diff options
Diffstat (limited to '0004-x86-setup-Move-trim_snb_memory-later-in-setup_arch-t.patch')
-rw-r--r-- | 0004-x86-setup-Move-trim_snb_memory-later-in-setup_arch-t.patch | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/0004-x86-setup-Move-trim_snb_memory-later-in-setup_arch-t.patch b/0004-x86-setup-Move-trim_snb_memory-later-in-setup_arch-t.patch new file mode 100644 index 0000000..fd004ef --- /dev/null +++ b/0004-x86-setup-Move-trim_snb_memory-later-in-setup_arch-t.patch @@ -0,0 +1,87 @@ +From 0ad14408305e590f26efe4437f925b40d283e67d Mon Sep 17 00:00:00 2001 +From: Mike Rapoport <rppt@linux.ibm.com> +Date: Tue, 13 Apr 2021 21:08:39 +0300 +Subject: x86/setup: Move trim_snb_memory() later in setup_arch() to fix boot + hangs + +Commit + + a799c2bd29d1 ("x86/setup: Consolidate early memory reservations") + +moved reservation of the memory inaccessible by Sandy Bride integrated +graphics very early, and, as a result, on systems with such devices +the first 1M was reserved by trim_snb_memory() which prevented the +allocation of the real mode trampoline and made the boot hang very +early. + +Since the purpose of trim_snb_memory() is to prevent problematic pages +ever reaching the graphics device, it is safe to reserve these pages +after memblock allocations are possible. + +Move trim_snb_memory() later in boot so that it will be called after +reserve_real_mode() and make comments describing trim_snb_memory() +operation more elaborate. + + [ bp: Massage a bit. ] + +Fixes: a799c2bd29d1 ("x86/setup: Consolidate early memory reservations") +Reported-by: Randy Dunlap <rdunlap@infradead.org> +Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> +Signed-off-by: Borislav Petkov <bp@suse.de> +Tested-by: Randy Dunlap <rdunlap@infradead.org> +Tested-by: Hugh Dickins <hughd@google.com> +Link: https://lkml.kernel.org/r/f67d3e03-af90-f790-baf4-8d412fe055af@infradead.org +--- + arch/x86/kernel/setup.c | 20 +++++++++++++++----- + 1 file changed, 15 insertions(+), 5 deletions(-) + +diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c +index 282d572e49af..7d466f51be1f 100644 +--- a/arch/x86/kernel/setup.c ++++ b/arch/x86/kernel/setup.c +@@ -634,11 +634,16 @@ static void __init trim_snb_memory(void) + printk(KERN_DEBUG "reserving inaccessible SNB gfx pages\n"); + + /* +- * Reserve all memory below the 1 MB mark that has not +- * already been reserved. ++ * SandyBridge integrated graphics devices have a bug that prevents ++ * them from accessing certain memory ranges, namely anything below ++ * 1M and in the pages listed in bad_pages[] above. ++ * ++ * To avoid these pages being ever accessed by SNB gfx devices ++ * reserve all memory below the 1 MB mark and bad_pages that have ++ * not already been reserved at boot time. + */ + memblock_reserve(0, 1<<20); +- ++ + for (i = 0; i < ARRAY_SIZE(bad_pages); i++) { + if (memblock_reserve(bad_pages[i], PAGE_SIZE)) + printk(KERN_WARNING "failed to reserve 0x%08lx\n", +@@ -747,8 +752,6 @@ static void __init early_reserve_memory(void) + + reserve_ibft_region(); + reserve_bios_regions(); +- +- trim_snb_memory(); + } + + /* +@@ -1082,6 +1085,13 @@ void __init setup_arch(char **cmdline_p) + + reserve_real_mode(); + ++ /* ++ * Reserving memory causing GPU hangs on Sandy Bridge integrated ++ * graphics devices should be done after we allocated memory under ++ * 1M for the real mode trampoline. ++ */ ++ trim_snb_memory(); ++ + init_mem_mapping(); + + idt_setup_early_pf(); +-- +cgit v1.2.3-1-gf6bb5 + |