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Diffstat (limited to 'arch/parisc/kernel/cache.c')
-rw-r--r--arch/parisc/kernel/cache.c413
1 files changed, 259 insertions, 154 deletions
diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c
index 422f3e1e6d9c..483bfafd930c 100644
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -20,6 +20,7 @@
#include <linux/sched.h>
#include <linux/sched/mm.h>
#include <linux/syscalls.h>
+#include <linux/vmalloc.h>
#include <asm/pdc.h>
#include <asm/cache.h>
#include <asm/cacheflush.h>
@@ -31,20 +32,31 @@
#include <asm/mmu_context.h>
#include <asm/cachectl.h>
+#define PTR_PAGE_ALIGN_DOWN(addr) PTR_ALIGN_DOWN(addr, PAGE_SIZE)
+
+/*
+ * When nonzero, use _PAGE_ACCESSED bit to try to reduce the number
+ * of page flushes done flush_cache_page_if_present. There are some
+ * pros and cons in using this option. It may increase the risk of
+ * random segmentation faults.
+ */
+#define CONFIG_FLUSH_PAGE_ACCESSED 0
+
int split_tlb __ro_after_init;
int dcache_stride __ro_after_init;
int icache_stride __ro_after_init;
EXPORT_SYMBOL(dcache_stride);
+/* Internal implementation in arch/parisc/kernel/pacache.S */
void flush_dcache_page_asm(unsigned long phys_addr, unsigned long vaddr);
EXPORT_SYMBOL(flush_dcache_page_asm);
void purge_dcache_page_asm(unsigned long phys_addr, unsigned long vaddr);
void flush_icache_page_asm(unsigned long phys_addr, unsigned long vaddr);
-
-/* Internal implementation in arch/parisc/kernel/pacache.S */
void flush_data_cache_local(void *); /* flushes local data-cache only */
void flush_instruction_cache_local(void); /* flushes local code-cache only */
+static void flush_kernel_dcache_page_addr(const void *addr);
+
/* On some machines (i.e., ones with the Merced bus), there can be
* only a single PxTLB broadcast at a time; this must be guaranteed
* by software. We need a spinlock around all TLB flushes to ensure
@@ -321,6 +333,18 @@ __flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr,
{
if (!static_branch_likely(&parisc_has_cache))
return;
+
+ /*
+ * The TLB is the engine of coherence on parisc. The CPU is
+ * entitled to speculate any page with a TLB mapping, so here
+ * we kill the mapping then flush the page along a special flush
+ * only alias mapping. This guarantees that the page is no-longer
+ * in the cache for any process and nor may it be speculatively
+ * read in (until the user or kernel specifically accesses it,
+ * of course).
+ */
+ flush_tlb_page(vma, vmaddr);
+
preempt_disable();
flush_dcache_page_asm(physaddr, vmaddr);
if (vma->vm_flags & VM_EXEC)
@@ -328,46 +352,44 @@ __flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr,
preempt_enable();
}
-static void flush_user_cache_page(struct vm_area_struct *vma, unsigned long vmaddr)
+static void flush_kernel_dcache_page_addr(const void *addr)
{
- unsigned long flags, space, pgd, prot;
-#ifdef CONFIG_TLB_PTLOCK
- unsigned long pgd_lock;
-#endif
+ unsigned long vaddr = (unsigned long)addr;
+ unsigned long flags;
- vmaddr &= PAGE_MASK;
+ /* Purge TLB entry to remove translation on all CPUs */
+ purge_tlb_start(flags);
+ pdtlb(SR_KERNEL, addr);
+ purge_tlb_end(flags);
+ /* Use tmpalias flush to prevent data cache move-in */
preempt_disable();
+ flush_dcache_page_asm(__pa(vaddr), vaddr);
+ preempt_enable();
+}
- /* Set context for flush */
- local_irq_save(flags);
- prot = mfctl(8);
- space = mfsp(SR_USER);
- pgd = mfctl(25);
-#ifdef CONFIG_TLB_PTLOCK
- pgd_lock = mfctl(28);
-#endif
- switch_mm_irqs_off(NULL, vma->vm_mm, NULL);
- local_irq_restore(flags);
