From 0df4f266b3af90442bbeb5e685a84a80745beba0 Mon Sep 17 00:00:00 2001 From: Julien Grall Date: Fri, 7 Aug 2015 17:34:37 +0100 Subject: xen: Use correctly the Xen memory terminologies Based on include/xen/mm.h [1], Linux is mistakenly using MFN when GFN is meant, I suspect this is because the first support for Xen was for PV. This resulted in some misimplementation of helpers on ARM and confused developers about the expected behavior. For instance, with pfn_to_mfn, we expect to get an MFN based on the name. Although, if we look at the implementation on x86, it's returning a GFN. For clarity and avoid new confusion, replace any reference to mfn with gfn in any helpers used by PV drivers. The x86 code will still keep some reference of pfn_to_mfn which may be used by all kind of guests No changes as been made in the hypercall field, even though they may be invalid, in order to keep the same as the defintion in xen repo. Note that page_to_mfn has been renamed to xen_page_to_gfn to avoid a name to close to the KVM function gfn_to_page. Take also the opportunity to simplify simple construction such as pfn_to_mfn(page_to_pfn(page)) into xen_page_to_gfn. More complex clean up will come in follow-up patches. [1] http://xenbits.xen.org/gitweb/?p=xen.git;a=commitdiff;h=e758ed14f390342513405dd766e874934573e6cb Signed-off-by: Julien Grall Reviewed-by: Stefano Stabellini Acked-by: Dmitry Torokhov Acked-by: Wei Liu Signed-off-by: David Vrabel --- drivers/xen/tmem.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/xen/tmem.c') diff --git a/drivers/xen/tmem.c b/drivers/xen/tmem.c index 239738f944ba..28c97ff606f4 100644 --- a/drivers/xen/tmem.c +++ b/drivers/xen/tmem.c @@ -131,7 +131,7 @@ static int xen_tmem_new_pool(struct tmem_pool_uuid uuid, static int xen_tmem_put_page(u32 pool_id, struct tmem_oid oid, u32 index, unsigned long pfn) { - unsigned long gmfn = xen_pv_domain() ? pfn_to_mfn(pfn) : pfn; + unsigned long gmfn = pfn_to_gfn(pfn); return xen_tmem_op(TMEM_PUT_PAGE, pool_id, oid, index, gmfn, 0, 0, 0); @@ -140,7 +140,7 @@ static int xen_tmem_put_page(u32 pool_id, struct tmem_oid oid, static int xen_tmem_get_page(u32 pool_id, struct tmem_oid oid, u32 index, unsigned long pfn) { - unsigned long gmfn = xen_pv_domain() ? pfn_to_mfn(pfn) : pfn; + unsigned long gmfn = pfn_to_gfn(pfn); return xen_tmem_op(TMEM_GET_PAGE, pool_id, oid, index, gmfn, 0, 0, 0); -- cgit v1.2.3 From a76e3cc32d872acd5104278d21d2084da07c16a8 Mon Sep 17 00:00:00 2001 From: Julien Grall Date: Fri, 7 Aug 2015 17:34:38 +0100 Subject: xen/tmem: Use xen_page_to_gfn rather than pfn_to_gfn All the caller of xen_tmem_{get,put}_page have a struct page * in hand and call pfn_to_gfn for the only benefits of these 2 functions. Rather than passing the pfn in parameter, pass directly the page and use directly xen_page_to_gfn. Signed-off-by: Julien Grall Reviewed-by: Stefano Stabellini Signed-off-by: David Vrabel --- drivers/xen/tmem.c | 24 ++++++++---------------- 1 file changed, 8 insertions(+), 16 deletions(-) (limited to 'drivers/xen/tmem.c') diff --git a/drivers/xen/tmem.c b/drivers/xen/tmem.c index 28c97ff606f4..945fc4327201 100644 --- a/drivers/xen/tmem.c +++ b/drivers/xen/tmem.c @@ -129,21 +129,17 @@ static int xen_tmem_new_pool(struct tmem_pool_uuid uuid, /* xen generic tmem ops */ static int xen_tmem_put_page(u32 pool_id, struct tmem_oid oid, - u32 index, unsigned long pfn) + u32 index, struct page *page) { - unsigned long gmfn = pfn_to_gfn(pfn); - return xen_tmem_op(TMEM_PUT_PAGE, pool_id, oid, index, - gmfn, 0, 0, 0); + xen_page_to_gfn(page), 0, 0, 0); } static int xen_tmem_get_page(u32 pool_id, struct tmem_oid oid, - u32 index, unsigned long pfn) + u32 index, struct page *page) { - unsigned long gmfn = pfn_to_gfn(pfn); - return xen_tmem_op(TMEM_GET_PAGE, pool_id, oid, index, - gmfn, 0, 0, 0); + xen_page_to_gfn(page), 0, 0, 0); } static int xen_tmem_flush_page(u32 pool_id, struct tmem_oid oid, u32 index) @@ -173,14 +169,13 @@ static void tmem_cleancache_put_page(int pool, struct cleancache_filekey key, { u32 ind = (u32) index; struct tmem_oid oid = *(struct tmem_oid *)&key; - unsigned long pfn = page_to_pfn(page); if (pool < 0) return; if (ind != index) return; mb(); /* ensure page is quiescent; tmem may address it with an alias */ - (void)xen_tmem_put_page((u32)pool, oid, ind, pfn); + (void)xen_tmem_put_page((u32)pool, oid, ind, page); } static int tmem_cleancache_get_page(int pool, struct cleancache_filekey key, @@ -188,7 +183,6 @@ static int tmem_cleancache_get_page(int pool, struct cleancache_filekey key, { u32 ind = (u32) index; struct tmem_oid oid = *(struct tmem_oid *)&key; - unsigned long pfn = page_to_pfn(page); int ret; /* translate return values to linux semantics */ @@ -196,7 +190,7 @@ static int tmem_cleancache_get_page(int pool, struct cleancache_filekey key, return -1; if (ind != index) return -1; - ret = xen_tmem_get_page((u32)pool, oid, ind, pfn); + ret = xen_tmem_get_page((u32)pool, oid, ind, page); if (ret == 1) return 0; else @@ -287,7 +281,6 @@ static int tmem_frontswap_store(unsigned type, pgoff_t offset, { u64 ind64 = (u64)offset; u32 ind = (u32)offset; - unsigned long pfn = page_to_pfn(page); int pool = tmem_frontswap_poolid; int ret; @@ -296,7 +289,7 @@ static int tmem_frontswap_store(unsigned type, pgoff_t offset, if (ind64 != ind) return -1; mb(); /* ensure page is quiescent; tmem may address it with an alias */ - ret = xen_tmem_put_page(pool, oswiz(type, ind), iswiz(ind), pfn); + ret = xen_tmem_put_page(pool, oswiz(type, ind), iswiz(ind), page); /* translate Xen tmem return values to linux semantics */ if (ret == 1) return 0; @@ -313,7 +306,6 @@ static int tmem_frontswap_load(unsigned type, pgoff_t offset, { u64 ind64 = (u64)offset; u32 ind = (u32)offset; - unsigned long pfn = page_to_pfn(page); int pool = tmem_frontswap_poolid; int ret; @@ -321,7 +313,7 @@ static int tmem_frontswap_load(unsigned type, pgoff_t offset, return -1; if (ind64 != ind) return -1; - ret = xen_tmem_get_page(pool, oswiz(type, ind), iswiz(ind), pfn); + ret = xen_tmem_get_page(pool, oswiz(type, ind), iswiz(ind), page); /* translate Xen tmem return values to linux semantics */ if (ret == 1) return 0; -- cgit v1.2.3