2 files changed, 113 insertions, 0 deletions

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 41aca003ee82..71121d99235d 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -545,6 +545,103 @@ void xhci_endpoint_zero(struct xhci_hcd *xhci,
          */
 }
 
+/* Set up the scratchpad buffer array and scratchpad buffers, if needed. */
+static int scratchpad_alloc(struct xhci_hcd *xhci, gfp_t flags)
+{
+        int i;
+        struct device *dev = xhci_to_hcd(xhci)->self.controller;
+        int num_sp = HCS_MAX_SCRATCHPAD(xhci->hcs_params2);
+
+        xhci_dbg(xhci, "Allocating %d scratchpad buffers\n", num_sp);
+
+        if (!num_sp)
+                return 0;
+
+        xhci->scratchpad = kzalloc(sizeof(*xhci->scratchpad), flags);
+        if (!xhci->scratchpad)
+                goto fail_sp;
+
+        xhci->scratchpad->sp_array =
+                pci_alloc_consistent(to_pci_dev(dev),
+                                     num_sp * sizeof(u64),
+                                     &xhci->scratchpad->sp_dma);
+        if (!xhci->scratchpad->sp_array)
+                goto fail_sp2;
+
+        xhci->scratchpad->sp_buffers = kzalloc(sizeof(void *) * num_sp, flags);
+        if (!xhci->scratchpad->sp_buffers)
+                goto fail_sp3;
+
+        xhci->scratchpad->sp_dma_buffers =
+                kzalloc(sizeof(dma_addr_t) * num_sp, flags);
+
+        if (!xhci->scratchpad->sp_dma_buffers)
+                goto fail_sp4;
+
+        xhci->dcbaa->dev_context_ptrs[0] = xhci->scratchpad->sp_dma;
+        for (i = 0; i < num_sp; i++) {
+                dma_addr_t dma;
+                void *buf = pci_alloc_consistent(to_pci_dev(dev),
+                                                 xhci->page_size, &dma);
+                if (!buf)
+                        goto fail_sp5;
+
+                xhci->scratchpad->sp_array[i] = dma;
+                xhci->scratchpad->sp_buffers[i] = buf;
+                xhci->scratchpad->sp_dma_buffers[i] = dma;
+        }
+
+        return 0;
+
+ fail_sp5:
+        for (i = i - 1; i >= 0; i--) {
+                pci_free_consistent(to_pci_dev(dev), xhci->page_size,
+                                    xhci->scratchpad->sp_buffers[i],
+                                    xhci->scratchpad->sp_dma_buffers[i]);
+        }
+        kfree(xhci->scratchpad->sp_dma_buffers);
+
+ fail_sp4:
+        kfree(xhci->scratchpad->sp_buffers);
+
+ fail_sp3:
+        pci_free_consistent(to_pci_dev(dev), num_sp * sizeof(u64),
+                            xhci->scratchpad->sp_array,
+                            xhci->scratchpad->sp_dma);
+
+ fail_sp2:
+        kfree(xhci->scratchpad);
+        xhci->scratchpad = NULL;
+
+ fail_sp:
+        return -ENOMEM;
+}
+
+static void scratchpad_free(struct xhci_hcd *xhci)
+{
+        int num_sp;
+        int i;
+        struct pci_dev  *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
+
+        if (!xhci->scratchpad)
+                return;
+
+        num_sp = HCS_MAX_SCRATCHPAD(xhci->hcs_params2);
+
+        for (i = 0; i < num_sp; i++) {
+                pci_free_consistent(pdev, xhci->page_size,
+                                    xhci->scratchpad->sp_buffers[i],
+                                    xhci->scratchpad->sp_dma_buffers[i]);
+        }
+        kfree(xhci->scratchpad->sp_dma_buffers);
+        kfree(xhci->scratchpad->sp_buffers);
+        pci_free_consistent(pdev, num_sp * sizeof(u64),
+                            xhci->scratchpad->sp_array,
+                            xhci->scratchpad->sp_dma);
+        kfree(xhci->scratchpad);
+        xhci->scratchpad = NULL;
+}
+
 void xhci_mem_cleanup(struct xhci_hcd *xhci)
 {
         struct pci_dev  *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
@@ -593,6 +690,7 @@ void xhci_mem_cleanup(struct xhci_hcd *xhci)
 
         xhci->page_size = 0;
         xhci->page_shift = 0;
+        scratchpad_free(xhci);
 }
 
 int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
@@ -755,7 +853,11 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
         for (i = 0; i < MAX_HC_SLOTS; ++i)
                 xhci->devs[i] = 0;
 
+        if (scratchpad_alloc(xhci, flags))
+                goto fail;
+
         return 0;
+
 fail:
         xhci_warn(xhci, "Couldn't initialize memory\n");
         xhci_mem_cleanup(xhci);
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 074728e10225..5a09b9a26e0d 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -89,6 +89,7 @@ struct xhci_cap_regs {
 #define HCS_ERST_MAX(p)         (((p) >> 4) & 0xf)
 /* bit 26 Scratchpad restore - for save/restore HW state - not used yet */
 /* bits 27:31 number of Scratchpad buffers SW must allocate for the HW */
+#define HCS_MAX_SCRATCHPAD(p)   (((p) >> 27) & 0x1f)
 
 /* HCSPARAMS3 - hcs_params3 - bitmasks */
 /* bits 0:7, Max U1 to U0 latency for the roothub ports */
@@ -951,6 +952,13 @@ struct xhci_erst {
         unsigned int            erst_size;
 };
 
+struct xhci_scratchpad {
+        u64 *sp_array;
+        dma_addr_t sp_dma;
+        void **sp_buffers;
+        dma_addr_t *sp_dma_buffers;
+};
+
 /*
  * Each segment table entry is 4*32bits long.  1K seems like an ok size:
  * (1K bytes * 8bytes/bit) / (4*32 bits) = 64 segment entries in the table,
@@ -1005,6 +1013,9 @@ struct xhci_hcd {
         struct xhci_ring        *cmd_ring;
         struct xhci_ring        *event_ring;
         struct xhci_erst        erst;
+        /* Scratchpad */
+        struct xhci_scratchpad  *scratchpad;
+
         /* slot enabling and address device helpers */
         struct completion       addr_dev;
         int slot_id;