lguest: get rid of lg variable assignments

We can save some lines of code by getting rid of
*lg = cpu... lines of code spread everywhere by now.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 58 insertions, 57 deletions

diff --git a/drivers/lguest/page_tables.c b/drivers/lguest/page_tables.c
index c9acafcab2aa..983e9020cef8 100644
--- a/drivers/lguest/page_tables.c
+++ b/drivers/lguest/page_tables.c
@@ -68,17 +68,17 @@ static DEFINE_PER_CPU(pte_t *, switcher_pte_pages);
  * page directory entry (PGD) for that address.  Since we keep track of several
  * page tables, the "i" argument tells us which one we're interested in (it's
  * usually the current one). */
-static pgd_t *spgd_addr(struct lguest *lg, u32 i, unsigned long vaddr)
+static pgd_t *spgd_addr(struct lg_cpu *cpu, u32 i, unsigned long vaddr)
 {
         unsigned int index = pgd_index(vaddr);
 
         /* We kill any Guest trying to touch the Switcher addresses. */
         if (index >= SWITCHER_PGD_INDEX) {
-                kill_guest(lg, "attempt to access switcher pages");
+                kill_guest(cpu, "attempt to access switcher pages");
                 index = 0;
         }
         /* Return a pointer index'th pgd entry for the i'th page table. */
-        return &lg->pgdirs[i].pgdir[index];
+        return &cpu->lg->pgdirs[i].pgdir[index];
 }
 
 /* This routine then takes the page directory entry returned above, which
@@ -137,7 +137,7 @@ static unsigned long get_pfn(unsigned long virtpfn, int write)
  * entry can be a little tricky.  The flags are (almost) the same, but the
  * Guest PTE contains a virtual page number: the CPU needs the real page
  * number. */
-static pte_t gpte_to_spte(struct lguest *lg, pte_t gpte, int write)
+static pte_t gpte_to_spte(struct lg_cpu *cpu, pte_t gpte, int write)
 {
         unsigned long pfn, base, flags;
 
@@ -148,7 +148,7 @@ static pte_t gpte_to_spte(struct lguest *lg, pte_t gpte, int write)
         flags = (pte_flags(gpte) & ~_PAGE_GLOBAL);
 
         /* The Guest's pages are offset inside the Launcher. */
-        base = (unsigned long)lg->mem_base / PAGE_SIZE;
+        base = (unsigned long)cpu->lg->mem_base / PAGE_SIZE;
 
         /* We need a temporary "unsigned long" variable to hold the answer from
          * get_pfn(), because it returns 0xFFFFFFFF on failure, which wouldn't
@@ -156,7 +156,7 @@ static pte_t gpte_to_spte(struct lguest *lg, pte_t gpte, int write)
          * page, given the virtual number. */
         pfn = get_pfn(base + pte_pfn(gpte), write);
         if (pfn == -1UL) {
-                kill_guest(lg, "failed to get page %lu", pte_pfn(gpte));
+                kill_guest(cpu, "failed to get page %lu", pte_pfn(gpte));
                 /* When we destroy the Guest, we'll go through the shadow page
                  * tables and release_pte() them.  Make sure we don't think
                  * this one is valid! */
@@ -176,17 +176,18 @@ static void release_pte(pte_t pte)
 }
 /*:*/
 
-static void check_gpte(struct lguest *lg, pte_t gpte)
+static void check_gpte(struct lg_cpu *cpu, pte_t gpte)
 {
         if ((pte_flags(gpte) & (_PAGE_PWT|_PAGE_PSE))
-            || pte_pfn(gpte) >= lg->pfn_limit)
-                kill_guest(lg, "bad page table entry");
+            || pte_pfn(gpte) >= cpu->lg->pfn_limit)
+                kill_guest(cpu, "bad page table entry");
 }
 
-static void check_gpgd(struct lguest *lg, pgd_t gpgd)
+static void check_gpgd(struct lg_cpu *cpu, pgd_t gpgd)
 {
-        if ((pgd_flags(gpgd) & ~_PAGE_TABLE) || pgd_pfn(gpgd) >= lg->pfn_limit)
-                kill_guest(lg, "bad page directory entry");
+        if ((pgd_flags(gpgd) & ~_PAGE_TABLE) ||
+           (pgd_pfn(gpgd) >= cpu->lg->pfn_limit))
+                kill_guest(cpu, "bad page directory entry");
 }
 
 /*H:330
@@ -206,27 +207,26 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
         unsigned long gpte_ptr;
         pte_t gpte;
         pte_t *spte;
-        struct lguest *lg = cpu->lg;
 
