msm: kgsl: Stop using memdesc->usermem

It shouldn't be illegal for memory descriptors to have multiple virtual
memory mappings under certain circumstances. If that is the case
tracking a single usermem address for each memdesc no longer makes much
sense. Get rid of the memdesc->usermem member and use an atomic counter
to track mappings instead.

Change-Id: Ic0dedbad31bafcd1019ccc8e68657cb7e3c72727
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Harshitha Sai Neelati <hsaine@codeaurora.org>
Signed-off-by: Kamal Agrawal <kamaagra@codeaurora.org>

5 files changed, 56 insertions, 40 deletions

diff --git a/drivers/gpu/msm/kgsl.c b/drivers/gpu/msm/kgsl.c
index 268e7231162a..da379ddcfbfa 100644
--- a/drivers/gpu/msm/kgsl.c
+++ b/drivers/gpu/msm/kgsl.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2008-2020, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2008-2021, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -266,6 +266,7 @@ kgsl_mem_entry_create(void)
 		/* put this ref in the caller functions after init */
 		kref_get(&entry->refcount);
 	}
+	atomic_set(&entry->map_count, 0);
 	return entry;
 }
 #ifdef CONFIG_DMA_SHARED_BUFFER
@@ -2138,7 +2139,7 @@ static int check_vma(unsigned long hostptr, u64 size)
 	return true;
 }
 
-static int memdesc_sg_virt(struct kgsl_memdesc *memdesc)
+static int memdesc_sg_virt(struct kgsl_memdesc *memdesc, unsigned long useraddr)
 {
 	int ret = 0;
 	long npages = 0, i;
@@ -2160,13 +2161,13 @@ static int memdesc_sg_virt(struct kgsl_memdesc *memdesc)
 	}
 
 	down_read(&current->mm->mmap_sem);
-	if (!check_vma(memdesc->useraddr, memdesc->size)) {
+	if (!check_vma(useraddr, memdesc->size)) {
 		up_read(&current->mm->mmap_sem);
 		ret = ~EFAULT;
 		goto out;
 	}
 
-	npages = get_user_pages(current, current->mm, memdesc->useraddr,
+	npages = get_user_pages(current, current->mm, useraddr,
 				sglen, write ? FOLL_WRITE : 0, pages, NULL);
 	up_read(&current->mm->mmap_sem);
 
@@ -2205,7 +2206,6 @@ static int kgsl_setup_anon_useraddr(struct kgsl_pagetable *pagetable,
 
 	entry->memdesc.pagetable = pagetable;
 	entry->memdesc.size = (uint64_t) size;
-	entry->memdesc.useraddr = hostptr;
 	entry->memdesc.flags |= KGSL_MEMFLAGS_USERMEM_ADDR;
 
 	if (kgsl_memdesc_use_cpu_map(&entry->memdesc)) {
@@ -2213,15 +2213,15 @@ static int kgsl_setup_anon_useraddr(struct kgsl_pagetable *pagetable,
 
 		/* Register the address in the database */
 		ret = kgsl_mmu_set_svm_region(pagetable,
-			(uint64_t) entry->memdesc.useraddr, (uint64_t) size);
+			(uint64_t) hostptr, (uint64_t) size);
 
 		if (ret)
 			return ret;
 
-		entry->memdesc.gpuaddr = (uint64_t)  entry->memdesc.useraddr;
+		entry->memdesc.gpuaddr = (uint64_t) hostptr;
 	}
 
-	return memdesc_sg_virt(&entry->memdesc);
+	return memdesc_sg_virt(&entry->memdesc, hostptr);
 }
 
 static int match_file(const void *p, struct file *file, unsigned int fd)
@@ -2306,8 +2306,8 @@ static int kgsl_setup_dmabuf_useraddr(struct kgsl_device *device,
 		return ret;
 	}
 
-	/* Setup the user addr/cache mode for cache operations */
-	entry->memdesc.useraddr = hostptr;
+	/* Setup the cache mode for cache operations */
+
 	_setup_cache_mode(entry, vma);
 	up_read(&current->mm->mmap_sem);
 	return 0;
@@ -3325,7 +3325,12 @@ long kgsl_ioctl_gpumem_get_info(struct kgsl_device_private *dev_priv,
 	param->flags = (unsigned int) entry->memdesc.flags;
 	param->size = (size_t) entry->memdesc.size;
 	param->mmapsize = (size_t) kgsl_memdesc_footprint(&entry->memdesc);
-	param->useraddr = entry->memdesc.useraddr;
+	/*
+	 * Entries can have multiple user mappings so thre isn't any one address
+	 * we can report. Plus, the user should already know their mappings, so
+	 * there isn't any value in reporting it back to them.
+	 */
+	param->useraddr = 0;
 
 	kgsl_mem_entry_put(entry);
 	return result;
@@ -3791,9 +3796,6 @@ static int _sparse_bind(struct kgsl_process_private *process,
 	if (memdesc->gpuaddr)
 		return -EINVAL;
 
