diff options
Diffstat (limited to 'ANDROID_3.4.5/arch/x86/xen/p2m.c')
-rw-r--r-- | ANDROID_3.4.5/arch/x86/xen/p2m.c | 949 |
1 files changed, 0 insertions, 949 deletions
diff --git a/ANDROID_3.4.5/arch/x86/xen/p2m.c b/ANDROID_3.4.5/arch/x86/xen/p2m.c deleted file mode 100644 index 1b267e75..00000000 --- a/ANDROID_3.4.5/arch/x86/xen/p2m.c +++ /dev/null @@ -1,949 +0,0 @@ -/* - * Xen leaves the responsibility for maintaining p2m mappings to the - * guests themselves, but it must also access and update the p2m array - * during suspend/resume when all the pages are reallocated. - * - * The p2m table is logically a flat array, but we implement it as a - * three-level tree to allow the address space to be sparse. - * - * Xen - * | - * p2m_top p2m_top_mfn - * / \ / \ - * p2m_mid p2m_mid p2m_mid_mfn p2m_mid_mfn - * / \ / \ / / - * p2m p2m p2m p2m p2m p2m p2m ... - * - * The p2m_mid_mfn pages are mapped by p2m_top_mfn_p. - * - * The p2m_top and p2m_top_mfn levels are limited to 1 page, so the - * maximum representable pseudo-physical address space is: - * P2M_TOP_PER_PAGE * P2M_MID_PER_PAGE * P2M_PER_PAGE pages - * - * P2M_PER_PAGE depends on the architecture, as a mfn is always - * unsigned long (8 bytes on 64-bit, 4 bytes on 32), leading to - * 512 and 1024 entries respectively. - * - * In short, these structures contain the Machine Frame Number (MFN) of the PFN. - * - * However not all entries are filled with MFNs. Specifically for all other - * leaf entries, or for the top root, or middle one, for which there is a void - * entry, we assume it is "missing". So (for example) - * pfn_to_mfn(0x90909090)=INVALID_P2M_ENTRY. - * - * We also have the possibility of setting 1-1 mappings on certain regions, so - * that: - * pfn_to_mfn(0xc0000)=0xc0000 - * - * The benefit of this is, that we can assume for non-RAM regions (think - * PCI BARs, or ACPI spaces), we can create mappings easily b/c we - * get the PFN value to match the MFN. - * - * For this to work efficiently we have one new page p2m_identity and - * allocate (via reserved_brk) any other pages we need to cover the sides - * (1GB or 4MB boundary violations). All entries in p2m_identity are set to - * INVALID_P2M_ENTRY type (Xen toolstack only recognizes that and MFNs, - * no other fancy value). - * - * On lookup we spot that the entry points to p2m_identity and return the - * identity value instead of dereferencing and returning INVALID_P2M_ENTRY. - * If the entry points to an allocated page, we just proceed as before and - * return the PFN. If the PFN has IDENTITY_FRAME_BIT set we unmask that in - * appropriate functions (pfn_to_mfn). - * - * The reason for having the IDENTITY_FRAME_BIT instead of just returning the - * PFN is that we could find ourselves where pfn_to_mfn(pfn)==pfn for a - * non-identity pfn. To protect ourselves against we elect to set (and get) the - * IDENTITY_FRAME_BIT on all identity mapped PFNs. - * - * This simplistic diagram is used to explain the more subtle piece of code. - * There is also a digram of the P2M at the end that can help. - * Imagine your E820 looking as so: - * - * 1GB 2GB - * /-------------------+---------\/----\ /----------\ /---+-----\ - * | System RAM | Sys RAM ||ACPI| | reserved | | Sys RAM | - * \-------------------+---------/\----/ \----------/ \---+-----/ - * ^- 1029MB ^- 2001MB - * - * [1029MB = 263424 (0x40500), 2001MB = 512256 (0x7D100), - * 2048MB = 524288 (0x80000)] - * - * And dom0_mem=max:3GB,1GB is passed in to the guest, meaning memory past 1GB - * is actually not present (would have to kick the balloon driver to put it