Patch to kill ioremap_mm
John Rose
johnrose at austin.ibm.com
Fri May 6 02:21:30 EST 2005
<apologies for resend>
Hi David-
Given that we use a separate allocation scheme for imalloc mappings,
does it make sense to lump these into the vmalloc mm_struct, and to
share the vmalloc address space? This saves lines of code, but is it as
clear as the existing (separate) layout?
Thanks-
John
On Wed, 2005-05-04 at 20:42, David Gibson wrote:
> Can anyone see any problems with this patch. If not, I'll send it on
> to akpm.
>
> Currently ppc64 has two mm_structs for the kernel, init_mm and also
> ioremap_mm. The latter really isn't necessary: this patch abolishes
> it, instead restricting vmallocs to the lower 1TB of the init_mm's
> range and placing io mappings in the upper 1TB. This simplifies the
> code in a number of places, and gets rid of an unecessary set of
> pagetables.
>
> Index: working-2.6/include/asm-ppc64/pgtable.h
> ===================================================================
> --- working-2.6.orig/include/asm-ppc64/pgtable.h 2005-05-05 10:58:04.000000000 +1000
> +++ working-2.6/include/asm-ppc64/pgtable.h 2005-05-05 11:12:59.000000000 +1000
> @@ -53,7 +53,8 @@
> * Define the address range of the vmalloc VM area.
> */
> #define VMALLOC_START (0xD000000000000000ul)
> -#define VMALLOC_END (VMALLOC_START + EADDR_MASK)
> +#define VMALLOC_SIZE (0x10000000000UL)
> +#define VMALLOC_END (VMALLOC_START + VMALLOC_SIZE)
>
> /*
> * Bits in a linux-style PTE. These match the bits in the
> @@ -239,9 +240,6 @@
> /* This now only contains the vmalloc pages */
> #define pgd_offset_k(address) pgd_offset(&init_mm, address)
>
> -/* to find an entry in the ioremap page-table-directory */
> -#define pgd_offset_i(address) (ioremap_pgd + pgd_index(address))
> -
> /*
> * The following only work if pte_present() is true.
> * Undefined behaviour if not..
> @@ -459,15 +457,12 @@
> #define __HAVE_ARCH_PTE_SAME
> #define pte_same(A,B) (((pte_val(A) ^ pte_val(B)) & ~_PAGE_HPTEFLAGS) == 0)
>
> -extern unsigned long ioremap_bot, ioremap_base;
> -
> #define pmd_ERROR(e) \
> printk("%s:%d: bad pmd %08x.\n", __FILE__, __LINE__, pmd_val(e))
> #define pgd_ERROR(e) \
> printk("%s:%d: bad pgd %08x.\n", __FILE__, __LINE__, pgd_val(e))
>
> extern pgd_t swapper_pg_dir[];
> -extern pgd_t ioremap_dir[];
>
> extern void paging_init(void);
>
> Index: working-2.6/include/asm-ppc64/imalloc.h
> ===================================================================
> --- working-2.6.orig/include/asm-ppc64/imalloc.h 2005-05-05 10:58:04.000000000 +1000
> +++ working-2.6/include/asm-ppc64/imalloc.h 2005-05-05 11:13:39.000000000 +1000
> @@ -4,9 +4,9 @@
> /*
> * Define the address range of the imalloc VM area.
> */
> -#define PHBS_IO_BASE IOREGIONBASE
> -#define IMALLOC_BASE (IOREGIONBASE + 0x80000000ul) /* Reserve 2 gigs for PHBs */
> -#define IMALLOC_END (IOREGIONBASE + EADDR_MASK)
> +#define PHBS_IO_BASE VMALLOC_END
> +#define IMALLOC_BASE (PHBS_IO_BASE + 0x80000000ul) /* Reserve 2 gigs for PHBs */
> +#define IMALLOC_END (VMALLOC_START + EADDR_MASK)
>
>
> /* imalloc region types */
> @@ -21,4 +21,6 @@
> int region_type);
> unsigned long im_free(void *addr);
>
> +extern unsigned long ioremap_bot;
> +
> #endif /* _PPC64_IMALLOC_H */
> Index: working-2.6/include/asm-ppc64/page.h
> ===================================================================
> --- working-2.6.orig/include/asm-ppc64/page.h 2005-05-05 10:58:04.000000000 +1000
> +++ working-2.6/include/asm-ppc64/page.h 2005-05-05 11:14:02.000000000 +1000
> @@ -202,9 +202,7 @@
> #define PAGE_OFFSET ASM_CONST(0xC000000000000000)
> #define KERNELBASE PAGE_OFFSET
> #define VMALLOCBASE ASM_CONST(0xD000000000000000)
> -#define IOREGIONBASE ASM_CONST(0xE000000000000000)
>
> -#define IO_REGION_ID (IOREGIONBASE >> REGION_SHIFT)
> #define VMALLOC_REGION_ID (VMALLOCBASE >> REGION_SHIFT)
> #define KERNEL_REGION_ID (KERNELBASE >> REGION_SHIFT)
> #define USER_REGION_ID (0UL)
> Index: working-2.6/arch/ppc64/kernel/eeh.c
> ===================================================================
> --- working-2.6.orig/arch/ppc64/kernel/eeh.c 2005-04-26 15:37:55.000000000 +1000
> +++ working-2.6/arch/ppc64/kernel/eeh.c 2005-05-05 11:23:40.000000000 +1000
> @@ -505,7 +505,7 @@
> pte_t *ptep;
> unsigned long pa;
>
> - ptep = find_linux_pte(ioremap_mm.pgd, token);
> + ptep = find_linux_pte(init_mm.pgd, token);
> if (!ptep)
> return token;
> pa = pte_pfn(*ptep) << PAGE_SHIFT;
> Index: working-2.6/arch/ppc64/kernel/process.c
> ===================================================================
> --- working-2.6.orig/arch/ppc64/kernel/process.c 2005-04-26 15:37:55.000000000 +1000
> +++ working-2.6/arch/ppc64/kernel/process.c 2005-05-05 11:16:20.000000000 +1000
> @@ -58,14 +58,6 @@
> struct task_struct *last_task_used_altivec = NULL;
> #endif
>
> -struct mm_struct ioremap_mm = {
> - .pgd = ioremap_dir,
> - .mm_users = ATOMIC_INIT(2),
> - .mm_count = ATOMIC_INIT(1),
> - .cpu_vm_mask = CPU_MASK_ALL,
> - .page_table_lock = SPIN_LOCK_UNLOCKED,
> -};
> -
> /*
> * Make sure the floating-point register state in the
> * the thread_struct is up to date for task tsk.