         /* First step: get the top-level Guest page table entry. */
-        gpgd = lgread(lg, gpgd_addr(cpu, vaddr), pgd_t);
+        gpgd = lgread(cpu, gpgd_addr(cpu, vaddr), pgd_t);
         /* Toplevel not present?  We can't map it in. */
         if (!(pgd_flags(gpgd) & _PAGE_PRESENT))
                 return 0;
 
         /* Now look at the matching shadow entry. */
-        spgd = spgd_addr(lg, cpu->cpu_pgd, vaddr);
+        spgd = spgd_addr(cpu, cpu->cpu_pgd, vaddr);
         if (!(pgd_flags(*spgd) & _PAGE_PRESENT)) {
                 /* No shadow entry: allocate a new shadow PTE page. */
                 unsigned long ptepage = get_zeroed_page(GFP_KERNEL);
                 /* This is not really the Guest's fault, but killing it is
                  * simple for this corner case. */
                 if (!ptepage) {
-                        kill_guest(lg, "out of memory allocating pte page");
+                        kill_guest(cpu, "out of memory allocating pte page");
                         return 0;
                 }
                 /* We check that the Guest pgd is OK. */
-                check_gpgd(lg, gpgd);
+                check_gpgd(cpu, gpgd);
                 /* And we copy the flags to the shadow PGD entry.  The page
                  * number in the shadow PGD is the page we just allocated. */
                 *spgd = __pgd(__pa(ptepage) | pgd_flags(gpgd));
@@ -235,7 +235,7 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
         /* OK, now we look at the lower level in the Guest page table: keep its
          * address, because we might update it later. */
         gpte_ptr = gpte_addr(gpgd, vaddr);
-        gpte = lgread(lg, gpte_ptr, pte_t);
+        gpte = lgread(cpu, gpte_ptr, pte_t);
 
         /* If this page isn't in the Guest page tables, we can't page it in. */
         if (!(pte_flags(gpte) & _PAGE_PRESENT))
@@ -252,7 +252,7 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
 
         /* Check that the Guest PTE flags are OK, and the page number is below
          * the pfn_limit (ie. not mapping the Launcher binary). */
-        check_gpte(lg, gpte);
+        check_gpte(cpu, gpte);
 
         /* Add the _PAGE_ACCESSED and (for a write) _PAGE_DIRTY flag */
         gpte = pte_mkyoung(gpte);
@@ -268,17 +268,17 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
         /* If this is a write, we insist that the Guest page is writable (the
          * final arg to gpte_to_spte()). */
         if (pte_dirty(gpte))
-                *spte = gpte_to_spte(lg, gpte, 1);
+                *spte = gpte_to_spte(cpu, gpte, 1);
         else
                 /* If this is a read, don't set the "writable" bit in the page
                  * table entry, even if the Guest says it's writable.  That way
                  * we will come back here when a write does actually occur, so
                  * we can update the Guest's _PAGE_DIRTY flag. */
-                *spte = gpte_to_spte(lg, pte_wrprotect(gpte), 0);
+                *spte = gpte_to_spte(cpu, pte_wrprotect(gpte), 0);
 
         /* Finally, we write the Guest PTE entry back: we've set the
          * _PAGE_ACCESSED and maybe the _PAGE_DIRTY flags. */
-        lgwrite(lg, gpte_ptr, pte_t, gpte);
+        lgwrite(cpu, gpte_ptr, pte_t, gpte);
 
         /* The fault is fixed, the page table is populated, the mapping
          * manipulated, the result returned and the code complete.  A small
@@ -303,7 +303,7 @@ static int page_writable(struct lg_cpu *cpu, unsigned long vaddr)
         unsigned long flags;
 
         /* Look at the current top level entry: is it present? */
-        spgd = spgd_addr(cpu->lg, cpu->cpu_pgd, vaddr);
+        spgd = spgd_addr(cpu, cpu->cpu_pgd, vaddr);
         if (!(pgd_flags(*spgd) & _PAGE_PRESENT))
                 return 0;
 
@@ -320,7 +320,7 @@ static int page_writable(struct lg_cpu *cpu, unsigned long vaddr)
 void pin_page(struct lg_cpu *cpu, unsigned long vaddr)
 {
         if (!page_writable(cpu, vaddr) && !demand_page(cpu, vaddr, 2))
-                kill_guest(cpu->lg, "bad stack page %#lx", vaddr);
+                kill_guest(cpu, "bad stack page %#lx", vaddr);
 }
 