in). - * - * When we are told to set the PFNs for identity mapping (see patch: "xen/setup: - * Set identity mapping for non-RAM E820 and E820 gaps.") we pass in the start - * of the PFN and the end PFN (263424 and 512256 respectively). The first step - * is to reserve_brk a top leaf page if the p2m[1] is missing. The top leaf page - * covers 512^2 of page estate (1GB) and in case the start or end PFN is not - * aligned on 512^2*PAGE_SIZE (1GB) we loop on aligned 1GB PFNs from start pfn - * to end pfn. We reserve_brk top leaf pages if they are missing (means they - * point to p2m_mid_missing). - * - * With the E820 example above, 263424 is not 1GB aligned so we allocate a - * reserve_brk page which will cover the PFNs estate from 0x40000 to 0x80000. - * Each entry in the allocate page is "missing" (points to p2m_missing). - * - * Next stage is to determine if we need to do a more granular boundary check - * on the 4MB (or 2MB depending on architecture) off the start and end pfn's. - * We check if the start pfn and end pfn violate that boundary check, and if - * so reserve_brk a middle (p2m[x][y]) leaf page. This way we have a much finer - * granularity of setting which PFNs are missing and which ones are identity. - * In our example 263424 and 512256 both fail the check so we reserve_brk two - * pages. Populate them with INVALID_P2M_ENTRY (so they both have "missing" - * values) and assign them to p2m[1][2] and p2m[1][488] respectively. - * - * At this point we would at minimum reserve_brk one page, but could be up to - * three. Each call to set_phys_range_identity has at maximum a three page - * cost. If we were to query the P2M at this stage, all those entries from - * start PFN through end PFN (so 1029MB -> 2001MB) would return - * INVALID_P2M_ENTRY ("missing"). - * - * The next step is to walk from the start pfn to the end pfn setting - * the IDENTITY_FRAME_BIT on each PFN. This is done in set_phys_range_identity. - * If we find that the middle leaf is pointing to p2m_missing we can swap it - * over to p2m_identity - this way covering 4MB (or 2MB) PFN space. At this - * point we do not need to worry about boundary aligment (so no need to - * reserve_brk a middle page, figure out which PFNs are "missing" and which - * ones are identity), as that has been done earlier. If we find that the - * middle leaf is not occupied by p2m_identity or p2m_missing, we dereference - * that page (which covers 512 PFNs) and set the appropriate PFN with - * IDENTITY_FRAME_BIT. In our example 263424 and 512256 end up there, and we - * set from p2m[1][2][256->511] and p2m[1][488][0->256] with - * IDENTITY_FRAME_BIT set. - * - * All other regions that are void (or not filled) either point to p2m_missing - * (considered missing) or have the default value of INVALID_P2M_ENTRY (also - * considered missing). In our case, p2m[1][2][0->255] and p2m[1][488][257->511] - * contain the INVALID_P2M_ENTRY value and are considered "missing." - * - * This is what the p2m ends up looking (for the E820 above) with this - * fabulous drawing: - * - * p2m /--------------\ - * /-----\ | &mfn_list[0],| /-----------------\ - * | 0 |------>| &mfn_list[1],| /---------------\ | ~0, ~0, .. | - * |-----| | ..., ~0, ~0 | | ~0, ~0, [x]---+----->| IDENTITY [@256] | - * | 1 |---\ \--------------/ | [p2m_identity]+\ | IDENTITY [@257] | - * |-----| \ | [p2m_identity]+\\ | .... | - * | 2 |--\ \-------------------->| ... | \\ \----------------/ - * |-----| \ \---------------/ \\ - * | 3 |\ \ \\ p2m_identity - * |-----| \ \-------------------->/---------------\ /-----------------\ - * | .. +->+ | [p2m_identity]+-->| ~0, ~0, ~0, ... | - * \-----/ / | [p2m_identity]+-->| ..., ~0 | - * / /---------------\ | .... | \-----------------/ - * / | IDENTITY[@0] | /-+-[x], ~0, ~0.. | - * / | IDENTITY[@256]|<----/ \---------------/ - * / | ~0, ~0, .... | - * | \---------------/ - * | - * p2m_missing p2m_missing - * /------------------\ /------------\ - * | [p2m_mid_missing]+---->| ~0, ~0, ~0 | - * | [p2m_mid_missing]+---->| ..., ~0 | - * \------------------/ \------------/ - * - * where ~0 is INVALID_P2M_ENTRY. IDENTITY is (PFN | IDENTITY_BIT) - */ - -#include <linux/init.h> -#include <linux/module.h> -#include <linux/list.h> -#include <linux/hash.h> -#include <linux/sched.h> -#include <linux/seq_file.h> - -#include <asm/cache.h> -#include <asm/setup.h> - -#include <asm/xen/page.h> -#include <asm/xen/hypercall.h> -#include <asm/xen/hypervisor.h> -#include <xen/grant_table.h> - -#include "multicalls.h" -#include "xen-ops.h" - -static void __init m2p_override_init(void); - -unsigned long xen_max_p2m_pfn __read_mostly; - -#define P2M_PER_PAGE (PAGE_SIZE / sizeof(unsigned long)) -#define P2M_MID_PER_PAGE (PAGE_SIZE / sizeof(unsigned long *)) -#define P2M_TOP_PER_PAGE (PAGE_SIZE / sizeof(unsigned long **)) - -#define MAX_P2M_PFN (P2M_TOP_PER_PAGE * P2M_MID_PER_PAGE * P2M_PER_PAGE) - -/* Placeholders for holes in the address space */ -static RESERVE_BRK_ARRAY(unsigned long, p2m_missing, P2M_PER_PAGE); -static RESERVE_BRK_ARRAY(unsigned long *, p2m_mid_missing, P2M_MID_PER_PAGE); -static RESERVE_BRK_ARRAY(unsigned long, p2m_mid_missing_mfn, P2M_MID_PER_PAGE); - -static RESERVE_BRK_ARRAY(unsigned long **, p2m_top, P2M_TOP_PER_PAGE); -static RESERVE_BRK_ARRAY(unsigned long, p2m_top_mfn, P2M_TOP_PER_PAGE); -static RESERVE_BRK_ARRAY(unsigned long *, p2m_top_mfn_p, P2M_TOP_PER_PAGE); - -static RESERVE_BRK_ARRAY(unsigned long, p2m_identity, P2M_PER_PAGE); - -RESERVE_BRK(p2m_mid, PAGE_SIZE * (MAX_DOMAIN_PAGES / (P2M_PER_PAGE * P2M_MID_PER_PAGE))); -RESERVE_BRK(p2m_mid_mfn, PAGE_SIZE * (MAX_DOMAIN_PAGES / (P2M_PER_PAGE * P2M_MID_PER_PAGE))); - -/* We might hit two boundary violations at the start and end, at max each - * boundary violation will require three middle nodes. */ -RESERVE_BRK(p2m_mid_identity, PAGE_SIZE * 2 * 3); - -static inline unsigned p2m_top_index(unsigned long pfn) -{ - BUG_ON(pfn >= MAX_P2M_PFN); - return pfn / (P2M_MID_PER_PAGE * P2M_PER_PAGE); -} - -static inline unsigned p2m_mid_index(unsigned long pfn) -{ - return (pfn / P2M_PER_PAGE) % P2M_MID_PER_PAGE; -} - -static inline unsigned p2m_index(unsigned long pfn) -{ - return pfn % P2M_PER_PAGE; -} - -static void p2m_top_init(unsigned long ***top) -{ - unsigned i; - - for (i = 0; i < P2M_TOP_PER_PAGE; i++) - top[i] = p2m_mid_missing; -} - -static void p2m_top_mfn_init(unsigned long *top) -{ - unsigned i; - - for (i = 0; i < P2M_TOP_PER_PAGE; i++) - top[i] = virt_to_mfn(p2m_mid_missing_mfn); -} - -static void p2m_top_mfn_p_init(unsigned long **top) -{ - unsigned i; - - for (i = 0; i < P2M_TOP_PER_PAGE; i++) - top[i] = p2m_mid_missing_mfn; -} - -static void p2m_mid_init(unsigned long **mid) -{ - unsigned i; - - for (i = 0; i < P2M_MID_PER_PAGE; i++) - mid[i] = p2m_missing; -} - -static void p2m_mid_mfn_init(unsigned long *mid) -{ - unsigned i; - - for (i = 0; i < P2M_MID_PER_PAGE; i++) - mid[i] = virt_to_mfn(p2m_missing); -} - -static void p2m_init(unsigned long *p2m) -{ - unsigned i; - - for (i = 0; i < P2M_MID_PER_PAGE; i++) - p2m[i] = INVALID_P2M_ENTRY; -} - -/* - * Build the parallel p2m_top_mfn and p2m_mid_mfn structures - * - * This is called