-
- flush_user_dcache_range_asm(vmaddr, vmaddr + PAGE_SIZE);
- if (vma->vm_flags & VM_EXEC)
- flush_user_icache_range_asm(vmaddr, vmaddr + PAGE_SIZE);
- flush_tlb_page(vma, vmaddr);
+static void flush_kernel_icache_page_addr(const void *addr)
+{
+ unsigned long vaddr = (unsigned long)addr;
+ unsigned long flags;
- /* Restore previous context */
- local_irq_save(flags);
-#ifdef CONFIG_TLB_PTLOCK
- mtctl(pgd_lock, 28);
-#endif
- mtctl(pgd, 25);
- mtsp(space, SR_USER);
- mtctl(prot, 8);
- local_irq_restore(flags);
+ /* Purge TLB entry to remove translation on all CPUs */
+ purge_tlb_start(flags);
+ pdtlb(SR_KERNEL, addr);
+ purge_tlb_end(flags);
+ /* Use tmpalias flush to prevent instruction cache move-in */
+ preempt_disable();
+ flush_icache_page_asm(__pa(vaddr), vaddr);
preempt_enable();
}
+void kunmap_flush_on_unmap(const void *addr)
+{
+ flush_kernel_dcache_page_addr(addr);
+}
+EXPORT_SYMBOL(kunmap_flush_on_unmap);
+
void flush_icache_pages(struct vm_area_struct *vma, struct page *page,
unsigned int nr)
{
@@ -375,13 +397,16 @@ void flush_icache_pages(struct vm_area_struct *vma, struct page *page,
for (;;) {
flush_kernel_dcache_page_addr(kaddr);
- flush_kernel_icache_page(kaddr);
+ flush_kernel_icache_page_addr(kaddr);
if (--nr == 0)
break;
kaddr += PAGE_SIZE;
}
}
+/*
+ * Walk page directory for MM to find PTEP pointer for address ADDR.
+ */
static inline pte_t *get_ptep(struct mm_struct *mm, unsigned long addr)
{
pte_t *ptep = NULL;
@@ -410,6 +435,41 @@ static inline bool pte_needs_flush(pte_t pte)
== (_PAGE_PRESENT | _PAGE_ACCESSED);
}
+/*
+ * Return user physical address. Returns 0 if page is not present.
+ */
+static inline unsigned long get_upa(struct mm_struct *mm, unsigned long addr)
+{
+ unsigned long flags, space, pgd, prot, pa;
+#ifdef CONFIG_TLB_PTLOCK
+ unsigned long pgd_lock;
+#endif
+
+ /* Save context */
+ local_irq_save(flags);
+ prot = mfctl(8);
+ space = mfsp(SR_USER);
+ pgd = mfctl(25);
+#ifdef CONFIG_TLB_PTLOCK
+ pgd_lock = mfctl(28);
+#endif
+
+ /* Set context for lpa_user */
+ switch_mm_irqs_off(NULL, mm, NULL);
+ pa = lpa_user(addr);
+
+ /* Restore previous context */
+#ifdef CONFIG_TLB_PTLOCK
+ mtctl(pgd_lock, 28);
+#endif
+ mtctl(pgd, 25);
+ mtsp(space, SR_USER);
+ mtctl(prot, 8);
+ local_irq_restore(flags);
+
+ return pa;
+}
+
void flush_dcache_folio(struct folio *folio)
{
struct address_space *mapping = folio_flush_mapping(folio);
@@ -458,50 +518,23 @@ void flush_dcache_folio(struct folio *folio)
if (addr + nr * PAGE_SIZE > vma->vm_end)
nr = (vma->vm_end - addr) / PAGE_SIZE;
- if (parisc_requires_coherency()) {
- for (i = 0; i < nr; i++) {
- pte_t *ptep = get_ptep(vma->vm_mm,
- addr + i * PAGE_SIZE);
- if (!ptep)
- continue;
- if (pte_needs_flush(*ptep))
- flush_user_cache_page(vma,
- addr + i * PAGE_SIZE);
- /* Optimise accesses to the same table? */
- pte_unmap(ptep);
- }
- } else {
+ if (old_addr == 0 || (old_addr & (SHM_COLOUR - 1))
+ != (addr & (SHM_COLOUR - 1))) {
+ for (i = 0; i < nr; i++)
+ __flush_cache_page(vma,
+ addr + i * PAGE_SIZE,
+ (pfn + i) * PAGE_SIZE);
/*
- * The TLB is the engine of coherence on parisc:
- * The CPU is entitled to speculate any page
- * with a TLB mapping, so here we kill the
- * mapping then flush the page along a special
- * flush only alias mapping. This guarantees that
- * the page is no-longer in the cache for any
- * process and nor may it be speculatively read
- * in (until the user or kernel specifically
- * accesses it, of course)
+ * Software is allowed to have any number
+ * of private mappings to a page.
