[PATCH v2 1/9] powerpc/mem: Move cache flushing functions into mm/cacheflush.c
Christophe Leroy
christophe.leroy at csgroup.eu
Fri Apr 9 01:30:24 AEST 2021
Cache flushing functions are in the middle of completely
unrelated stuff in mm/mem.c
Create a dedicated mm/cacheflush.c for those functions.
Also cleanup the list of included headers.
Signed-off-by: Christophe Leroy <christophe.leroy at csgroup.eu>
---
arch/powerpc/mm/Makefile | 3 +-
arch/powerpc/mm/cacheflush.c | 255 +++++++++++++++++++++++++++++++
arch/powerpc/mm/mem.c | 281 -----------------------------------
3 files changed, 257 insertions(+), 282 deletions(-)
create mode 100644 arch/powerpc/mm/cacheflush.c
diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile
index 3b4e9e4e25ea..c3df3a8501d4 100644
--- a/arch/powerpc/mm/Makefile
+++ b/arch/powerpc/mm/Makefile
@@ -8,7 +8,8 @@ ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC)
obj-y := fault.o mem.o pgtable.o mmap.o maccess.o \
init_$(BITS).o pgtable_$(BITS).o \
pgtable-frag.o ioremap.o ioremap_$(BITS).o \
- init-common.o mmu_context.o drmem.o
+ init-common.o mmu_context.o drmem.o \
+ cacheflush.o
obj-$(CONFIG_PPC_MMU_NOHASH) += nohash/
obj-$(CONFIG_PPC_BOOK3S_32) += book3s32/
obj-$(CONFIG_PPC_BOOK3S_64) += book3s64/
diff --git a/arch/powerpc/mm/cacheflush.c b/arch/powerpc/mm/cacheflush.c
new file mode 100644
index 000000000000..40613d2fda37
--- /dev/null
+++ b/arch/powerpc/mm/cacheflush.c
@@ -0,0 +1,255 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/highmem.h>
+#include <linux/kprobes.h>
+
+/**
+ * flush_coherent_icache() - if a CPU has a coherent icache, flush it
+ * @addr: The base address to use (can be any valid address, the whole cache will be flushed)
+ * Return true if the cache was flushed, false otherwise
+ */
+static inline bool flush_coherent_icache(unsigned long addr)
+{
+ /*
+ * For a snooping icache, we still need a dummy icbi to purge all the
+ * prefetched instructions from the ifetch buffers. We also need a sync
+ * before the icbi to order the the actual stores to memory that might
+ * have modified instructions with the icbi.
+ */
+ if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) {
+ mb(); /* sync */
+ allow_read_from_user((const void __user *)addr, L1_CACHE_BYTES);
+ icbi((void *)addr);
+ prevent_read_from_user((const void __user *)addr, L1_CACHE_BYTES);
+ mb(); /* sync */
+ isync();
+ return true;
+ }
+
+ return false;
+}
+
+/**
+ * invalidate_icache_range() - Flush the icache by issuing icbi across an address range
+ * @start: the start address
+ * @stop: the stop address (exclusive)
+ */
+static void invalidate_icache_range(unsigned long start, unsigned long stop)
+{
+ unsigned long shift = l1_icache_shift();
+ unsigned long bytes = l1_icache_bytes();
+ char *addr = (char *)(start & ~(bytes - 1));
+ unsigned long size = stop - (unsigned long)addr + (bytes - 1);
+ unsigned long i;
+
+ for (i = 0; i < size >> shift; i++, addr += bytes)
+ icbi(addr);
+
+ mb(); /* sync */
+ isync();
+}
+
+/**
+ * flush_icache_range: Write any modified data cache blocks out to memory
+ * and invalidate the corresponding blocks in the instruction cache
+ *
+ * Generic code will call this after writing memory, before executing from it.
