerpc/include/asm/highmem.h @@ -38,9 +38,15 @@ extern pte_t *pkmap_page_table; * easily, subsequent pte tables have to be allocated in one physical * chunk of RAM. */ +#if defined(CONFIG_PPC32_64K_PAGES) || defined(CONFIG_PPC32_256K_PAGES) +#define PKMAP_ORDER (27 - PAGE_SHIFT) +#define LAST_PKMAP (1 << PKMAP_ORDER) +#define PKMAP_BASE (FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1)) +#else #define LAST_PKMAP (1 << PTE_SHIFT) -#define LAST_PKMAP_MASK (LAST_PKMAP-1) #define PKMAP_BASE ((FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1)) & PMD_MASK) +#endif +#define LAST_PKMAP_MASK (LAST_PKMAP-1) #define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT) #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h index e088545..1de90b4 100644 --- a/arch/powerpc/include/asm/page.h +++ b/arch/powerpc/include/asm/page.h @@ -15,12 +15,17 @@ #include <asm/types.h> /* - * On PPC32 page size is 4K. For PPC64 we support either 4K or 64K software + * On regular PPC32 page size is 4K (but we support 4K/16K/64K/256K pages + * on PPC44x). For PPC64 we support either 4K or 64K software * page size. When using 64K pages however, whether we are really supporting * 64K pages in HW or not is irrelevant to those definitions. */ -#ifdef CONFIG_PPC_64K_PAGES +#if defined(CONFIG_PPC32_256K_PAGES) +#define PAGE_SHIFT 18 +#elif defined(CONFIG_PPC32_64K_PAGES) || defined(CONFIG_PPC_64K_PAGES) #define PAGE_SHIFT 16 +#elif defined(CONFIG_PPC32_16K_PAGES) +#define PAGE_SHIFT 14 #else #define PAGE_SHIFT 12 #endif @@ -140,11 +145,19 @@ typedef struct { pte_basic_t pte; } pte_t; /* 64k pages additionally define a bigger "real PTE" type that gathers * the "second half" part of the PTE for pseudo 64k pages */ +#ifdef CONFIG_PPC64 #ifdef CONFIG_PPC_64K_PAGES typedef struct { pte_t pte; unsigned long hidx; } real_pte_t; #else typedef struct { pte_t pte; } real_pte_t; #endif +#else +#ifdef CONFIG_PPC32_4K_PAGES +typedef struct { pte_t pte; } real_pte_t; +#else +typedef struct { pte_t pte; unsigned long hidx; } real_pte_t; +#endif +#endif /* !CONFIG_PPC64 */ /* PMD level */ #ifdef CONFIG_PPC64 @@ -180,12 +193,19 @@ typedef pte_basic_t pte_t; #define pte_val(x) (x) #define __pte(x) (x) +#ifdef CONFIG_PPC64 #ifdef CONFIG_PPC_64K_PAGES typedef struct { pte_t pte; unsigned long hidx; } real_pte_t; #else typedef unsigned long real_pte_t; #endif - +#else +#ifdef CONFIG_PPC32_4K_PAGES +typedef unsigned long real_pte_t; +#else +typedef struct { pte_t pte; unsigned long hidx; } real_pte_t; +#endif +#endif /* !PPC64 */ #ifdef CONFIG_PPC64 typedef unsigned long pmd_t; diff --git a/arch/powerpc/include/asm/page_32.h b/arch/powerpc/include/asm/page_32.h index ebfae53..d176270 100644 --- a/arch/powerpc/include/asm/page_32.h +++ b/arch/powerpc/include/asm/page_32.h @@ -20,7 +20,11 @@ */ #ifdef CONFIG_PTE_64BIT typedef unsigned long long pte_basic_t; +#ifdef CONFIG_PPC32_256K_PAGES +#define PTE_SHIFT (PAGE_SHIFT - 7) +#else #define PTE_SHIFT (PAGE_SHIFT - 3) /* 512 ptes per page */ +#endif #else typedef unsigned long pte_basic_t; #define PTE_SHIFT (PAGE_SHIFT - 2) /* 1024 ptes per page */ diff --git a/arch/powerpc/include/asm/ppc_page_asm.h b/arch/powerpc/include/asm/ppc_page_asm.h new file mode 100644 index 0000000..e1250fa --- /dev/null +++ b/arch/powerpc/include/asm/ppc_page_asm.h @@ -0,0 +1,75 @@ +/* + * arch/powerpc/include/asm/ppc_page_asm.h + * + * 2007 (C) DENX Software Engineering. + * + * This file is licensed under the terms of the GNU General Public License + * version 2. This program is licensed "as is" without any warranty of + * any kind, whether express or implied. + * + * The page definitions used in the asm files ppc_44x.S and misc.S. + * PAGE_SIZE = 4K and 64K are only supported on the PPC44x. + * + */ +#ifndef PPC_PAGE_ASM_H +#define PPC_PAGE_ASM_H + +#include <asm/page.h> + +#if (PAGE_SHIFT == 12) +/* + * PAGE_SIZE 4K + * PAGE_SHIFT 12 + * PTE_SHIFT 9 + * PMD_SHIFT 21 + */ +#define PPC44x_TLBE_SIZE PPC44x_TLB_4K +#define PPC44x_PGD_OFF_SH 13 /*(32 - PMD_SHIFT + 2)*/ +#define PPC44x_PGD_OFF_M1 19 /*(PMD_SHIFT - 2)*/ +#define PPC44x_PTE_ADD_SH 23 /*32 - PMD_SHIFT + PTE_SHIFT + 3*/ +#define PPC44x_PTE_ADD_M1 20 /*32 - 3 - PTE_SHIFT*/ +#define PPC44x_RPN_M2 19 /*31 - PAGE_SHIFT*/ +#elif (PAGE_SHIFT == 14) +/* + * PAGE_SIZE 16K + * PAGE_SHIFT 14 + * PTE_SHIFT 11 + * PMD_SHIFT 25 + */ +#define PPC44x_TLBE_SIZE PPC44x_TLB_16K +#define PPC44x_PGD_OFF_SH 9 /*(32 - PMD_SHIFT + 2)*/ +#define PPC44x_PGD_OFF_M1 23 /*(PMD_SHIFT - 2)*/ +#define PPC44x_PTE_ADD_SH 21 /*32 - PMD_SHIFT + PTE_SHIFT + 3*/ +#define PPC44x_PTE_ADD_M1 18 /*32 - 3 - PTE_SHIFT*/ +#define PPC44x_RPN_M2 17 /*31 - PAGE_SHIFT*/ +#elif (PAGE_SHIFT == 16) +/* + * PAGE_SIZE 64K + * PAGE_SHIFT 16 + * PTE_SHIFT 13 + * PMD_SHIFT 29 + */ +#define PPC44x_TLBE_SIZE PPC44x_TLB_64K +#define PPC44x_PGD_OFF_SH 5 /*(32 - PMD_SHIFT + 2)*/ +#define PPC44x_PGD_OFF_M1 27 /*(PMD_SHIFT - 2)*/ +#define PPC44x_PTE_ADD_SH 19 /*32 - PMD_SHIFT + PTE_SHIFT + 3*/ +#define PPC44x_PTE_ADD_M1 16 /*32 - 3 - PTE_SHIFT*/ +#define PPC44x_RPN_M2 15 /*31 - PAGE_SHIFT*/ +#elif (PAGE_SHIFT == 18) +/* + * PAGE_SIZE 256K + * PAGE_SHIFT 18 + * PTE_SHIFT 11 + * PMD_SHIFT 29 + */ +#define PPC44x_TLBE_SIZE PPC44x_TLB_256K +#define PPC44x_PGD_OFF_SH 5 /*(32 - PMD_SHIFT + 2)*/ +#define PPC44x_PGD_OFF_M1 27 /*(PMD_SHIFT - 2)*/ +#define PPC44x_PTE_ADD_SH 17 /*32 - PMD_SHIFT + PTE_SHIFT + 3*/ +#define PPC44x_PTE_ADD_M1 18 /*32 - 3 - PTE_SHIFT*/ +#define PPC44x_RPN_M2 13 /*31 - PAGE_SHIFT*/ +#else +#error "Unsupported PAGE_SIZE" +#endif + +#endif diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h index 9665a26..4e7cd1f 100644 --- a/arch/powerpc/include/asm/thread_info.h +++ b/arch/powerpc/include/asm/thread_info.h @@ -15,8 +15,12 @@ #ifdef CONFIG_PPC64 #define THREAD_SHIFT 14 #else +#if defined(CONFIG_PPC32_256K_PAGES) +#define THREAD_SHIFT 15 +#else #define THREAD_SHIFT 13 #endif +#endif #define THREAD_SIZE (1 << THREAD_SHIFT) diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S index f3a1ea9..c0a99a4 100644 --- a/arch/powerpc/kernel/head_44x.S +++ b/arch/powerpc/kernel/head_44x.S @@ -36,6 +36,7 @@ #include <asm/thread_info.h> #include <asm/ppc_asm.h> #include <asm/asm-offsets.h> +#include <asm/ppc_page_asm.h> #include "head_booke.h" @@ -391,12 +392,14 @@ interrupt_base: rlwimi r13,r12,10,30,30 /* Load the PTE */ - rlwinm r12, r10, 13, 19, 29 /* Compute pgdir/pmd offset */ + /* Compute pgdir/pmd offset */ + rlwinm r12, r10, PPC44x_PGD_OFF_SH, PPC44x_PGD_OFF_M1, 29 lwzx r11, r12, r11 /* Get pgd/pmd entry */ rlwinm. r12, r11, 0, 0, 20 /* Extract pt base address */ beq 2f /* Bail if no table */ - rlwimi r12, r10, 23, 20, 28 /* Compute pte address */ + /* Compute pte address */ + rlwimi r12, r10, PPC44x_PTE_ADD_SH, PPC44x_PTE_ADD_M1, 28 lwz r11, 0(r12) /* Get high word of pte entry */ lwz r12, 4(r12) /* Get low word of pte entry */ @@ -485,12 +488,14 @@ tlb_44x_patch_hwater_D: /* Make up the required permissions */ li r13,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_HWEXEC - rlwinm r12, r10, 13, 19, 29 /* Compute pgdir/pmd offset */ + /* Compute pgdir/pmd offset */ + rlwinm r12, r10, PPC44x_PGD_OFF_SH, PPC44x_PGD_OFF_M1, 29 lwzx r11, r12, r11 /* Get pgd/pmd entry */ rlwinm. r12, r11, 0, 0, 20 /* Extract pt base address */ beq 2f /* Bail if no table */ - rlwimi r12, r10, 23, 20, 28 /* Compute pte address */ + /* Compute pte address */ + rlwimi