diff mbox

[1/2] xen/arm: remove handling of XENFEAT_grant_map_identity

Message ID 1412244417-12251-1-git-send-email-stefano.stabellini@eu.citrix.com
State New
Headers show

Commit Message

Stefano Stabellini Oct. 2, 2014, 10:06 a.m. UTC 
Keep the definition of the flag.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
 arch/arm/xen/enlighten.c |    5 ---
 arch/arm/xen/mm32.c      |   85 +---------------------------------------------
 2 files changed, 1 insertion(+), 89 deletions(-)

Comments

David Vrabel Oct. 2, 2014, 10:36 a.m. UTC | #1 
On 02/10/14 11:06, Stefano Stabellini wrote:
> Keep the definition of the flag.

If this is going away in Xen, you can get rid of the flag as well.

I think you should explain why it's being removed as well.

Should this be tagged for stable as well?

David
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Stefano Stabellini Oct. 2, 2014, 11:31 a.m. UTC | #2 
On Thu, 2 Oct 2014, David Vrabel wrote:
> On 02/10/14 11:06, Stefano Stabellini wrote:
> > Keep the definition of the flag.
> 
> If this is going away in Xen, you can get rid of the flag as well.
> 
> I think you should explain why it's being removed as well.

I want to keep the definition of the flag in Xen to avoid the number
being reused. I guess there is no need to keep it in Linux though.


> Should this be tagged for stable as well?

Yep
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diff mbox

Patch

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);