powerpc/85xx: flush dcache before resetting cores

When we do an mpic_reset_core we need to make sure the dcache is flushed.

Signed-off-by: Matthew McClintock <msm@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

diff --git a/arch/powerpc/platforms/85xx/smp.c b/arch/powerpc/platforms/85xx/smp.c
index c9a77fa62744b832a3f1340edd3196303a27c383..5c91a992f02b82049a6dbdaf21dc2974501f8b22 100644 (file)
--- a/arch/powerpc/platforms/85xx/smp.c
+++ b/arch/powerpc/platforms/85xx/smp.c
@@ -16,6 +16,7 @@
 #include <linux/delay.h>
 #include <linux/of.h>
 #include <linux/kexec.h>
+#include <linux/highmem.h>
 
 #include <asm/machdep.h>
 #include <asm/pgtable.h>
@@ -140,11 +141,60 @@ static void mpc85xx_smp_kexec_down(void *arg)
                ppc_md.kexec_cpu_down(0,1);
 }
 
+static void map_and_flush(unsigned long paddr)
+{
+       struct page *page = pfn_to_page(paddr >> PAGE_SHIFT);
+       unsigned long kaddr  = (unsigned long)kmap(page);
+
+       flush_dcache_range(kaddr, kaddr + PAGE_SIZE);
+       kunmap(page);
+}
+
+/**
+ * Before we reset the other cores, we need to flush relevant cache
+ * out to memory so we don't get anything corrupted, some of these flushes
+ * are performed out of an overabundance of caution as interrupts are not
+ * disabled yet and we can switch cores
+ */
+static void mpc85xx_smp_flush_dcache_kexec(struct kimage *image)
+{
+       kimage_entry_t *ptr, entry;
+       unsigned long paddr;
+       int i;
+
+       if (image->type == KEXEC_TYPE_DEFAULT) {
+               /* normal kexec images are stored in temporary pages */
+               for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE);
+                    ptr = (entry & IND_INDIRECTION) ?
+                               phys_to_virt(entry & PAGE_MASK) : ptr + 1) {
+                       if (!(entry & IND_DESTINATION)) {
+                               map_and_flush(entry);
+                       }
+               }
+               /* flush out last IND_DONE page */
+               map_and_flush(entry);
+       } else {
+               /* crash type kexec images are copied to the crash region */
+               for (i = 0; i < image->nr_segments; i++) {
+                       struct kexec_segment *seg = &image->segment[i];
+                       for (paddr = seg->mem; paddr < seg->mem + seg->memsz;
+                            paddr += PAGE_SIZE) {
+                               map_and_flush(paddr);
+                       }
+               }
+       }
+
+       /* also flush the kimage struct to be passed in as well */
+       flush_dcache_range((unsigned long)image,
+                          (unsigned long)image + sizeof(*image));
+}
+
 static void mpc85xx_smp_machine_kexec(struct kimage *image)
 {
        int timeout = INT_MAX;
        int i, num_cpus = num_present_cpus();
 
+       mpc85xx_smp_flush_dcache_kexec(image);
 
        if (image->type == KEXEC_TYPE_DEFAULT)
                smp_call_function(mpc85xx_smp_kexec_down, NULL, 0);