From 0c0e455bc006cc69c42775aab0aaf42a5e43eb09 Mon Sep 17 00:00:00 2001 From: John Baldwin Date: Sat, 24 Aug 2019 00:35:59 +0000 Subject: [PATCH] MFC 350551: Don't reset memory attributes when mapping physical addresses for ACPI. Previously, AcpiOsMemory was using pmap_mapbios which would always map the requested address Write-Back (WB). For several AMD Ryzen laptops, the BIOS uses AcpiOsMemory to directly access the PCI MCFG region in order to access PCI config registers. This has the side effect of remapping the MCFG region in the direct map as WB instead of UC hanging the laptops during boot. On the one laptop I examined in detail, the _PIC global method used to switch from 8259A PICs to I/O APICs uses a pair of PCI config space registers at offset 0x84 in the device at 0:0:0 to as a pair of address/data registers to access an indirect register in the chipset and clear a single bit to switch modes. To fix, alter the semantics of pmap_mapbios() such that it does not modify the attributes of any existing mappings and instead uses the existing attributes. If a new mapping is created, this new mapping uses WB (the default memory attribute). Special thanks to the gentleman whose name I don't have who brought two affected laptops to the hacker lounge at BSDCan. Direct access to the affected systems permitted finding the root cause within an hour or so. PR: 231760, 236899 --- sys/amd64/amd64/pmap.c | 50 +++++++++++++++++++++++++++--------------- sys/i386/i386/pmap.c | 39 ++++++++++++++++++++++++++------ 2 files changed, 64 insertions(+), 25 deletions(-) diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c index 6273c9e92d0..d0958aa51f7 100644 --- a/sys/amd64/amd64/pmap.c +++ b/sys/amd64/amd64/pmap.c @@ -1102,6 +1102,13 @@ static caddr_t crashdumpmap; #define PMAP_ENTER_NORECLAIM 0x1000000 /* Don't reclaim PV entries. */ #define PMAP_ENTER_NOREPLACE 0x2000000 /* Don't replace mappings. */ +/* + * Internal flags for pmap_mapdev_internal() and + * pmap_change_attr_locked(). + */ +#define MAPDEV_FLUSHCACHE 0x0000001 /* Flush cache after mapping. */ +#define MAPDEV_SETATTR 0x0000002 /* Modify existing attrs. */ + static void free_pv_chunk(struct pv_chunk *pc); static void free_pv_entry(pmap_t pmap, pv_entry_t pv); static pv_entry_t get_pv_entry(pmap_t pmap, struct rwlock **lockp); @@ -1122,7 +1129,7 @@ static pv_entry_t pmap_pvh_remove(struct md_page *pvh, pmap_t pmap, vm_offset_t va); static int pmap_change_attr_locked(vm_offset_t va, vm_size_t size, int mode, - bool noflush); + int flags); static boolean_t pmap_demote_pde(pmap_t pmap, pd_entry_t *pde, vm_offset_t va); static boolean_t pmap_demote_pde_locked(pmap_t pmap, pd_entry_t *pde, vm_offset_t va, struct rwlock **lockp); @@ -7713,7 +7720,7 @@ pmap_pde_attr(pd_entry_t *pde, int cache_bits, int mask) * NOT real memory. */ static void * -pmap_mapdev_internal(vm_paddr_t pa, vm_size_t size, int mode, bool noflush) +pmap_mapdev_internal(vm_paddr_t pa, vm_size_t size, int mode, int flags) { struct pmap_preinit_mapping *ppim; vm_offset_t va, offset; @@ -7747,7 +7754,8 @@ pmap_mapdev_internal(vm_paddr_t pa, vm_size_t size, int mode, bool noflush) for (i = 0; i < PMAP_PREINIT_MAPPING_COUNT; i++) { ppim = pmap_preinit_mapping + i; if (ppim->pa == pa && ppim->sz == size && - ppim->mode == mode) + (ppim->mode == mode || + (flags & MAPDEV_SETATTR) == 