linux_dsm_epyc7002/arch/x86/mm/iomap_32.c
Peter Zijlstra 3e4d3af501 mm: stack based kmap_atomic()
Keep the current interface but ignore the KM_type and use a stack based
approach.

The advantage is that we get rid of crappy code like:

	#define __KM_PTE			\
		(in_nmi() ? KM_NMI_PTE : 	\
		 in_irq() ? KM_IRQ_PTE :	\
		 KM_PTE0)

and in general can stop worrying about what context we're in and what kmap
slots might be appropriate for that.

The downside is that FRV kmap_atomic() gets more expensive.

For now we use a CPP trick suggested by Andrew:

  #define kmap_atomic(page, args...) __kmap_atomic(page)

to avoid having to touch all kmap_atomic() users in a single patch.

[ not compiled on:
  - mn10300: the arch doesn't actually build with highmem to begin with ]

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix up drivers/gpu/drm/i915/intel_overlay.c]
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:08 -07:00

119 lines
3.3 KiB
C

/*
* Copyright © 2008 Ingo Molnar
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*/
#include <asm/iomap.h>
#include <asm/pat.h>
#include <linux/module.h>
#include <linux/highmem.h>
static int is_io_mapping_possible(resource_size_t base, unsigned long size)
{
#if !defined(CONFIG_X86_PAE) && defined(CONFIG_PHYS_ADDR_T_64BIT)
/* There is no way to map greater than 1 << 32 address without PAE */
if (base + size > 0x100000000ULL)
return 0;
#endif
return 1;
}
int iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot)
{
unsigned long flag = _PAGE_CACHE_WC;
int ret;
if (!is_io_mapping_possible(base, size))
return -EINVAL;
ret = io_reserve_memtype(base, base + size, &flag);
if (ret)
return ret;
*prot = __pgprot(__PAGE_KERNEL | flag);
return 0;
}
EXPORT_SYMBOL_GPL(iomap_create_wc);
void iomap_free(resource_size_t base, unsigned long size)
{
io_free_memtype(base, base + size);
}
EXPORT_SYMBOL_GPL(iomap_free);
void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
{
unsigned long vaddr;
int idx, type;
pagefault_disable();
type = kmap_atomic_idx_push();
idx = type + KM_TYPE_NR * smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
set_pte(kmap_pte - idx, pfn_pte(pfn, prot));
arch_flush_lazy_mmu_mode();
return (void *)vaddr;
}
/*
* Map 'pfn' using protections 'prot'
*/
void __iomem *
iomap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
{
/*
* For non-PAT systems, promote PAGE_KERNEL_WC to PAGE_KERNEL_UC_MINUS.
* PAGE_KERNEL_WC maps to PWT, which translates to uncached if the
* MTRR is UC or WC. UC_MINUS gets the real intention, of the
* user, which is "WC if the MTRR is WC, UC if you can't do that."
*/
if (!pat_enabled && pgprot_val(prot) == pgprot_val(PAGE_KERNEL_WC))
prot = PAGE_KERNEL_UC_MINUS;
return (void __force __iomem *) kmap_atomic_prot_pfn(pfn, prot);
}
EXPORT_SYMBOL_GPL(iomap_atomic_prot_pfn);
void
iounmap_atomic(void __iomem *kvaddr)
{
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
if (vaddr >= __fix_to_virt(FIX_KMAP_END) &&
vaddr <= __fix_to_virt(FIX_KMAP_BEGIN)) {
int idx, type;
type = kmap_atomic_idx_pop();
idx = type + KM_TYPE_NR * smp_processor_id();
#ifdef CONFIG_DEBUG_HIGHMEM
WARN_ON_ONCE(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
#endif
/*
* Force other mappings to Oops if they'll try to access this
* pte without first remap it. Keeping stale mappings around
* is a bad idea also, in case the page changes cacheability
* attributes or becomes a protected page in a hypervisor.
*/
kpte_clear_flush(kmap_pte-idx, vaddr);
}
pagefault_enable();
}
EXPORT_SYMBOL_GPL(iounmap_atomic);