xen/arm: remove handling of XENFEAT_grant_map_identity

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>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>

2 files changed, 1 insertions, 89 deletions

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 0e15f011f9c8..c7ca936ebd99 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 3b99860fd7ae..a5a93fce913b 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);