xtensa: make fixmap region addressing grow with index
It's much easier to reason about alignment and coloring of regions located in the fixmap when fixmap index is just a PFN within the fixmap region. Change fixmap addressing so that index 0 corresponds to FIXADDR_START instead of the FIXADDR_TOP. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
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@ -23,8 +23,8 @@
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* Here we define all the compile-time 'special' virtual
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* Here we define all the compile-time 'special' virtual
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* addresses. The point is to have a constant address at
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* addresses. The point is to have a constant address at
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* compile time, but to set the physical address only
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* compile time, but to set the physical address only
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* in the boot process. We allocate these special addresses
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* in the boot process. We allocate these special addresses
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* from the end of the consistent memory region backwards.
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* from the start of the consistent memory region upwards.
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* Also this lets us do fail-safe vmalloc(), we
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* Also this lets us do fail-safe vmalloc(), we
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* can guarantee that these special addresses and
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* can guarantee that these special addresses and
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* vmalloc()-ed addresses never overlap.
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* vmalloc()-ed addresses never overlap.
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@ -47,7 +47,28 @@ enum fixed_addresses {
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#define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
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#define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
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#define FIXADDR_START ((FIXADDR_TOP - FIXADDR_SIZE) & PMD_MASK)
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#define FIXADDR_START ((FIXADDR_TOP - FIXADDR_SIZE) & PMD_MASK)
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#include <asm-generic/fixmap.h>
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#define __fix_to_virt(x) (FIXADDR_START + ((x) << PAGE_SHIFT))
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#define __virt_to_fix(x) (((x) - FIXADDR_START) >> PAGE_SHIFT)
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#ifndef __ASSEMBLY__
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/*
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* 'index to address' translation. If anyone tries to use the idx
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* directly without translation, we catch the bug with a NULL-deference
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* kernel oops. Illegal ranges of incoming indices are caught too.
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*/
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static __always_inline unsigned long fix_to_virt(const unsigned int idx)
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{
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BUILD_BUG_ON(idx >= __end_of_fixed_addresses);
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return __fix_to_virt(idx);
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}
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static inline unsigned long virt_to_fix(const unsigned long vaddr)
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{
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BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
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return __virt_to_fix(vaddr);
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}
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#endif
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#define kmap_get_fixmap_pte(vaddr) \
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#define kmap_get_fixmap_pte(vaddr) \
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pte_offset_kernel( \
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pte_offset_kernel( \
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@ -28,9 +28,9 @@ void *kmap_atomic(struct page *page)
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idx = type + KM_TYPE_NR * smp_processor_id();
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idx = type + KM_TYPE_NR * smp_processor_id();
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vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
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vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
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#ifdef CONFIG_DEBUG_HIGHMEM
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#ifdef CONFIG_DEBUG_HIGHMEM
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BUG_ON(!pte_none(*(kmap_pte - idx)));
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BUG_ON(!pte_none(*(kmap_pte + idx)));
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#endif
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#endif
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set_pte(kmap_pte - idx, mk_pte(page, PAGE_KERNEL_EXEC));
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set_pte(kmap_pte + idx, mk_pte(page, PAGE_KERNEL_EXEC));
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return (void *)vaddr;
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return (void *)vaddr;
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}
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}
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@ -51,7 +51,7 @@ void __kunmap_atomic(void *kvaddr)
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* is a bad idea also, in case the page changes cacheability
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* is a bad idea also, in case the page changes cacheability
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* attributes or becomes a protected page in a hypervisor.
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* attributes or becomes a protected page in a hypervisor.
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*/
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*/
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pte_clear(&init_mm, kvaddr, kmap_pte - idx);
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pte_clear(&init_mm, kvaddr, kmap_pte + idx);
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local_flush_tlb_kernel_range((unsigned long)kvaddr,
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local_flush_tlb_kernel_range((unsigned long)kvaddr,
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(unsigned long)kvaddr + PAGE_SIZE);
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(unsigned long)kvaddr + PAGE_SIZE);
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