[Xen-devel] [PATCH ARM v4 12/12] mini-os: added ARM grant table initialisation

[Thomas Leonard <talex5@xxxxxxxxx>]

On x86, we get told which pages to use, but on ARM we get the base
address in the FDT and have to map each page.

Signed-off-by: Thomas Leonard <talex5@xxxxxxxxx>
---
 extras/mini-os/ARM-TODO.txt     |  1 -
 extras/mini-os/arch/arm/mm.c    | 58 +++++++++++++++++++++++++++++++++++++++++
 extras/mini-os/arch/x86/mm.c    | 13 +++++++++
 extras/mini-os/gnttab.c         | 11 ++------
 extras/mini-os/include/gnttab.h |  1 +
 5 files changed, 74 insertions(+), 10 deletions(-)

diff --git a/extras/mini-os/ARM-TODO.txt b/extras/mini-os/ARM-TODO.txt
index 8f4f1da..e30760a 100644
--- a/extras/mini-os/ARM-TODO.txt
+++ b/extras/mini-os/ARM-TODO.txt
@@ -1,6 +1,5 @@
 * scheduling!
 * gic request_irq implementation, currently all IRQs all hardcoded in gic irq 
handler.
-* use device tree instead of the currently hardcoded values
 * Add virtual memory support and make vstart = 0 ( use 4k descriptors instead 
of 1M descriptors )
 * sched
 * fini_gnttab
diff --git a/extras/mini-os/arch/arm/mm.c b/extras/mini-os/arch/arm/mm.c
index be8e747..050e845 100644
--- a/extras/mini-os/arch/arm/mm.c
+++ b/extras/mini-os/arch/arm/mm.c
@@ -1,5 +1,7 @@
 #include <console.h>
+#include <xen/memory.h>
 #include <arch_mm.h>
+#include <mini-os/hypervisor.h>
 #include <libfdt.h>
 #include <lib.h>
 
@@ -102,3 +104,59 @@ void arch_init_p2m(unsigned long max_pfn)
 void arch_init_demand_mapping_area(unsigned long cur_pfn)
 {
 }
+
+/* Get Xen's sugggested physical page assignments for the grant table. */
+static grant_entry_t *get_gnttab_base(void)
+{
+    int hypervisor;
+
+    hypervisor = fdt_path_offset(device_tree, "/hypervisor");
+    BUG_ON(hypervisor < 0);
+
+    int len = 0;
+    const uint64_t *regs = fdt_getprop(device_tree, hypervisor, "reg", &len);
+    if (regs == NULL || len != 16) {
+            printk("Bad 'reg' property: %p %d\n", regs, len);
+            BUG();
+    }
+
+    unsigned int gnttab_base = fdt64_to_cpu(regs[0]);
+
+    printk("FDT suggests grant table base %lx\n", gnttab_base);
+
+    return (grant_entry_t *) gnttab_base;
+}
+
+grant_entry_t *arch_init_gnttab(int nr_grant_frames)
+{
+    struct xen_add_to_physmap xatp;
+    struct gnttab_setup_table setup;
+    xen_pfn_t frames[nr_grant_frames];
+    grant_entry_t *gnttab_table;
+    int i, rc;
+
+    gnttab_table = get_gnttab_base();
+
+    for (i = 0; i < nr_grant_frames; i++)
+    {
+        xatp.domid = DOMID_SELF;
+        xatp.size = 0;      /* Seems to be unused */
+        xatp.space = XENMAPSPACE_grant_table;
+        xatp.idx = i;
+        xatp.gpfn = (((unsigned long) gnttab_table) >> PAGE_SHIFT) + i;
+        rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp);
+        BUG_ON(rc != 0);
+    }
+
+    setup.dom = DOMID_SELF;
+    setup.nr_frames = nr_grant_frames;
+    set_xen_guest_handle(setup.frame_list, frames);
+    HYPERVISOR_grant_table_op(GNTTABOP_setup_table, &setup, 1);
+    if (setup.status != 0)
+    {
+        printk("GNTTABOP_setup_table failed; status = %d\n", setup.status);
+        BUG();
+    }
+
+    return gnttab_table;
+}
diff --git a/extras/mini-os/arch/x86/mm.c b/extras/mini-os/arch/x86/mm.c
index 35df15b..9c6d1b8 100644
--- a/extras/mini-os/arch/x86/mm.c
+++ b/extras/mini-os/arch/x86/mm.c
@@ -942,3 +942,16 @@ void arch_init_mm(unsigned long* start_pfn_p, unsigned 
long* max_pfn_p)
     *start_pfn_p = start_pfn;
     *max_pfn_p = max_pfn;
 }
+
+grant_entry_t *arch_init_gnttab(int nr_grant_frames)
+{
+    struct gnttab_setup_table setup;
+    unsigned long frames[nr_grant_frames];
+
+    setup.dom = DOMID_SELF;
+    setup.nr_frames = nr_grant_frames;
+    set_xen_guest_handle(setup.frame_list, frames);
+
+    HYPERVISOR_grant_table_op(GNTTABOP_setup_table, &setup, 1);
+    return map_frames(frames, nr_grant_frames);
+}
diff --git a/extras/mini-os/gnttab.c b/extras/mini-os/gnttab.c
index 2f1b3d7..f395d12 100644
--- a/extras/mini-os/gnttab.c
+++ b/extras/mini-os/gnttab.c
@@ -164,7 +164,7 @@ gnttabop_error(int16_t status)
 {
     status = -status;
     if (status < 0 || status >= ARRAY_SIZE(gnttabop_error_msgs))
-       return "bad status";
+        return "bad status";
     else
         return gnttabop_error_msgs[status];
 }
@@ -172,8 +172,6 @@ gnttabop_error(int16_t status)
 void
 init_gnttab(void)
 {
-    struct gnttab_setup_table setup;
-    unsigned long frames[NR_GRANT_FRAMES];
     int i;
 
 #ifdef GNT_DEBUG
@@ -182,12 +180,7 @@ init_gnttab(void)
     for (i = NR_RESERVED_ENTRIES; i < NR_GRANT_ENTRIES; i++)
         put_free_entry(i);
 
-    setup.dom = DOMID_SELF;
-    setup.nr_frames = NR_GRANT_FRAMES;
-    set_xen_guest_handle(setup.frame_list, frames);
-
-    HYPERVISOR_grant_table_op(GNTTABOP_setup_table, &setup, 1);
-    gnttab_table = map_frames(frames, NR_GRANT_FRAMES);
+    gnttab_table = arch_init_gnttab(NR_GRANT_FRAMES);
     printk("gnttab_table mapped at %p.\n", gnttab_table);
 }
 
diff --git a/extras/mini-os/include/gnttab.h b/extras/mini-os/include/gnttab.h
index acd6c39..c43ad42 100644
--- a/extras/mini-os/include/gnttab.h
+++ b/extras/mini-os/include/gnttab.h
@@ -12,5 +12,6 @@ unsigned long gnttab_end_transfer(grant_ref_t gref);
 int gnttab_end_access(grant_ref_t ref);
 const char *gnttabop_error(int16_t status);
 void fini_gnttab(void);
+grant_entry_t *arch_init_gnttab(int nr_grant_frames);
 
 #endif /* !__GNTTAB_H__ */
-- 
2.0.0


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel