gpu/drm, x86, PAT: PAT support for io_mapping_*
Make io_mapping_create_wc and io_mapping_free go through PAT to make sure that there are no memory type aliases. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Dave Airlie <airlied@redhat.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: Eric Anholt <eric@anholt.net> Cc: Keith Packard <keithp@keithp.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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7880f74645
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17581ad812
3 changed files with 48 additions and 5 deletions
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@ -24,7 +24,10 @@
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#include <asm/tlbflush.h>
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int
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is_io_mapping_possible(resource_size_t base, unsigned long size);
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reserve_io_memtype_wc(u64 base, unsigned long size, pgprot_t *prot);
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void
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free_io_memtype(u64 base, unsigned long size);
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void *
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iomap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot);
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@ -21,13 +21,13 @@
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#include <linux/module.h>
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#ifdef CONFIG_X86_PAE
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int
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static int
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is_io_mapping_possible(resource_size_t base, unsigned long size)
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{
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return 1;
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}
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#else
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int
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static int
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is_io_mapping_possible(resource_size_t base, unsigned long size)
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{
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/* There is no way to map greater than 1 << 32 address without PAE */
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@ -38,6 +38,44 @@ is_io_mapping_possible(resource_size_t base, unsigned long size)
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}
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#endif
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int
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reserve_io_memtype_wc(u64 base, unsigned long size, pgprot_t *prot)
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{
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unsigned long ret_flag;
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if (!is_io_mapping_possible(base, size))
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goto out_err;
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if (!pat_enabled) {
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*prot = pgprot_noncached(PAGE_KERNEL);
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return 0;
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}
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if (reserve_memtype(base, base + size, _PAGE_CACHE_WC, &ret_flag))
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goto out_err;
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if (ret_flag == _PAGE_CACHE_WB)
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goto out_free;
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if (kernel_map_sync_memtype(base, size, ret_flag))
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goto out_free;
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*prot = __pgprot(__PAGE_KERNEL | ret_flag);
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return 0;
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out_free:
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free_memtype(base, base + size);
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out_err:
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return -EINVAL;
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}
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void
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free_io_memtype(u64 base, unsigned long size)
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{
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if (pat_enabled)
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free_memtype(base, base + size);
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}
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/* Map 'pfn' using fixed map 'type' and protections 'prot'
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*/
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void *
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@ -49,8 +49,9 @@ static inline struct io_mapping *
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io_mapping_create_wc(resource_size_t base, unsigned long size)
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{
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struct io_mapping *iomap;
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pgprot_t prot;
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if (!is_io_mapping_possible(base, size))
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if (!reserve_io_memtype_wc(base, size, &prot))
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return NULL;
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iomap = kmalloc(sizeof(*iomap), GFP_KERNEL);
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@ -59,13 +60,14 @@ io_mapping_create_wc(resource_size_t base, unsigned long size)
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iomap->base = base;
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iomap->size = size;
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iomap->prot = pgprot_writecombine(__pgprot(__PAGE_KERNEL));
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iomap->prot = prot;
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return iomap;
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}
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static inline void
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io_mapping_free(struct io_mapping *mapping)
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{
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free_io_memtype(mapping->base, mapping->size);
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kfree(mapping);
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}
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