Define some helper functions to access the MMIO regions. We use these
in follow-on patches to read/write VAS hardware registers. They are
also used to later issue 'paste' instructions to submit requests to
the NX hardware engines.
Signed-off-by: Sukadev Bhattiprolu <suka...@linux.vnet.ibm.com>
---
Changelog [v8]:
Minor cleanup of error/debug messages
Changelog [v6]:
- Minor reorg to make setup/cleanup functions more symmetric
Changelog [v5]:
- [Ben Herrenschmidt]: Need cachable mapping for paste regions
and non-cachable mapping for the MMIO regions. So, just use
ioremap() for mapping the MMIO regions; use "winctx" instead
of "wc" to avoid collision with "write combine".
Changelog [v3]:
- Minor reorg/cleanup of map/unmap functions
Changelog [v2]:
- Get HVWC, UWC and paste addresses from window->vinst (i.e DT)
rather than kernel macros.
---
arch/powerpc/platforms/powernv/vas-window.c | 174 ++++++++++++++++++++++++++++
1 file changed, 174 insertions(+)
diff --git a/arch/powerpc/platforms/powernv/vas-window.c
b/arch/powerpc/platforms/powernv/vas-window.c
index de21acb..642814a2 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -7,11 +7,185 @@
* 2 of the License, or (at your option) any later version.
*/
+#define pr_fmt(fmt) "vas: " fmt
+
#include <linux/types.h>
#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/io.h>
#include "vas.h"
+/*
+ * Compute the paste address region for the window @window using the
+ * ->paste_base_addr and ->paste_win_id_shift we got from device tree.
+ */
+static void compute_paste_address(struct vas_window *window, u64 *addr, int
*len)
+{
+ int winid;
+ u64 base, shift;
+
+ base = window->vinst->paste_base_addr;
+ shift = window->vinst->paste_win_id_shift;
+ winid = window->winid;
+
+ *addr = base + (winid << shift);
+ if (len)
+ *len = PAGE_SIZE;
+
+ pr_debug("Txwin #%d: Paste addr 0x%llx\n", winid, *addr);
+}
+
+static inline void get_hvwc_mmio_bar(struct vas_window *window,
+ u64 *start, int *len)
+{
+ u64 pbaddr;
+
+ pbaddr = window->vinst->hvwc_bar_start;
+ *start = pbaddr + window->winid * VAS_HVWC_SIZE;
+ *len = VAS_HVWC_SIZE;
+}
+
+static inline void get_uwc_mmio_bar(struct vas_window *window,
+ u64 *start, int *len)
+{
+ u64 pbaddr;
+
+ pbaddr = window->vinst->uwc_bar_start;
+ *start = pbaddr + window->winid * VAS_UWC_SIZE;
+ *len = VAS_UWC_SIZE;
+}
+
+/*
+ * Map the paste bus address of the given send window into kernel address
+ * space. Unlike MMIO regions (map_mmio_region() below), paste region must
+ * be mapped cache-able and is only applicable to send windows.
+ */
+void *map_paste_region(struct vas_window *txwin)
+{
+ int len;
+ void *map;
+ char *name;
+ u64 start;
+
+ name = kasprintf(GFP_KERNEL, "window-v%d-w%d", txwin->vinst->vas_id,
+ txwin->winid);
+ if (!name)
+ goto free_name;
+
+ txwin->paste_addr_name = name;
+ compute_paste_address(txwin, &start, &len);
+
+ if (!request_mem_region(start, len, name)) {
+ pr_devel("%s(): request_mem_region(0x%llx, %d) failed\n",
+ __func__, start, len);
+ goto free_name;
+ }
+
+ map = ioremap_cache(start, len);
+ if (!map) {
+ pr_devel("%s(): ioremap_cache(0x%llx, %d) failed\n", __func__,
+ start, len);
+ goto free_name;
+ }
+
+ pr_devel("Mapped paste addr 0x%llx to kaddr 0x%p\n", start, map);
+ return map;
+
+free_name:
+ kfree(name);
+ return ERR_PTR(-ENOMEM);
+}
+
+
+static void *map_mmio_region(char *name, u64 start, int len)
+{
+ void *map;
+
+ if (!request_mem_region(start, len, name)) {
+ pr_devel("%s(): request_mem_region(0x%llx, %d) failed\n",
+ __func__, start, len);
+ return NULL;
+ }
+
+ map = ioremap(start, len);
+ if (!map) {
+ pr_devel("%s(): ioremap(0x%llx, %d) failed\n", __func__, start,
+ len);
+ return NULL;
+ }
+
+ return map;
+}
+
+static void unmap_region(void *addr, u64 start, int len)
+{
+ iounmap(addr);
+ release_mem_region((phys_addr_t)start, len);
+}
+
+/*
+ * Unmap the paste address region for a window.
+ */
+void unmap_paste_region(struct vas_window *window)
+{
+ int len;
+ u64 busaddr_start;
+
+ if (window->paste_kaddr) {
+ compute_paste_address(window, &busaddr_start, &len);
+ unmap_region(window->paste_kaddr, busaddr_start, len);
+ window->paste_kaddr = NULL;
+ kfree(window->paste_addr_name);
+ window->paste_addr_name = NULL;
+ }
+}
+
+/*
+ * Unmap the MMIO regions for a window.
+ */
+static void unmap_winctx_mmio_bars(struct vas_window *window)
+{
+ int len;
+ u64 busaddr_start;
+
+ if (window->hvwc_map) {
+ get_hvwc_mmio_bar(window, &busaddr_start, &len);
+ unmap_region(window->hvwc_map, busaddr_start, len);
+ window->hvwc_map = NULL;
+ }
+
+ if (window->uwc_map) {
+ get_uwc_mmio_bar(window, &busaddr_start, &len);
+ unmap_region(window->uwc_map, busaddr_start, len);
+ window->uwc_map = NULL;
+ }
+}
+
+/*
+ * Find the Hypervisor Window Context (HVWC) MMIO Base Address Region and the
+ * OS/User Window Context (UWC) MMIO Base Address Region for the given window.
+ * Map these bus addresses and save the mapped kernel addresses in @window.
+ */
+int map_winctx_mmio_bars(struct vas_window *window)
+{
+ int len;
+ u64 start;
+
+ get_hvwc_mmio_bar(window, &start, &len);
+ window->hvwc_map = map_mmio_region("HVWCM_Window", start, len);
+
+ get_uwc_mmio_bar(window, &start, &len);
+ window->uwc_map = map_mmio_region("UWCM_Window", start, len);
+
+ if (!window->hvwc_map || !window->uwc_map) {
+ unmap_winctx_mmio_bars(window);
+ return -1;
+ }
+
+ return 0;
+}
+
/* stub for now */
int vas_win_close(struct vas_window *window)
{
--
2.7.4