*/
- for (i = 0; i < nr; i++)
- flush_tlb_page(vma, addr + i * PAGE_SIZE);
- if (old_addr == 0 || (old_addr & (SHM_COLOUR - 1))
- != (addr & (SHM_COLOUR - 1))) {
- for (i = 0; i < nr; i++)
- __flush_cache_page(vma,
- addr + i * PAGE_SIZE,
- (pfn + i) * PAGE_SIZE);
- /*
- * Software is allowed to have any number
- * of private mappings to a page.
- */
- if (!(vma->vm_flags & VM_SHARED))
- continue;
- if (old_addr)
- pr_err("INEQUIVALENT ALIASES 0x%lx and 0x%lx in file %pD\n",
- old_addr, addr, vma->vm_file);
- if (nr == folio_nr_pages(folio))
- old_addr = addr;
- }
+ if (!(vma->vm_flags & VM_SHARED))
+ continue;
+ if (old_addr)
+ pr_err("INEQUIVALENT ALIASES 0x%lx and 0x%lx in file %pD\n",
+ old_addr, addr, vma->vm_file);
+ if (nr == folio_nr_pages(folio))
+ old_addr = addr;
}
WARN_ON(++count == 4096);
}
@@ -591,35 +624,28 @@ extern void purge_kernel_dcache_page_asm(unsigned long);
extern void clear_user_page_asm(void *, unsigned long);
extern void copy_user_page_asm(void *, void *, unsigned long);
-void flush_kernel_dcache_page_addr(const void *addr)
-{
- unsigned long flags;
-
- flush_kernel_dcache_page_asm(addr);
- purge_tlb_start(flags);
- pdtlb(SR_KERNEL, addr);
- purge_tlb_end(flags);
-}
-EXPORT_SYMBOL(flush_kernel_dcache_page_addr);
-
static void flush_cache_page_if_present(struct vm_area_struct *vma,
- unsigned long vmaddr, unsigned long pfn)
+ unsigned long vmaddr)
{
+#if CONFIG_FLUSH_PAGE_ACCESSED
bool needs_flush = false;
- pte_t *ptep;
+ pte_t *ptep, pte;
- /*
- * The pte check is racy and sometimes the flush will trigger
- * a non-access TLB miss. Hopefully, the page has already been
- * flushed.
- */
ptep = get_ptep(vma->vm_mm, vmaddr);
if (ptep) {
- needs_flush = pte_needs_flush(*ptep);
+ pte = ptep_get(ptep);
+ needs_flush = pte_needs_flush(pte);
pte_unmap(ptep);
}
if (needs_flush)
- flush_cache_page(vma, vmaddr, pfn);
+ __flush_cache_page(vma, vmaddr, PFN_PHYS(pte_pfn(pte)));
+#else
+ struct mm_struct *mm = vma->vm_mm;
+ unsigned long physaddr = get_upa(mm, vmaddr);
+
+ if (physaddr)
+ __flush_cache_page(vma, vmaddr, PAGE_ALIGN_DOWN(physaddr));
+#endif
}
void copy_user_highpage(struct page *to, struct page *from,
@@ -629,7 +655,7 @@ void copy_user_highpage(struct page *to, struct page *from,
kfrom = kmap_local_page(from);
kto = kmap_local_page(to);
- flush_cache_page_if_present(vma, vaddr, page_to_pfn(from));
+ __flush_cache_page(vma, vaddr, PFN_PHYS(page_to_pfn(from)));
copy_page_asm(kto, kfrom);
kunmap_local(kto);
kunmap_local(kfrom);
@@ -638,16 +664,17 @@ void copy_user_highpage(struct page *to, struct page *from,
void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
unsigned long user_vaddr, void *dst, void *src, int len)
{
- flush_cache_page_if_present(vma, user_vaddr, page_to_pfn(page));
+ __flush_cache_page(vma, user_vaddr, PFN_PHYS(page_to_pfn(page)));
memcpy(dst, src, len);
- flush_kernel_dcache_range_asm((unsigned long)dst, (unsigned long)dst + len);
+ flush_kernel_dcache_page_addr(PTR_PAGE_ALIGN_DOWN(dst));
}
void copy_from_user_page(struct vm_area_struct *vma, struct page *page,
unsigned long user_vaddr, void *dst, void *src, int len)
{
- flush_cache_page_if_present(vma, user_vaddr, page_to_pfn(page));
+ __flush_cache_page(vma, user_vaddr, PFN_PHYS(page_to_pfn(page)));
memcpy(dst, src, len);
+ flush_kernel_dcache_page_addr(PTR_PAGE_ALIGN_DOWN(src));
}
/* __flush_tlb_range()
@@ -681,32 +708,10 @@ int __flush_tlb_range(unsigned long sid, unsigned long start,
static void flush_cache_pages(struct vm_area_struct *vma, unsigned long start, unsigned long end)
{
- unsigned long addr, pfn;
- pte_t *ptep;
-
- for (addr = start; addr < end; addr += PAGE_SIZE) {
- bool needs_flush = false;
- /*
- * The vma can contain pages that aren't present. Although
- * the pte search is expensive, we need the pte to find the
- * page pfn and to check whether the page should be flushed.
