For obtaining the physical address, we always take the slow path
of slow_virt_to_phys(). In the future, we should probably special
case data addresses to avoid walking the page table. For obtaining
a virtual address, this patch introduces a slow path of
slow_xip_phys_to_virt().
Signed-off-by: Jim Kukunas <james.t.kuku...@linux.intel.com>
---
arch/x86/include/asm/page.h | 15 +++++++++++++++
arch/x86/mm/pageattr.c | 11 +++++++++++
2 files changed, 26 insertions(+)
diff --git a/arch/x86/include/asm/page.h b/arch/x86/include/asm/page.h
index 802dde3..b54c7be 100644
--- a/arch/x86/include/asm/page.h
+++ b/arch/x86/include/asm/page.h
@@ -6,6 +6,7 @@
#ifdef __KERNEL__
#include <asm/page_types.h>
+#include <asm/pgtable_types.h>
#ifdef CONFIG_X86_64
#include <asm/page_64.h>
@@ -37,8 +38,15 @@ static inline void copy_user_page(void *to, void *from,
unsigned long vaddr,
alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO | movableflags, vma, vaddr)
#define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
+
+#ifdef CONFIG_XIP_KERNEL /* TODO special case text translations */
+#define __pa(x) slow_virt_to_phys((void *)(x))
+#define __pa_nodebug slow_virt_to_phys((void *)(x))
+#else
#define __pa(x) __phys_addr((unsigned long)(x))
#define __pa_nodebug(x) __phys_addr_nodebug((unsigned long)(x))
+#endif
+
/* __pa_symbol should be used for C visible symbols.
This seems to be the official gcc blessed way to do such arithmetic. */
/*
@@ -51,7 +59,14 @@ static inline void copy_user_page(void *to, void *from,
unsigned long vaddr,
#define __pa_symbol(x) \
__phys_addr_symbol(__phys_reloc_hide((unsigned long)(x)))
+
+#ifdef CONFIG_XIP_KERNEL
+extern unsigned long slow_xip_phys_to_virt(phys_addr_t);
+
+#define __va(x) ((void
*)slow_xip_phys_to_virt((phys_addr_t)x))
+#else
#define __va(x) ((void *)((unsigned
long)(x)+PAGE_OFFSET))
+#endif
#define __boot_va(x) __va(x)
#define __boot_pa(x) __pa(x)
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 536ea2f..ca9e2ca 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -383,6 +383,17 @@ static pte_t *_lookup_address_cpa(struct cpa_data *cpa,
unsigned long address,
return lookup_address(address, level);
}
+#ifdef CONFIG_XIP_KERNEL
+unsigned long slow_xip_phys_to_virt(phys_addr_t x)
+{
+ if (x >= CONFIG_XIP_BASE && x <= (phys_addr_t)phys_sdata) {
+ unsigned long off = x - CONFIG_XIP_BASE;
+ return PAGE_OFFSET + off;
+ }
+ return x + PAGE_OFFSET;
+}
+#endif
+
/*
* Lookup the PMD entry for a virtual address. Return a pointer to the entry
* or NULL if not present.
--
2.1.0
--
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