1 files changed, 99 insertions, 0 deletions
diff --git a/arch/openrisc/mm/cache.c b/arch/openrisc/mm/cache.c
new file mode 100644
index 000000000000..f33df46dae4e
--- /dev/null
+++ b/arch/openrisc/mm/cache.c
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * OpenRISC cache.c
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * Modifications for the OpenRISC architecture:
+ * Copyright (C) 2015 Jan Henrik Weinstock <jan.weinstock@rwth-aachen.de>
+ */
+
+#include <asm/spr.h>
+#include <asm/spr_defs.h>
+#include <asm/cache.h>
+#include <asm/cacheflush.h>
+#include <asm/cpuinfo.h>
+#include <asm/tlbflush.h>
+
+/*
+ * Check if the cache component exists.
+ */
+bool cpu_cache_is_present(const unsigned int cache_type)
+{
+	unsigned long upr = mfspr(SPR_UPR);
+	unsigned long mask = SPR_UPR_UP | cache_type;
+
+	return !((upr & mask) ^ mask);
+}
+
+static __always_inline void cache_loop(unsigned long paddr, unsigned long end,
+				       const unsigned short reg, const unsigned int cache_type)
+{
+	if (!cpu_cache_is_present(cache_type))
+		return;
+
+	while (paddr < end) {
+		mtspr(reg, paddr);
+		paddr += L1_CACHE_BYTES;
+	}
+}
+
+static __always_inline void cache_loop_page(struct page *page, const unsigned short reg,
+					    const unsigned int cache_type)
+{
+	unsigned long paddr = page_to_pfn(page) << PAGE_SHIFT;
+	unsigned long end = paddr + PAGE_SIZE;
+
+	paddr &= ~(L1_CACHE_BYTES - 1);
+
+	cache_loop(paddr, end, reg, cache_type);
+}
+
+void local_dcache_page_flush(struct page *page)
+{
+	cache_loop_page(page, SPR_DCBFR, SPR_UPR_DCP);
+}
+EXPORT_SYMBOL(local_dcache_page_flush);
+
+void local_icache_page_inv(struct page *page)
+{
+	cache_loop_page(page, SPR_ICBIR, SPR_UPR_ICP);
+}
+EXPORT_SYMBOL(local_icache_page_inv);
+
+void local_dcache_range_flush(unsigned long start, unsigned long end)
+{
+	cache_loop(start, end, SPR_DCBFR, SPR_UPR_DCP);
+}
+
+void local_dcache_range_inv(unsigned long start, unsigned long end)
+{
+	cache_loop(start, end, SPR_DCBIR, SPR_UPR_DCP);
+}
+
+void local_icache_range_inv(unsigned long start, unsigned long end)
+{
+	cache_loop(start, end, SPR_ICBIR, SPR_UPR_ICP);
+}
+
+void update_cache(struct vm_area_struct *vma, unsigned long address,
+	pte_t *pte)
+{
+	unsigned long pfn = pte_val(*pte) >> PAGE_SHIFT;
+	struct folio *folio = page_folio(pfn_to_page(pfn));
+	int dirty = !test_and_set_bit(PG_dc_clean, &folio->flags.f);
+
+	/*
+	 * Since icaches do not snoop for updated data on OpenRISC, we
+	 * must write back and invalidate any dirty pages manually. We
+	 * can skip data pages, since they will not end up in icaches.
+	 */
+	if ((vma->vm_flags & VM_EXEC) && dirty) {
+		unsigned int nr = folio_nr_pages(folio);
+
+		while (nr--)
+			sync_icache_dcache(folio_page(folio, nr));
+	}
+}