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Commit 406a590ba105bfb7b67952f0a5f948e0d374e03e

Authored by Rusty Russell
1 parent 74ff582cd6
Exists in smarc-l5.0.0_1.0.0-ga and in 5 other branches imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga

lguest: prepare to make SWITCHER_ADDR a variable. 

We currently use the whole top PGD entry for the switcher, but that's
hitting the fixmap in some configurations (mainly, large NR_CPUS).
Introduce a variable, currently set to the constant.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Showing 3 changed files with 14 additions and 10 deletions Side-by-side Diff

arch/x86/include/asm/lguest.h
Diff comments   View file @ 406a590
... ... @@ -23,6 +23,8 @@
23 23 #else
24 24 #define SWITCHER_ADDR 0xFFC00000
25 25 #endif
  26 +/* Where we map the Switcher, in both Host and Guest. */
  27 +extern unsigned long switcher_addr;
26 28  
27 29 /* Found in switcher.S */
28 30 extern unsigned long default_idt_entries[];
drivers/lguest/core.c
Diff comments   View file @ 406a590
... ... @@ -20,7 +20,7 @@
20 20 #include <asm/asm-offsets.h>
21 21 #include "lg.h"
22 22  
23   -
  23 +unsigned long switcher_addr;
24 24 static struct vm_struct *switcher_vma;
25 25 static struct page **switcher_page;
26 26  
27 27  
28 28  
29 29  
... ... @@ -75,25 +75,27 @@
75 75 }
76 76 }
77 77  
  78 + switcher_addr = SWITCHER_ADDR;
  79 +
78 80 /*
79 81 * First we check that the Switcher won't overlap the fixmap area at
80 82 * the top of memory. It's currently nowhere near, but it could have
81 83 * very strange effects if it ever happened.
82 84 */
83   - if (SWITCHER_ADDR + (TOTAL_SWITCHER_PAGES+1)*PAGE_SIZE > FIXADDR_START){
  85 + if (switcher_addr + (TOTAL_SWITCHER_PAGES+1)*PAGE_SIZE > FIXADDR_START){
84 86 err = -ENOMEM;
85 87 printk("lguest: mapping switcher would thwack fixmap\n");
86 88 goto free_pages;
87 89 }
88 90  
89 91 /*
90   - * Now we reserve the "virtual memory area" we want: 0xFFC00000
91   - * (SWITCHER_ADDR). We might not get it in theory, but in practice
92   - * it's worked so far. The end address needs +1 because __get_vm_area
93   - * allocates an extra guard page, so we need space for that.
  92 + * Now we reserve the "virtual memory area" we want. We might
  93 + * not get it in theory, but in practice it's worked so far.
  94 + * The end address needs +1 because __get_vm_area allocates an
  95 + * extra guard page, so we need space for that.
94 96 */
95 97 switcher_vma = __get_vm_area(TOTAL_SWITCHER_PAGES * PAGE_SIZE,
96   - VM_ALLOC, SWITCHER_ADDR, SWITCHER_ADDR
  98 + VM_ALLOC, switcher_addr, switcher_addr
97 99 + (TOTAL_SWITCHER_PAGES+1) * PAGE_SIZE);
98 100 if (!switcher_vma) {
99 101 err = -ENOMEM;
... ... @@ -103,7 +105,7 @@
103 105  
104 106 /*
105 107 * This code actually sets up the pages we've allocated to appear at
106   - * SWITCHER_ADDR. map_vm_area() takes the vma we allocated above, the
  108 + * switcher_addr. map_vm_area() takes the vma we allocated above, the
107 109 * kind of pages we're mapping (kernel pages), and a pointer to our
108 110 * array of struct pages. It increments that pointer, but we don't
109 111 * care.
drivers/lguest/x86/core.c
Diff comments   View file @ 406a590
... ... @@ -59,14 +59,14 @@
59 59 /* Offset from where switcher.S was compiled to where we've copied it */
60 60 static unsigned long switcher_offset(void)
61 61 {
62   - return SWITCHER_ADDR - (unsigned long)start_switcher_text;
  62 + return switcher_addr - (unsigned long)start_switcher_text;
63 63 }
64 64  
65 65 /* This cpu's struct lguest_pages. */
66 66 static struct lguest_pages *lguest_pages(unsigned int cpu)
67 67 {
68 68 return &(((struct lguest_pages *)
69   - (SWITCHER_ADDR + SHARED_SWITCHER_PAGES*PAGE_SIZE))[cpu]);
  69 + (switcher_addr + SHARED_SWITCHER_PAGES*PAGE_SIZE))[cpu]);
70 70 }
71 71  
72 72 static DEFINE_PER_CPU(struct lg_cpu *, lg_last_cpu);