-	if (memdesc->useraddr != 0)
-		return -EINVAL;
-
 	pagetable = memdesc->pagetable;
 
 	/* Clear out any mappings */
@@ -4073,7 +4075,12 @@ long kgsl_ioctl_gpuobj_info(struct kgsl_device_private *dev_priv,
 	param->flags = entry->memdesc.flags;
 	param->size = entry->memdesc.size;
 	param->va_len = kgsl_memdesc_footprint(&entry->memdesc);
-	param->va_addr = (uint64_t) entry->memdesc.useraddr;
+	/*
+	 * Entries can have multiple user mappings so thre isn't any one address
+	 * we can report. Plus, the user should already know their mappings, so
+	 * there isn't any value in reporting it back to them.
+	 */
+	param->va_addr = 0;
 
 	kgsl_mem_entry_put(entry);
 	return 0;
@@ -4241,6 +4248,8 @@ static void kgsl_gpumem_vm_open(struct vm_area_struct *vma)
 
 	if (kgsl_mem_entry_get(entry) == 0)
 		vma->vm_private_data = NULL;
+
+	atomic_inc(&entry->map_count);
 }
 
 static int
@@ -4264,7 +4273,8 @@ kgsl_gpumem_vm_close(struct vm_area_struct *vma)
 	if (!entry)
 		return;
 
-	entry->memdesc.useraddr = 0;
+	atomic_dec(&entry->map_count);
+
 	kgsl_mem_entry_put(entry);
 }
 
@@ -4303,7 +4313,8 @@ get_mmap_entry(struct kgsl_process_private *private,
 		}
 	}
 
-	if (entry->memdesc.useraddr != 0) {
+	/* Don't allow ourselves to remap user memory */
+	if (entry->memdesc.flags & KGSL_MEMFLAGS_USERMEM_ADDR) {
 		ret = -EBUSY;
 		goto err_put;
 	}
@@ -4627,9 +4638,9 @@ static int kgsl_mmap(struct file *file, struct vm_area_struct *vma)
 
 	vma->vm_file = file;
 
-	entry->memdesc.useraddr = vma->vm_start;
+	atomic_inc(&entry->map_count);
 
-	trace_kgsl_mem_mmap(entry);
+	trace_kgsl_mem_mmap(entry, vma->vm_start);
 	return 0;
 }
 
diff --git a/drivers/gpu/msm/kgsl.h b/drivers/gpu/msm/kgsl.h
index 6b8ef82d340f..6e6edf67064d 100644
--- a/drivers/gpu/msm/kgsl.h
+++ b/drivers/gpu/msm/kgsl.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2008-2016,2018-2019, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2008-2016,2018-2019,2021, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -197,11 +197,9 @@ struct kgsl_memdesc_ops {
  * @pagetable: Pointer to the pagetable that the object is mapped in
  * @hostptr: Kernel virtual address
  * @hostptr_count: Number of threads using hostptr
- * @useraddr: User virtual address (if applicable)
  * @gpuaddr: GPU virtual address
  * @physaddr: Physical address of the memory object
  * @size: Size of the memory object
- * @mapsize: Size of memory mapped in userspace
  * @priv: Internal flags and settings
  * @sgt: Scatter gather table for allocated pages
  * @ops: Function hooks for the memdesc memory type
@@ -216,11 +214,9 @@ struct kgsl_memdesc {
 	struct kgsl_pagetable *pagetable;
 	void *hostptr;
 	unsigned int hostptr_count;
-	unsigned long useraddr;
 	uint64_t gpuaddr;
 	phys_addr_t physaddr;
 	uint64_t size;
-	uint64_t mapsize;
 	unsigned int priv;
 	struct sg_table *sgt;
 	struct kgsl_memdesc_ops *ops;
@@ -278,6 +274,11 @@ struct kgsl_mem_entry {
 	struct work_struct work;
 	spinlock_t bind_lock;
 	struct rb_root bind_tree;
+	/*
+	 * @map_count: Count how many vmas this object is mapped in - used for
+	 * debugfs accounting
+	 */
+	atomic_t map_count;
 };
 
