From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steffen Persvold Date: Sat, 15 Sep 2001 12:36:34 +0000 Subject: Re: [Linux-ia64] Re: Status on ioremap patch MIME-Version: 1 Content-Type: multipart/mixed; boundary="------------AC339179474D5777E08517A4" Message-Id: List-Id: References: In-Reply-To: To: linux-ia64@vger.kernel.org This is a multi-part message in MIME format. --------------AC339179474D5777E08517A4 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit David Mosberger wrote: > > >>>>> On Fri, 14 Sep 2001 23:57:03 +0200, Steffen Persvold said: > > Steffen> So, how about that patch guys ? Any chance you'll put it > Steffen> into the mainstream IA64 kernel ??? > > I haven't looked at it yet, but am planning to do so as part of the > 2.4.10 patch. > I just discovered that several files in arch/ia64/kernel (more specifically acpi.c, efi.c and iosapic.c) calls ioremap with 0 as size argument. This is ok with the current ioremap implementation which always uses region 6 and therefore in theory doesn't need a size since it's mapped all the time. However with my patch you will get a NULL pointer in return if you specify size as 0. Because of this I've modified my original patch to accept 0 as size argument and return the region 6 address when this is the case. This means that we cannot get rid of region 6 yet since some of the source files seem to depend on it. Attached is my new version of the patch. (Please note that the old ioremap() methods in asm/io.h is just disabled with '#if 0') Regards, -- Steffen Persvold | Scali Computer AS | Try out the world's best mailto:sp@scali.no | http://www.scali.com | performing MPI implementation: Tel: (+47) 2262 8950 | Olaf Helsets vei 6 | - ScaMPI 1.12.2 - Fax: (+47) 2262 8951 | N0621 Oslo, NORWAY | >300MBytes/s and <4uS latency --------------AC339179474D5777E08517A4 Content-Type: text/plain; charset=us-ascii; name="ia64-ioremap3.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="ia64-ioremap3.patch" --- linux-2.4.4/arch/ia64/mm/Makefile.~1~ Thu Jan 4 21:50:17 2001 +++ linux-2.4.4/arch/ia64/mm/Makefile Sat Aug 11 21:20:03 2001 @@ -9,6 +9,6 @@ O_TARGET := mm.o -obj-y := init.o fault.o tlb.o extable.o +obj-y := init.o fault.o ioremap.o tlb.o extable.o include $(TOPDIR)/Rules.make --- linux-2.4.4/arch/ia64/mm/ioremap.c.~1~ Tue May 5 22:32:27 1998 +++ linux-2.4.4/arch/ia64/mm/ioremap.c Sat Sep 15 13:20:25 2001 @@ -0,0 +1,162 @@ +/* + * arch/ia64/mm/ioremap.c + * + * IA64 version + * Copyright (C) 2001 Scali AS + * Author(s): Steffen Persvold (sp@scali.com) + * + * Derived from "arch/i386/mm/ioremap.c" + * (C) Copyright 1995 1996 Linus Torvalds + * + * Re-map IO memory to kernel address space so that we can access it. + */ + +#include +#include +#include + +static inline void remap_area_pte(pte_t * pte, unsigned long address, unsigned long size, + unsigned long phys_addr, unsigned long flags) +{ + unsigned long end; + + address &= ~PMD_MASK; + end = address + size; + if (end > PMD_SIZE) + end = PMD_SIZE; + if (address >= end) + BUG(); + do { + if (!pte_none(*pte)) { + printk("remap_area_pte: page already exists\n"); + BUG(); + } + set_pte(pte, mk_pte_phys(phys_addr, __pgprot(__DIRTY_BITS | _PAGE_PL_0 | + _PAGE_AR_RWX | (flags & _PAGE_MA_MASK)))); + address += PAGE_SIZE; + phys_addr += PAGE_SIZE; + pte++; + } while (address && (address < end)); +} + +static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size, + unsigned long phys_addr, unsigned long flags) +{ + unsigned long end; + + address &= ~PGDIR_MASK; + end = address + size; + if (end > PGDIR_SIZE) + end = PGDIR_SIZE; + phys_addr -= address; + if (address >= end) + BUG(); + do { + pte_t * pte = pte_alloc(&init_mm, pmd, address); + if (!pte) + return -ENOMEM; + remap_area_pte(pte, address, end - address, address + phys_addr, flags); + address = (address + PMD_SIZE) & PMD_MASK; + pmd++; + } while (address && (address < end)); + return 0; +} + +static int remap_area_pages(unsigned long address, unsigned long phys_addr, + unsigned long size, unsigned long flags) +{ + int error; + pgd_t * dir; + unsigned long end = address + size; + + phys_addr -= address; + dir = pgd_offset_k(address); + flush_cache_all(); + if (address >= end) + BUG(); + spin_lock(&init_mm.page_table_lock); + do { + pmd_t *pmd; + pmd = pmd_alloc(&init_mm, dir, address); + error = -ENOMEM; + if (!pmd) + break; + if (remap_area_pmd(pmd, address, end - address, + phys_addr + address, flags)) + break; + error = 0; + address = (address + PGDIR_SIZE) & PGDIR_MASK; + dir++; + } while (address && (address < end)); + spin_unlock(&init_mm.page_table_lock); + flush_tlb_all(); + return error; +} + +/* + * Generic mapping function (not visible outside): + */ + +/* + * Remap an arbitrary physical address space into the kernel virtual + * address space. Needed when the kernel wants to access high addresses + * directly. + * + * NOTE! We need to allow non-page-aligned mappings too: we will obviously + * have to convert them into an offset in a page-aligned mapping, but the + * caller shouldn't need to know that small detail. + */ +void * __ia64_ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags) +{ + void * addr; + struct vm_struct * area; + unsigned long offset, last_addr; + + /* If size is zero we can't set up a dynamic map, + * use the uncached region. + */ + if (!size) + return (void *) (__IA64_UNCACHED_OFFSET | (phys_addr)); + + /* Don't allow wraparound */ + last_addr = phys_addr + size - 1; + if (last_addr < phys_addr) + return NULL; + + /* + * Don't allow anybody to remap normal RAM that we're using.. + */ + if (phys_addr < virt_to_phys(high_memory)) + return NULL; + + /* + * Mappings have to be page-aligned + */ + offset = phys_addr & ~PAGE_MASK; + phys_addr &= PAGE_MASK; + size = PAGE_ALIGN(last_addr) - phys_addr; + + /* + * Ok, go for it.. + */ + area = get_vm_area(size, VM_IOREMAP); + if (!area) + return NULL; + addr = area->addr; + + if ((flags & _PAGE_MA_MASK) == 0) + flags = _PAGE_MA_UC; + + if (remap_area_pages(VMALLOC_VMADDR(addr), phys_addr, size, flags)) { + vfree(addr); + return NULL; + } + return (void *) (offset + (char *)addr); +} + +void __ia64_iounmap(void *addr) +{ + /* We can't do vfree() on addresses in the uncached region */ + if ((unsigned long)addr < __IA64_UNCACHED_OFFSET) + return vfree(addr); +} --- linux-2.4.4/arch/ia64/kernel/ia64_ksyms.c.~1~ Thu Apr 5 21:51:47 2001 +++ linux-2.4.4/arch/ia64/kernel/ia64_ksyms.c Sat Aug 11 23:57:12 2001 @@ -39,6 +39,8 @@ EXPORT_SYMBOL(ip_fast_csum); #include +EXPORT_SYMBOL(__ia64_ioremap); +EXPORT_SYMBOL(__ia64_iounmap); EXPORT_SYMBOL(__ia64_memcpy_fromio); EXPORT_SYMBOL(__ia64_memcpy_toio); EXPORT_SYMBOL(__ia64_memset_c_io); --- linux-2.4.4/include/asm-ia64/io.h.~1~ Thu Apr 5 21:51:47 2001 +++ linux-2.4.4/include/asm-ia64/io.h Sat Sep 15 13:25:50 2001 @@ -32,6 +32,7 @@ #include #include #include +#include /* * Change virtual addresses to physical addresses and vv. @@ -372,7 +373,15 @@ * accept both, thus the casts. * * On ia-64, we access the physical I/O memory space through the uncached kernel region. + * + * Which is not a good idea if we want speed on large PIO operations. This is now changed + * to map dynamically so that we can use the page table attributes to decide the caching. */ + +extern void * __ia64_ioremap(unsigned long offset, unsigned long size, unsigned long flags); +extern void __ia64_iounmap(void *addr); + +#if 0 static inline void * ioremap (unsigned long offset, unsigned long size) { @@ -385,6 +394,25 @@ } #define ioremap_nocache(o,s) ioremap(o,s) +#else +static inline void * +ioremap (unsigned long offset, unsigned long size) +{ + return __ia64_ioremap(offset, size, _PAGE_MA_WC); +} + +static inline void * +ioremap_nocache (unsigned long offset, unsigned long size) +{ + return __ia64_ioremap(offset, size, _PAGE_MA_UC); +} + +static inline void +iounmap (void *addr) +{ + __ia64_iounmap(addr); +} +#endif # ifdef __KERNEL__ --- linux-2.4.4/include/asm-ia64/pgtable.h.~1~ Thu Apr 5 21:51:47 2001 +++ linux-2.4.4/include/asm-ia64/pgtable.h Sat Aug 11 23:59:36 2001 @@ -125,7 +125,6 @@ # ifndef __ASSEMBLY__ #include -#include #include /* @@ -329,11 +328,7 @@ /* The offset in the 1-level directory is given by the 3 region bits (61..63) and the seven level-1 bits (33-39). */ -static inline pgd_t* -pgd_offset (struct mm_struct *mm, unsigned long address) -{ - return mm->pgd + pgd_index(address); -} +#define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address)) /* In the kernel's mapped region we have a full 43 bit space available and completely ignore the region number (since we know its in region number 5). */ --------------AC339179474D5777E08517A4--