+ *
+ * @start: the start address
+ * @stop: the stop address (exclusive)
+ */
+void flush_icache_range(unsigned long start, unsigned long stop)
+{
+ if (flush_coherent_icache(start))
+ return;
+
+ clean_dcache_range(start, stop);
+
+ if (IS_ENABLED(CONFIG_44x)) {
+ /*
+ * Flash invalidate on 44x because we are passed kmapped
+ * addresses and this doesn't work for userspace pages due to
+ * the virtually tagged icache.
+ */
+ iccci((void *)start);
+ mb(); /* sync */
+ isync();
+ } else
+ invalidate_icache_range(start, stop);
+}
+EXPORT_SYMBOL(flush_icache_range);
+
+#if !defined(CONFIG_PPC_8xx) && !defined(CONFIG_PPC64)
+/**
+ * flush_dcache_icache_phys() - Flush a page by it's physical address
+ * @physaddr: the physical address of the page
+ */
+static void flush_dcache_icache_phys(unsigned long physaddr)
+{
+ unsigned long bytes = l1_dcache_bytes();
+ unsigned long nb = PAGE_SIZE / bytes;
+ unsigned long addr = physaddr & PAGE_MASK;
+ unsigned long msr, msr0;
+ unsigned long loop1 = addr, loop2 = addr;
+
+ msr0 = mfmsr();
+ msr = msr0 & ~MSR_DR;
+ /*
+ * This must remain as ASM to prevent potential memory accesses
+ * while the data MMU is disabled
+ */
+ asm volatile(
+ " mtctr %2;\n"
+ " mtmsr %3;\n"
+ " isync;\n"
+ "0: dcbst 0, %0;\n"
+ " addi %0, %0, %4;\n"
+ " bdnz 0b;\n"
+ " sync;\n"
+ " mtctr %2;\n"
+ "1: icbi 0, %1;\n"
+ " addi %1, %1, %4;\n"
+ " bdnz 1b;\n"
+ " sync;\n"
+ " mtmsr %5;\n"
+ " isync;\n"
+ : "+&r" (loop1), "+&r" (loop2)
+ : "r" (nb), "r" (msr), "i" (bytes), "r" (msr0)
+ : "ctr", "memory");
+}
+NOKPROBE_SYMBOL(flush_dcache_icache_phys)
+#endif // !defined(CONFIG_PPC_8xx) && !defined(CONFIG_PPC64)
+
+/*
+ * This is called when a page has been modified by the kernel.
+ * It just marks the page as not i-cache clean. We do the i-cache
+ * flush later when the page is given to a user process, if necessary.
+ */
+void flush_dcache_page(struct page *page)
+{
+ if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
+ return;
+ /* avoid an atomic op if possible */
+ if (test_bit(PG_dcache_clean, &page->flags))
+ clear_bit(PG_dcache_clean, &page->flags);
+}
+EXPORT_SYMBOL(flush_dcache_page);
+
+static void flush_dcache_icache_hugepage(struct page *page)
+{
+ int i;
+ void *start;
+
+ BUG_ON(!PageCompound(page));
+
+ for (i = 0; i < compound_nr(page); i++) {
+ if (!PageHighMem(page)) {
+ __flush_dcache_icache(page_address(page+i));
+ } else {
+ start = kmap_atomic(page+i);
+ __flush_dcache_icache(start);
+ kunmap_atomic(start);
+ }
+ }
+}
+
+void flush_dcache_icache_page(struct page *page)
+{
+
+ if (PageCompound(page))
+ return flush_dcache_icache_hugepage(page);
+
+#if defined(CONFIG_PPC_8xx) || defined(CONFIG_PPC64)
+ /* On 8xx there is no need to kmap since highmem is not supported */
+ __flush_dcache_icache(page_address(page));
+#else
+ if (IS_ENABLED(CONFIG_BOOKE) || sizeof(phys_addr_t) > sizeof(void *)) {
+ void *start = kmap_atomic(page);
+ __flush_dcache_icache(start);
+ kunmap_atomic(start);
+ } else {
+ unsigned long addr = page_to_pfn(page) << PAGE_SHIFT;
+
+ if (flush_coherent_icache(addr))
+ return;
+ flush_dcache_icache_phys(addr);
+ }
+#endif
+}
+EXPORT_SYMBOL(flush_dcache_icache_page);
+
+/**
+ * __flush_dcache_icache(): Flush a particular page from the data cache to RAM.
