From a5593e0b329a14dea41ea173380dbf1533de2bd2 Mon Sep 17 00:00:00 2001 From: "venkatesh.pallipadi@intel.com" Date: Thu, 9 Apr 2009 14:26:48 -0700 Subject: x86, PAT: Change order of cpa and free in set_memory_wb To be free of aliasing due to races, set_memory_* interfaces should follow ordering of reserving, changing memtype to UC/WC, changing memtype back to WB followed by free. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Suresh Siddha LKML-Reference: <20090409212708.512280000@intel.com> Signed-off-by: Ingo Molnar --- arch/x86/mm/pageattr.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'arch/x86/mm/pageattr.c') diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index d71e1b636ce..d487eaa17bf 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -1021,15 +1021,19 @@ int _set_memory_wb(unsigned long addr, int numpages) int set_memory_wb(unsigned long addr, int numpages) { + int ret = _set_memory_wb(addr, numpages); free_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE); - - return _set_memory_wb(addr, numpages); + return ret; } EXPORT_SYMBOL(set_memory_wb); int set_memory_array_wb(unsigned long *addr, int addrinarray) { int i; + int ret; + + ret = change_page_attr_clear(addr, addrinarray, + __pgprot(_PAGE_CACHE_MASK), 1); for (i = 0; i < addrinarray; i++) { unsigned long start = __pa(addr[i]); @@ -1042,8 +1046,7 @@ int set_memory_array_wb(unsigned long *addr, int addrinarray) } free_memtype(start, end); } - return change_page_attr_clear(addr, addrinarray, - __pgprot(_PAGE_CACHE_MASK), 1); + return ret; } EXPORT_SYMBOL(set_memory_array_wb); -- cgit v1.2.3-70-g09d2 From 9fa3ab390abfc8b49fc0dd7c845b0ad224ec429f Mon Sep 17 00:00:00 2001 From: "venkatesh.pallipadi@intel.com" Date: Thu, 9 Apr 2009 14:26:49 -0700 Subject: x86, PAT: Handle faults cleanly in set_memory_ APIs Handle faults and do proper cleanups in set_memory_*() functions. In some cases, these functions were not doing proper free on failure paths. With the changes to tracking memtype of RAM pages in struct page instead of pat list, we do not need the changes in commits c5e147. This patch reverts that change. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Suresh Siddha LKML-Reference: <20090409212708.653222000@intel.com> Signed-off-by: Ingo Molnar --- arch/x86/mm/pageattr.c | 113 ++++++++++++++++++++++++++++--------------------- 1 file changed, 65 insertions(+), 48 deletions(-) (limited to 'arch/x86/mm/pageattr.c') diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index d487eaa17bf..985eef80c55 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -945,52 +945,56 @@ int _set_memory_uc(unsigned long addr, int numpages) int set_memory_uc(unsigned long addr, int numpages) { + int ret; + /* * for now UC MINUS. see comments in ioremap_nocache() */ - if (reserve_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE, - _PAGE_CACHE_UC_MINUS, NULL)) - return -EINVAL; + ret = reserve_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE, + _PAGE_CACHE_UC_MINUS, NULL); + if (ret) + goto out_err; + + ret = _set_memory_uc(addr, numpages); + if (ret) + goto out_free; + + return 0; - return _set_memory_uc(addr, numpages); +out_free: + free_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE); +out_err: + return ret; } EXPORT_SYMBOL(set_memory_uc); int set_memory_array_uc(unsigned long *addr, int addrinarray) { - unsigned long start; - unsigned long end; - int i; + int i, j; + int ret; + /* * for now UC MINUS. see comments in ioremap_nocache() */ for (i = 0; i < addrinarray; i++) { - start = __pa(addr[i]); - for (end = start + PAGE_SIZE; i < addrinarray - 1; end += PAGE_SIZE) { - if (end != __pa(addr[i + 1])) - break; - i++; - } - if (reserve_memtype(start, end, _PAGE_CACHE_UC_MINUS, NULL)) - goto out; + ret = reserve_memtype(__pa(addr[i]), __pa(addr[i]) + PAGE_SIZE, + _PAGE_CACHE_UC_MINUS, NULL); + if (ret) + goto out_free; } - return change_page_attr_set(addr, addrinarray, + ret = change_page_attr_set(addr, addrinarray, __pgprot(_PAGE_CACHE_UC_MINUS), 1); -out: - for (i = 0; i < addrinarray; i++) { - unsigned long tmp = __pa(addr[i]); - - if (tmp == start) - break; - for (end = tmp + PAGE_SIZE; i < addrinarray - 1; end += PAGE_SIZE) { - if (end != __pa(addr[i + 1])) - break; - i++; - } - free_memtype(tmp, end); - } - return -EINVAL; + if (ret) + goto out_free; + + return 0; + +out_free: + for (j = 0; j < i; j++) + free_memtype(__pa(addr[j]), __pa(addr[j]) + PAGE_SIZE); + + return ret; } EXPORT_SYMBOL(set_memory_array_uc); @@ -1002,14 +1006,26 @@ int _set_memory_wc(unsigned long addr, int numpages) int set_memory_wc(unsigned long addr, int numpages) { + int ret; + if (!pat_enabled) return set_memory_uc(addr, numpages); - if (reserve_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE, - _PAGE_CACHE_WC, NULL)) - return -EINVAL; + ret = reserve_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE, + _PAGE_CACHE_WC, NULL); + if (ret) + goto out_err; - return _set_memory_wc(addr, numpages); + ret = _set_memory_wc(addr, numpages); + if (ret) + goto out_free; + + return 0; + +out_free: + free_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE); +out_err: + return ret; } EXPORT_SYMBOL(set_memory_wc); @@ -1021,9 +1037,14 @@ int _set_memory_wb(unsigned long addr, int numpages) int set_memory_wb(unsigned long addr, int numpages) { - int ret = _set_memory_wb(addr, numpages); + int ret; + + ret = _set_memory_wb(addr, numpages); + if (ret) + return ret; + free_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE); - return ret; + return 0; } EXPORT_SYMBOL(set_memory_wb); @@ -1034,19 +1055,13 @@ int set_memory_array_wb(unsigned long *addr, int addrinarray) ret = change_page_attr_clear(addr, addrinarray, __pgprot(_PAGE_CACHE_MASK), 1); + if (ret) + return ret; - for (i = 0; i < addrinarray; i++) { - unsigned long start = __pa(addr[i]); - unsigned long end; + for (i = 0; i < addrinarray; i++) + free_memtype(__pa(addr[i]), __pa(addr[i]) + PAGE_SIZE); - for (end = start + PAGE_SIZE; i < addrinarray - 1; end += PAGE_SIZE) { - if (end != __pa(addr[i + 1])) - break; - i++; - } - free_memtype(start, end); - } - return ret; + return 0; } EXPORT_SYMBOL(set_memory_array_wb); @@ -1139,6 +1154,8 @@ int set_pages_array_wb(struct page **pages, int addrinarray) retval = cpa_clear_pages_array(pages, addrinarray, __pgprot(_PAGE_CACHE_MASK)); + if (retval) + return retval; for (i = 0; i < addrinarray; i++) { start = (unsigned long)page_address(pages[i]); @@ -1146,7 +1163,7 @@ int set_pages_array_wb(struct page **pages, int addrinarray) free_memtype(start, end); } - return retval; + return 0; } EXPORT_SYMBOL(set_pages_array_wb); -- cgit v1.2.3-70-g09d2 From 3869c4aa18835c8c61b44bd0f3ace36e9d3b5bd0 Mon Sep 17 00:00:00 2001 From: "venkatesh.pallipadi@intel.com" Date: Thu, 9 Apr 2009 14:26:50 -0700 Subject: x86, PAT: Changing memtype to WC ensuring no WB alias As per SDM, there should not be any aliasing of a WC with any cacheable type across CPUs. That is if one CPU is changing the identity map memtype to _WC, no other CPU at the time of this change should not have a TLB for this page that carries a WB attribute. SDM suggests to make the page not present. But for that we will have to handle any page faults that can potentially happen due to these pages being not present. Other way to deal with this without having any WB mapping is to change the page first to UC and then to WC. This ensures that we meet the SDM requirement of no cacheable alais to WC page. This also has same or lower overhead than marking the page not present and making it present later. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Suresh Siddha LKML-Reference: <20090409212708.797481000@intel.com> Signed-off-by: Ingo Molnar --- arch/x86/mm/pageattr.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'arch/x86/mm/pageattr.c') diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 985eef80c55..797f9f107cb 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -1000,8 +1000,15 @@ EXPORT_SYMBOL(set_memory_array_uc); int _set_memory_wc(unsigned long addr, int numpages) { - return change_page_attr_set(&addr, numpages, + int ret; + ret = change_page_attr_set(&addr, numpages, + __pgprot(_PAGE_CACHE_UC_MINUS), 0); + + if (!ret) { + ret = change_page_attr_set(&addr, numpages, __pgprot(_PAGE_CACHE_WC), 0); + } + return ret; } int set_memory_wc(unsigned long addr, int numpages) -- cgit v1.2.3-70-g09d2