- */
- ptep = get_ptep(vma->vm_mm, addr);
- if (ptep) {
- needs_flush = pte_needs_flush(*ptep);
- pfn = pte_pfn(*ptep);
- pte_unmap(ptep);
- }
- if (needs_flush) {
- if (parisc_requires_coherency()) {
- flush_user_cache_page(vma, addr);
- } else {
- if (WARN_ON(!pfn_valid(pfn)))
- return;
- __flush_cache_page(vma, addr, PFN_PHYS(pfn));
- }
- }
- }
+ unsigned long addr;
+
+ for (addr = start; addr < end; addr += PAGE_SIZE)
+ flush_cache_page_if_present(vma, addr);
}
static inline unsigned long mm_total_size(struct mm_struct *mm)
@@ -757,21 +762,19 @@ void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned
if (WARN_ON(IS_ENABLED(CONFIG_SMP) && arch_irqs_disabled()))
return;
flush_tlb_range(vma, start, end);
- flush_cache_all();
+ if (vma->vm_flags & VM_EXEC)
+ flush_cache_all();
+ else
+ flush_data_cache();
return;
}
- flush_cache_pages(vma, start, end);
+ flush_cache_pages(vma, start & PAGE_MASK, end);
}
void flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr, unsigned long pfn)
{
- if (WARN_ON(!pfn_valid(pfn)))
- return;
- if (parisc_requires_coherency())
- flush_user_cache_page(vma, vmaddr);
- else
- __flush_cache_page(vma, vmaddr, PFN_PHYS(pfn));
+ __flush_cache_page(vma, vmaddr, PFN_PHYS(pfn));
}
void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
@@ -779,34 +782,133 @@ void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned lon
if (!PageAnon(page))
return;
- if (parisc_requires_coherency()) {
- if (vma->vm_flags & VM_SHARED)
- flush_data_cache();
- else
- flush_user_cache_page(vma, vmaddr);
+ __flush_cache_page(vma, vmaddr, PFN_PHYS(page_to_pfn(page)));
+}
+
+int ptep_clear_flush_young(struct vm_area_struct *vma, unsigned long addr,
+ pte_t *ptep)
+{
+ pte_t pte = ptep_get(ptep);
+
+ if (!pte_young(pte))
+ return 0;
+ set_pte(ptep, pte_mkold(pte));
+#if CONFIG_FLUSH_PAGE_ACCESSED
+ __flush_cache_page(vma, addr, PFN_PHYS(pte_pfn(pte)));
+#endif
+ return 1;
+}
+
+/*
+ * After a PTE is cleared, we have no way to flush the cache for
+ * the physical page. On PA8800 and PA8900 processors, these lines
+ * can cause random cache corruption. Thus, we must flush the cache
+ * as well as the TLB when clearing a PTE that's valid.
+ */
+pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long addr,
+ pte_t *ptep)
+{
+ struct mm_struct *mm = (vma)->vm_mm;
+ pte_t pte = ptep_get_and_clear(mm, addr, ptep);
+ unsigned long pfn = pte_pfn(pte);
+
+ if (pfn_valid(pfn))
+ __flush_cache_page(vma, addr, PFN_PHYS(pfn));
+ else if (pte_accessible(mm, pte))
+ flush_tlb_page(vma, addr);
+
+ return pte;
+}
+
+/*
+ * The physical address for pages in the ioremap case can be obtained
+ * from the vm_struct struct. I wasn't able to successfully handle the
+ * vmalloc and vmap cases. We have an array of struct page pointers in
+ * the uninitialized vmalloc case but the flush failed using page_to_pfn.
