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Subject[PATCH v8 01/13] xen/arm: remove handling of XENFEAT_grant_map_identity
Date
The feature has been removed from Xen. Also Linux cannot use it on ARM32
without CONFIG_ARM_LPAE.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

---
Changes in v2:

- remove the definition of XENFEAT_grant_map_identity.
---
arch/arm/xen/enlighten.c | 5 ---
arch/arm/xen/mm32.c | 85 +-------------------------------------
include/xen/interface/features.h | 3 --
3 files changed, 1 insertion(+), 92 deletions(-)

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 0e15f01..c7ca936 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -261,11 +261,6 @@ static int __init xen_guest_init(void)

xen_setup_features();

- if (!xen_feature(XENFEAT_grant_map_identity)) {
- pr_warn("Please upgrade your Xen.\n"
- "If your platform has any non-coherent DMA devices, they won't work properly.\n");
- }
-
if (xen_feature(XENFEAT_dom0))
xen_start_info->flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
else
diff --git a/arch/arm/xen/mm32.c b/arch/arm/xen/mm32.c
index 3b99860..a5a93fc 100644
--- a/arch/arm/xen/mm32.c
+++ b/arch/arm/xen/mm32.c
@@ -5,70 +5,6 @@

#include <xen/features.h>

-static DEFINE_PER_CPU(unsigned long, xen_mm32_scratch_virt);
-static DEFINE_PER_CPU(pte_t *, xen_mm32_scratch_ptep);
-
-static int alloc_xen_mm32_scratch_page(int cpu)
-{
- struct page *page;
- unsigned long virt;
- pmd_t *pmdp;
- pte_t *ptep;
-
- if (per_cpu(xen_mm32_scratch_ptep, cpu) != NULL)
- return 0;
-
- page = alloc_page(GFP_KERNEL);
- if (page == NULL) {
- pr_warn("Failed to allocate xen_mm32_scratch_page for cpu %d\n", cpu);
- return -ENOMEM;
- }
-
- virt = (unsigned long)__va(page_to_phys(page));
- pmdp = pmd_offset(pud_offset(pgd_offset_k(virt), virt), virt);
- ptep = pte_offset_kernel(pmdp, virt);
-
- per_cpu(xen_mm32_scratch_virt, cpu) = virt;
- per_cpu(xen_mm32_scratch_ptep, cpu) = ptep;
-
- return 0;
-}
-
-static int xen_mm32_cpu_notify(struct notifier_block *self,
- unsigned long action, void *hcpu)
-{
- int cpu = (long)hcpu;
- switch (action) {
- case CPU_UP_PREPARE:
- if (alloc_xen_mm32_scratch_page(cpu))
- return NOTIFY_BAD;
- break;
- default:
- break;
- }
- return NOTIFY_OK;
-}
-
-static struct notifier_block xen_mm32_cpu_notifier = {
- .notifier_call = xen_mm32_cpu_notify,
-};
-
-static void* xen_mm32_remap_page(dma_addr_t handle)
-{
- unsigned long virt = get_cpu_var(xen_mm32_scratch_virt);
- pte_t *ptep = __get_cpu_var(xen_mm32_scratch_ptep);
-
- *ptep = pfn_pte(handle >> PAGE_SHIFT, PAGE_KERNEL);
- local_flush_tlb_kernel_page(virt);
-
- return (void*)virt;
-}
-
-static void xen_mm32_unmap(void *vaddr)
-{
- put_cpu_var(xen_mm32_scratch_virt);
-}
-

/* functions called by SWIOTLB */

@@ -88,13 +24,7 @@ static void dma_cache_maint(dma_addr_t handle, unsigned long offset,

if (!pfn_valid(pfn))
{
- /* Cannot map the page, we don't know its physical address.
- * Return and hope for the best */
- if (!xen_feature(XENFEAT_grant_map_identity))
- return;
- vaddr = xen_mm32_remap_page(handle) + offset;
- op(vaddr, len, dir);
- xen_mm32_unmap(vaddr - offset);
+ /* TODO: cache flush */
} else {
struct page *page = pfn_to_page(pfn);

@@ -181,22 +111,9 @@ void xen_dma_sync_single_for_device(struct device *hwdev,

int __init xen_mm32_init(void)
{
- int cpu;
-
if (!xen_initial_domain())
return 0;

- register_cpu_notifier(&xen_mm32_cpu_notifier);
- get_online_cpus();
- for_each_online_cpu(cpu) {
- if (alloc_xen_mm32_scratch_page(cpu)) {
- put_online_cpus();
- unregister_cpu_notifier(&xen_mm32_cpu_notifier);
- return -ENOMEM;
- }
- }
- put_online_cpus();
-
return 0;
}
arch_initcall(xen_mm32_init);
diff --git a/include/xen/interface/features.h b/include/xen/interface/features.h
index 14334d0..131a6cc 100644
--- a/include/xen/interface/features.h
+++ b/include/xen/interface/features.h
@@ -53,9 +53,6 @@
/* operation as Dom0 is supported */
#define XENFEAT_dom0 11

-/* Xen also maps grant references at pfn = mfn */
-#define XENFEAT_grant_map_identity 12
-
#define XENFEAT_NR_SUBMAPS 1

#endif /* __XEN_PUBLIC_FEATURES_H__ */
--
1.7.10.4


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