--- /dev/null
+From stable-owner@vger.kernel.org Fri Apr 28 12:31:03 2023
+From: Alexandre Ghiti <alexghiti@rivosinc.com>
+Date: Fri, 28 Apr 2023 12:29:26 +0200
+Subject: riscv: Move early dtb mapping into the fixmap region
+To: Conor Dooley <conor.dooley@microchip.com>, stable@vger.kernel.org
+Cc: Alexandre Ghiti <alexghiti@rivosinc.com>, Palmer Dabbelt <palmer@rivosinc.com>
+Message-ID: <20230428102928.16470-2-alexghiti@rivosinc.com>
+
+From: Alexandre Ghiti <alexghiti@rivosinc.com>
+
+commit ef69d2559fe91f23d27a3d6fd640b5641787d22e upstream.
+
+riscv establishes 2 virtual mappings:
+
+- early_pg_dir maps the kernel which allows to discover the system
+ memory
+- swapper_pg_dir installs the final mapping (linear mapping included)
+
+We used to map the dtb in early_pg_dir using DTB_EARLY_BASE_VA, and this
+mapping was not carried over in swapper_pg_dir. It happens that
+early_init_fdt_scan_reserved_mem() must be called before swapper_pg_dir is
+setup otherwise we could allocate reserved memory defined in the dtb.
+And this function initializes reserved_mem variable with addresses that
+lie in the early_pg_dir dtb mapping: when those addresses are reused
+with swapper_pg_dir, this mapping does not exist and then we trap.
+
+The previous "fix" was incorrect as early_init_fdt_scan_reserved_mem()
+must be called before swapper_pg_dir is set up otherwise we could
+allocate in reserved memory defined in the dtb.
+
+So move the dtb mapping in the fixmap region which is established in
+early_pg_dir and handed over to swapper_pg_dir.
+
+This patch had to be backported because:
+- the documentation for sv57 is not present here (as sv48/57 are not
+ present)
+
+Fixes: 922b0375fc93 ("riscv: Fix memblock reservation for device tree blob")
+Fixes: 8f3a2b4a96dc ("RISC-V: Move DT mapping outof fixmap")
+Fixes: 50e63dd8ed92 ("riscv: fix reserved memory setup")
+Reported-by: Conor Dooley <conor.dooley@microchip.com>
+Link: https://lore.kernel.org/all/f8e67f82-103d-156c-deb0-d6d6e2756f5e@microchip.com/
+Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
+Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
+Tested-by: Conor Dooley <conor.dooley@microchip.com>
+Link: https://lore.kernel.org/r/20230329081932.79831-2-alexghiti@rivosinc.com
+Cc: stable@vger.kernel.org # 6.1.x
+Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ Documentation/riscv/vm-layout.rst | 4 +-
+ arch/riscv/include/asm/fixmap.h | 8 ++++
+ arch/riscv/include/asm/pgtable.h | 8 +++-
+ arch/riscv/kernel/setup.c | 1
+ arch/riscv/mm/init.c | 61 +++++++++++++++++++++-----------------
+ 5 files changed, 50 insertions(+), 32 deletions(-)
+
+--- a/Documentation/riscv/vm-layout.rst
++++ b/Documentation/riscv/vm-layout.rst
+@@ -47,7 +47,7 @@ RISC-V Linux Kernel SV39
+ | Kernel-space virtual memory, shared between all processes:
+ ____________________________________________________________|___________________________________________________________
+ | | | |
+- ffffffc6fee00000 | -228 GB | ffffffc6feffffff | 2 MB | fixmap
++ ffffffc6fea00000 | -228 GB | ffffffc6feffffff | 6 MB | fixmap
+ ffffffc6ff000000 | -228 GB | ffffffc6ffffffff | 16 MB | PCI io
+ ffffffc700000000 | -228 GB | ffffffc7ffffffff | 4 GB | vmemmap
+ ffffffc800000000 | -224 GB | ffffffd7ffffffff | 64 GB | vmalloc/ioremap space
+@@ -83,7 +83,7 @@ RISC-V Linux Kernel SV48
+ | Kernel-space virtual memory, shared between all processes:
+ ____________________________________________________________|___________________________________________________________
+ | | | |
+- ffff8d7ffee00000 | -114.5 TB | ffff8d7ffeffffff | 2 MB | fixmap
++ ffff8d7ffea00000 | -114.5 TB | ffff8d7ffeffffff | 6 MB | fixmap
+ ffff8d7fff000000 | -114.5 TB | ffff8d7fffffffff | 16 MB | PCI io
+ ffff8d8000000000 | -114.5 TB | ffff8f7fffffffff | 2 TB | vmemmap
+ ffff8f8000000000 | -112.5 TB | ffffaf7fffffffff | 32 TB | vmalloc/ioremap space
+--- a/arch/riscv/include/asm/fixmap.h
++++ b/arch/riscv/include/asm/fixmap.h
+@@ -22,6 +22,14 @@
+ */
+ enum fixed_addresses {
+ FIX_HOLE,
++ /*
++ * The fdt fixmap mapping must be PMD aligned and will be mapped
++ * using PMD entries in fixmap_pmd in 64-bit and a PGD entry in 32-bit.
