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freifunkist-firmware/target/linux/brcm2708/patches-4.14/950-0156-vcsm-Revert-to-do-...

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From 3e471b58fb766ed5b45ff8b560231da4704c946d Mon Sep 17 00:00:00 2001
From: Sugizaki Yukimasa <i.can.speak.c.and.basic@gmail.com>
Date: Wed, 10 Jan 2018 06:25:51 +0900
Subject: [PATCH 156/454] vcsm: Revert to do page-table-walk-based cache
manipulating on some ioctl calls
On FLUSH, INVALID, CLEAN_INVALID ioctl calls, cache operations based on
page table walk were used in case that the buffer of the cache is not
pinned. So reverted to do page-table-based cache manipulating.
Signed-off-by: Sugizaki Yukimasa <i.can.speak.c.and.basic@gmail.com>
---
drivers/char/broadcom/vc_sm/vmcs_sm.c | 141 ++++++++++++++++++++------
1 file changed, 110 insertions(+), 31 deletions(-)
--- a/drivers/char/broadcom/vc_sm/vmcs_sm.c
+++ b/drivers/char/broadcom/vc_sm/vmcs_sm.c
@@ -1256,7 +1256,33 @@ static const struct vm_operations_struct
.fault = vcsm_vma_fault,
};
-static int clean_invalid_mem_2d(const void __user *addr,
+/* Converts VCSM_CACHE_OP_* to an operating function. */
+static void (*cache_op_to_func(const unsigned cache_op))
+ (const void*, const void*)
+{
+ switch (cache_op) {
+ case VCSM_CACHE_OP_NOP:
+ return NULL;
+
+ case VCSM_CACHE_OP_INV:
+ return dmac_inv_range;
+
+ case VCSM_CACHE_OP_CLEAN:
+ return dmac_clean_range;
+
+ case VCSM_CACHE_OP_FLUSH:
+ return dmac_flush_range;
+
+ default:
+ pr_err("[%s]: Invalid cache_op: 0x%08x\n", __func__, cache_op);
+ return NULL;
+ }
+}
+
+/*
+ * Clean/invalid/flush cache of which buffer is already pinned (i.e. accessed).
+ */
+static int clean_invalid_contiguous_mem_2d(const void __user *addr,
const size_t block_count, const size_t block_size, const size_t stride,
const unsigned cache_op)
{
@@ -1268,22 +1294,9 @@ static int clean_invalid_mem_2d(const vo
return -EINVAL;
}
- switch (cache_op) {
- case VCSM_CACHE_OP_NOP:
- return 0;
- case VCSM_CACHE_OP_INV:
- op_fn = dmac_inv_range;
- break;
- case VCSM_CACHE_OP_CLEAN:
- op_fn = dmac_clean_range;
- break;
- case VCSM_CACHE_OP_FLUSH:
- op_fn = dmac_flush_range;
- break;
- default:
- pr_err("[%s]: Invalid cache_op: 0x%08x\n", __func__, cache_op);
+ op_fn = cache_op_to_func(cache_op);
+ if (op_fn == NULL)
return -EINVAL;
- }
for (i = 0; i < block_count; i ++, addr += stride)
op_fn(addr, addr + block_size);
@@ -1291,14 +1304,73 @@ static int clean_invalid_mem_2d(const vo
return 0;
}
-static int clean_invalid_mem(const void __user *addr, const size_t size,
+/* Clean/invalid/flush cache of which buffer may be non-pinned. */
+/* The caller must lock current->mm->mmap_sem for read. */
+static int clean_invalid_mem_walk(unsigned long addr, const size_t size,
const unsigned cache_op)
{
- return clean_invalid_mem_2d(addr, 1, size, 0, cache_op);
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
+ unsigned long pgd_next, pud_next, pmd_next;
+ const unsigned long end = ALIGN(addr + size, PAGE_SIZE);
+ void (*op_fn)(const void*, const void*);
+
+ addr &= PAGE_MASK;
+
+ if (addr >= end)
+ return 0;
+
+ op_fn = cache_op_to_func(cache_op);
+ if (op_fn == NULL)
+ return -EINVAL;
+
+ /* Walk PGD */
+ pgd = pgd_offset(current->mm, addr);
+ do {
+ pgd_next = pgd_addr_end(addr, end);
+
+ if (pgd_none(*pgd) || pgd_bad(*pgd))
+ continue;
+
+ /* Walk PUD */
+ pud = pud_offset(pgd, addr);
+ do {
+ pud_next = pud_addr_end(addr, pgd_next);