both at boot time, and after resuming from suspend: - * - At boot time we're called very early, and must use extend_brk() - * to allocate memory. - * - * - After resume we're called from within stop_machine, but the mfn - * tree should alreay be completely allocated. - */ -void __ref xen_build_mfn_list_list(void) -{ - unsigned long pfn; - - /* Pre-initialize p2m_top_mfn to be completely missing */ - if (p2m_top_mfn == NULL) { - p2m_mid_missing_mfn = extend_brk(PAGE_SIZE, PAGE_SIZE); - p2m_mid_mfn_init(p2m_mid_missing_mfn); - - p2m_top_mfn_p = extend_brk(PAGE_SIZE, PAGE_SIZE); - p2m_top_mfn_p_init(p2m_top_mfn_p); - - p2m_top_mfn = extend_brk(PAGE_SIZE, PAGE_SIZE); - p2m_top_mfn_init(p2m_top_mfn); - } else { - /* Reinitialise, mfn's all change after migration */ - p2m_mid_mfn_init(p2m_mid_missing_mfn); - } - - for (pfn = 0; pfn < xen_max_p2m_pfn; pfn += P2M_PER_PAGE) { - unsigned topidx = p2m_top_index(pfn); - unsigned mididx = p2m_mid_index(pfn); - unsigned long **mid; - unsigned long *mid_mfn_p; - - mid = p2m_top[topidx]; - mid_mfn_p = p2m_top_mfn_p[topidx]; - - /* Don't bother allocating any mfn mid levels if - * they're just missing, just update the stored mfn, - * since all could have changed over a migrate. - */ - if (mid == p2m_mid_missing) { - BUG_ON(mididx); - BUG_ON(mid_mfn_p != p2m_mid_missing_mfn); - p2m_top_mfn[topidx] = virt_to_mfn(p2m_mid_missing_mfn); - pfn += (P2M_MID_PER_PAGE - 1) * P2M_PER_PAGE; - continue; - } - - if (mid_mfn_p == p2m_mid_missing_mfn) { - /* - * XXX boot-time only! We should never find - * missing parts of the mfn tree after - * runtime. extend_brk() will BUG if we call - * it too late. - */ - mid_mfn_p = extend_brk(PAGE_SIZE, PAGE_SIZE); - p2m_mid_mfn_init(mid_mfn_p); - - p2m_top_mfn_p[topidx] = mid_mfn_p; - } - - p2m_top_mfn[topidx] = virt_to_mfn(mid_mfn_p); - mid_mfn_p[mididx] = virt_to_mfn(mid[mididx]); - } -} - -void xen_setup_mfn_list_list(void) -{ - BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info); - - HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list = - virt_to_mfn(p2m_top_mfn); - HYPERVISOR_shared_info->arch.max_pfn = xen_max_p2m_pfn; -} - -/* Set up p2m_top to point to the domain-builder provided p2m pages */ -void __init xen_build_dynamic_phys_to_machine(void) -{ - unsigned long *mfn_list = (unsigned long *)xen_start_info->mfn_list; - unsigned long max_pfn = min(MAX_DOMAIN_PAGES, xen_start_info->nr_pages); - unsigned long pfn; - - xen_max_p2m_pfn = max_pfn; - - p2m_missing = extend_brk(PAGE_SIZE, PAGE_SIZE); - p2m_init(p2m_missing); - - p2m_mid_missing = extend_brk(PAGE_SIZE, PAGE_SIZE); - p2m_mid_init(p2m_mid_missing); - - p2m_top = extend_brk(PAGE_SIZE, PAGE_SIZE); - p2m_top_init(p2m_top); - - p2m_identity = extend_brk(PAGE_SIZE, PAGE_SIZE); - p2m_init(p2m_identity); - - /* - * The domain builder gives us a pre-constructed p2m array in - * mfn_list for all the pages initially given to us, so we just - * need to graft that into our tree structure. - */ - for (pfn = 0; pfn < max_pfn; pfn += P2M_PER_PAGE) { - unsigned topidx = p2m_top_index(pfn); - unsigned mididx = p2m_mid_index(pfn); - - if (p2m_top[topidx] == p2m_mid_missing) { - unsigned long **mid = extend_brk(PAGE_SIZE, PAGE_SIZE); - p2m_mid_init(mid); - - p2m_top[topidx] = mid; - } - - /* - * As long as the mfn_list has enough entries to completely - * fill a p2m page, pointing into the array is ok. But if - * not the entries beyond the last pfn will be undefined. - */ - if (unlikely(pfn + P2M_PER_PAGE > max_pfn)) { - unsigned long p2midx; - - p2midx = max_pfn % P2M_PER_PAGE; - for ( ; p2midx < P2M_PER_PAGE; p2midx++) - mfn_list[pfn + p2midx] = INVALID_P2M_ENTRY; - } - p2m_top[topidx][mididx] = &mfn_list[pfn]; - } - - m2p_override_init(); -} - -unsigned long get_phys_to_machine(unsigned long pfn) -{ - unsigned topidx, mididx, idx; - - if (unlikely(pfn >= MAX_P2M_PFN)) - return INVALID_P2M_ENTRY; - - topidx = p2m_top_index(pfn); - mididx = p2m_mid_index(pfn); - idx = p2m_index(pfn); - - /* - * The INVALID_P2M_ENTRY is filled in both p2m_*identity - * and in p2m_*missing, so returning the INVALID_P2M_ENTRY - * would be wrong. - */ - if (p2m_top[topidx][mididx] == p2m_identity) - return IDENTITY_FRAME(pfn); - - return p2m_top[topidx][mididx][idx]; -} -EXPORT_SYMBOL_GPL(get_phys_to_machine); - -static void *alloc_p2m_page(void) -{ - return (void *)__get_free_page(GFP_KERNEL | __GFP_REPEAT); -} - -static void free_p2m_page(void *p) -{ - free_page((unsigned long)p); -} - -/* - * Fully allocate the p2m structure for a given pfn. We need to check - * that both the top and mid levels are allocated, and make sure the - * parallel mfn tree is kept in sync. We may race with other cpus, so - * the new pages are installed with cmpxchg; if we lose the race then - * simply free the page we allocated and use the one that's there. - */ -static bool alloc_p2m(unsigned long pfn) -{ - unsigned topidx, mididx; - unsigned long ***top_p, **mid; - unsigned long *top_mfn_p, *mid_mfn; - - topidx = p2m_top_index(pfn); - mididx = p2m_mid_index(pfn); - - top_p = &p2m_top[topidx]; - mid = *top_p; - - if (mid == p2m_mid_missing) { - /* Mid level is missing, allocate a new one */ - mid = alloc_p2m_page(); - if (!mid) - return false; - - p2m_mid_init(mid); - - if (cmpxchg(top_p, p2m_mid_missing, mid) != p2m_mid_missing) - free_p2m_page(mid); - } - - top_mfn_p = &p2m_top_mfn[topidx]; - mid_mfn = p2m_top_mfn_p[topidx]; - - BUG_ON(virt_to_mfn(mid_mfn) != *top_mfn_p); - - if (mid_mfn == p2m_mid_missing_mfn) { - /* Separately check the mid mfn level */ - unsigned long missing_mfn; - unsigned long mid_mfn_mfn; - - mid_mfn = alloc_p2m_page(); - if (!mid_mfn) - return false; - - p2m_mid_mfn_init(mid_mfn); - - missing_mfn = virt_to_mfn(p2m_mid_missing_mfn); - mid_mfn_mfn = virt_to_mfn(mid_mfn); - if (cmpxchg(top_mfn_p, missing_mfn, mid_mfn_mfn) != missing_mfn) - free_p2m_page(mid_mfn); - else - p2m_top_mfn_p[topidx] = mid_mfn; - } - - if (p2m_top[topidx][mididx] == p2m_identity || - p2m_top[topidx][mididx] == p2m_missing) { - /* p2m leaf page is missing */ - unsigned long *p2m; - unsigned long *p2m_orig = p2m_top[topidx][mididx]; - - p2m = alloc_p2m_page(); - if (!p2m) - return false; - - p2m_init(p2m); - - if (cmpxchg(&mid[mididx], p2m_orig, p2m) != p2m_orig) - free_p2m_page(p2m); - else - mid_mfn[mididx] = virt_to_mfn(p2m); - } - - return true; -} - -static bool __init __early_alloc_p2m(unsigned long pfn) -{ - unsigned topidx, mididx, idx; - - topidx = p2m_top_index(pfn); - mididx = p2m_mid_index(pfn); - idx = p2m_index(pfn); - - /* Pfff.. No boundary cross-over, lets get out. */ - if (!idx) - return false; - - WARN(p2m_top[topidx][mididx] == p2m_identity, - "P2M[%d][%d] == IDENTITY, should be MISSING (or alloced)!\n", - topidx, mididx); - - /* - * Could be done by xen_build_dynamic_phys_to_machine.. - */ - if (p2m_top[topidx][mididx] != p2m_missing) - return false; - - /* Boundary cross-over for the edges: */ - if (idx) { - unsigned long *p2m = extend_brk(PAGE_SIZE, PAGE_SIZE); - unsigned long *mid_mfn_p; - - p2m_init(p2m); - - p2m_top[topidx][mididx] = p2m; - - /* For save/restore we need to MFN of the P2M saved */ - - mid_mfn_p = p2m_top_mfn_p[topidx]; - WARN(mid_mfn_p[mididx] != virt_to_mfn(p2m_missing), - "P2M_TOP_P[%d][%d] != MFN of p2m_missing!