Lines Matching refs:PAT
4 PAT (Page Attribute Table)
7 x86 Page Attribute Table (PAT) allows for setting the memory attribute at the
8 page level granularity. PAT is complementary to the MTRR settings which allows
9 for setting of memory types over physical address ranges. However, PAT is
16 PAT allows for different types of memory attributes. The most commonly used
28 PAT APIs
108 With PAT support, a new API pgprot_writecombine is being added. So, drivers can
120 MTRR effects on PAT / non-PAT systems
124 using ioremap*() calls on x86 for both non-PAT and PAT systems. Ideally
126 be a no-op on PAT enabled systems. The region over which a arch_phys_wc_add()
127 is made, should already have been ioremapped with WC attributes or PAT entries,
139 MTRR Non-PAT PAT Linux ioremap value Effective memory type
141 PAT Non-PAT | PAT
165 Over time writes to /proc/mtrr will be deprecated in favor of using PAT based
174 PAT debugging
177 With CONFIG_DEBUG_FS enabled, PAT memtype list can be examined by::
181 PAT memtype list:
198 This list shows physical address ranges and various PAT settings used to
201 Another, more verbose way of getting PAT related debug messages is with
205 PAT Initialization
208 The following table describes how PAT is initialized under various
209 configurations. The PAT MSR must be updated by Linux in order to support WC
210 and WT attributes. Otherwise, the PAT MSR has the value programmed in it
211 by the firmware. Note, Xen enables WC attribute in the PAT MSR for guests.
214 MTRR PAT Call Sequence PAT State PAT MSR
216 E E MTRR -> PAT init Enabled OS
217 E D MTRR -> PAT init Disabled -
218 D E MTRR -> PAT disable Disabled BIOS
219 D D MTRR -> PAT disable Disabled -
220 - np/E PAT -> PAT disable Disabled BIOS
221 - np/D PAT -> PAT disable Disabled -
222 E !P/E MTRR -> PAT init Disabled BIOS
223 D !P/E MTRR -> PAT disable Disabled BIOS
224 !M !P/E MTRR stub -> PAT disable Disabled BIOS
235 Enabled PAT state set to enabled
236 Disabled PAT state set to disabled
237 OS PAT initializes PAT MSR with OS setting
238 BIOS PAT keeps PAT MSR with BIOS setting