r12, r10, PPC44x_PTE_ADD_SH, PPC44x_PTE_ADD_M1, 28 lwz r11, 0(r12) /* Get high word of pte entry */ lwz r12, 4(r12) /* Get low word of pte entry */ @@ -554,14 +559,14 @@ tlb_44x_patch_hwater_I: */ finish_tlb_load: /* Combine RPN & ERPN an write WS 0 */ - rlwimi r11,r12,0,0,19 + rlwimi r11,r12,0,0,PPC44x_RPN_M2 tlbwe r11,r13,PPC44x_TLB_XLAT /* * Create WS1. This is the faulting address (EPN), * page size, and valid flag. */ - li r11,PPC44x_TLB_VALID | PPC44x_TLB_4K + li r11,PPC44x_TLB_VALID | PPC44x_TLBE_SIZE rlwimi r10,r11,0,20,31 /* Insert valid and page size*/ tlbwe r10,r13,PPC44x_TLB_PAGEID /* Write PAGEID */ @@ -634,12 +639,12 @@ _GLOBAL(set_context) * goes at the beginning of the data segment, which is page-aligned. */ .data - .align 12 + .align PAGE_SHIFT .globl sdata sdata: .globl empty_zero_page empty_zero_page: - .space 4096 + .space PAGE_SIZE /* * To support >32-bit physical addresses, we use an 8KB pgdir. diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h index fce2df9..4f802df 100644 --- a/arch/powerpc/kernel/head_booke.h +++ b/arch/powerpc/kernel/head_booke.h @@ -20,7 +20,9 @@ beq 1f; \ mfspr r1,SPRN_SPRG3; /* if from user, start at top of */\ lwz r1,THREAD_INFO-THREAD(r1); /* this thread's kernel stack */\ - addi r1,r1,THREAD_SIZE; \ + lis r11,THREAD_SIZE@h; \ + ori r11,r11,THREAD_SIZE@l; \ + add r1,r1,r11; \ 1: subi r1,r1,INT_FRAME_SIZE; /* Allocate an exception frame */\ mr r11,r1; \ stw r10,_CCR(r11); /* save various registers */\ @@ -112,7 +114,8 @@ andi. r10,r10,MSR_PR; \ mfspr r11,SPRN_SPRG3; /* if from user, start at top of */\ lwz r11,THREAD_INFO-THREAD(r11); /* this thread's kernel stack */\ - addi r11,r11,EXC_LVL_FRAME_OVERHEAD; /* allocate stack frame */\ + addis r11,r11,EXC_LVL_FRAME_OVERHEAD@ha; /* allocate stack frame */\ + addi r11,r11,EXC_LVL_FRAME_OVERHEAD@l; /* allocate stack frame */\ beq 1f; \ /* COMING FROM USER MODE */ \ stw r9,_CCR(r11); /* save CR */\ diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S index 7a6dfbc..97463ba 100644 --- a/arch/powerpc/kernel/misc_32.S +++ b/arch/powerpc/kernel/misc_32.S @@ -29,6 +29,7 @@ #include <asm/asm-offsets.h> #include <asm/processor.h> #include <asm/kexec.h> +#include <asm/ppc_page_asm.h> .text @@ -589,8 +590,8 @@ _GLOBAL(__flush_dcache_icache) BEGIN_FTR_SECTION blr END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE) - rlwinm r3,r3,0,0,19 /* Get page base address */ - li r4,4096/L1_CACHE_BYTES /* Number of lines in a page */ + rlwinm r3,r3,0,0,PPC44x_RPN_M2 /* Get page base address */ + li r4,PAGE_SIZE/L1_CACHE_BYTES /* Number of lines in a page */ mtctr r4 mr r6,r3 0: dcbst 0,r3 /* Write line to ram */ @@ -630,8 +631,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE) rlwinm r0,r10,0,28,26 /* clear DR */ mtmsr r0 isync - rlwinm r3,r3,0,0,19 /* Get page base address */ - li r4,4096/L1_CACHE_BYTES /* Number of lines in a page */ + rlwinm r3,r3,0,0,PPC44x_RPN_M2 /* Get page base address */ + li r4,PAGE_SIZE/L1_CACHE_BYTES /* Number of lines in a page */ mtctr r4 mr r6,r3 0: dcbst 0,r3 /* Write line to ram */ @@ -655,7 +656,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE) * void clear_pages(void *page, int order) ; */ _GLOBAL(clear_pages) - li r0,4096/L1_CACHE_BYTES + li r0,PAGE_SIZE/L1_CACHE_BYTES slw r0,r0,r4 mtctr r0 #ifdef CONFIG_8xx @@ -713,7 +714,7 @@ _GLOBAL(copy_page) dcbt r5,r4 li r11,L1_CACHE_BYTES+4 #endif /* MAX_COPY_PREFETCH */ - li r0,4096/L1_CACHE_BYTES - MAX_COPY_PREFETCH + li r0,PAGE_SIZE/L1_CACHE_BYTES - MAX_COPY_PREFETCH crclr 4*cr0+eq 2: mtctr r0 diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c index 2001abd..efaf46a 100644 --- a/arch/powerpc/mm/pgtable_32.c +++ b/arch/powerpc/mm/pgtable_32.c @@ -400,7 +400,7 @@ void kernel_map_pages(struct page *page, int numpages, int enable) #endif /* CONFIG_DEBUG_PAGEALLOC */ static int fixmaps; -unsigned long FIXADDR_TOP = 0xfffff000; +unsigned long FIXADDR_TOP = (-PAGE_SIZE); EXPORT_SYMBOL(FIXADDR_TOP); void __set_fixmap (enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags) -- 1.5.6.1 ^ permalink raw reply related [flat|nested] 25+ messages in thread
* Re: [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for 2008-09-10 21:53 ` [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for Ilya Yanok @ 2008-09-11 16:57 ` prodyut hazarika 2008-09-11 18:15 ` Re[2]: " Yuri Tikhonov ` (2 more replies) 2008-09-11 22:37 ` prodyut hazarika 2008-09-12 3:48 ` David Gibson 2 siblings, 3 replies; 25+ messages in thread From: prodyut hazarika @ 2008-09-11 16:57 UTC (permalink / raw) To: Ilya Yanok; +Cc: linuxppc-dev, wd, dzu I was planning to post a similar patch. Good that you already posted it :-) I will try to finish off similar patch for 40x processors. > > +choice > + prompt "Page size" > + depends on 44x && PPC32 > + default PPC32_4K_PAGES > + help > + The PAGE_SIZE definition. Increasing the page size may > + improve the system performance in some dedicated cases. > + If unsure, set it to 4 KB. > + You should mention an example of dedicated cases (eg. RAID). I think this help should mention that for page size 256KB, you will need to have a special version of binutils, since the ELF standard mentions page sizes only upto 64KB. > -#ifdef CONFIG_PPC_64K_PAGES > +#if defined(CONFIG_PPC32_256K_PAGES) > +#define PAGE_SHIFT 18 > +#elif defined(CONFIG_PPC32_64K_PAGES) || defined(CONFIG_PPC_64K_PAGES) > #define PAGE_SHIFT 16 > +#elif defined(CONFIG_PPC32_16K_PAGES) > +#define PAGE_SHIFT 14 > #else > #define PAGE_SHIFT 12 > #endif Why should the new defines be inside CONFIG_PPC_64K_PAGES? The definition CONFIG_PPC_64K_PAGES is repeated. Shouldn't these defines be like this: #if defined(CONFIG_PPC32_256K_PAGES) #define PAGE_SHIFT 18 #elif defined(CONFIG_PPC32_64K_PAGES) || defined(CONFIG_PPC_64K_PAGES) #define PAGE_SHIFT 16 #elif defined(CONFIG_PPC32_16K_PAGES) #define PAGE_SHIFT 14 #else #define PAGE_SHIFT 12 #endif > +#elif (PAGE_SHIFT == 14) > +/* > + * PAGE_SIZE 16K > + * PAGE_SHIFT 14 > + * PTE_SHIFT 11 > + * PMD_SHIFT 25 > + */ > +#define PPC44x_TLBE_SIZE PPC44x_TLB_16K > +#define PPC44x_PGD_OFF_SH 9 /*(32 - PMD_SHIFT + 2)*/ > +#define PPC44x_PGD_OFF_M1 23 /*(PMD_SHIFT - 2)*/ > +#define PPC44x_PTE_ADD_SH 21 /*32 - PMD_SHIFT + PTE_SHIFT + 3*/ > +#define PPC44x_PTE_ADD_M1 18 /*32 - 3 - PTE_SHIFT*/ > +#define PPC44x_RPN_M2 17 /*31 - PAGE_SHIFT*/ Please change PPC44x_PGD_OFF_SH to PPC44x_PGD_OFF_SHIFT. SH sounds very confusing. I don't like the MI and M2 names too. Change PPC44x_RPN_M2 to PPC44x_RPN_MASK. Change M1 to MASK in PPC44x_PGD_OFF_M1 and PPC44x_PTE_ADD_M1 . Is there no way a define like #define PPC44x_PGD_OFF_SH (32 - PMD_SHIFT + 2) be used in assembly file. If yes, we can avoid repeating the defines. I think these 44x specific defines should go to asm/mmu-44x.h since I am planning to post a patch for 40x. For those processors, the defines below will changes as: #define PPC44x_PTE_ADD_SH (32 - PMD_SHIFT + PTE_SHIFT + 2) #define PPC44x_PTE_ADD_M1 (32 - 2 - PTE_SHIFT) Since these defines are not generic, they should be put in the mmu specific header file rather than adding a new header file. When 40x processors are supported, the corresponding defines can go to include/asm/mmu-40x.h > +#elif (PAGE_SHIFT == 18) > +/* > + * PAGE_SIZE 256K > + * PAGE_SHIFT 18 > + * PTE_SHIFT 11 > + * PMD_SHIFT 29 > + */ > +#define PPC44x_TLBE_SIZE PPC44x_TLB_256K > +#define PPC44x_PGD_OFF_SH 5 /*(32 - PMD_SHIFT + 2)*/ > +#define PPC44x_PGD_OFF_M1 27 /*(PMD_SHIFT - 2)*/ > +#define PPC44x_PTE_ADD_SH 17 /*32 - PMD_SHIFT + PTE_SHIFT + 3*/ > +#define PPC44x_PTE_ADD_M1 18 /*32 - 3 - PTE_SHIFT*/ > +#define PPC44x_RPN_M2 13 /*31 - PAGE_SHIFT*/ For 256KB page size, I cannot understand why PTE_SHIFT is 11. Since each PTE entry is 8 byte, PTE_SHIFT should have been 15. But then there would be no bits in the Effective address for the 1st level PGDIR offset. On what basis PTE_SHIFT of 11 is chosen? This overflow problem happens only for 256KB page size. ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re[2]: [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for 2008-09-11 16:57 ` prodyut hazarika @ 2008-09-11 18:15 ` Yuri Tikhonov 2008-09-11 20:09 ` Josh Boyer 2008-09-11 18:28 ` Ilya Yanok 2008-09-13 17:49 ` Benjamin Herrenschmidt 2 siblings, 1 reply; 25+ messages in thread From: Yuri Tikhonov @ 2008-09-11 18:15 UTC (permalink / raw) To: prodyut hazarika; +Cc: linuxppc-dev, dzu, wd, Ilya Yanok =0D=0AHello, On Thursday, September 11, 2008 you wrote: > I was planning to post a similar patch. Good that you already posted > it :-) I will try to finish off similar patch for 40x processors. >> >> +choice >> + prompt "Page size" >> + depends on 44x && PPC32 >> + default PPC32_4K_PAGES >> + help >> + The PAGE_SIZE definition. Increasing the page size may >> + improve the system performance in some dedicated cases. >> + If unsure, set it to 4 KB. >> + > You should mention an example of dedicated cases (eg. RAID). ACK. > I think this help should mention that for page size 256KB, you will > need to have a special version of binutils, since the ELF standard > mentions page sizes only upto 64KB. Right. We use ELDK-4.2 for compiling applications to be run on 256K PAGE_SIZE kernel. This toolchain includes necessary changes for ELF_MAXPAGESIZE in binutils/bfd/elf32-ppc.c. >> -#ifdef CONFIG_PPC_64K_PAGES >> +#if defined(CONFIG_PPC32_256K_PAGES) >> +#define PAGE_SHIFT 18 >> +#elif defined(CONFIG_PPC32_64K_PAGES) || defined(CONFIG_PPC_64K_PAGES) >> #define PAGE_SHIFT 16 >> +#elif defined(CONFIG_PPC32_16K_PAGES) >> +#define PAGE_SHIFT 14 >> #else >> #define PAGE_SHIFT 12 >> #endif > Why should the new defines be inside CONFIG_PPC_64K_PAGES? The > definition CONFIG_PPC_64K_PAGES is repeated. We decided to introduce new CONFIG_PPC32_64K_PAGES option to distinguish using 64K pages on PPC32 and PPC64, so PAGE_SHIFT will be defined as 16 when the CONFIG_PPC_64K_PAGES option is set on some PPC64 platform, and as 16 when the CONFIG_PPC32_64K_PAGES option is set on some ppc44x PPC32 platform. > Shouldn't these defines be like this: > #if defined(CONFIG_PPC32_256K_PAGES) > #define PAGE_SHIFT 18 > #elif defined(CONFIG_PPC32_64K_PAGES) || defined(CONFIG_PPC_64K_PAGES) > #define PAGE_SHIFT 16 > #elif defined(CONFIG_PPC32_16K_PAGES) > #define PAGE_SHIFT 14 > #else > #define PAGE_SHIFT 12 > #endif Admittedly, I don't see the difference between your version and Ilya's one. Am I missing something ? >> +#elif (PAGE_SHIFT =3D=3D 14) >> +/* >> + * PAGE_SIZE 16K >> + * PAGE_SHIFT 14 >> + * PTE_SHIFT 11 >> + * PMD_SHIFT 25 >> + */ >> +#define PPC44x_TLBE_SIZE PPC44x_TLB_16K >> +#define PPC44x_PGD_OFF_SH 9 /*(32 - PMD_SHIFT + 2)*/ >> +#define PPC44x_PGD_OFF_M1 23 /*(PMD_SHIFT - 2)*/ >> +#define PPC44x_PTE_ADD_SH 21 /*32 - PMD_SHIFT + PTE_SHIFT + 3*/ >> +#define PPC44x_PTE_ADD_M1 18 /*32 - 3 - PTE_SHIFT*/ >> +#define PPC44x_RPN_M2 17 /*31 - PAGE_SHIFT*/ > Please change PPC44x_PGD_OFF_SH to PPC44x_PGD_OFF_SHIFT. SH sounds > very confusing. I don't like the MI and M2 names too. Change > PPC44x_RPN_M2 to PPC44x_RPN_MASK. Change M1 to MASK in > PPC44x_PGD_OFF_M1 and PPC44x_PTE_ADD_M1 . > Is there no way a define like > #define PPC44x_PGD_OFF_SH (32 - PMD_SHIFT + 2) > be used in assembly file. If yes, we can avoid repeating the defines. > I think these 44x specific defines should go to asm/mmu-44x.h since I > am planning to post a patch for 40x. For those processors, the defines > below will changes as: > #define PPC44x_PTE_ADD_SH (32 - PMD_SHIFT + PTE_SHIFT + 2) > #define PPC44x_PTE_ADD_M1 (32 - 2 - PTE_SHIFT) > Since these defines are not generic, they should be put in the mmu > specific header file rather than adding a new header file. When 40x > processors are supported, the corresponding defines can go to > include/asm/mmu-40x.h >> +#elif (PAGE_SHIFT =3D=3D 18) >> +/* >> + * PAGE_SIZE 256K >> + * PAGE_SHIFT 18 >> + * PTE_SHIFT 11 >> + * PMD_SHIFT 29 >> + */ >> +#define PPC44x_TLBE_SIZE PPC44x_TLB_256K >> +#define PPC44x_PGD_OFF_SH 5 /*(32 - PMD_SHIFT + 2)*/ >> +#define PPC44x_PGD_OFF_M1 27 /*(PMD_SHIFT - 2)*/ >> +#define PPC44x_PTE_ADD_SH 17 /*32 - PMD_SHIFT + PTE_SHIFT + 3*/ >> +#define PPC44x_PTE_ADD_M1 18 /*32 - 3 - PTE_SHIFT*/ >> +#define PPC44x_RPN_M2 13 /*31 - PAGE_SHIFT*/ > For 256KB page size, I cannot understand why PTE_SHIFT is 11. Since > each PTE entry is 8 byte, PTE_SHIFT should have been 15. But then > there would be no bits in the Effective address for the 1st level > PGDIR offset. On what basis PTE_SHIFT of 11 is chosen? This overflow > problem happens only for 256KB page size. We should use smaller PTE area in address to free some bits for PGDIR part. I guess the only impact this approach has is ineffective usage of memory pages allocated for PTE tables, since having PTE_SHIFT of 11 we use only 1/16 of pages with PTEs. Regards, Yuri -- Yuri Tikhonov, Senior Software Engineer Emcraft Systems, www.emcraft.com ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for 2008-09-11 18:15 ` Re[2]: " Yuri Tikhonov @ 2008-09-11 20:09 ` Josh Boyer 2008-09-11 23:38 ` Ilya Yanok 0 siblings, 1 reply; 25+ messages in thread From: Josh Boyer @ 2008-09-11 20:09 UTC (permalink / raw) To: Yuri Tikhonov; +Cc: linuxppc-dev, prodyut hazarika, wd, dzu, Ilya Yanok On Thu, Sep 11, 2008 at 10:15:07PM +0400, Yuri Tikhonov wrote: >> I think this help should mention that for page size 256KB, you will >> need to have a special version of binutils, since the ELF standard >> mentions page sizes only upto 64KB. > > Right. We use ELDK-4.2 for compiling applications to be run on 256K >PAGE_SIZE kernel. This toolchain includes necessary changes for >ELF_MAXPAGESIZE in binutils/bfd/elf32-ppc.c. Ok, but not everyone does. And I think setting the page size to this should be harder, maybe even dependent upon CONFIG_BROKEN. I need to look over the patch a bit more, but some of the comments you've already gotten seem valid. josh ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for 2008-09-11 20:09 ` Josh Boyer @ 2008-09-11 23:38 ` Ilya Yanok 2008-09-12 0:47 ` Josh Boyer 0 siblings, 1 reply; 25+ messages in thread From: Ilya Yanok @ 2008-09-11 23:38 UTC (permalink / raw) To: Josh Boyer; +Cc: linuxppc-dev, prodyut hazarika, dzu, wd Hello Josh, Josh Boyer wrote: > Ok, but not everyone does. And I think setting the page size to this > should be harder, maybe even dependent upon CONFIG_BROKEN. > Well, we are violating ELF standard here... CONFIG_BROKEN seems to be adequate for me. > I need to look over the patch a bit more, but some of the comments you've > already gotten seem valid. > I'll address them and post updated patch in a few days. Regards, Ilya. ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for 2008-09-11 23:38 ` Ilya Yanok @ 2008-09-12 0:47 ` Josh Boyer 0 siblings, 0 replies; 25+ messages in thread From: Josh Boyer @ 2008-09-12 0:47 UTC (permalink / raw) To: Ilya Yanok; +Cc: linuxppc-dev, prodyut hazarika, dzu, wd On Fri, 12 Sep 2008 03:38:39 +0400 Ilya Yanok <yanok@emcraft.com> wrote: > Hello Josh, > > Josh Boyer wrote: > > Ok, but not everyone does. And I think setting the page size to this > > should be harder, maybe even dependent upon CONFIG_BROKEN. > > > > Well, we are violating ELF standard here... CONFIG_BROKEN seems to be > adequate for me. Right, that was my thinking as well. You can add an explanation for that in the help text. josh ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for 2008-09-11 16:57 ` prodyut hazarika 2008-09-11 18:15 ` Re[2]: " Yuri Tikhonov @ 2008-09-11 18:28 ` Ilya Yanok 2008-09-11 18:38 ` prodyut hazarika 2008-09-11 18:53 ` prodyut hazarika 2008-09-13 17:49 ` Benjamin Herrenschmidt 2 siblings, 2 replies; 25+ messages in thread From: Ilya Yanok @ 2008-09-11 18:28 UTC (permalink / raw) To: prodyut hazarika; +Cc: linuxppc-dev, wd, dzu Hi, prodyut hazarika wrote: >> +choice >> + prompt "Page size" >> + depends on 44x && PPC32 >> + default PPC32_4K_PAGES >> + help >> + The PAGE_SIZE definition. Increasing the page size may >> + improve the system performance in some dedicated cases. >> + If unsure, set it to 4 KB. >> + >> > You should mention an example of dedicated cases (eg. RAID). > I think this help should mention that for page size 256KB, you will > need to have a special version of binutils, since the ELF standard > mentions page sizes only upto 64KB. > Agreed. >> -#ifdef CONFIG_PPC_64K_PAGES >> +#if defined(CONFIG_PPC32_256K_PAGES) >> +#define PAGE_SHIFT 18 >> +#elif defined(CONFIG_PPC32_64K_PAGES) || defined(CONFIG_PPC_64K_PAGES) >> #define PAGE_SHIFT 16 >> +#elif defined(CONFIG_PPC32_16K_PAGES) >> +#define PAGE_SHIFT 14 >> #else >> #define PAGE_SHIFT 12 >> #endif >> > > Why should the new defines be inside CONFIG_PPC_64K_PAGES? The > I think you missed first '-' on the first line. > definition CONFIG_PPC_64K_PAGES is repeated. > Shouldn't these defines be like this: > #if defined(CONFIG_PPC32_256K_PAGES) > #define PAGE_SHIFT 18 > #elif defined(CONFIG_PPC32_64K_PAGES) || defined(CONFIG_PPC_64K_PAGES) > #define PAGE_SHIFT 16 > #elif defined(CONFIG_PPC32_16K_PAGES) > #define PAGE_SHIFT 14 > #else > #define PAGE_SHIFT 12 > #endif > And they do actually :) > Please change PPC44x_PGD_OFF_SH to PPC44x_PGD_OFF_SHIFT. SH sounds > very confusing. I don't like the MI and M2 names too. Change > PPC44x_RPN_M2 to PPC44x_RPN_MASK. Change M1 to MASK in > PPC44x_PGD_OFF_M1 and PPC44x_PTE_ADD_M1 . > Agreed. > Is there no way a define like > #define PPC44x_PGD_OFF_SH (32 - PMD_SHIFT + 2) > be used in assembly file. If yes, we can avoid repeating the defines. > We can use defined like this, problem is that PMD_SHIFT and PTE_SHIFT declared inside #ifndef __ASSEMBLY__ > I think these 44x specific defines should go to asm/mmu-44x.h since I > Agreed. > For 256KB page size, I cannot understand why PTE_SHIFT is 11. Since > each PTE entry is 8 byte, PTE_SHIFT should have been 15. But then > there would be no bits in the Effective address for the 1st level > PGDIR offset. On what basis PTE_SHIFT of 11 is chosen? This overflow > problem happens only for 256KB page size. > I think Yuri has commented on this already. Any comments on the issues mentioned in introductory message? Regards, Ilya. ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for 2008-09-11 18:28 ` Ilya Yanok @ 2008-09-11 18:38 ` prodyut hazarika 2008-09-11 22:44 ` Ilya Yanok 2008-09-11 18:53 ` prodyut hazarika 1 sibling, 1 reply; 25+ messages in thread From: prodyut hazarika @ 2008-09-11 18:38 UTC (permalink / raw) To: Ilya Yanok; +Cc: linuxppc-dev, wd, dzu > > I think you missed first '-' on the first line. > I was not too careful :-) >> I think these 44x specific defines should go to asm/mmu-44x.h since I >> > > Agreed. > It would be great to have user-friendly names. Also moving to the mmu-4xx specific header files hides the changes to 4xx files. >> For 256KB page size, I cannot understand why PTE_SHIFT is 11. Since >> each PTE entry is 8 byte, PTE_SHIFT should have been 15. But then >> there would be no bits in the Effective address for the 1st level >> PGDIR offset. On what basis PTE_SHIFT of 11 is chosen? This overflow >> problem happens only for 256KB page size. >> > > I think Yuri has commented on this already. > Thanks. In file arch/powerpc/mm/pgtable_32.c, we have: #ifdef CONFIG_PTE_64BIT /* 44x uses an 8kB pgdir because it has 8-byte Linux PTEs. */ #define PGDIR_ORDER 1 #else #define PGDIR_ORDER 0 #endif pgd_t *pgd_alloc(struct mm_struct *mm) { pgd_t *ret; ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, PGDIR_ORDER); return ret; } Thus, we allocate 2 pages for 44x processors for PGD. This is needed only for 4K page. We are anyway not using the whole 64K or 256K page for the PGD. So there is no point to waste an additional 64K or 256KB page Change this to: #ifdef CONFIG_PTE_64BIT #if (PAGE_SHIFT == 12) /* 44x uses an 8kB pgdir because it has 8-byte Linux PTEs. */ #define PGDIR_ORDER 1 #else #define PGDIR_ORDER 0 #endif #else #define PGDIR_ORDER 0 #endif ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for 2008-09-11 18:38 ` prodyut hazarika @ 2008-09-11 22:44 ` Ilya Yanok 2008-09-11 23:52 ` Re[2]: " Yuri Tikhonov 0 siblings, 1 reply; 25+ messages in thread From: Ilya Yanok @ 2008-09-11 22:44 UTC (permalink / raw) To: prodyut hazarika; +Cc: linuxppc-dev, wd, dzu Hi, prodyut hazarika wrote: > In file arch/powerpc/mm/pgtable_32.c, we have: > > #ifdef CONFIG_PTE_64BIT > /* 44x uses an 8kB pgdir because it has 8-byte Linux PTEs. */ > #define PGDIR_ORDER 1 > #else > #define PGDIR_ORDER 0 > #endif > pgd_t *pgd_alloc(struct mm_struct *mm) > { > pgd_t *ret; > > ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, PGDIR_ORDER); > return ret; > } > > Thus, we allocate 2 pages for 44x processors for PGD. This is needed > only for 4K page. > We are anyway not using the whole 64K or 256K page for the PGD. So > there is no point to waste an additional 64K or 256KB page > Ok. Not sure I'm right but I think 16K case doesn't need second page too. (PGDIR_SHIFT=25, so sizeof(pgd_t)<<(32-PGDIR_SHIFT) < 16KB) > Change this to: > #ifdef CONFIG_PTE_64BIT > #if (PAGE_SHIFT == 12) > I think #ifdef CONFIG_PTE_64BIT is a little bit confusing here... Actually PGDIR_ORDER should be something like max(32 + 2 - PGDIR_SHIFT - PAGE_SHIFT, 0) > /* 44x uses an 8kB pgdir because it has 8-byte Linux PTEs. */ > #define PGDIR_ORDER 1 > #else > #define PGDIR_ORDER 0 > #endif > #else > #define PGDIR_ORDER 0 > #endif > Yuri, any comments? Regards, Ilya. ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re[2]: [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for 2008-09-11 22:44 ` Ilya Yanok @ 2008-09-11 23:52 ` Yuri Tikhonov 0 siblings, 0 replies; 25+ messages in thread From: Yuri Tikhonov @ 2008-09-11 23:52 UTC (permalink / raw) To: Ilya Yanok; +Cc: linuxppc-dev, prodyut hazarika, wd, dzu =0D=0AHi Ilya, On Friday, September 12, 2008 you wrote: > Hi, > prodyut hazarika wrote: >> In file arch/powerpc/mm/pgtable_32.c, we have: >> >> #ifdef CONFIG_PTE_64BIT >> /* 44x uses an 8kB pgdir because it has 8-byte Linux PTEs. */ >> #define PGDIR_ORDER 1 >> #else >> #define PGDIR_ORDER 0 >> #endif >> pgd_t *pgd_alloc(struct mm_struct *mm) >> { >> pgd_t *ret; >> >> ret =3D (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, PGDIR_O= RDER); >> return ret; >> } >> >> Thus, we allocate 2 pages for 44x processors for PGD. This is needed >> only for 4K page. >> We are anyway not using the whole 64K or 256K page for the PGD. So >> there is no point to waste an additional 64K or 256KB page >> =20 > Ok. Not sure I'm right but I think 16K case doesn't need second page=20 > too. (PGDIR_SHIFT=3D25, so sizeof(pgd_t)<<(32-PGDIR_SHIFT) < 16KB) ACK, no need need in a second page when working with 16K pages. Prodyut's approach addresses this too, but ... >> Change this to: >> #ifdef CONFIG_PTE_64BIT >> #if (PAGE_SHIFT =3D=3D 12) >> =20 > I think #ifdef CONFIG_PTE_64BIT is a little bit confusing here... =20 > Actually PGDIR_ORDER should be something like max(32 + 2 - PGDIR_SHIFT > - PAGE_SHIFT, 0) >> /* 44x uses an 8kB pgdir because it has 8-byte Linux PTEs. */ >> #define PGDIR_ORDER 1 >> #else >> #define PGDIR_ORDER 0 >> #endif >> #else >> #define PGDIR_ORDER 0 >> #endif >> =20 > Yuri, any comments? ... as for me, I like your approach more. Regards, Yuri -- Yuri Tikhonov, Senior Software Engineer Emcraft Systems, www.emcraft.com ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for 2008-09-11 18:28 ` Ilya Yanok 2008-09-11 18:38 ` prodyut hazarika @ 2008-09-11 18:53 ` prodyut hazarika 2008-09-11 21:51 ` Ilya Yanok 1 sibling, 1 reply; 25+ messages in thread From: prodyut hazarika @ 2008-09-11 18:53 UTC (permalink / raw) To: Ilya Yanok; +Cc: linuxppc-dev, wd, dzu > > Any comments on the issues mentioned in introductory message? > I am reviewing the changes more thoroughly. I will give additional comments within the next 2-3 days. I am working on putting similar support for 405EX (Kilauea board), but having some issues. I will post the patch after I am done with it. Also, it would be great if you could point me what changes are necessary to recompile the binutils. I would like to test the 256KB changes on my Canyonlands board. I have got 16KB/64KB working. Regards, Prodyut Hazarika ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for 2008-09-11 18:53 ` prodyut hazarika @ 2008-09-11 21:51 ` Ilya Yanok 0 siblings, 0 replies; 25+ messages in thread From: Ilya Yanok @ 2008-09-11 21:51 UTC (permalink / raw) To: prodyut hazarika; +Cc: linuxppc-dev, wd, dzu Hi, prodyut hazarika wrote: > Also, it would be great if you could point me what changes are > necessary to recompile the binutils. > I would like to test the 256KB changes on my Canyonlands board. I have > got 16KB/64KB working. > I think this should be enough: --- binutils-2.16.1/ld/emulparams/elf32ppc.sh.orig 2007-08-21 14:18:56.000000000 +0200 +++ binutils-2.16.1/ld/emulparams/elf32ppc.sh 2007-08-21 14:19:42.000000000 +0200 @@ -8,7 +8,7 @@ GENERATE_PIE_SCRIPT=yes SCRIPT_NAME=elf OUTPUT_FORMAT="elf32-powerpc" TEXT_START_ADDR=0x01800000 -MAXPAGESIZE=0x10000 +MAXPAGESIZE=0x40000 COMMONPAGESIZE=0x1000 ARCH=powerpc:common MACHINE= --- binutils-2.16.1/bfd/elf32-ppc.c.orig 2007-09-04 13:11:29.000000000 +0200 +++ binutils-2.16.1/bfd/elf32-ppc.c 2007-09-04 13:10:25.000000000 +0200 @@ -6197,7 +6197,7 @@ #ifdef __QNXTARGET__ #define ELF_MAXPAGESIZE 0x1000 #else -#define ELF_MAXPAGESIZE 0x10000 +#define ELF_MAXPAGESIZE 0x40000 #endif #define ELF_MINPAGESIZE 0x1000 #define elf_info_to_howto ppc_elf_info_to_howto And you need to rebuild the whole RFS with patched binutils of cause. Regards, Ilya. ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for 2008-09-11 16:57 ` prodyut hazarika 2008-09-11 18:15 ` Re[2]: " Yuri Tikhonov 2008-09-11 18:28 ` Ilya Yanok @ 2008-09-13 17:49 ` Benjamin Herrenschmidt 2008-09-13 23:37 ` Josh Boyer 2 siblings, 1 reply; 25+ messages in thread From: Benjamin Herrenschmidt @ 2008-09-13 17:49 UTC (permalink / raw) To: prodyut hazarika; +Cc: linuxppc-dev, dzu, wd, Ilya Yanok On Thu, 2008-09-11 at 09:57 -0700, prodyut hazarika wrote: > You should mention an example of dedicated cases (eg. RAID). > I think this help should mention that for page size 256KB, you will > need to have a special version of binutils, since the ELF standard > mentions page sizes only upto 64KB. He should also put a BIG FAT warning with 256K pages. Those will -not- work with most existing userspace. The maximum page size supported by the current userspace ABI is 64K as this is the alignment requirement of our toolchain for the various program sections. (Note that uClibc last I looked was also still broken with >4K pages but that shouldn't be a big deal to fix). Ben. ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for 2008-09-13 17:49 ` Benjamin Herrenschmidt @ 2008-09-13 23:37 ` Josh Boyer 0 siblings, 0 replies; 25+ messages in thread From: Josh Boyer @ 2008-09-13 23:37 UTC (permalink / raw) To: benh; +Cc: linuxppc-dev, prodyut hazarika, wd, dzu, Ilya Yanok On Sat, 13 Sep 2008 10:49:13 -0700 Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote: > On Thu, 2008-09-11 at 09:57 -0700, prodyut hazarika wrote: > > > You should mention an example of dedicated cases (eg. RAID). > > I think this help should mention that for page size 256KB, you will > > need to have a special version of binutils, since the ELF standard > > mentions page sizes only upto 64KB. > > He should also put a BIG FAT warning with 256K pages. Those will -not- > work with most existing userspace. The maximum page size supported by > the current userspace ABI is 64K as this is the alignment requirement of > our toolchain for the various program sections. I think that's been noted like 5 times now :) josh ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for 2008-09-10 21:53 ` [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for Ilya Yanok 2008-09-11 16:57 ` prodyut hazarika @ 2008-09-11 22:37 ` prodyut hazarika 2008-09-11 23:20 ` Re[2]: " Yuri Tikhonov 2008-09-12 3:48 ` David Gibson 2 siblings, 1 reply; 25+ messages in thread From: prodyut hazarika @ 2008-09-11 22:37 UTC (permalink / raw) To: Ilya Yanok; +Cc: linuxppc-dev, wd, dzu > /* > * Create WS1. This is the faulting address (EPN), > * page size, and valid flag. > */ > - li r11,PPC44x_TLB_VALID | PPC44x_TLB_4K > + li r11,PPC44x_TLB_VALID | PPC44x_TLBE_SIZE > rlwimi r10,r11,0,20,31 /* Insert valid and page size*/ > tlbwe r10,r13,PPC44x_TLB_PAGEID /* Write PAGEID */ > Change > rlwimi r10,r11,0,20,31 /* Insert valid and page size*/ to > rlwimi r10,r11,0,PPC44x_PTE_ADD_M1,31 /* Insert valid and page size*/ ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re[2]: [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for 2008-09-11 22:37 ` prodyut hazarika @ 2008-09-11 23:20 ` Yuri Tikhonov 0 siblings, 0 replies; 25+ messages in thread From: Yuri Tikhonov @ 2008-09-11 23:20 UTC (permalink / raw) To: prodyut hazarika; +Cc: linuxppc-dev, dzu, wd, Ilya Yanok =0D=0AHello Prodyut, Thanks for your comments. Some answers below. On Friday, September 12, 2008 you wrote: >> /* >> * Create WS1. This is the faulting address (EPN), >> * page size, and valid flag. >> */ >> - li r11,PPC44x_TLB_VALID | PPC44x_TLB_4K >> + li r11,PPC44x_TLB_VALID | PPC44x_TLBE_SIZE >> rlwimi r10,r11,0,20,31 /* Insert valid and page = size*/ >> tlbwe r10,r13,PPC44x_TLB_PAGEID /* Write PAGEID */ >> > Change >> rlwimi r10,r11,0,20,31 /* Insert valid and page = size*/ > to >> rlwimi r10,r11,0,PPC44x_PTE_ADD_M1,31 /* Insert = valid and page size*/ Agree. We'll fix this. I guess this works for us, because we used the large EPN mask here