\n", - topidx, mididx); - mid_mfn_p[mididx] = virt_to_mfn(p2m); - - } - return idx != 0; -} -unsigned long __init set_phys_range_identity(unsigned long pfn_s, - unsigned long pfn_e) -{ - unsigned long pfn; - - if (unlikely(pfn_s >= MAX_P2M_PFN || pfn_e >= MAX_P2M_PFN)) - return 0; - - if (unlikely(xen_feature(XENFEAT_auto_translated_physmap))) - return pfn_e - pfn_s; - - if (pfn_s > pfn_e) - return 0; - - for (pfn = (pfn_s & ~(P2M_MID_PER_PAGE * P2M_PER_PAGE - 1)); - pfn < ALIGN(pfn_e, (P2M_MID_PER_PAGE * P2M_PER_PAGE)); - pfn += P2M_MID_PER_PAGE * P2M_PER_PAGE) - { - unsigned topidx = p2m_top_index(pfn); - unsigned long *mid_mfn_p; - unsigned long **mid; - - mid = p2m_top[topidx]; - mid_mfn_p = p2m_top_mfn_p[topidx]; - if (mid == p2m_mid_missing) { - mid = extend_brk(PAGE_SIZE, PAGE_SIZE); - - p2m_mid_init(mid); - - p2m_top[topidx] = mid; - - BUG_ON(mid_mfn_p != p2m_mid_missing_mfn); - } - /* And the save/restore P2M tables.. */ - if (mid_mfn_p == p2m_mid_missing_mfn) { - mid_mfn_p = extend_brk(PAGE_SIZE, PAGE_SIZE); - p2m_mid_mfn_init(mid_mfn_p); - - p2m_top_mfn_p[topidx] = mid_mfn_p; - p2m_top_mfn[topidx] = virt_to_mfn(mid_mfn_p); - /* Note: we don't set mid_mfn_p[midix] here, - * look in __early_alloc_p2m */ - } - } - - __early_alloc_p2m(pfn_s); - __early_alloc_p2m(pfn_e); - - for (pfn = pfn_s; pfn < pfn_e; pfn++) - if (!__set_phys_to_machine(pfn, IDENTITY_FRAME(pfn))) - break; - - if (!WARN((pfn - pfn_s) != (pfn_e - pfn_s), - "Identity mapping failed. We are %ld short of 1-1 mappings!\n", - (pfn_e - pfn_s) - (pfn - pfn_s))) - printk(KERN_DEBUG "1-1 mapping on %lx->%lx\n", pfn_s, pfn); - - return pfn - pfn_s; -} - -/* Try to install p2m mapping; fail if intermediate bits missing */ -bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn) -{ - unsigned topidx, mididx, idx; - - if (unlikely(xen_feature(XENFEAT_auto_translated_physmap))) { - BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY); - return true; - } - if (unlikely(pfn >= MAX_P2M_PFN)) { - BUG_ON(mfn != INVALID_P2M_ENTRY); - return true; - } - - topidx = p2m_top_index(pfn); - mididx = p2m_mid_index(pfn); - idx = p2m_index(pfn); - - /* For sparse holes were the p2m leaf has real PFN along with - * PCI holes, stick in the PFN as the MFN value. - */ - if (mfn != INVALID_P2M_ENTRY && (mfn & IDENTITY_FRAME_BIT)) { - if (p2m_top[topidx][mididx] == p2m_identity) - return true; - - /* Swap over from MISSING to IDENTITY if needed. */ - if (p2m_top[topidx][mididx] == p2m_missing) { - WARN_ON(cmpxchg(&p2m_top[topidx][mididx], p2m_missing, - p2m_identity) != p2m_missing); - return true; - } - } - - if (p2m_top[topidx][mididx] == p2m_missing) - return mfn == INVALID_P2M_ENTRY; - - p2m_top[topidx][mididx][idx] = mfn; - - return true; -} - -bool set_phys_to_machine(unsigned long pfn, unsigned long mfn) -{ - if (unlikely(!__set_phys_to_machine(pfn, mfn))) { - if (!alloc_p2m(pfn)) - return false; - - if (!__set_phys_to_machine(pfn, mfn)) - return false; - } - - return true; -} - -#define M2P_OVERRIDE_HASH_SHIFT 10 -#define M2P_OVERRIDE_HASH (1 << M2P_OVERRIDE_HASH_SHIFT) - -static RESERVE_BRK_ARRAY(struct list_head, m2p_overrides, M2P_OVERRIDE_HASH); -static DEFINE_SPINLOCK(m2p_override_lock); - -static void __init m2p_override_init(void) -{ - unsigned i; - - m2p_overrides = extend_brk(sizeof(*m2p_overrides) * M2P_OVERRIDE_HASH, - sizeof(unsigned long)); - - for (i = 0; i < M2P_OVERRIDE_HASH; i++) - INIT_LIST_HEAD(&m2p_overrides[i]); -} - -static unsigned long mfn_hash(unsigned