++ */
++ FIX_FDT_END,
++ FIX_FDT = FIX_FDT_END + FIX_FDT_SIZE / PAGE_SIZE - 1,
++
++ /* Below fixmaps will be mapped using fixmap_pte */
+ FIX_PTE,
+ FIX_PMD,
+ FIX_PUD,
+--- a/arch/riscv/include/asm/pgtable.h
++++ b/arch/riscv/include/asm/pgtable.h
+@@ -87,9 +87,13 @@
+
+ #define FIXADDR_TOP PCI_IO_START
+ #ifdef CONFIG_64BIT
+-#define FIXADDR_SIZE PMD_SIZE
++#define MAX_FDT_SIZE PMD_SIZE
++#define FIX_FDT_SIZE (MAX_FDT_SIZE + SZ_2M)
++#define FIXADDR_SIZE (PMD_SIZE + FIX_FDT_SIZE)
+ #else
+-#define FIXADDR_SIZE PGDIR_SIZE
++#define MAX_FDT_SIZE PGDIR_SIZE
++#define FIX_FDT_SIZE MAX_FDT_SIZE
++#define FIXADDR_SIZE (PGDIR_SIZE + FIX_FDT_SIZE)
+ #endif
+ #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
+
+--- a/arch/riscv/kernel/setup.c
++++ b/arch/riscv/kernel/setup.c
+@@ -283,7 +283,6 @@ void __init setup_arch(char **cmdline_p)
+ else
+ pr_err("No DTB found in kernel mappings\n");
+ #endif
+- early_init_fdt_scan_reserved_mem();
+ misc_mem_init();
+
+ init_resources();
+--- a/arch/riscv/mm/init.c
++++ b/arch/riscv/mm/init.c
+@@ -57,7 +57,6 @@ unsigned long empty_zero_page[PAGE_SIZE
+ EXPORT_SYMBOL(empty_zero_page);
+
+ extern char _start[];
+-#define DTB_EARLY_BASE_VA PGDIR_SIZE
+ void *_dtb_early_va __initdata;
+ uintptr_t _dtb_early_pa __initdata;
+
+@@ -236,6 +235,14 @@ static void __init setup_bootmem(void)
+ set_max_mapnr(max_low_pfn - ARCH_PFN_OFFSET);
+
+ reserve_initrd_mem();
++
++ /*
++ * No allocation should be done before reserving the memory as defined
++ * in the device tree, otherwise the allocation could end up in a
++ * reserved region.
++ */
++ early_init_fdt_scan_reserved_mem();
++
+ /*
+ * If DTB is built in, no need to reserve its memblock.