+ * Note: this is necessary because the instruction cache does *not*
+ * snoop from the data cache.
+ *
+ * @page: the address of the page to flush
+ */
+void __flush_dcache_icache(void *p)
+{
+ unsigned long addr = (unsigned long)p;
+
+ if (flush_coherent_icache(addr))
+ return;
+
+ clean_dcache_range(addr, addr + PAGE_SIZE);
+
+ /*
+ * We don't flush the icache on 44x. Those have a virtual icache and we
+ * don't have access to the virtual address here (it's not the page
+ * vaddr but where it's mapped in user space). The flushing of the
+ * icache on these is handled elsewhere, when a change in the address
+ * space occurs, before returning to user space.
+ */
+
+ if (mmu_has_feature(MMU_FTR_TYPE_44x))
+ return;
+
+ invalidate_icache_range(addr, addr + PAGE_SIZE);
+}
+
+void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
+{
+ clear_page(page);
+
+ /*
+ * We shouldn't have to do this, but some versions of glibc
+ * require it (ld.so assumes zero filled pages are icache clean)
+ * - Anton
+ */
+ flush_dcache_page(pg);
+}
+EXPORT_SYMBOL(clear_user_page);
+
+void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
+ struct page *pg)
+{
+ copy_page(vto, vfrom);
+
+ /*
+ * We should be able to use the following optimisation, however
+ * there are two problems.
+ * Firstly a bug in some versions of binutils meant PLT sections
+ * were not marked executable.
+ * Secondly the first word in the GOT section is blrl, used
+ * to establish the GOT address. Until recently the GOT was
+ * not marked executable.
+ * - Anton
+ */
+#if 0
+ if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
+ return;
+#endif
+
+ flush_dcache_page(pg);
+}
+
+void flush_icache_user_page(struct vm_area_struct *vma, struct page *page,
+ unsigned long addr, int len)
+{
+ unsigned long maddr;
+
+ maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
+ flush_icache_range(maddr, maddr + len);
+ kunmap(page);
+}
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 7a59a5c9aa5d..6564b4d81324 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -12,45 +12,15 @@
* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
*/
-#include <linux/export.h>
-#include <linux/sched.h>
-#include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/string.h>
-#include <linux/gfp.h>
-#include <linux/types.h>
-#include <linux/mm.h>
-#include <linux/stddef.h>
-#include <linux/init.h>
#include <linux/memblock.h>
#include <linux/highmem.h>
-#include <linux/initrd.h>
-#include <linux/pagemap.h>
#include <linux/suspend.h>
-#include <linux/hugetlb.h>
-#include <linux/slab.h>
-#include <linux/vmalloc.h>
-#include <linux/memremap.h>
#include <linux/dma-direct.h>
-#include <linux/kprobes.h>
-#include <asm/prom.h>
-#include <asm/io.h>
-#include <asm/mmu_context.h>
-#include <asm/mmu.h>
-#include <asm/smp.h>
#include <asm/machdep.h>
-#include <asm/btext.h>
-#include <asm/tlb.h>
-#include <asm/sections.h>
-#include <asm/sparsemem.h>
-#include <asm/vdso.h>
-#include <asm/fixmap.h>
-#include <asm/swiotlb.h>
#include <asm/rtas.h>
#include <asm/kasan.h>
#include <asm/svm.h>
-#include <asm/mmzone.h>
#include <mm/mmu_decl.h>
@@ -340,257 +310,6 @@ void free_initmem(void)
free_initmem_default(POISON_FREE_INITMEM);
}
-/**
- * flush_coherent_icache() - if a CPU has a coherent icache, flush it
- * @addr: The base address to use (can be any valid address, the whole cache will be flushed)
- * Return true if the cache was flushed, false otherwise
- */
-static inline bool flush_coherent_icache(unsigned long addr)
-{
- /*
- * For a snooping icache, we still need a dummy icbi to purge all the
- * prefetched instructions from the ifetch buffers. We also need a sync
- * before the icbi to order the the actual stores to memory that might
- * have modified instructions with the icbi.
