Re: [PATCH] powerpc/8xx: Fix permanently mapped IMMR region.
On 11/18/2019 11:17 AM, Michael Ellerman wrote: Christophe Leroy writes: When not using large TLBs, the IMMR region is still mapped as a whole block in the FIXMAP area. Do not remove pages mapped in the FIXMAP region when initialising paging. Properly report that the IMMR region is block-mapped even when not using large TLBs. Signed-off-by: Christophe Leroy --- arch/powerpc/mm/mem.c| 8 arch/powerpc/mm/nohash/8xx.c | 13 +++-- 2 files changed, 7 insertions(+), 14 deletions(-) This blows up pmac32_defconfig + qemu mac99 for me with: NET: Registered protocol family 1 RPC: Registered named UNIX socket transport module. RPC: Registered udp transport module. RPC: Registered tcp transport module. RPC: Registered tcp NFSv4.1 backchannel transport module. PCI: CLS 0 bytes, default 32 Trying to unpack rootfs image as initramfs... BUG: Unable to handle kernel data access on write at 0xfffdf000 I tested it with pmac32_defconfig and qemu mac99 and don't get the problem: NET: Registered protocol family 1 RPC: Registered named UNIX socket transport module. RPC: Registered udp transport module. RPC: Registered tcp transport module. RPC: Registered tcp NFSv4.1 backchannel transport module. PCI: CLS 0 bytes, default 32 Initialise system trusted keyrings workingset: timestamp_bits=30 max_order=15 bucket_order=0 NFS: Registering the id_resolver key type Key type id_resolver registered ... Looks like I don't get that 'Trying to unpack rootfs image as initramfs...', do you change anything to pmac32_defconfig ? Anyway, when rebasing this patch on next branch, only the arch/powerpc/mm/nohash/8xx.c change remains. The other part is already applied through another patch. So I believe the remaining part is safe to apply Christophe
Re: [PATCH] powerpc/8xx: Fix permanently mapped IMMR region.
Michael Ellerman a écrit : Christophe Leroy writes: When not using large TLBs, the IMMR region is still mapped as a whole block in the FIXMAP area. Do not remove pages mapped in the FIXMAP region when initialising paging. Properly report that the IMMR region is block-mapped even when not using large TLBs. Signed-off-by: Christophe Leroy --- arch/powerpc/mm/mem.c| 8 arch/powerpc/mm/nohash/8xx.c | 13 +++-- 2 files changed, 7 insertions(+), 14 deletions(-) This blows up pmac32_defconfig + qemu mac99 for me with: Ok, then there is still something I have not understood about fixmap. I'll look at it next week Christophe
Re: [PATCH] powerpc/8xx: Fix permanently mapped IMMR region.
Christophe Leroy writes: > When not using large TLBs, the IMMR region is still > mapped as a whole block in the FIXMAP area. > > Do not remove pages mapped in the FIXMAP region when > initialising paging. > > Properly report that the IMMR region is block-mapped even > when not using large TLBs. > > Signed-off-by: Christophe Leroy > --- > arch/powerpc/mm/mem.c| 8 > arch/powerpc/mm/nohash/8xx.c | 13 +++-- > 2 files changed, 7 insertions(+), 14 deletions(-) This blows up pmac32_defconfig + qemu mac99 for me with: NET: Registered protocol family 1 RPC: Registered named UNIX socket transport module. RPC: Registered udp transport module. RPC: Registered tcp transport module. RPC: Registered tcp NFSv4.1 backchannel transport module. PCI: CLS 0 bytes, default 32 Trying to unpack rootfs image as initramfs... BUG: Unable to handle kernel data access on write at 0xfffdf000 Faulting instruction address: 0xc001eb4c Oops: Kernel access of bad area, sig: 11 [#1] BE PAGE_SIZE=4K MMU=Hash PowerMac Modules linked in: CPU: 0 PID: 1 Comm: swapper Not tainted 5.4.0-rc2-gcc49+ #50 NIP: c001eb4c LR: c0394214 CTR: 0080 REGS: ef0b5a70 TRAP: 0300 Not tainted (5.4.0-rc2-gcc49+) MSR: 9032 CR: 44088444 XER: 2000 DAR: fffdf000 DSISR: 4200 GPR00: 0080 ef0b5b28 ef0b fffdf000 ef2001e4 fffdeffc fffe GPR08: ef2011e8 0008 0009 0004 28088442 c0005734 GPR16: c07f c0735600 ef09f500 GPR24: fffdf000 fffdf000 ef0b5c38 1000 1000 NIP [c001eb4c] memcpy+0x88/0x10c LR [c0394214] iov_iter_copy_from_user_atomic+0x1fc/0x468 Call Trace: [ef0b5b28] [c0394060] iov_iter_copy_from_user_atomic+0x48/0x468 (unreliable) [ef0b5b68] [c0131438] generic_perform_write+0xfc/0x218 [ef0b5bb8] [c01360bc] __generic_file_write_iter+0x134/0x26c [ef0b5bf8] [c0136324] generic_file_write_iter+0x130/0x1d8 [ef0b5c28] [c01a1754] __vfs_write+0x170/0x220 [ef0b5ca8] [c01a34f0] vfs_write+0xcc/0x1e0 [ef0b5cd8] [c01a386c] ksys_write+0xd0/0x120 [ef0b5d08] [c08a03a4] xwrite+0x44/0xa4 [ef0b5d28] [c08a0b64] do_copy+0x94/0xdc [ef0b5d48] [c08a0044] write_buffer+0x40/0x68 [ef0b5d68] [c08a00cc] flush_buffer+0x60/0xe4 [ef0b5d98] [c08e87bc] __gunzip+0x2f0/0x3d0 [ef0b5dd8] [c08a0974] unpack_to_rootfs+0x1d8/0x334 [ef0b5e38] [c08a1238] populate_rootfs+0x80/0x168 [ef0b5e68] [c0005494] do_one_initcall+0x58/0x1f4 [ef0b5ed8] [c089e918] kernel_init_freeable+0x198/0x29c [ef0b5f18] [c000574c] kernel_init+0x18/0x110 [ef0b5f38] [c0016274] ret_from_kernel_thread+0x14/0x1c Instruction dump: 4200fff0 5400f0bf 7c0903a6 41820010 85240004 95260004 4200fff8 54a0d97f 54a506fe 3964 7c0903a6 4182004c <7c0b37ec> 80e40004 81040008 8124000c ---[ end trace 52276ec2410ac084 ]--- cheers
[PATCH] powerpc/8xx: Fix permanently mapped IMMR region.
When not using large TLBs, the IMMR region is still
mapped as a whole block in the FIXMAP area.
Do not remove pages mapped in the FIXMAP region when
initialising paging.
Properly report that the IMMR region is block-mapped even
when not using large TLBs.
Signed-off-by: Christophe Leroy
---
arch/powerpc/mm/mem.c| 8
arch/powerpc/mm/nohash/8xx.c | 13 +++--
2 files changed, 7 insertions(+), 14 deletions(-)
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 69f99128a8d6..8e221d8744ba 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -216,14 +216,6 @@ void __init paging_init(void)
unsigned long long total_ram = memblock_phys_mem_size();
phys_addr_t top_of_ram = memblock_end_of_DRAM();
-#ifdef CONFIG_PPC32
- unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1);
- unsigned long end = __fix_to_virt(FIX_HOLE);
-
- for (; v < end; v += PAGE_SIZE)
- map_kernel_page(v, 0, __pgprot(0)); /* XXX gross */
-#endif
-
#ifdef CONFIG_HIGHMEM
map_kernel_page(PKMAP_BASE, 0, __pgprot(0));/* XXX gross */
pkmap_page_table = virt_to_kpte(PKMAP_BASE);
diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c
index 4a06cb342da2..e6918235fe04 100644
--- a/arch/powerpc/mm/nohash/8xx.c
+++ b/arch/powerpc/mm/nohash/8xx.c
@@ -21,33 +21,34 @@ extern int __map_without_ltlbs;
static unsigned long block_mapped_ram;
/*
- * Return PA for this VA if it is in an area mapped with LTLBs.
+ * Return PA for this VA if it is in an area mapped with LTLBs or fixmap.
* Otherwise, returns 0
*/
phys_addr_t v_block_mapped(unsigned long va)
{
unsigned long p = PHYS_IMMR_BASE;
- if (__map_without_ltlbs)
- return 0;
if (va >= VIRT_IMMR_BASE && va < VIRT_IMMR_BASE + IMMR_SIZE)
return p + va - VIRT_IMMR_BASE;
+ if (__map_without_ltlbs)
+ return 0;
if (va >= PAGE_OFFSET && va < PAGE_OFFSET + block_mapped_ram)
return __pa(va);
return 0;
}
/*
- * Return VA for a given PA mapped with LTLBs or 0 if not mapped
+ * Return VA for a given PA mapped with LTLBs or fixmap
+ * Return 0 if not mapped
*/
unsigned long p_block_mapped(phys_addr_t pa)
{
unsigned long p = PHYS_IMMR_BASE;
- if (__map_without_ltlbs)
- return 0;
if (pa >= p && pa < p + IMMR_SIZE)
return VIRT_IMMR_BASE + pa - p;
+ if (__map_without_ltlbs)
+ return 0;
if (pa < block_mapped_ram)
return (unsigned long)__va(pa);
return 0;
--
2.13.3