> Index: working-2.6/include/asm-ppc64/processor.h
> ===================================================================
> --- working-2.6.orig/include/asm-ppc64/processor.h 2005-04-26 15:38:02.000000000 +1000
> +++ working-2.6/include/asm-ppc64/processor.h 2005-05-05 11:24:46.000000000 +1000
> @@ -590,16 +590,6 @@
> }
>
> /*
> - * Note: the vm_start and vm_end fields here should *not*
> - * be in kernel space. (Could vm_end == vm_start perhaps?)
> - */
> -#define IOREMAP_MMAP { &ioremap_mm, 0, 0x1000, NULL, \
> - PAGE_SHARED, VM_READ | VM_WRITE | VM_EXEC, \
> - 1, NULL, NULL }
> -
> -extern struct mm_struct ioremap_mm;
> -
> -/*
> * Return saved PC of a blocked thread. For now, this is the "user" PC
> */
> #define thread_saved_pc(tsk) \
> Index: working-2.6/arch/ppc64/mm/hash_utils.c
> ===================================================================
> --- working-2.6.orig/arch/ppc64/mm/hash_utils.c 2005-05-05 10:58:04.000000000 +1000
> +++ working-2.6/arch/ppc64/mm/hash_utils.c 2005-05-05 11:17:03.000000000 +1000
> @@ -310,10 +310,6 @@
>
> vsid = get_vsid(mm->context.id, ea);
> break;
> - case IO_REGION_ID:
> - mm = &ioremap_mm;
> - vsid = get_kernel_vsid(ea);
> - break;
> case VMALLOC_REGION_ID:
> mm = &init_mm;
> vsid = get_kernel_vsid(ea);
> Index: working-2.6/arch/ppc64/mm/init.c
> ===================================================================
> --- working-2.6.orig/arch/ppc64/mm/init.c 2005-05-05 10:58:04.000000000 +1000
> +++ working-2.6/arch/ppc64/mm/init.c 2005-05-05 11:22:54.000000000 +1000
> @@ -144,7 +144,7 @@
>
> pte = pte_offset_kernel(pmd, addr);
> do {
> - pte_t ptent = ptep_get_and_clear(&ioremap_mm, addr, pte);
> + pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
> WARN_ON(!pte_none(ptent) && !pte_present(ptent));
> } while (pte++, addr += PAGE_SIZE, addr != end);
> }
> @@ -181,13 +181,13 @@
>
> static void unmap_im_area(unsigned long addr, unsigned long end)
> {
> - struct mm_struct *mm = &ioremap_mm;
> + struct mm_struct *mm = &init_mm;
> unsigned long next;
> pgd_t *pgd;
>
> spin_lock(&mm->page_table_lock);
>
> - pgd = pgd_offset_i(addr);
> + pgd = pgd_offset_k(addr);
> flush_cache_vunmap(addr, end);
> do {
> next = pgd_addr_end(addr, end);
> @@ -214,21 +214,21 @@
> unsigned long vsid;
>
> if (mem_init_done) {
> - spin_lock(&ioremap_mm.page_table_lock);
> - pgdp = pgd_offset_i(ea);
> - pudp = pud_alloc(&ioremap_mm, pgdp, ea);
> + spin_lock(&init_mm.page_table_lock);
> + pgdp = pgd_offset_k(ea);
> + pudp = pud_alloc(&init_mm, pgdp, ea);
> if (!pudp)
> return -ENOMEM;
> - pmdp = pmd_alloc(&ioremap_mm, pudp, ea);
> + pmdp = pmd_alloc(&init_mm, pudp, ea);
> if (!pmdp)
> return -ENOMEM;
> - ptep = pte_alloc_kernel(&ioremap_mm, pmdp, ea);
> + ptep = pte_alloc_kernel(&init_mm, pmdp, ea);
> if (!ptep)
> return -ENOMEM;
> pa = abs_to_phys(pa);
> - set_pte_at(&ioremap_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
> + set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
> __pgprot(flags)));
> - spin_unlock(&ioremap_mm.page_table_lock);
> + spin_unlock(&init_mm.page_table_lock);
> } else {
> unsigned long va, vpn, hash, hpteg;
>
>
>
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