- */
- if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) {
- mb(); /* sync */
- allow_read_from_user((const void __user *)addr, L1_CACHE_BYTES);
- icbi((void *)addr);
- prevent_read_from_user((const void __user *)addr, L1_CACHE_BYTES);
- mb(); /* sync */
- isync();
- return true;
- }
-
- return false;
-}
-
-/**
- * invalidate_icache_range() - Flush the icache by issuing icbi across an address range
- * @start: the start address
- * @stop: the stop address (exclusive)
- */
-static void invalidate_icache_range(unsigned long start, unsigned long stop)
-{
- unsigned long shift = l1_icache_shift();
- unsigned long bytes = l1_icache_bytes();
- char *addr = (char *)(start & ~(bytes - 1));
- unsigned long size = stop - (unsigned long)addr + (bytes - 1);
- unsigned long i;
-
- for (i = 0; i < size >> shift; i++, addr += bytes)
- icbi(addr);
-
- mb(); /* sync */
- isync();
-}
-
-/**
- * flush_icache_range: Write any modified data cache blocks out to memory
- * and invalidate the corresponding blocks in the instruction cache
- *
- * Generic code will call this after writing memory, before executing from it.
- *
- * @start: the start address
- * @stop: the stop address (exclusive)
- */
-void flush_icache_range(unsigned long start, unsigned long stop)
-{
- if (flush_coherent_icache(start))
- return;
-
- clean_dcache_range(start, stop);
-
- if (IS_ENABLED(CONFIG_44x)) {
- /*
- * Flash invalidate on 44x because we are passed kmapped
- * addresses and this doesn't work for userspace pages due to
- * the virtually tagged icache.
- */
- iccci((void *)start);
- mb(); /* sync */
- isync();
- } else
- invalidate_icache_range(start, stop);
-}
-EXPORT_SYMBOL(flush_icache_range);
-
-#if !defined(CONFIG_PPC_8xx) && !defined(CONFIG_PPC64)
-/**
- * flush_dcache_icache_phys() - Flush a page by it's physical address
- * @physaddr: the physical address of the page
- */
-static void flush_dcache_icache_phys(unsigned long physaddr)
-{
- unsigned long bytes = l1_dcache_bytes();
- unsigned long nb = PAGE_SIZE / bytes;
- unsigned long addr = physaddr & PAGE_MASK;
- unsigned long msr, msr0;
- unsigned long loop1 = addr, loop2 = addr;
-
- msr0 = mfmsr();
- msr = msr0 & ~MSR_DR;
- /*
- * This must remain as ASM to prevent potential memory accesses
- * while the data MMU is disabled
- */
- asm volatile(
- " mtctr %2;\n"
- " mtmsr %3;\n"
- " isync;\n"
- "0: dcbst 0, %0;\n"
- " addi %0, %0, %4;\n"
- " bdnz 0b;\n"
- " sync;\n"
- " mtctr %2;\n"
- "1: icbi 0, %1;\n"
- " addi %1, %1, %4;\n"
- " bdnz 1b;\n"
- " sync;\n"
- " mtmsr %5;\n"
- " isync;\n"
- : "+&r" (loop1), "+&r" (loop2)
- : "r" (nb), "r" (msr), "i" (bytes), "r" (msr0)
- : "ctr", "memory");
-}
-NOKPROBE_SYMBOL(flush_dcache_icache_phys)
-#endif // !defined(CONFIG_PPC_8xx) && !defined(CONFIG_PPC64)
-
-/*
- * This is called when a page has been modified by the kernel.
