From 9999e48639b3cecb08ffb37358bcba3b48161b29 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 10 May 2024 08:50:17 +0000
Subject: [PATCH] add ax88772_rst
---
kernel/arch/mips/include/asm/pgtable-32.h | 86 ++++++++++++++++++++++++++----------------
1 files changed, 53 insertions(+), 33 deletions(-)
diff --git a/kernel/arch/mips/include/asm/pgtable-32.h b/kernel/arch/mips/include/asm/pgtable-32.h
index 215fb48..6c0532d 100644
--- a/kernel/arch/mips/include/asm/pgtable-32.h
+++ b/kernel/arch/mips/include/asm/pgtable-32.h
@@ -16,12 +16,29 @@
#include <asm/cachectl.h>
#include <asm/fixmap.h>
-#define __ARCH_USE_5LEVEL_HACK
#include <asm-generic/pgtable-nopmd.h>
#ifdef CONFIG_HIGHMEM
#include <asm/highmem.h>
#endif
+
+/*
+ * Regarding 32-bit MIPS huge page support (and the tradeoff it entails):
+ *
+ * We use the same huge page sizes as 64-bit MIPS. Assuming a 4KB page size,
+ * our 2-level table layout would normally have a PGD entry cover a contiguous
+ * 4MB virtual address region (pointing to a 4KB PTE page of 1,024 32-bit pte_t
+ * pointers, each pointing to a 4KB physical page). The problem is that 4MB,
+ * spanning both halves of a TLB EntryLo0,1 pair, requires 2MB hardware page
+ * support, not one of the standard supported sizes (1MB,4MB,16MB,...).
+ * To correct for this, when huge pages are enabled, we halve the number of
+ * pointers a PTE page holds, making its last half go to waste. Correspondingly,
+ * we double the number of PGD pages. Overall, page table memory overhead
+ * increases to match 64-bit MIPS, but PTE lookups remain CPU cache-friendly.
+ *
+ * NOTE: We don't yet support huge pages if extended-addressing is enabled
+ * (i.e. EVA, XPA, 36-bit Alchemy/Netlogic).
+ */
extern int temp_tlb_entry;
@@ -44,7 +61,12 @@
*/
/* PGDIR_SHIFT determines what a third-level page table entry can map */
-#define PGDIR_SHIFT (2 * PAGE_SHIFT + PTE_ORDER - PTE_T_LOG2)
+#if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) && !defined(CONFIG_PHYS_ADDR_T_64BIT)
+# define PGDIR_SHIFT (2 * PAGE_SHIFT + PTE_ORDER - PTE_T_LOG2 - 1)
+#else
+# define PGDIR_SHIFT (2 * PAGE_SHIFT + PTE_ORDER - PTE_T_LOG2)
+#endif
+
#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
#define PGDIR_MASK (~(PGDIR_SIZE-1))
@@ -52,14 +74,23 @@
* Entries per page directory level: we use two-level, so
* we don't really have any PUD/PMD directory physically.
*/
-#define __PGD_ORDER (32 - 3 * PAGE_SHIFT + PGD_T_LOG2 + PTE_T_LOG2)
+#if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) && !defined(CONFIG_PHYS_ADDR_T_64BIT)
+# define __PGD_ORDER (32 - 3 * PAGE_SHIFT + PGD_T_LOG2 + PTE_T_LOG2 + 1)
+#else
+# define __PGD_ORDER (32 - 3 * PAGE_SHIFT + PGD_T_LOG2 + PTE_T_LOG2)
+#endif
+
#define PGD_ORDER (__PGD_ORDER >= 0 ? __PGD_ORDER : 0)
#define PUD_ORDER aieeee_attempt_to_allocate_pud
-#define PMD_ORDER 1
+#define PMD_ORDER aieeee_attempt_to_allocate_pmd
#define PTE_ORDER 0
#define PTRS_PER_PGD (USER_PTRS_PER_PGD * 2)
-#define PTRS_PER_PTE ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t))
+#if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) && !defined(CONFIG_PHYS_ADDR_T_64BIT)
+# define PTRS_PER_PTE ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t) / 2)
+#else
+# define PTRS_PER_PTE ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t))
+#endif
#define USER_PTRS_PER_PGD (0x80000000UL/PGDIR_SIZE)
#define FIRST_USER_ADDRESS 0UL
@@ -87,7 +118,7 @@
extern void load_pgd(unsigned long pg_dir);
-extern pte_t invalid_pte_table[PAGE_SIZE/sizeof(pte_t)];
+extern pte_t invalid_pte_table[PTRS_PER_PTE];
/*
* Empty pgd/pmd entries point to the invalid_pte_table.
@@ -97,7 +128,19 @@
return pmd_val(pmd) == (unsigned long) invalid_pte_table;
}
-#define pmd_bad(pmd) (pmd_val(pmd) & ~PAGE_MASK)
+static inline int pmd_bad(pmd_t pmd)
+{
+#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
+ /* pmd_huge(pmd) but inline */
+ if (unlikely(pmd_val(pmd) & _PAGE_HUGE))
+ return 0;
+#endif
+
+ if (unlikely(pmd_val(pmd) & ~PAGE_MASK))
+ return 1;
+
+ return 0;
+}
static inline int pmd_present(pmd_t pmd)
{
@@ -149,36 +192,13 @@
#else
#define pte_pfn(x) ((unsigned long)((x).pte >> _PFN_SHIFT))
#define pfn_pte(pfn, prot) __pte(((unsigned long long)(pfn) << _PFN_SHIFT) | pgprot_val(prot))
+#define pfn_pmd(pfn, prot) __pmd(((unsigned long long)(pfn) << _PFN_SHIFT) | pgprot_val(prot))
#endif
#endif /* defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32) */
#define pte_page(x) pfn_to_page(pte_pfn(x))
-#define __pgd_offset(address) pgd_index(address)
-#define __pud_offset(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
-#define __pmd_offset(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
-
-/* to find an entry in a kernel page-table-directory */
-#define pgd_offset_k(address) pgd_offset(&init_mm, address)
-
-#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
-
-/* to find an entry in a page-table-directory */
-#define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr))
-
-/* Find an entry in the third-level page table.. */
-#define __pte_offset(address) \
- (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
-#define pte_offset(dir, address) \
- ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address))
-#define pte_offset_kernel(dir, address) \
- ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address))
-
-#define pte_offset_map(dir, address) \
- ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address))
-#define pte_unmap(pte) ((void)(pte))
-
-#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
+#if defined(CONFIG_CPU_R3K_TLB)
/* Swap entries must have VALID bit cleared. */
#define __swp_type(x) (((x).val >> 10) & 0x1f)
@@ -223,6 +243,6 @@
#endif /* defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32) */
-#endif /* defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX) */
+#endif /* defined(CONFIG_CPU_R3K_TLB) */
#endif /* _ASM_PGTABLE_32_H */
--
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