0)) return ((void *)(ppim->va + offset)); } /* @@ -7756,9 +7764,12 @@ pmap_mapdev_internal(vm_paddr_t pa, vm_size_t size, int mode, bool noflush) */ if (pa < dmaplimit && pa + size <= dmaplimit) { va = PHYS_TO_DMAP(pa); - PMAP_LOCK(kernel_pmap); - i = pmap_change_attr_locked(va, size, mode, noflush); - PMAP_UNLOCK(kernel_pmap); + if ((flags & MAPDEV_SETATTR) != 0) { + PMAP_LOCK(kernel_pmap); + i = pmap_change_attr_locked(va, size, mode, flags); + PMAP_UNLOCK(kernel_pmap); + } else + i = 0; if (!i) return ((void *)(va + offset)); } @@ -7769,7 +7780,7 @@ pmap_mapdev_internal(vm_paddr_t pa, vm_size_t size, int mode, bool noflush) for (tmpsize = 0; tmpsize < size; tmpsize += PAGE_SIZE) pmap_kenter_attr(va + tmpsize, pa + tmpsize, mode); pmap_invalidate_range(kernel_pmap, va, va + tmpsize); - if (!noflush) + if ((flags & MAPDEV_FLUSHCACHE) != 0) pmap_invalidate_cache_range(va, va + tmpsize); return ((void *)(va + offset)); } @@ -7778,28 +7789,31 @@ void * pmap_mapdev_attr(vm_paddr_t pa, vm_size_t size, int mode) { - return (pmap_mapdev_internal(pa, size, mode, false)); + return (pmap_mapdev_internal(pa, size, mode, MAPDEV_FLUSHCACHE | + MAPDEV_SETATTR)); } void * pmap_mapdev(vm_paddr_t pa, vm_size_t size) { - return (pmap_mapdev_internal(pa, size, PAT_UNCACHEABLE, false)); + return (pmap_mapdev_attr(pa, size, PAT_UNCACHEABLE)); } void * pmap_mapdev_pciecfg(vm_paddr_t pa, vm_size_t size) { - return (pmap_mapdev_internal(pa, size, PAT_UNCACHEABLE, true)); + return (pmap_mapdev_internal(pa, size, PAT_UNCACHEABLE, + MAPDEV_SETATTR)); } void * pmap_mapbios(vm_paddr_t pa, vm_size_t size) { - return (pmap_mapdev_internal(pa, size, PAT_WRITE_BACK, false)); + return (pmap_mapdev_internal(pa, size, PAT_WRITE_BACK, + MAPDEV_FLUSHCACHE)); } void @@ -7938,13 +7952,13 @@ pmap_change_attr(vm_offset_t va, vm_size_t size, int mode) int error; PMAP_LOCK(kernel_pmap); - error = pmap_change_attr_locked(va, size, mode, false); + error = pmap_change_attr_locked(va, size, mode, MAPDEV_FLUSHCACHE); PMAP_UNLOCK(kernel_pmap); return (error); } static int -pmap_change_attr_locked(vm_offset_t va, vm_size_t size, int mode, bool noflush) +pmap_change_attr_locked(vm_offset_t va, vm_size_t size, int mode, int flags) { vm_offset_t base, offset, tmpva; vm_paddr_t pa_start, pa_end, pa_end1; @@ -8061,7 +8075,7 @@ pmap_change_attr_locked(vm_offset_t va, vm_size_t size, int mode, bool noflush) /* Run ended, update direct map. */ error = pmap_change_attr_locked( PHYS_TO_DMAP(pa_start), - pa_end - pa_start, mode, noflush); + pa_end - pa_start, mode, flags); if (error != 0) break; /* Start physical address run. */ @@ -8091,7 +8105,7 @@ pmap_change_attr_locked(vm_offset_t va, vm_size_t size, int mode, bool noflush) /* Run ended, update direct map. */ error = pmap_change_attr_locked( PHYS_TO_DMAP(pa_start), - pa_end - pa_start, mode, noflush); + pa_end - pa_start, mode, flags); if (error != 0) break; /* Start physical address run. */ @@ -8119,7 +8133,7 @@ pmap_change_attr_locked(vm_offset_t va, vm_size_t size, int mode, bool noflush) /* Run ended, update direct map. */ error = pmap_change_attr_locked( PHYS_TO_DMAP(pa_start), - pa_end - pa_start, mode, noflush); + pa_end - pa_start, mode, flags); if (error != 0) break; /* Start physical address run. */ @@ -8134,7 +8148,7 @@ pmap_change_attr_locked(vm_offset_t va, vm_size_t size, int