which covered more bits in EPN field of TLB entries, than it was required for 16/64/256K PAGE_SIZE cases: TLB Word 0 / bits 0..21: EPN (Effective Page Number) [from 4 to 22 bits] TLB Word 0 / bit 22 : V (Valid bit) [1 bit] TLB Word 0 / bits 24..27 : SIZE (Page Size) [4 bits] Thus, doing 'rlwimi' we masked our V/SIZE bits and cleared EPN for all 4/16/64/256K PAGE_SIZE cases. Regards, Yuri -- Yuri Tikhonov, Senior Software Engineer Emcraft Systems, www.emcraft.com ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for 2008-09-10 21:53 ` [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for Ilya Yanok 2008-09-11 16:57 ` prodyut hazarika 2008-09-11 22:37 ` prodyut hazarika @ 2008-09-12 3:48 ` David Gibson 2008-09-13 17:46 ` Benjamin Herrenschmidt 2008-09-26 23:35 ` Ilya Yanok 2 siblings, 2 replies; 25+ messages in thread From: David Gibson @ 2008-09-12 3:48 UTC (permalink / raw) To: Ilya Yanok; +Cc: linuxppc-dev, wd, dzu On Thu, Sep 11, 2008 at 01:53:06AM +0400, Ilya Yanok wrote: > This patch adds support for page sizes bigger than 4KB (16KB/64KB/256KB) on > PPC 44x. [snip] > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index 587da5e..ca93157 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -413,6 +413,29 @@ config PPC_64K_PAGES > while on hardware with such support, it will be used to map > normal application pages. > > +choice > + prompt "Page size" > + depends on 44x && PPC32 > + default PPC32_4K_PAGES > + help > + The PAGE_SIZE definition. Increasing the page size may > + improve the system performance in some dedicated cases. > + If unsure, set it to 4 KB. > + > +config PPC32_4K_PAGES > + bool "4k page size" > + > +config PPC32_16K_PAGES > + bool "16k page size" > + > +config PPC32_64K_PAGES > + bool "64k page size" > + > +config PPC32_256K_PAGES > + bool "256k page size" > + I don't see any reason to have a separate set of config options for 32 and 64-bit. Just make the once choice, but only have the individual pagesize options enabled on machines that support them. [snip] > index e088545..1de90b4 100644 > --- a/arch/powerpc/include/asm/page.h > +++ b/arch/powerpc/include/asm/page.h > @@ -15,12 +15,17 @@ > #include <asm/types.h> > > /* > - * On PPC32 page size is 4K. For PPC64 we support either 4K or 64K software > + * On regular PPC32 page size is 4K (but we support 4K/16K/64K/256K pages > + * on PPC44x). For PPC64 we support either 4K or 64K software > * page size. When using 64K pages however, whether we are really supporting > * 64K pages in HW or not is irrelevant to those definitions. > */ > -#ifdef CONFIG_PPC_64K_PAGES > +#if defined(CONFIG_PPC32_256K_PAGES) > +#define PAGE_SHIFT 18 > +#elif defined(CONFIG_PPC32_64K_PAGES) || defined(CONFIG_PPC_64K_PAGES) > #define PAGE_SHIFT 16 > +#elif defined(CONFIG_PPC32_16K_PAGES) > +#define PAGE_SHIFT 14 > #else > #define PAGE_SHIFT 12 > #endif > @@ -140,11 +145,19 @@ typedef struct { pte_basic_t pte; } pte_t; > /* 64k pages additionally define a bigger "real PTE" type that gathers > * the "second half" part of the PTE for pseudo 64k pages > */ > +#ifdef CONFIG_PPC64 > #ifdef CONFIG_PPC_64K_PAGES > typedef struct { pte_t pte; unsigned long hidx; } real_pte_t; > #else > typedef struct { pte_t pte; } real_pte_t; > #endif > +#else > +#ifdef CONFIG_PPC32_4K_PAGES > +typedef struct { pte_t pte; } real_pte_t; > +#else > +typedef struct { pte_t pte; unsigned long hidx; } real_pte_t; I don't think you should need a real_pte_t type for the 32-bit implementation. It's just there because of how we implement 64k granularity page allocation on hardware that only does 4k translations. [snip] > diff --git a/arch/powerpc/include/asm/page_32.h b/arch/powerpc/include/asm/page_32.h > index ebfae53..d176270 100644 > --- a/arch/powerpc/include/asm/page_32.h > +++ b/arch/powerpc/include/asm/page_32.h > @@ -20,7 +20,11 @@ > */ > #ifdef CONFIG_PTE_64BIT > typedef unsigned long long pte_basic_t; > +#ifdef CONFIG_PPC32_256K_PAGES > +#define PTE_SHIFT (PAGE_SHIFT - 7) This doesn't look right. You should be eliding one of the levels of page table if you don't need it, rather than leaving the bottom level PTE page largely empty. [snip] > +#if (PAGE_SHIFT == 12) > +/* > + * PAGE_SIZE 4K > + * PAGE_SHIFT 12 > + * PTE_SHIFT 9 > + * PMD_SHIFT 21 > + */ > +#define PPC44x_TLBE_SIZE PPC44x_TLB_4K > +#define PPC44x_PGD_OFF_SH 13 /*(32 - PMD_SHIFT + 2)*/ > +#define PPC44x_PGD_OFF_M1 19 /*(PMD_SHIFT - 2)*/ > +#define PPC44x_PTE_ADD_SH 23 /*32 - PMD_SHIFT + PTE_SHIFT + 3*/ > +#define PPC44x_PTE_ADD_M1 20 /*32 - 3 - PTE_SHIFT*/ > +#define PPC44x_RPN_M2 19 /*31 - PAGE_SHIFT*/ Uh.. you have the formulae for these things right there in the comments, so why aren't you using those and avoiding this nasty multiway ifdef... [snip] > diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h > index 9665a26..4e7cd1f 100644 > --- a/arch/powerpc/include/asm/thread_info.h > +++ b/arch/powerpc/include/asm/thread_info.h > @@ -15,8 +15,12 @@ > #ifdef CONFIG_PPC64 > #define THREAD_SHIFT 14 > #else > +#if defined(CONFIG_PPC32_256K_PAGES) > +#define THREAD_SHIFT 15 Hrm.. more peculiar special cases for 256K pages. I think it might be clearer if you split the patch into one which supports page sizes up to 64k, then another that does the extra hacks for 256k pages. [snip] > @@ -391,12 +392,14 @@ interrupt_base: > rlwimi r13,r12,10,30,30 > > /* Load the PTE */ > - rlwinm r12, r10, 13, 19, 29 /* Compute pgdir/pmd offset */ > + /* Compute pgdir/pmd offset */ > + rlwinm r12, r10, PPC44x_PGD_OFF_SH, PPC44x_PGD_OFF_M1, 29 I agree with others that these constants need better names. Or even derive the values from PMD_SHIFT or whatnot right here inline, rather than defining special constants. [snip] > diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h > index fce2df9..4f802df 100644 > --- a/arch/powerpc/kernel/head_booke.h > +++ b/arch/powerpc/kernel/head_booke.h > @@ -20,7 +20,9 @@ > beq 1f; \ > mfspr r1,SPRN_SPRG3; /* if from user, start at top of */\ > lwz r1,THREAD_INFO-THREAD(r1); /* this thread's kernel stack */\ > - addi r1,r1,THREAD_SIZE; \ > + lis r11,THREAD_SIZE@h; \ > + ori r11,r11,THREAD_SIZE@l; \ > + add r1,r1,r11; > \ It would be nice if we could avoid the extra instruction here when the page sizes isn't big enough to require it. > 1: subi r1,r1,INT_FRAME_SIZE; /* Allocate an exception frame */\ > mr r11,r1; \ > stw r10,_CCR(r11); /* save various registers */\ > @@ -112,7 +114,8 @@ > andi. r10,r10,MSR_PR; \ > mfspr r11,SPRN_SPRG3; /* if from user, start at top of */\ > lwz r11,THREAD_INFO-THREAD(r11); /* this thread's kernel stack */\ > - addi r11,r11,EXC_LVL_FRAME_OVERHEAD; /* allocate stack frame */\ > + addis r11,r11,EXC_LVL_FRAME_OVERHEAD@ha; /* allocate stack frame */\ > + addi r11,r11,EXC_LVL_FRAME_OVERHEAD@l; /* allocate stack frame */\ And here. