From 8ef838e5ff7b3c005d7fbc725e17bcccd0e1e1eb Mon Sep 17 00:00:00 2001 From: Thomas Hellstrom Date: Thu, 28 Feb 2008 13:47:15 +0100 Subject: Add a compat kmap_atomic_prot_pfn to do quick kernel map / unmaps of PCI- or high memory. This is substantially more efficient than drm_bo_kmap, since the mapping only lives on a single processor. Unmapping is done use kunmap_atomic(). Flushes only a single tlb() entry. Add a support utility int drm_bo_pfn_prot() that returns the pfn and desired page protection for a given bo offset. This is all intended for relocations in bound TTMS or vram. Mapping-accessing-unmapping must be atomic, either using preempt_xx() macros or a spinlock. --- linux-core/drm_compat.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'linux-core/drm_compat.c') diff --git a/linux-core/drm_compat.c b/linux-core/drm_compat.c index a745a7d9..32e43a0a 100644 --- a/linux-core/drm_compat.c +++ b/linux-core/drm_compat.c @@ -729,3 +729,35 @@ void *idr_replace(struct idr *idp, void *ptr, int id) } EXPORT_SYMBOL(idr_replace); #endif + +#if defined(CONFIG_X86) + +#define drm_kmap_get_fixmap_pte(vaddr) \ + pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), vaddr), (vaddr)), (vaddr)) + +void *kmap_atomic_prot_pfn(unsigned long pfn, enum km_type type, + pgprot_t protection) +{ + enum fixed_addresses idx; + unsigned long vaddr; + static pte_t *km_pte; + static int initialized = 0; + + if (unlikely(!initialized)) { + km_pte = drm_kmap_get_fixmap_pte(__fix_to_virt(FIX_KMAP_BEGIN)); + initialized = 1; + } + + pagefault_disable(); + idx = type + KM_TYPE_NR*smp_processor_id(); + vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); + set_pte(km_pte-idx, pfn_pte(pfn, protection)); + + return (void*) vaddr; +} + +EXPORT_SYMBOL(kmap_atomic_prot_pfn); + +#endif + + -- cgit v1.2.3