1 files changed, 13 insertions, 1 deletions

diff --git a/drivers/scsi/aacraid/comminit.c b/drivers/scsi/aacraid/comminit.c
index 16310443b55a..d598eba630d0 100644
--- a/drivers/scsi/aacraid/comminit.c
+++ b/drivers/scsi/aacraid/comminit.c
@@ -54,6 +54,7 @@ static int aac_alloc_comm(struct aac_dev *dev, void **commaddr, unsigned long co
         const unsigned long printfbufsiz = 256;
         struct aac_init *init;
         dma_addr_t phys;
+        unsigned long aac_max_hostphysmempages;
 
         size = fibsize + sizeof(struct aac_init) + commsize + commalign + printfbufsiz;
 
@@ -90,7 +91,18 @@ static int aac_alloc_comm(struct aac_dev *dev, void **commaddr, unsigned long co
         init->AdapterFibsPhysicalAddress = cpu_to_le32((u32)phys);
         init->AdapterFibsSize = cpu_to_le32(fibsize);
         init->AdapterFibAlign = cpu_to_le32(sizeof(struct hw_fib));
-        init->HostPhysMemPages = cpu_to_le32(AAC_MAX_HOSTPHYSMEMPAGES);
+        /*
+         * number of 4k pages of host physical memory. The aacraid fw needs
+         * this number to be less than 4gb worth of pages. New firmware doesn't
+         * have any issues with the mapping system, but older Firmware did, and
+         * had *troubles* dealing with the math overloading past 32 bits, thus
+         * we must limit this field.
+         */
+        aac_max_hostphysmempages = dma_get_required_mask(&dev->pdev->dev) >> 12;
+        if (aac_max_hostphysmempages < AAC_MAX_HOSTPHYSMEMPAGES)
+                init->HostPhysMemPages = cpu_to_le32(aac_max_hostphysmempages);
+        else
+                init->HostPhysMemPages = cpu_to_le32(AAC_MAX_HOSTPHYSMEMPAGES);
 
         init->InitFlags = 0;
         if (dev->comm_interface == AAC_COMM_MESSAGE) {