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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /arch/xtensa/mm/mmu.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/xtensa/mm/mmu.c')
-rw-r--r--arch/xtensa/mm/mmu.c119
1 files changed, 119 insertions, 0 deletions
diff --git a/arch/xtensa/mm/mmu.c b/arch/xtensa/mm/mmu.c
new file mode 100644
index 0000000000..92e158c69c
--- /dev/null
+++ b/arch/xtensa/mm/mmu.c
@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * xtensa mmu stuff
+ *
+ * Extracted from init.c
+ */
+#include <linux/memblock.h>
+#include <linux/percpu.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/cache.h>
+
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+#include <asm/mmu_context.h>
+#include <asm/page.h>
+#include <asm/initialize_mmu.h>
+#include <asm/io.h>
+
+DEFINE_PER_CPU(unsigned long, asid_cache) = ASID_USER_FIRST;
+
+#if defined(CONFIG_HIGHMEM)
+static void * __init init_pmd(unsigned long vaddr, unsigned long n_pages)
+{
+ pmd_t *pmd = pmd_off_k(vaddr);
+ pte_t *pte;
+ unsigned long i;
+
+ n_pages = ALIGN(n_pages, PTRS_PER_PTE);
+
+ pr_debug("%s: vaddr: 0x%08lx, n_pages: %ld\n",
+ __func__, vaddr, n_pages);
+
+ pte = memblock_alloc_low(n_pages * sizeof(pte_t), PAGE_SIZE);
+ if (!pte)
+ panic("%s: Failed to allocate %lu bytes align=%lx\n",
+ __func__, n_pages * sizeof(pte_t), PAGE_SIZE);
+
+ for (i = 0; i < n_pages; ++i)
+ pte_clear(NULL, 0, pte + i);
+
+ for (i = 0; i < n_pages; i += PTRS_PER_PTE, ++pmd) {
+ pte_t *cur_pte = pte + i;
+
+ BUG_ON(!pmd_none(*pmd));
+ set_pmd(pmd, __pmd(((unsigned long)cur_pte) & PAGE_MASK));
+ BUG_ON(cur_pte != pte_offset_kernel(pmd, 0));
+ pr_debug("%s: pmd: 0x%p, pte: 0x%p\n",
+ __func__, pmd, cur_pte);
+ }
+ return pte;
+}
+
+static void __init fixedrange_init(void)
+{
+ BUILD_BUG_ON(FIXADDR_START < TLBTEMP_BASE_1 + TLBTEMP_SIZE);
+ init_pmd(FIXADDR_START, __end_of_fixed_addresses);
+}
+#endif
+
+void __init paging_init(void)
+{
+#ifdef CONFIG_HIGHMEM
+ fixedrange_init();
+ pkmap_page_table = init_pmd(PKMAP_BASE, LAST_PKMAP);
+ kmap_init();
+#endif
+}
+
+/*
+ * Flush the mmu and reset associated register to default values.
+ */
+void init_mmu(void)
+{
+#if !(XCHAL_HAVE_PTP_MMU && XCHAL_HAVE_SPANNING_WAY)
+ /*
+ * Writing zeros to the instruction and data TLBCFG special
+ * registers ensure that valid values exist in the register.
+ *
+ * For existing PGSZID<w> fields, zero selects the first element
+ * of the page-size array. For nonexistent PGSZID<w> fields,
+ * zero is the best value to write. Also, when changing PGSZID<w>
+ * fields, the corresponding TLB must be flushed.
+ */
+ set_itlbcfg_register(0);
+ set_dtlbcfg_register(0);
+#endif
+ init_kio();
+ local_flush_tlb_all();
+
+ /* Set rasid register to a known value. */
+
+ set_rasid_register(ASID_INSERT(ASID_USER_FIRST));
+
+ /* Set PTEVADDR special register to the start of the page
+ * table, which is in kernel mappable space (ie. not
+ * statically mapped). This register's value is undefined on
+ * reset.
+ */
+ set_ptevaddr_register(XCHAL_PAGE_TABLE_VADDR);
+}
+
+void init_kio(void)
+{
+#if XCHAL_HAVE_PTP_MMU && XCHAL_HAVE_SPANNING_WAY && defined(CONFIG_USE_OF)
+ /*
+ * Update the IO area mapping in case xtensa_kio_paddr has changed
+ */
+ write_dtlb_entry(__pte(xtensa_kio_paddr + CA_WRITEBACK),
+ XCHAL_KIO_CACHED_VADDR + 6);
+ write_itlb_entry(__pte(xtensa_kio_paddr + CA_WRITEBACK),
+ XCHAL_KIO_CACHED_VADDR + 6);
+ write_dtlb_entry(__pte(xtensa_kio_paddr + CA_BYPASS),
+ XCHAL_KIO_BYPASS_VADDR + 6);
+ write_itlb_entry(__pte(xtensa_kio_paddr + CA_BYPASS),
+ XCHAL_KIO_BYPASS_VADDR + 6);
+#endif
+}