+ * Otherwise, do reserve it but avoid using
+@@ -279,9 +286,6 @@ pgd_t trampoline_pg_dir[PTRS_PER_PGD] __
+ static pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
+
+ pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
+-static p4d_t __maybe_unused early_dtb_p4d[PTRS_PER_P4D] __initdata __aligned(PAGE_SIZE);
+-static pud_t __maybe_unused early_dtb_pud[PTRS_PER_PUD] __initdata __aligned(PAGE_SIZE);
+-static pmd_t __maybe_unused early_dtb_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE);
+
+ #ifdef CONFIG_XIP_KERNEL
+ #define pt_ops (*(struct pt_alloc_ops *)XIP_FIXUP(&pt_ops))
+@@ -626,9 +630,6 @@ static void __init create_p4d_mapping(p4
+ #define trampoline_pgd_next (pgtable_l5_enabled ? \
+ (uintptr_t)trampoline_p4d : (pgtable_l4_enabled ? \
+ (uintptr_t)trampoline_pud : (uintptr_t)trampoline_pmd))
+-#define early_dtb_pgd_next (pgtable_l5_enabled ? \
+- (uintptr_t)early_dtb_p4d : (pgtable_l4_enabled ? \
+- (uintptr_t)early_dtb_pud : (uintptr_t)early_dtb_pmd))
+ #else
+ #define pgd_next_t pte_t
+ #define alloc_pgd_next(__va) pt_ops.alloc_pte(__va)
+@@ -636,7 +637,6 @@ static void __init create_p4d_mapping(p4
+ #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \
+ create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
+ #define fixmap_pgd_next ((uintptr_t)fixmap_pte)
+-#define early_dtb_pgd_next ((uintptr_t)early_dtb_pmd)
+ #define create_p4d_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
+ #define create_pud_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
+ #define create_pmd_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
+@@ -859,32 +859,28 @@ static void __init create_kernel_page_ta
+ * this means 2 PMD entries whereas for 32-bit kernel, this is only 1 PGDIR
+ * entry.
+ */
+-static void __init create_fdt_early_page_table(pgd_t *pgdir, uintptr_t dtb_pa)
++static void __init create_fdt_early_page_table(pgd_t *pgdir,
++ uintptr_t fix_fdt_va,
++ uintptr_t dtb_pa)
+ {
+-#ifndef CONFIG_BUILTIN_DTB
+ uintptr_t pa = dtb_pa & ~(PMD_SIZE - 1);
+
+- create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA,
+- IS_ENABLED(CONFIG_64BIT) ? early_dtb_pgd_next : pa,
+- PGDIR_SIZE,
+- IS_ENABLED(CONFIG_64BIT) ? PAGE_TABLE : PAGE_KERNEL);
+-
+- if (pgtable_l5_enabled)
+- create_p4d_mapping(early_dtb_p4d, DTB_EARLY_BASE_VA,
+- (uintptr_t)early_dtb_pud, P4D_SIZE, PAGE_TABLE);
+-
+- if (pgtable_l4_enabled)
+- create_pud_mapping(early_dtb_pud, DTB_EARLY_BASE_VA,
+- (uintptr_t)early_dtb_pmd, PUD_SIZE, PAGE_TABLE);
++#ifndef CONFIG_BUILTIN_DTB
++ /* Make sure the fdt fixmap address is always aligned on PMD size */
++ BUILD_BUG_ON(FIX_FDT % (PMD_SIZE / PAGE_SIZE));
+
+- if (IS_ENABLED(CONFIG_64BIT)) {
+- create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA,
++ /* In 32-bit only, the fdt lies in its own PGD */
++ if (!IS_ENABLED(CONFIG_64BIT)) {
++ create_pgd_mapping(early_pg_dir, fix_fdt_va,
++ pa, MAX_FDT_SIZE, PAGE_KERNEL);
++ } else {
++ create_pmd_mapping(fixmap_pmd, fix_fdt_va,
+ pa, PMD_SIZE, PAGE_KERNEL);
+- create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA + PMD_SIZE,
++ create_pmd_mapping(fixmap_pmd, fix_fdt_va + PMD_SIZE,
+ pa + PMD_SIZE, PMD_SIZE, PAGE_KERNEL);
+ }
+
+- dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PMD_SIZE - 1));
++ dtb_early_va = (void *)fix_fdt_va + (dtb_pa & (PMD_SIZE - 1));
+ #else
+ /*
+ * For 64-bit kernel, __va can't be used since it would return a linear
+@@ -1054,7 +1050,8 @@ asmlinkage void __init setup_vm(uintptr_
+ create_kernel_page_table(early_pg_dir, true);
+
+ /* Setup early mapping for FDT early scan */
+- create_fdt_early_page_table(early_pg_dir, dtb_pa);
++ create_fdt_early_page_table(early_pg_dir,
++ __fix_to_virt(FIX_FDT), dtb_pa);
+
+ /*
+ * Bootime fixmap only can handle PMD_SIZE mapping. Thus, boot-ioremap
+@@ -1096,6 +1093,16 @@ static void __init setup_vm_final(void)
+ u64 i;
+
+ /* Setup swapper PGD for fixmap */
++#if !defined(CONFIG_64BIT)
++ /*
++ * In 32-bit, the device tree lies in a pgd entry, so it must be copied
++ * directly in swapper_pg_dir in addition to the pgd entry that points
++ * to fixmap_pte.
