[nuttx] branch master updated: riscv_addrenv_utils.c: Determine page table flags by type of vaddr

[xiaoxiang]

This is an automated email from the ASF dual-hosted git repository.

xiaoxiang pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/nuttx.git


The following commit(s) were added to refs/heads/master by this push:
     new 7901ed0fe3 riscv_addrenv_utils.c: Determine page table flags by type 
of vaddr
7901ed0fe3 is described below

commit 7901ed0fe3a99c27ee03e26f8578a50fe0264c5e
Author: Ville Juven <ville.ju...@unikie.com>
AuthorDate: Wed Oct 4 15:54:49 2023 +0300

    riscv_addrenv_utils.c: Determine page table flags by type of vaddr
    
    Use kernel page table flags if the mapped virtual address is in kernel
    space.
---
 arch/risc-v/src/common/riscv_addrenv_utils.c | 24 ++++++++++++++++++++++--
 arch/risc-v/src/common/riscv_mmu.h           |  4 ++++
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/arch/risc-v/src/common/riscv_addrenv_utils.c 
b/arch/risc-v/src/common/riscv_addrenv_utils.c
index 810563aedd..e13fb89ff9 100644
--- a/arch/risc-v/src/common/riscv_addrenv_utils.c
+++ b/arch/risc-v/src/common/riscv_addrenv_utils.c
@@ -63,13 +63,22 @@ uintptr_t riscv_get_pgtable(arch_addrenv_t *addrenv, 
uintptr_t vaddr)
   uintptr_t paddr;
   uintptr_t ptprev;
   uint32_t  ptlevel;
+  uint32_t  flags;
 
   /* Get the current level MAX_LEVELS-1 entry corresponding to this vaddr */
 
   ptlevel = ARCH_SPGTS;
   ptprev  = riscv_pgvaddr(addrenv->spgtables[ARCH_SPGTS - 1]);
-  paddr   = mmu_pte_to_paddr(mmu_ln_getentry(ptlevel, ptprev, vaddr));
+  if (!ptprev)
+    {
+      /* Something is very wrong */
+
+      return 0;
+    }
+
+  /* Find the physical address of the final level page table */
 
+  paddr = mmu_pte_to_paddr(mmu_ln_getentry(ptlevel, ptprev, vaddr));
   if (!paddr)
     {
       /* No page table has been allocated... allocate one now */
@@ -77,10 +86,21 @@ uintptr_t riscv_get_pgtable(arch_addrenv_t *addrenv, 
uintptr_t vaddr)
       paddr = mm_pgalloc(1);
       if (paddr)
         {
+          /* Determine page table flags */
+
+          if (riscv_uservaddr(vaddr))
+            {
+              flags = MMU_UPGT_FLAGS;
+            }
+          else
+            {
+              flags = MMU_KPGT_FLAGS;
+            }
+
           /* Wipe the page and assign it */
 
           riscv_pgwipe(paddr);
-          mmu_ln_setentry(ptlevel, ptprev, paddr, vaddr, MMU_UPGT_FLAGS);
+          mmu_ln_setentry(ptlevel, ptprev, paddr, vaddr, flags);
         }
     }
 
diff --git a/arch/risc-v/src/common/riscv_mmu.h 
b/arch/risc-v/src/common/riscv_mmu.h
index 0c0c6b5373..6c9d1baebb 100644
--- a/arch/risc-v/src/common/riscv_mmu.h
+++ b/arch/risc-v/src/common/riscv_mmu.h
@@ -59,6 +59,10 @@
 
 #define MMU_IO_FLAGS            (PTE_R | PTE_W | PTE_G)
 
+/* Flags for kernel page tables */
+
+#define MMU_KPGT_FLAGS          (PTE_G)
+
 /* Kernel FLASH and RAM are mapped globally */
 
 #define MMU_KTEXT_FLAGS         (PTE_R | PTE_X | PTE_G)