 struct kgsl_device_private;
diff --git a/drivers/gpu/msm/kgsl_debugfs.c b/drivers/gpu/msm/kgsl_debugfs.c
index 30769de41a70..36bb4d801df9 100644
--- a/drivers/gpu/msm/kgsl_debugfs.c
+++ b/drivers/gpu/msm/kgsl_debugfs.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2002,2008-2017,2020, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2002,2008-2017,2020-2021, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -149,7 +149,11 @@ static int print_mem_entry(void *data, void *ptr)
 	flags[3] = get_alignflag(m);
 	flags[4] = get_cacheflag(m);
 	flags[5] = kgsl_memdesc_use_cpu_map(m) ? 'p' : '-';
-	flags[6] = (m->useraddr) ? 'Y' : 'N';
+	/*
+	 * Show Y if at least one vma has this entry
+	 * mapped (could be multiple)
+	 */
+	flags[6] = atomic_read(&entry->map_count) ? 'Y' : 'N';
 	flags[7] = kgsl_memdesc_is_secured(m) ?  's' : '-';
 	flags[8] = m->flags & KGSL_MEMFLAGS_SPARSE_PHYS ? 'P' : '-';
 	flags[9] = '\0';
@@ -160,12 +164,16 @@ static int print_mem_entry(void *data, void *ptr)
 		kgsl_get_egl_counts(entry, &egl_surface_count,
 						&egl_image_count);
 
-	seq_printf(s, "%pK %pK %16llu %5d %9s %10s %16s %5d %16llu %6d %6d",
+	seq_printf(s, "%pK %d %16llu %5d %9s %10s %16s %5d %16d %6d %6d",
 			(uint64_t *)(uintptr_t) m->gpuaddr,
-			(unsigned long *) m->useraddr,
-			m->size, entry->id, flags,
+			/*
+			 * Show zero for the useraddr - we can't reliably track
+			 * that value for multiple vmas anyway
+			 */
+			0, m->size, entry->id, flags,
 			memtype_str(usermem_type),
-			usage, (m->sgt ? m->sgt->nents : 0), m->mapsize,
+			usage, (m->sgt ? m->sgt->nents : 0),
+			atomic_read(&entry->map_count),
 			egl_surface_count, egl_image_count);
 
 	if (entry->metadata[0] != 0)
@@ -235,7 +243,7 @@ static int process_mem_seq_show(struct seq_file *s, void *ptr)
 	if (ptr == SEQ_START_TOKEN) {
 		seq_printf(s, "%16s %16s %16s %5s %9s %10s %16s %5s %16s %6s %6s\n",
 			"gpuaddr", "useraddr", "size", "id", "flags", "type",
-			"usage", "sglen", "mapsize", "eglsrf", "eglimg");
+			"usage", "sglen", "mapcount", "eglsrf", "eglimg");
 		return 0;
 	} else
 		return print_mem_entry(s, ptr);
diff --git a/drivers/gpu/msm/kgsl_sharedmem.c b/drivers/gpu/msm/kgsl_sharedmem.c
index b233211620da..0f5e7a0ebc29 100644
--- a/drivers/gpu/msm/kgsl_sharedmem.c
+++ b/drivers/gpu/msm/kgsl_sharedmem.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2002,2007-2017,2020, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2002,2007-2017,2020-2021, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -373,8 +373,6 @@ static int kgsl_page_alloc_vmfault(struct kgsl_memdesc *memdesc,
 		get_page(page);
 		vmf->page = page;
 
-		memdesc->mapsize += PAGE_SIZE;
-
 		return 0;
 	}
 
@@ -504,8 +502,6 @@ static int kgsl_contiguous_vmfault(struct kgsl_memdesc *memdesc,
 	else if (ret == -EFAULT)
 		return VM_FAULT_SIGBUS;
 
-	memdesc->mapsize += PAGE_SIZE;
-
 	return VM_FAULT_NOPAGE;
 }
 
diff --git a/drivers/gpu/msm/kgsl_trace.h b/drivers/gpu/msm/kgsl_trace.h
index 2d9bca7e7d7f..5f325729f71e 100644
--- a/drivers/gpu/msm/kgsl_trace.h
+++ b/drivers/gpu/msm/kgsl_trace.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2011-2016,2020, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2011-2016,2020-2021, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -433,9 +433,9 @@ TRACE_EVENT(kgsl_mem_alloc,
 
 TRACE_EVENT(kgsl_mem_mmap,
 
-	TP_PROTO(struct kgsl_mem_entry *mem_entry),
+	TP_PROTO(struct kgsl_mem_entry *mem_entry, unsigned long useraddr),
 
-	TP_ARGS(mem_entry),
+	TP_ARGS(mem_entry, useraddr),
 
 	TP_STRUCT__entry(
 		__field(unsigned long, useraddr)
@@ -447,7 +447,7 @@ TRACE_EVENT(kgsl_mem_mmap,
 	),
 
 	TP_fast_assign(
-		__entry->useraddr = mem_entry->memdesc.useraddr;
+		__entry->useraddr = useraddr;
 		__entry->gpuaddr = mem_entry->memdesc.gpuaddr;
 		__entry->size = mem_entry->memdesc.size;
 		kgsl_get_memory_usage(__entry->usage, sizeof(__entry->usage),