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for 2008-09-12 3:48 ` David Gibson @ 2008-09-13 17:46 ` Benjamin Herrenschmidt 2008-09-26 23:43 ` Ilya Yanok 2008-09-26 23:35 ` Ilya Yanok 1 sibling, 1 reply; 25+ messages in thread From: Benjamin Herrenschmidt @ 2008-09-13 17:46 UTC (permalink / raw) To: David Gibson; +Cc: linuxppc-dev, dzu, wd, Ilya Yanok > [snip] > > diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h > > index fce2df9..4f802df 100644 > > --- a/arch/powerpc/kernel/head_booke.h > > +++ b/arch/powerpc/kernel/head_booke.h > > @@ -20,7 +20,9 @@ > > beq 1f; \ > > mfspr r1,SPRN_SPRG3; /* if from user, start at top of */\ > > lwz r1,THREAD_INFO-THREAD(r1); /* this thread's kernel stack */\ > > - addi r1,r1,THREAD_SIZE; \ > > + lis r11,THREAD_SIZE@h; \ > > + ori r11,r11,THREAD_SIZE@l; \ > > + add r1,r1,r11; > > \ > > It would be nice if we could avoid the extra instruction here when the > page sizes isn't big enough to require it. As a matter of fact, I don't see why THREAD_SIZE should ever need that, there is no reason to change the kernel stack size. > > 1: subi r1,r1,INT_FRAME_SIZE; /* Allocate an exception frame */\ > > mr r11,r1; \ > > stw r10,_CCR(r11); /* save various registers */\ > > @@ -112,7 +114,8 @@ > > andi. r10,r10,MSR_PR; \ > > mfspr r11,SPRN_SPRG3; /* if from user, start at top of */\ > > lwz r11,THREAD_INFO-THREAD(r11); /* this thread's kernel stack */\ > > - addi r11,r11,EXC_LVL_FRAME_OVERHEAD; /* allocate stack frame */\ > > + addis r11,r11,EXC_LVL_FRAME_OVERHEAD@ha; /* allocate stack frame */\ > > + addi r11,r11,EXC_LVL_FRAME_OVERHEAD@l; /* allocate stack frame */\ > > And here. Same comment. That size doesn't need to change and can remain safely below 32k Ben. ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for 2008-09-13 17:46 ` Benjamin Herrenschmidt @ 2008-09-26 23:43 ` Ilya Yanok 0 siblings, 0 replies; 25+ messages in thread From: Ilya Yanok @ 2008-09-26 23:43 UTC (permalink / raw) To: benh; +Cc: linuxppc-dev, wd, dzu, David Gibson Hello Benjamin, Benjamin Herrenschmidt wrote: >> [snip] >> >>> diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h >>> index fce2df9..4f802df 100644 >>> --- a/arch/powerpc/kernel/head_booke.h >>> +++ b/arch/powerpc/kernel/head_booke.h >>> @@ -20,7 +20,9 @@ >>> beq 1f; \ >>> mfspr r1,SPRN_SPRG3; /* if from user, start at top of */\ >>> lwz r1,THREAD_INFO-THREAD(r1); /* this thread's kernel stack */\ >>> - addi r1,r1,THREAD_SIZE; \ >>> + lis r11,THREAD_SIZE@h; \ >>> + ori r11,r11,THREAD_SIZE@l; \ >>> + add r1,r1,r11; >>> \ >>> >> It would be nice if we could avoid the extra instruction here when the >> page sizes isn't big enough to require it. >> > > As a matter of fact, I don't see why THREAD_SIZE should ever need that, > there is no reason to change the kernel stack size. > Well, this was introduced because of that: kernel/fork.c [179]: max_threads = mempages / (8 * THREAD_SIZE / PAGE_SIZE); With THREAD_SIZE=8K we will get mempages divided by zero if PAGE_SIZE is bigger than 64K. (Well, another reason not to use >64K pages). Not sure this is the right way to fix it. Regards, Ilya. ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for 2008-09-12 3:48 ` David Gibson 2008-09-13 17:46 ` Benjamin Herrenschmidt @ 2008-09-26 23:35 ` Ilya Yanok 2008-09-29 2:58 ` David Gibson 1 sibling, 1 reply; 25+ messages in thread From: Ilya Yanok @ 2008-09-26 23:35 UTC (permalink / raw) To: linuxppc-dev; +Cc: wd, dzu Hello David, David Gibson wrote: > I don't see any reason to have a separate set of config options for 32 > and 64-bit. Just make the once choice, but only have the individual > pagesize options enabled on machines that support them. > Well. I can see some. First, on PPC64 kernel emulates 64K pages on hardware that can't do it and we are not going to do such an emulation on PPC32 now. Then CONFIG_PPC_64K_PAGES selects PPC_HAS_HASH_64K and our code has nothing to do with it. And last but not least, we don't use PPC64 kernels for now so we just tried not to break something we can't test. But if everybody thinks that having a single option is a good idea I'll do it that way. > I don't think you should need a real_pte_t type for the 32-bit > implementation. It's just there because of how we implement > 64k granularity page allocation on hardware that only does 4k > translations. > You are right. Thanks. >> diff --git a/arch/powerpc/include/asm/page_32.h b/arch/powerpc/include/asm/page_32.h >> index ebfae53..d176270 100644 >> --- a/arch/powerpc/include/asm/page_32.h >> +++ b/arch/powerpc/include/asm/page_32.h >> @@ -20,7 +20,11 @@ >> */ >> #ifdef CONFIG_PTE_64BIT >> typedef unsigned long long pte_basic_t; >> +#ifdef CONFIG_PPC32_256K_PAGES >> +#define PTE_SHIFT (PAGE_SHIFT - 7) >> > > This doesn't look right. You should be eliding one of the levels of > page table if you don't need it, rather than leaving the bottom level > PTE page largely empty. > Hm... We have only two levels really so if we elide one there will be only one left. Don't sure if kernel can work with this... >> +#if (PAGE_SHIFT == 12) >> +/* >> + * PAGE_SIZE 4K >> + * PAGE_SHIFT 12 >> + * PTE_SHIFT 9 >> + * PMD_SHIFT 21 >> + */ >> +#define PPC44x_TLBE_SIZE PPC44x_TLB_4K >> +#define PPC44x_PGD_OFF_SH 13 /*(32 - PMD_SHIFT + 2)*/ >> +#define PPC44x_PGD_OFF_M1 19 /*(PMD_SHIFT - 2)*/ >> +#define PPC44x_PTE_ADD_SH 23 /*32 - PMD_SHIFT + PTE_SHIFT + 3*/ >> +#define PPC44x_PTE_ADD_M1 20 /*32 - 3 - PTE_SHIFT*/ >> +#define PPC44x_RPN_M2 19 /*31 - PAGE_SHIFT*/ >> > > Uh.. you have the formulae for these things right there in the > comments, so why aren't you using those and avoiding this nasty > multiway ifdef... > We need to get PMD_SHIFT and friends out of #ifndef __ASSEMBLY__ for that. And some of them are under include/asm-generic so patch becomes not powerpc-specific... >> diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h >> index 9665a26..4e7cd1f 100644 >> --- a/arch/powerpc/include/asm/thread_info.h >> +++ b/arch/powerpc/include/asm/thread_info.h >> @@ -15,8 +15,12 @@ >> #ifdef CONFIG_PPC64 >> #define THREAD_SHIFT 14 >> #else >> +#if defined(CONFIG_PPC32_256K_PAGES) >> +#define THREAD_SHIFT 15 >> > > Hrm.. more peculiar special cases for 256K pages. I think it might be > clearer if you split the patch into one which supports page sizes up > to 64k, then another that does the extra hacks for 256k pages. > Agreed. >> diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h >> index fce2df9..4f802df 100644 >> --- a/arch/powerpc/kernel/head_booke.h >> +++ b/arch/powerpc/kernel/head_booke.h >> @@ -20,7 +20,9 @@ >> beq 1f; \ >> mfspr r1,SPRN_SPRG3; /* if from user, start at top of */\ >> lwz r1,THREAD_INFO-THREAD(r1); /* this thread's kernel stack */\ >> - addi r1,r1,THREAD_SIZE; \ >> + lis r11,THREAD_SIZE@h; \ >> + ori r11,r11,THREAD_SIZE@l; \ >> + add r1,r1,r11; >> \ >> > > It would be nice if we could avoid the extra instruction here when the > page sizes isn't big enough to require it. > Ok. This is going to go to 256K-dirty-hacks.patch anyway. Regards, Ilya. ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for 2008-09-26 23:35 ` Ilya Yanok @ 2008-09-29 2:58 ` David Gibson 0 siblings, 0 replies; 25+ messages in thread From: David Gibson @ 2008-09-29 2:58 UTC (permalink / raw) To: Ilya Yanok; +Cc: linuxppc-dev, wd, dzu On Sat, Sep 27, 2008 at 03:35:27AM +0400, Ilya Yanok wrote: > Hello David, > > David Gibson wrote: >> I don't see any reason to have a separate set of config options for 32 >> and 64-bit. Just make the once choice, but only have the individual >> pagesize options enabled on machines that support them. > > Well. I can see some. First, on PPC64 kernel emulates 64K pages on > hardware that can't do it and we are not going to do such an emulation > on PPC32 now. So? > Then CONFIG_PPC_64K_PAGES selects PPC_HAS_HASH_64K and our > code has nothing to do with it. Well, obviously the generic 64K option wouldn't select PPC_HAS_HASH_64K. That would be dependent on both 64K_PAGES and PPC64. > And last but not least, we don't use > PPC64 kernels for now so we just tried not to break something we can't > test. But if everybody thinks that having a single option is a good idea > I'll do it that way. Hrm, well that has something to be said for it. But it's not hard to at least build a ppc64 kernel to test if you've broken that. >> I don't think you should need a real_pte_t type for the 32-bit >> implementation. It's just there because of how we implement >> 64k granularity page allocation on hardware that only does 4k >> translations. > > You are right. Thanks. > >>> diff --git a/arch/powerpc/include/asm/page_32.h b/arch/powerpc/include/asm/page_32.h >>> index ebfae53..d176270 100644 >>> --- a/arch/powerpc/include/asm/page_32.h >>> +++ b/arch/powerpc/include/asm/page_32.h >>> @@ -20,7 +20,11 @@ >>> */ >>> #ifdef CONFIG_PTE_64BIT >>> typedef unsigned long long pte_basic_t; >>> +#ifdef CONFIG_PPC32_256K_PAGES >>> +#define PTE_SHIFT (PAGE_SHIFT - 7) >>> >> >> This doesn't look right. You should be eliding one of the levels of >> page table if you don't need it, rather than leaving the bottom level >> PTE page largely empty. > > Hm... We have only two levels really so if we elide one there will be > only one left. Don't sure if kernel can work with this... Ah.. that's a point. But again this is a 256K specific hack, so we can worry about it later. >>> +#if (PAGE_SHIFT == 12) >>> +/* >>> + * PAGE_SIZE 4K >>> + * PAGE_SHIFT 12 >>> + * PTE_SHIFT 9 >>> + * PMD_SHIFT 21 >>> + */ >>> +#define PPC44x_TLBE_SIZE PPC44x_TLB_4K >>> +#define PPC44x_PGD_OFF_SH 13 /*(32 - PMD_SHIFT + 2)*/ >>> +#define PPC44x_PGD_OFF_M1 19 /*(PMD_SHIFT - 2)*/ >>> +#define PPC44x_PTE_ADD_SH 23 /*32 - PMD_SHIFT + PTE_SHIFT + 3*/ >>> +#define PPC44x_PTE_ADD_M1 20 /*32 - 3 - PTE_SHIFT*/ >>> +#define PPC44x_RPN_M2 19 /*31 - PAGE_SHIFT*/ >>> >> >> Uh.. you have the formulae for these things right there in the >> comments, so why aren't you using those and avoiding this nasty >> multiway ifdef... > > We need to get PMD_SHIFT and friends out of #ifndef __ASSEMBLY__ for > that. And some of them are under include/asm-generic so patch becomes > not powerpc-specific... So use arch/powerpc/kernel/asm-offsets.c, that's what it's for. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson ^ permalink raw reply [flat|nested] 25+ messages in thread
* [PATCH] mm: fix ENTRIES_PER_PAGEPAGE overflow with 256KB pages 2008-09-10 21:53 [RFC PATCH] Support for big page sizes on 44x Ilya Yanok 2008-09-10 21:53 ` [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for Ilya Yanok @ 2008-09-10 21:53 ` Ilya Yanok 2008-09-12 3:50 ` David Gibson 1 sibling, 1 reply; 25+ messages in thread From: Ilya Yanok @ 2008-09-10 21:53 UTC (permalink / raw) To: linuxppc-dev; +Cc: Ilya Yanok, dzu, wd ENTRIES_PER_PAGEPAGE define in mm/shmem.c becomes zero if page size is 256KB. This patch fixes this. Signed-off-by: Ilya Yanok <yanok@emcraft.com> --- mm/shmem.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/shmem.c b/mm/shmem.c index 04fb4f1..c603427 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -59,7 +59,7 @@ #define TMPFS_MAGIC 0x01021994 #define ENTRIES_PER_PAGE (PAGE_CACHE_SIZE/sizeof(unsigned long)) -#define ENTRIES_PER_PAGEPAGE (ENTRIES_PER_PAGE*ENTRIES_PER_PAGE) +#define ENTRIES_PER_PAGEPAGE ((unsigned long long)ENTRIES_PER_PAGE*ENTRIES_PER_PAGE) #define BLOCKS_PER_PAGE (PAGE_CACHE_SIZE/512) #define SHMEM_MAX_INDEX (SHMEM_NR_DIRECT + (ENTRIES_PER_PAGEPAGE/2) * (ENTRIES_PER_PAGE+1)) @@ -519,7 +519,7 @@ static void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end) struct shmem_inode_info *info = SHMEM_I(inode); unsigned long idx; unsigned long size; - unsigned long limit; + unsigned long long limit; unsigned long stage; unsigned long diroff; struct page **dir; @@ -535,7 +535,7 @@ static void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end) int punch_hole; spinlock_t *needs_lock; spinlock_t *punch_lock; - unsigned long upper_limit; + unsigned long long upper_limit; inode->i_ctime = inode->i_mtime = CURRENT_TIME; idx = (start + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; -- 1.5.6.1 ^ permalink raw reply related [flat|nested] 25+ messages in thread
* Re: [PATCH] mm: fix ENTRIES_PER_PAGEPAGE overflow with 256KB pages 2008-09-10 21:53 ` [PATCH] mm: fix ENTRIES_PER_PAGEPAGE overflow with 256KB pages Ilya Yanok @ 2008-09-12 3:50 ` David Gibson 2008-09-12 5:29 ` prodyut hazarika 0 siblings, 1 reply; 25+ messages in thread From: David Gibson @ 2008-09-12 3:50 UTC (permalink / raw) To: Ilya Yanok; +Cc: linuxppc-dev, wd, dzu On Thu, Sep 11, 2008 at 01:53:07AM +0400, Ilya Yanok wrote: > ENTRIES_PER_PAGEPAGE define in mm/shmem.c becomes zero if page size is > 256KB. This patch fixes this. This looks.. dubious. You're making a change to generic code for a powerpc feature. Plus it's not entirely clear that simply increasing the variable size is a good fix here. Again, I think since this is a 256k page special case it will simplify things to get the <=64k stuff first, then handle this in another patch. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson ^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH] mm: fix ENTRIES_PER_PAGEPAGE overflow with 256KB pages 2008-09-12 3:50 ` David Gibson @ 2008-09-12 5:29 ` prodyut hazarika 0 siblings, 0 replies; 25+ messages in thread From: prodyut hazarika @ 2008-09-12 5:29 UTC (permalink / raw) To: Ilya Yanok, linuxppc-dev, dzu, wd > On Thu, Sep 11, 2008 at 01:53:07AM +0400, Ilya Yanok wrote: >> ENTRIES_PER_PAGEPAGE define in mm/shmem.c becomes zero if page size is >> 256KB. This patch fixes this. > > This looks.. dubious. You're making a change to generic code for a > powerpc feature. Plus it's not entirely clear that simply increasing > the variable size is a good fix here. Again, I think since this is a > 256k page special case it will simplify things to get the <=64k stuff > first, then handle this in another patch. 16KB/64KB patch would not really need any hacks like the 256KB. The changes for 16/64KB can be totally hidden under 4xx specific files. So I too think that this patch should be split into 2 patches. ^ permalink raw reply [flat|nested] 25+ messages in thread
end of thread, other threads:[~2008-09-29 2:58 UTC | newest] Thread overview: 25+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2008-09-10 21:53 [RFC PATCH] Support for big page sizes on 44x Ilya Yanok 2008-09-10 21:53 ` [PATCH] powerpc: add support for PAGE_SIZEs greater than 4KB for Ilya Yanok 2008-09-11 16:57 ` prodyut hazarika 2008-09-11 18:15 ` Re[2]: " Yuri Tikhonov 2008-09-11 20:09 ` Josh Boyer 2008-09-11 23:38 ` Ilya Yanok 2008-09-12 0:47 ` Josh Boyer 2008-09-11 18:28 ` Ilya Yanok 2008-09-11 18:38 ` prodyut hazarika 2008-09-11 22:44 ` Ilya Yanok 2008-09-11 23:52 ` Re[2]: " Yuri Tikhonov 2008-09-11 18:53 ` prodyut hazarika 2008-09-11 21:51 ` Ilya Yanok 2008-09-13 17:49 ` Benjamin Herrenschmidt 2008-09-13 23:37 ` Josh Boyer 2008-09-11 22:37 ` prodyut hazarika 2008-09-11 23:20 ` Re[2]: " Yuri Tikhonov 2008-09-12 3:48 ` David Gibson 2008-09-13 17:46 ` Benjamin Herrenschmidt 2008-09-26 23:43 ` Ilya Yanok 2008-09-26 23:35 ` Ilya Yanok 2008-09-29 2:58 ` David Gibson 2008-09-10 21:53 ` [PATCH] mm: fix ENTRIES_PER_PAGEPAGE overflow with 256KB pages Ilya Yanok 2008-09-12 3:50 ` David Gibson 2008-09-12 5:29 ` prodyut hazarika
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