 /*H:450 If we chase down the release_pgd() code, it looks like this: */
@@ -372,14 +372,14 @@ unsigned long guest_pa(struct lg_cpu *cpu, unsigned long vaddr)
         pte_t gpte;
 
         /* First step: get the top-level Guest page table entry. */
-        gpgd = lgread(cpu->lg, gpgd_addr(cpu, vaddr), pgd_t);
+        gpgd = lgread(cpu, gpgd_addr(cpu, vaddr), pgd_t);
         /* Toplevel not present?  We can't map it in. */
         if (!(pgd_flags(gpgd) & _PAGE_PRESENT))
-                kill_guest(cpu->lg, "Bad address %#lx", vaddr);
+                kill_guest(cpu, "Bad address %#lx", vaddr);
 
-        gpte = lgread(cpu->lg, gpte_addr(gpgd, vaddr), pte_t);
+        gpte = lgread(cpu, gpte_addr(gpgd, vaddr), pte_t);
         if (!(pte_flags(gpte) & _PAGE_PRESENT))
-                kill_guest(cpu->lg, "Bad address %#lx", vaddr);
+                kill_guest(cpu, "Bad address %#lx", vaddr);
 
         return pte_pfn(gpte) * PAGE_SIZE | (vaddr & ~PAGE_MASK);
 }
@@ -404,16 +404,16 @@ static unsigned int new_pgdir(struct lg_cpu *cpu,
                               int *blank_pgdir)
 {
         unsigned int next;
-        struct lguest *lg = cpu->lg;
 
         /* We pick one entry at random to throw out.  Choosing the Least
          * Recently Used might be better, but this is easy. */
-        next = random32() % ARRAY_SIZE(lg->pgdirs);
+        next = random32() % ARRAY_SIZE(cpu->lg->pgdirs);
         /* If it's never been allocated at all before, try now. */
-        if (!lg->pgdirs[next].pgdir) {
-                lg->pgdirs[next].pgdir = (pgd_t *)get_zeroed_page(GFP_KERNEL);
+        if (!cpu->lg->pgdirs[next].pgdir) {
+                cpu->lg->pgdirs[next].pgdir =
+                                        (pgd_t *)get_zeroed_page(GFP_KERNEL);
                 /* If the allocation fails, just keep using the one we have */
-                if (!lg->pgdirs[next].pgdir)
+                if (!cpu->lg->pgdirs[next].pgdir)
                         next = cpu->cpu_pgd;
                 else
                         /* This is a blank page, so there are no kernel
@@ -421,9 +421,9 @@ static unsigned int new_pgdir(struct lg_cpu *cpu,
                         *blank_pgdir = 1;
         }
         /* Record which Guest toplevel this shadows. */
-        lg->pgdirs[next].gpgdir = gpgdir;
+        cpu->lg->pgdirs[next].gpgdir = gpgdir;
         /* Release all the non-kernel mappings. */
-        flush_user_mappings(lg, next);
+        flush_user_mappings(cpu->lg, next);
 
         return next;
 }
@@ -436,13 +436,12 @@ static unsigned int new_pgdir(struct lg_cpu *cpu,
 void guest_new_pagetable(struct lg_cpu *cpu, unsigned long pgtable)
 {
         int newpgdir, repin = 0;
-        struct lguest *lg = cpu->lg;
 
         /* Look to see if we have this one already. */
-        newpgdir = find_pgdir(lg, pgtable);
+        newpgdir = find_pgdir(cpu->lg, pgtable);
         /* If not, we allocate or mug an existing one: if it's a fresh one,
          * repin gets set to 1. */
-        if (newpgdir == ARRAY_SIZE(lg->pgdirs))
+        if (newpgdir == ARRAY_SIZE(cpu->lg->pgdirs))
                 newpgdir = new_pgdir(cpu, pgtable, &repin);
         /* Change the current pgd index to the new one. */
         cpu->cpu_pgd = newpgdir;
@@ -499,11 +498,11 @@ void guest_pagetable_clear_all(struct lg_cpu *cpu)
  * _PAGE_ACCESSED then we can put a read-only PTE entry in immediately, and if
  * they set _PAGE_DIRTY then we can put a writable PTE entry in immediately.
  */
-static void do_set_pte(struct lguest *lg, int idx,
+static void do_set_pte(struct lg_cpu *cpu, int idx,
                        unsigned long vaddr, pte_t gpte)
 {
         /* Look up the matching shadow page directory entry. */
-        pgd_t *spgd = spgd_addr(lg, idx, vaddr);
+        pgd_t *spgd = spgd_addr(cpu, idx, vaddr);
 