long mfn) -{ - return hash_long(mfn, M2P_OVERRIDE_HASH_SHIFT); -} - -/* Add an MFN override for a particular page */ -int m2p_add_override(unsigned long mfn, struct page *page, - struct gnttab_map_grant_ref *kmap_op) -{ - unsigned long flags; - unsigned long pfn; - unsigned long uninitialized_var(address); - unsigned level; - pte_t *ptep = NULL; - - pfn = page_to_pfn(page); - if (!PageHighMem(page)) { - address = (unsigned long)__va(pfn << PAGE_SHIFT); - ptep = lookup_address(address, &level); - if (WARN(ptep == NULL || level != PG_LEVEL_4K, - "m2p_add_override: pfn %lx not mapped", pfn)) - return -EINVAL; - } - WARN_ON(PagePrivate(page)); - SetPagePrivate(page); - set_page_private(page, mfn); - page->index = pfn_to_mfn(pfn); - - if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)))) - return -ENOMEM; - - if (kmap_op != NULL) { - if (!PageHighMem(page)) { - struct multicall_space mcs = - xen_mc_entry(sizeof(*kmap_op)); - - MULTI_grant_table_op(mcs.mc, - GNTTABOP_map_grant_ref, kmap_op, 1); - - xen_mc_issue(PARAVIRT_LAZY_MMU); - } - /* let's use dev_bus_addr to record the old mfn instead */ - kmap_op->dev_bus_addr = page->index; - page->index = (unsigned long) kmap_op; - } - spin_lock_irqsave(&m2p_override_lock, flags); - list_add(&page->lru, &m2p_overrides[mfn_hash(mfn)]); - spin_unlock_irqrestore(&m2p_override_lock, flags); - - return 0; -} -EXPORT_SYMBOL_GPL(m2p_add_override); -int m2p_remove_override(struct page *page, bool clear_pte) -{ - unsigned long flags; - unsigned long mfn; - unsigned long pfn; - unsigned long uninitialized_var(address); - unsigned level; - pte_t *ptep = NULL; - - pfn = page_to_pfn(page); - mfn = get_phys_to_machine(pfn); - if (mfn == INVALID_P2M_ENTRY || !(mfn & FOREIGN_FRAME_BIT)) - return -EINVAL; - - if (!PageHighMem(page)) { - address = (unsigned long)__va(pfn << PAGE_SHIFT); - ptep = lookup_address(address, &level); - - if (WARN(ptep == NULL || level != PG_LEVEL_4K, - "m2p_remove_override: pfn %lx not mapped", pfn)) - return -EINVAL; - } - - spin_lock_irqsave(&m2p_override_lock, flags); - list_del(&page->lru); - spin_unlock_irqrestore(&m2p_override_lock, flags); - WARN_ON(!PagePrivate(page)); - ClearPagePrivate(page); - - if (clear_pte) { - struct gnttab_map_grant_ref *map_op = - (struct gnttab_map_grant_ref *) page->index; - set_phys_to_machine(pfn, map_op->dev_bus_addr); - if (!PageHighMem(page)) { - struct multicall_space mcs; - struct gnttab_unmap_grant_ref *unmap_op; - - /* - * It might be that we queued all the m2p grant table - * hypercalls in a multicall, then m2p_remove_override - * get called before the multicall has actually been - * issued. In this case handle is going to -1 because - * it hasn't been modified yet. - */ - if (map_op->handle == -1) - xen_mc_flush(); - /* - * Now if map_op->handle is negative it means that the - * hypercall actually returned an error. - */ - if (map_op->handle == GNTST_general_error) { - printk(KERN_WARNING "m2p_remove_override: " - "pfn %lx mfn %lx, failed to modify kernel mappings", - pfn, mfn); - return -1; - } - - mcs = xen_mc_entry( - sizeof(struct gnttab_unmap_grant_ref)); - unmap_op = mcs.args; - unmap_op->host_addr = map_op->host_addr; - unmap_op->handle = map_op->handle; - unmap_op->dev_bus_addr = 0; - - MULTI_grant_table_op(mcs.mc, - GNTTABOP_unmap_grant_ref, unmap_op, 1); - - xen_mc_issue(PARAVIRT_LAZY_MMU); - - set_pte_at(&init_mm, address, ptep, - pfn_pte(pfn, PAGE_KERNEL)); - __flush_tlb_single(address); - map_op->host_addr = 0; - } - } else - set_phys_to_machine(pfn, page->index); - - return 0; -} -EXPORT_SYMBOL_GPL(m2p_remove_override); - -struct