+ if (pud_none(*pud) || pud_bad(*pud))
+ continue;
+
+ /* Walk PMD */
+ pmd = pmd_offset(pud, addr);
+ do {
+ pmd_next = pmd_addr_end(addr, pud_next);
+ if (pmd_none(*pmd) || pmd_bad(*pmd))
+ continue;
+
+ /* Walk PTE */
+ pte = pte_offset_map(pmd, addr);
+ do {
+ if (pte_none(*pte) || !pte_present(*pte))
+ continue;
+
+ op_fn((const void __user*) addr,
+ (const void __user*) (addr + PAGE_SIZE));
+ } while (pte++, addr += PAGE_SIZE, addr != pmd_next);
+ pte_unmap(pte);
+
+ } while (pmd++, addr = pmd_next, addr != pud_next);
+
+ } while (pud++, addr = pud_next, addr != pgd_next);
+
+ } while (pgd++, addr = pgd_next, addr != end);
+
+ return 0;
}
-static int clean_invalid_resource(const void __user *addr, const size_t size,
- const unsigned cache_op, const int usr_hdl,
+/* Clean/invalid/flush cache of buffer in resource */
+static int clean_invalid_resource_walk(const void __user *addr,
+ const size_t size, const unsigned cache_op, const int usr_hdl,
struct sm_resource_t *resource)
{
int err;
@@ -1355,7 +1427,10 @@ static int clean_invalid_resource(const
return -EFAULT;
}
- err = clean_invalid_mem(addr, size, cache_op);
+ down_read(&current->mm->mmap_sem);
+ err = clean_invalid_mem_walk((unsigned long) addr, size, cache_op);
+ up_read(&current->mm->mmap_sem);
+
if (err)
resource->res_stats[stat_failure]++;
@@ -2004,7 +2079,7 @@ static int vc_sm_ioctl_unlock(struct sm_
const unsigned long start = map->vma->vm_start;
const unsigned long end = map->vma->vm_end;
- ret = clean_invalid_mem((void __user*) start, end - start,
+ ret = clean_invalid_mem_walk(start, end - start,
VCSM_CACHE_OP_FLUSH);
if (ret)
goto error;
@@ -2886,7 +2961,7 @@ static long vc_sm_ioctl(struct file *fil
goto out;
}
- ret = clean_invalid_resource((void __user*) ioparam.addr,
+ ret = clean_invalid_resource_walk((void __user*) ioparam.addr,
ioparam.size, VCSM_CACHE_OP_FLUSH, ioparam.handle,
resource);
vmcs_sm_release_resource(resource, 0);
@@ -2917,7 +2992,7 @@ static long vc_sm_ioctl(struct file *fil
goto out;
}
- ret = clean_invalid_resource((void __user*) ioparam.addr,
+ ret = clean_invalid_resource_walk((void __user*) ioparam.addr,
ioparam.size, VCSM_CACHE_OP_INV, ioparam.handle, resource);
vmcs_sm_release_resource(resource, 0);
if (ret)
@@ -2951,16 +3026,19 @@ static long vc_sm_ioctl(struct file *fil
goto out;
}
- ret = clean_invalid_resource((void __user*) ioparam.s[i].addr,
- ioparam.s[i].size, ioparam.s[i].cmd,
- ioparam.s[i].handle, resource);
+ ret = clean_invalid_resource_walk(
+ (void __user*) ioparam.s[i].addr, ioparam.s[i].size,
+ ioparam.s[i].cmd, ioparam.s[i].handle, resource);
vmcs_sm_release_resource(resource, 0);
if (ret)
goto out;
}
}
break;
- /* Flush/Invalidate the cache for a given mapping. */
+ /*
+ * Flush/Invalidate the cache for a given mapping.
+ * Blocks must be pinned (i.e. accessed) before this call.
+ */
case VMCS_SM_CMD_CLEAN_INVALID2:
{
int i;
@@ -2993,12 +3071,13 @@ static long vc_sm_ioctl(struct file *fil
for (i = 0; i < ioparam.op_count; i++) {
const struct vmcs_sm_ioctl_clean_invalid_block * const op = block + i;
- ret = clean_invalid_mem_2d((void __user*) op->start_address,
- op->block_count, op->block_size,
- op->inter_block_stride, op->invalidate_mode);
if (op->invalidate_mode == VCSM_CACHE_OP_NOP)
continue;
+ ret = clean_invalid_contiguous_mem_2d(
+ (void __user*) op->start_address, op->block_count,
+ op->block_size, op->inter_block_stride,
+ op->invalidate_mode);
if (ret)
break;
}