         /* If the top level isn't present, there's no entry to update. */
         if (pgd_flags(*spgd) & _PAGE_PRESENT) {
@@ -515,8 +514,8 @@ static void do_set_pte(struct lguest *lg, int idx,
                  * as well put that entry they've given us in now.  This shaves
                  * 10% off a copy-on-write micro-benchmark. */
                 if (pte_flags(gpte) & (_PAGE_DIRTY | _PAGE_ACCESSED)) {
-                        check_gpte(lg, gpte);
-                        *spte = gpte_to_spte(lg, gpte,
+                        check_gpte(cpu, gpte);
+                        *spte = gpte_to_spte(cpu, gpte,
                                              pte_flags(gpte) & _PAGE_DIRTY);
                 } else
                         /* Otherwise kill it and we can demand_page() it in
@@ -535,22 +534,22 @@ static void do_set_pte(struct lguest *lg, int idx,
  *
  * The benefit is that when we have to track a new page table, we can copy keep
  * all the kernel mappings.  This speeds up context switch immensely. */
-void guest_set_pte(struct lguest *lg,
+void guest_set_pte(struct lg_cpu *cpu,
                    unsigned long gpgdir, unsigned long vaddr, pte_t gpte)
 {
         /* Kernel mappings must be changed on all top levels.  Slow, but
          * doesn't happen often. */
-        if (vaddr >= lg->kernel_address) {
+        if (vaddr >= cpu->lg->kernel_address) {
                 unsigned int i;
-                for (i = 0; i < ARRAY_SIZE(lg->pgdirs); i++)
-                        if (lg->pgdirs[i].pgdir)
-                                do_set_pte(lg, i, vaddr, gpte);
+                for (i = 0; i < ARRAY_SIZE(cpu->lg->pgdirs); i++)
+                        if (cpu->lg->pgdirs[i].pgdir)
+                                do_set_pte(cpu, i, vaddr, gpte);
         } else {
                 /* Is this page table one we have a shadow for? */
-                int pgdir = find_pgdir(lg, gpgdir);
-                if (pgdir != ARRAY_SIZE(lg->pgdirs))
+                int pgdir = find_pgdir(cpu->lg, gpgdir);
+                if (pgdir != ARRAY_SIZE(cpu->lg->pgdirs))
                         /* If so, do the update. */
-                        do_set_pte(lg, pgdir, vaddr, gpte);
+                        do_set_pte(cpu, pgdir, vaddr, gpte);
         }
 }
 
@@ -601,21 +600,23 @@ int init_guest_pagetable(struct lguest *lg, unsigned long pgtable)
 }
 
 /* When the Guest calls LHCALL_LGUEST_INIT we do more setup. */
-void page_table_guest_data_init(struct lguest *lg)
+void page_table_guest_data_init(struct lg_cpu *cpu)
 {
         /* We get the kernel address: above this is all kernel memory. */
-        if (get_user(lg->kernel_address, &lg->lguest_data->kernel_address)
+        if (get_user(cpu->lg->kernel_address,
+                     &cpu->lg->lguest_data->kernel_address)
             /* We tell the Guest that it can't use the top 4MB of virtual
              * addresses used by the Switcher. */
-            || put_user(4U*1024*1024, &lg->lguest_data->reserve_mem)
-            || put_user(lg->pgdirs[0].gpgdir, &lg->lguest_data->pgdir))
-                kill_guest(lg, "bad guest page %p", lg->lguest_data);
+            || put_user(4U*1024*1024, &cpu->lg->lguest_data->reserve_mem)
+            || put_user(cpu->lg->pgdirs[0].gpgdir, &cpu->lg->lguest_data->pgdir))
+                kill_guest(cpu, "bad guest page %p", cpu->lg->lguest_data);
 
         /* In flush_user_mappings() we loop from 0 to
          * "pgd_index(lg->kernel_address)".  This assumes it won't hit the
          * Switcher mappings, so check that now. */
-        if (pgd_index(lg->kernel_address) >= SWITCHER_PGD_INDEX)
-                kill_guest(lg, "bad kernel address %#lx", lg->kernel_address);
+        if (pgd_index(cpu->lg->kernel_address) >= SWITCHER_PGD_INDEX)
+                kill_guest(cpu, "bad kernel address %#lx",
+                                 cpu->lg->kernel_address);
 }
 
 /* When a Guest dies, our cleanup is fairly simple. */