mode, bool noflush) pa_end1 = MIN(pa_end, dmaplimit); if (pa_start != pa_end1) error = pmap_change_attr_locked(PHYS_TO_DMAP(pa_start), - pa_end1 - pa_start, mode, noflush); + pa_end1 - pa_start, mode, flags); } /* @@ -8143,7 +8157,7 @@ pmap_change_attr_locked(vm_offset_t va, vm_size_t size, int mode, bool noflush) */ if (changed) { pmap_invalidate_range(kernel_pmap, base, tmpva); - if (!noflush) + if ((flags & MAPDEV_FLUSHCACHE) != 0) pmap_invalidate_cache_range(base, tmpva); } return (error); diff --git a/sys/i386/i386/pmap.c b/sys/i386/i386/pmap.c index 8770698868f..afb785228da 100644 --- a/sys/i386/i386/pmap.c +++ b/sys/i386/i386/pmap.c @@ -292,6 +292,11 @@ int pti; #define PMAP_ENTER_NORECLAIM 0x1000000 /* Don't reclaim PV entries. */ #define PMAP_ENTER_NOREPLACE 0x2000000 /* Don't replace mappings. */ +/* + * Internal flags for pmap_mapdev_internal(). + */ +#define MAPDEV_SETATTR 0x0000001 /* Modify existing attrs. */ + static void free_pv_chunk(struct pv_chunk *pc); static void free_pv_entry(pmap_t pmap, pv_entry_t pv); static pv_entry_t get_pv_entry(pmap_t pmap, boolean_t try); @@ -5466,11 +5471,12 @@ pmap_pde_attr(pd_entry_t *pde, int cache_bits) * routine is intended to be used for mapping device memory, * NOT real memory. */ -void * -pmap_mapdev_attr(vm_paddr_t pa, vm_size_t size, int mode) +static void * +pmap_mapdev_internal(vm_paddr_t pa, vm_size_t size, int mode, int flags) { struct pmap_preinit_mapping *ppim; vm_offset_t va, offset; + vm_page_t m; vm_size_t tmpsize; int i; @@ -5478,9 +5484,11 @@ pmap_mapdev_attr(vm_paddr_t pa, vm_size_t size, int mode) size = round_page(offset + size); pa = pa & PG_FRAME; - if (pa < PMAP_MAP_LOW && pa + size <= PMAP_MAP_LOW) + if (pa < PMAP_MAP_LOW && pa + size <= PMAP_MAP_LOW) { va = pa + PMAP_MAP_LOW; - else if (!pmap_initialized) { + if ((flags & MAPDEV_SETATTR) == 0) + return ((void *)(va + offset)); + } else if (!pmap_initialized) { va = 0; for (i = 0; i < PMAP_PREINIT_MAPPING_COUNT; i++) { ppim = pmap_preinit_mapping + i; @@ -5503,20 +5511,37 @@ pmap_mapdev_attr(vm_paddr_t pa, vm_size_t size, int mode) for (i = 0; i < PMAP_PREINIT_MAPPING_COUNT; i++) { ppim = pmap_preinit_mapping + i; if (ppim->pa == pa && ppim->sz == size && - ppim->mode == mode) + (ppim->mode == mode || + (flags & MAPDEV_SETATTR) == 0)) return ((void *)(ppim->va + offset)); } va = kva_alloc(size); if (va == 0) panic("%s: Couldn't allocate KVA", __func__); } - for (tmpsize = 0; tmpsize < size; tmpsize += PAGE_SIZE) + for (tmpsize = 0; tmpsize < size; tmpsize += PAGE_SIZE) { + if ((flags & MAPDEV_SETATTR) == 0 && pmap_initialized) { + m = PHYS_TO_VM_PAGE(pa); + if (m != NULL && VM_PAGE_TO_PHYS(m) == pa) { + pmap_kenter_attr(va + tmpsize, pa + tmpsize, + m->md.pat_mode); + continue; + } + } pmap_kenter_attr(va + tmpsize, pa + tmpsize, mode); + } pmap_invalidate_range(kernel_pmap, va, va + tmpsize); pmap_invalidate_cache_range(va, va + size); return ((void *)(va + offset)); } +void * +pmap_mapdev_attr(vm_paddr_t pa, vm_size_t size, int mode) +{ + + return (pmap_mapdev_internal(pa, size, mode, MAPDEV_SETATTR)); +} + void * pmap_mapdev(vm_paddr_t pa, vm_size_t size) { @@ -5528,7 +5553,7 @@ void * pmap_mapbios(vm_paddr_t pa, vm_size_t size) { - return (pmap_mapdev_attr(pa, size, PAT_WRITE_BACK)); + return (pmap_mapdev_internal(pa, size, PAT_WRITE_BACK, 0)); } void -- 2.45.0