- * It just marks the page as not i-cache clean. We do the i-cache
- * flush later when the page is given to a user process, if necessary.
- */
-void flush_dcache_page(struct page *page)
-{
- if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
- return;
- /* avoid an atomic op if possible */
- if (test_bit(PG_dcache_clean, &page->flags))
- clear_bit(PG_dcache_clean, &page->flags);
-}
-EXPORT_SYMBOL(flush_dcache_page);
-
-static void flush_dcache_icache_hugepage(struct page *page)
-{
- int i;
- void *start;
-
- BUG_ON(!PageCompound(page));
-
- for (i = 0; i < compound_nr(page); i++) {
- if (!PageHighMem(page)) {
- __flush_dcache_icache(page_address(page+i));
- } else {
- start = kmap_atomic(page+i);
- __flush_dcache_icache(start);
- kunmap_atomic(start);
- }
- }
-}
-
-void flush_dcache_icache_page(struct page *page)
-{
-
- if (PageCompound(page))
- return flush_dcache_icache_hugepage(page);
-
-#if defined(CONFIG_PPC_8xx) || defined(CONFIG_PPC64)
- /* On 8xx there is no need to kmap since highmem is not supported */
- __flush_dcache_icache(page_address(page));
-#else
- if (IS_ENABLED(CONFIG_BOOKE) || sizeof(phys_addr_t) > sizeof(void *)) {
- void *start = kmap_atomic(page);
- __flush_dcache_icache(start);
- kunmap_atomic(start);
- } else {
- unsigned long addr = page_to_pfn(page) << PAGE_SHIFT;
-
- if (flush_coherent_icache(addr))
- return;
- flush_dcache_icache_phys(addr);
- }
-#endif
-}
-EXPORT_SYMBOL(flush_dcache_icache_page);
-
-/**
- * __flush_dcache_icache(): Flush a particular page from the data cache to RAM.
- * Note: this is necessary because the instruction cache does *not*
- * snoop from the data cache.
- *
- * @page: the address of the page to flush
- */
-void __flush_dcache_icache(void *p)
-{
- unsigned long addr = (unsigned long)p;
-
- if (flush_coherent_icache(addr))
- return;
-
- clean_dcache_range(addr, addr + PAGE_SIZE);
-
- /*
- * We don't flush the icache on 44x. Those have a virtual icache and we
- * don't have access to the virtual address here (it's not the page
- * vaddr but where it's mapped in user space). The flushing of the
- * icache on these is handled elsewhere, when a change in the address
- * space occurs, before returning to user space.
- */
-
- if (mmu_has_feature(MMU_FTR_TYPE_44x))
- return;
-
- invalidate_icache_range(addr, addr + PAGE_SIZE);
-}
-
-void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
-{
- clear_page(page);
-
- /*
- * We shouldn't have to do this, but some versions of glibc
- * require it (ld.so assumes zero filled pages are icache clean)
- * - Anton
- */
- flush_dcache_page(pg);
-}
-EXPORT_SYMBOL(clear_user_page);
-
-void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
- struct page *pg)
-{
- copy_page(vto, vfrom);
-
- /*
- * We should be able to use the following optimisation, however
- * there are two problems.
- * Firstly a bug in some versions of binutils meant PLT sections
- * were not marked executable.
- * Secondly the first word in the GOT section is blrl, used
- * to establish the GOT address. Until recently the GOT was
- * not marked executable.
- * - Anton
- */
-#if 0
- if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
- return;
-#endif
-
- flush_dcache_page(pg);
-}
-
-void flush_icache_user_page(struct vm_area_struct *vma, struct page *page,
- unsigned long addr, int len)
-{
- unsigned long maddr;
-
- maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
- flush_icache_range(maddr, maddr + len);
- kunmap(page);
-}
-
/*
* System memory should not be in /proc/iomem but various tools expect it
* (eg kdump).
--
2.25.0
More information about the Linuxppc-dev
mailing list