+ */
+void flush_cache_vmap(unsigned long start, unsigned long end)
+{
+ unsigned long addr, physaddr;
+ struct vm_struct *vm;
+
+ /* Prevent cache move-in */
+ flush_tlb_kernel_range(start, end);
+
+ if (end - start >= parisc_cache_flush_threshold) {
+ flush_cache_all();
return;
}
- flush_tlb_page(vma, vmaddr);
- preempt_disable();
- flush_dcache_page_asm(page_to_phys(page), vmaddr);
- preempt_enable();
+ if (WARN_ON_ONCE(!is_vmalloc_addr((void *)start))) {
+ flush_cache_all();
+ return;
+ }
+
+ vm = find_vm_area((void *)start);
+ if (WARN_ON_ONCE(!vm)) {
+ flush_cache_all();
+ return;
+ }
+
+ /* The physical addresses of IOREMAP regions are contiguous */
+ if (vm->flags & VM_IOREMAP) {
+ physaddr = vm->phys_addr;
+ for (addr = start; addr < end; addr += PAGE_SIZE) {
+ preempt_disable();
+ flush_dcache_page_asm(physaddr, start);
+ flush_icache_page_asm(physaddr, start);
+ preempt_enable();
+ physaddr += PAGE_SIZE;
+ }
+ return;
+ }
+
+ flush_cache_all();
}
+EXPORT_SYMBOL(flush_cache_vmap);
+/*
+ * The vm_struct has been retired and the page table is set up. The
+ * last page in the range is a guard page. Its physical address can't
+ * be determined using lpa, so there is no way to flush the range
+ * using flush_dcache_page_asm.
+ */
+void flush_cache_vunmap(unsigned long start, unsigned long end)
+{
+ /* Prevent cache move-in */
+ flush_tlb_kernel_range(start, end);
+ flush_data_cache();
+}
+EXPORT_SYMBOL(flush_cache_vunmap);
+
+/*
+ * On systems with PA8800/PA8900 processors, there is no way to flush
+ * a vmap range other than using the architected loop to flush the
+ * entire cache. The page directory is not set up, so we can't use
+ * fdc, etc. FDCE/FICE don't work to flush a portion of the cache.
+ * L2 is physically indexed but FDCE/FICE instructions in virtual
+ * mode output their virtual address on the core bus, not their
+ * real address. As a result, the L2 cache index formed from the
+ * virtual address will most likely not be the same as the L2 index
+ * formed from the real address.
+ */
void flush_kernel_vmap_range(void *vaddr, int size)
{
unsigned long start = (unsigned long)vaddr;
unsigned long end = start + size;
- if ((!IS_ENABLED(CONFIG_SMP) || !arch_irqs_disabled()) &&
- (unsigned long)size >= parisc_cache_flush_threshold) {
- flush_tlb_kernel_range(start, end);
- flush_data_cache();
+ flush_tlb_kernel_range(start, end);
+
+ if (!static_branch_likely(&parisc_has_dcache))
+ return;
+
+ /* If interrupts are disabled, we can only do local flush */
+ if (WARN_ON(IS_ENABLED(CONFIG_SMP) && arch_irqs_disabled())) {
+ flush_data_cache_local(NULL);
return;
}
- flush_kernel_dcache_range_asm(start, end);
- flush_tlb_kernel_range(start, end);
+ flush_data_cache();
}
EXPORT_SYMBOL(flush_kernel_vmap_range);
@@ -818,15 +920,18 @@ void invalidate_kernel_vmap_range(void *vaddr, int size)
/* Ensure DMA is complete */
asm_syncdma();
- if ((!IS_ENABLED(CONFIG_SMP) || !arch_irqs_disabled()) &&
- (unsigned long)size >= parisc_cache_flush_threshold) {
- flush_tlb_kernel_range(start, end);
- flush_data_cache();
+ flush_tlb_kernel_range(start, end);
+
+ if (!static_branch_likely(&parisc_has_dcache))
+ return;
+
+ /* If interrupts are disabled, we can only do local flush */
+ if (WARN_ON(IS_ENABLED(CONFIG_SMP) && arch_irqs_disabled())) {
+ flush_data_cache_local(NULL);
return;
}
- purge_kernel_dcache_range_asm(start, end);
- flush_tlb_kernel_range(start, end);
+ flush_data_cache();
}
EXPORT_SYMBOL(invalidate_kernel_vmap_range);