++ */
++ unsigned long idx = pgd_index(__fix_to_virt(FIX_FDT));
++
++ set_pgd(&swapper_pg_dir[idx], early_pg_dir[idx]);
++#endif
+ create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
+ __pa_symbol(fixmap_pgd_next),
+ PGDIR_SIZE, PAGE_TABLE);
--- /dev/null
+From stable-owner@vger.kernel.org Fri Apr 28 12:33:03 2023
+From: Alexandre Ghiti <alexghiti@rivosinc.com>
+Date: Fri, 28 Apr 2023 12:29:28 +0200
+Subject: riscv: No need to relocate the dtb as it lies in the fixmap region
+To: Conor Dooley <conor.dooley@microchip.com>, stable@vger.kernel.org
+Cc: Alexandre Ghiti <alexghiti@rivosinc.com>, Palmer Dabbelt <palmer@rivosinc.com>
+Message-ID: <20230428102928.16470-4-alexghiti@rivosinc.com>
+
+From: Alexandre Ghiti <alexghiti@rivosinc.com>
+
+commit 1b50f956c8fe9082bdee4a9cfd798149c52f7043 upstream.
+
+We used to access the dtb via its linear mapping address but now that the
+dtb early mapping was moved in the fixmap region, we can keep using this
+address since it is present in swapper_pg_dir, and remove the dtb
+relocation.
+
+Note that the relocation was wrong anyway since early_memremap() is
+restricted to 256K whereas the maximum fdt size is 2MB.
+
+Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
+Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
+Tested-by: Conor Dooley <conor.dooley@microchip.com>
+Link: https://lore.kernel.org/r/20230329081932.79831-4-alexghiti@rivosinc.com
+Cc: stable@vger.kernel.org # 6.1.x
+Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/riscv/mm/init.c | 21 ++-------------------
+ 1 file changed, 2 insertions(+), 19 deletions(-)
+
+--- a/arch/riscv/mm/init.c
++++ b/arch/riscv/mm/init.c
+@@ -249,25 +249,8 @@ static void __init setup_bootmem(void)
+ * early_init_fdt_reserve_self() since __pa() does
+ * not work for DTB pointers that are fixmap addresses
+ */
+- if (!IS_ENABLED(CONFIG_BUILTIN_DTB)) {
+- /*
+- * In case the DTB is not located in a memory region we won't
+- * be able to locate it later on via the linear mapping and
+- * get a segfault when accessing it via __va(dtb_early_pa).
+- * To avoid this situation copy DTB to a memory region.
+- * Note that memblock_phys_alloc will also reserve DTB region.
+- */
+- if (!memblock_is_memory(dtb_early_pa)) {
+- size_t fdt_size = fdt_totalsize(dtb_early_va);
+- phys_addr_t new_dtb_early_pa = memblock_phys_alloc(fdt_size, PAGE_SIZE);
+- void *new_dtb_early_va = early_memremap(new_dtb_early_pa, fdt_size);
+-
+- memcpy(new_dtb_early_va, dtb_early_va, fdt_size);
+- early_memunmap(new_dtb_early_va, fdt_size);
+- _dtb_early_pa = new_dtb_early_pa;
+- } else
+- memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
+- }
++ if (!IS_ENABLED(CONFIG_BUILTIN_DTB))
++ memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
+
+ dma_contiguous_reserve(dma32_phys_limit);
+ if (IS_ENABLED(CONFIG_64BIT))
projects / thirdparty / kernel / stable-queue.git / commitdiff