page *m2p_find_override(unsigned long mfn) -{ - unsigned long flags; - struct list_head *bucket = &m2p_overrides[mfn_hash(mfn)]; - struct page *p, *ret; - - ret = NULL; - - spin_lock_irqsave(&m2p_override_lock, flags); - - list_for_each_entry(p, bucket, lru) { - if (page_private(p) == mfn) { - ret = p; - break; - } - } - - spin_unlock_irqrestore(&m2p_override_lock, flags); - - return ret; -} - -unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn) -{ - struct page *p = m2p_find_override(mfn); - unsigned long ret = pfn; - - if (p) - ret = page_to_pfn(p); - - return ret; -} -EXPORT_SYMBOL_GPL(m2p_find_override_pfn); - -#ifdef CONFIG_XEN_DEBUG_FS -#include <linux/debugfs.h> -#include "debugfs.h" -static int p2m_dump_show(struct seq_file *m, void *v) -{ - static const char * const level_name[] = { "top", "middle", - "entry", "abnormal", "error"}; -#define TYPE_IDENTITY 0 -#define TYPE_MISSING 1 -#define TYPE_PFN 2 -#define TYPE_UNKNOWN 3 - static const char * const type_name[] = { - [TYPE_IDENTITY] = "identity", - [TYPE_MISSING] = "missing", - [TYPE_PFN] = "pfn", - [TYPE_UNKNOWN] = "abnormal"}; - unsigned long pfn, prev_pfn_type = 0, prev_pfn_level = 0; - unsigned int uninitialized_var(prev_level); - unsigned int uninitialized_var(prev_type); - - if (!p2m_top) - return 0; - - for (pfn = 0; pfn < MAX_DOMAIN_PAGES; pfn++) { - unsigned topidx = p2m_top_index(pfn); - unsigned mididx = p2m_mid_index(pfn); - unsigned idx = p2m_index(pfn); - unsigned lvl, type; - - lvl = 4; - type = TYPE_UNKNOWN; - if (p2m_top[topidx] == p2m_mid_missing) { - lvl = 0; type = TYPE_MISSING; - } else if (p2m_top[topidx] == NULL) { - lvl = 0; type = TYPE_UNKNOWN; - } else if (p2m_top[topidx][mididx] == NULL) { - lvl = 1; type = TYPE_UNKNOWN; - } else if (p2m_top[topidx][mididx] == p2m_identity) { - lvl = 1; type = TYPE_IDENTITY; - } else if (p2m_top[topidx][mididx] == p2m_missing) { - lvl = 1; type = TYPE_MISSING; - } else if (p2m_top[topidx][mididx][idx] == 0) { - lvl = 2; type = TYPE_UNKNOWN; - } else if (p2m_top[topidx][mididx][idx] == IDENTITY_FRAME(pfn)) { - lvl = 2; type = TYPE_IDENTITY; - } else if (p2m_top[topidx][mididx][idx] == INVALID_P2M_ENTRY) { - lvl = 2; type = TYPE_MISSING; - } else if (p2m_top[topidx][mididx][idx] == pfn) { - lvl = 2; type = TYPE_PFN; - } else if (p2m_top[topidx][mididx][idx] != pfn) { - lvl = 2; type = TYPE_PFN; - } - if (pfn == 0) { - prev_level = lvl; - prev_type = type; - } - if (pfn == MAX_DOMAIN_PAGES-1) { - lvl = 3; - type = TYPE_UNKNOWN; - } - if (prev_type != type) { - seq_printf(m, " [0x%lx->0x%lx] %s\n", - prev_pfn_type, pfn, type_name[prev_type]); - prev_pfn_type = pfn; - prev_type = type; - } - if (prev_level != lvl) { - seq_printf(m, " [0x%lx->0x%lx] level %s\n", - prev_pfn_level, pfn, level_name[prev_level]); - prev_pfn_level = pfn; - prev_level = lvl; - } - } - return 0; -#undef TYPE_IDENTITY -#undef TYPE_MISSING -#undef TYPE_PFN -#undef TYPE_UNKNOWN -} - -static int p2m_dump_open(struct inode *inode, struct file *filp) -{ - return single_open(filp, p2m_dump_show, NULL); -} - -static const struct file_operations p2m_dump_fops = { - .open = p2m_dump_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, -}; - -static struct dentry *d_mmu_debug; - -static int __init xen_p2m_debugfs(void) -{ - struct dentry *d_xen = xen_init_debugfs(); - - if (d_xen == NULL) - return -ENOMEM; - - d_mmu_debug = debugfs_create_dir("mmu", d_xen); - - debugfs_create_file("p2m", 0600, d_mmu_debug, NULL, &p2m_dump_fops); - return 0; -} -fs_initcall(xen_p2m_debugfs); -#endif /* CONFIG_XEN_DEBUG_FS */ |