This patch adds the following hcall wrapper functions to allocate,
modify and deallocate VAS windows, and retrieve VAS capabilities.
H_ALLOCATE_VAS_WINDOW: Allocate VAS window
H_DEALLOCATE_VAS_WINDOW: Close VAS window
H_MODIFY_VAS_WINDOW: Setup window before using
H_QUERY_VAS_CAPABILITIES: Get VAS capabilities
Signed-off-by: Haren Myneni <haren@xxxxxxxxxxxxx>
Reviewed-by: Nicholas Piggin <npiggin@xxxxxxxxx>
---
arch/powerpc/platforms/pseries/vas.c | 181 +++++++++++++++++++++++++++
1 file changed, 181 insertions(+)
create mode 100644 arch/powerpc/platforms/pseries/vas.c
diff --git a/arch/powerpc/platforms/pseries/vas.c b/arch/powerpc/platforms/pseries/vas.c
new file mode 100644
index 000000000000..fec280979d50
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/vas.c
@@ -0,0 +1,181 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2020-21 IBM Corp.
+ */
+
+#define pr_fmt(fmt) "vas: " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/types.h>
+#include <linux/delay.h>
+#include <asm/hvcall.h>
+#include <asm/plpar_wrappers.h>
+#include <asm/vas.h>
+#include "vas.h"
+
+#define VAS_INVALID_WIN_ADDRESS 0xFFFFFFFFFFFFFFFFul
+#define VAS_DEFAULT_DOMAIN_ID 0xFFFFFFFFFFFFFFFFul
+/* phyp allows one credit per window right now */
+#define DEF_WIN_CREDS 1
+
+static long hcall_return_busy_check(long rc)
+{
+ /* Check if we are stalled for some time */
+ if (H_IS_LONG_BUSY(rc)) {
+ msleep(get_longbusy_msecs(rc));
+ rc = H_BUSY;
+ } else if (rc == H_BUSY) {
+ cond_resched();
+ }
+
+ return rc;
+}
+
+/*
+ * Allocate VAS window HCALL
+ */
+static int h_allocate_vas_window(struct pseries_vas_window *win, u64 *domain,
+ u8 wintype, u16 credits)
+{
+ long retbuf[PLPAR_HCALL9_BUFSIZE] = {0};
+ long rc;
+
+ do {
+ rc = plpar_hcall9(H_ALLOCATE_VAS_WINDOW, retbuf, wintype,
+ credits, domain[0], domain[1], domain[2],
+ domain[3], domain[4], domain[5]);
+
+ rc = hcall_return_busy_check(rc);
+ } while (rc == H_BUSY);
+
+ switch (rc) {
+ case H_SUCCESS:
+ if (win->win_addr == VAS_INVALID_WIN_ADDRESS) {
+ pr_err("HCALL(%x): COPY/PASTE is not supported\n",
+ H_ALLOCATE_VAS_WINDOW);
+ return -ENOTSUPP;
+ }
+ win->vas_win.winid = retbuf[0];
+ win->win_addr = retbuf[1];
+ win->complete_irq = retbuf[2];
+ win->fault_irq = retbuf[3];
+ return 0;
+ case H_PARAMETER:
+ pr_err("HCALL(%x): Invalid window type (%u)\n",
+ H_ALLOCATE_VAS_WINDOW, wintype);
+ return -EINVAL;
+ case H_CONSTRAINED:
+ pr_err("HCALL(%x): Credits(%u) are not available\n",
+ H_ALLOCATE_VAS_WINDOW, credits);
+ return -EPERM;
+ default:
+ pr_err("HCALL(%x): Failed with error %ld\n",
+ H_ALLOCATE_VAS_WINDOW, rc);
+ return -EIO;
+ }
+}
+
+/*
+ * Deallocate VAS window HCALL.
+ */
+static int h_deallocate_vas_window(u64 winid)
+{
+ long rc;
+
+ do {
+ rc = plpar_hcall_norets(H_DEALLOCATE_VAS_WINDOW, winid);
+
+ rc = hcall_return_busy_check(rc);
+ } while (rc == H_BUSY);
+
+ switch (rc) {
+ case H_SUCCESS:
+ return 0;
+ case H_PARAMETER:
+ pr_err("HCALL(%x): Invalid window ID %llu\n",
+ H_DEALLOCATE_VAS_WINDOW, winid);
+ return -EINVAL;
+ default:
+ pr_err("HCALL(%x): Failed with error %ld for window(%llu)\n",
+ H_DEALLOCATE_VAS_WINDOW, rc, winid);
+ return -EIO;
+ }
+}
+
+/*
+ * Modify VAS window.
+ * After the window is opened with allocate window HCALL, configure it
+ * with flags and LPAR PID before using.
+ */
+static int h_modify_vas_window(struct pseries_vas_window *win)
+{
+ long rc;
+ u32 lpid = mfspr(SPRN_PID);
+
+ /*
+ * AMR value is not supported in Linux VAS implementation
+ * phyp ignores it if 0 is passed.
+ */
+ do {
+ rc = plpar_hcall_norets(H_MODIFY_VAS_WINDOW,
+ win->vas_win.winid, lpid, 0,
+ VAS_MOD_WIN_FLAGS, 0);
+
+ rc = hcall_return_busy_check(rc);
+ } while (rc == H_BUSY);
+
+ switch (rc) {
+ case H_SUCCESS:
+ return 0;
+ case H_PARAMETER:
+ pr_err("HCALL(%x): Invalid window ID %u\n",
+ H_MODIFY_VAS_WINDOW, win->vas_win.winid);
+ return -EINVAL;
+ case H_P2:
+ pr_err("HCALL(%x): Window(%d): Invalid LPAR Process ID %u\n",
+ H_MODIFY_VAS_WINDOW, lpid, win->vas_win.winid);
+ return -EINVAL;
+ default:
+ pr_err("HCALL(%x): Failed with error %ld for window(%u)\n",
+ H_MODIFY_VAS_WINDOW, rc, win->vas_win.winid);
+ return -EIO;
+ }
+}
+
+/*
+ * This HCALL is used to determine the capabilities that pHyp provides.
+ * @hcall: H_QUERY_VAS_CAPABILITIES or H_QUERY_NX_CAPABILITIES
+ * @query_type: If 0 is passed, phyp returns the overall capabilities
+ * which provides all feature(s) that are available. Then
+ * query phyp to get the corresponding capabilities for
+ * the specific feature.
+ * Example: H_QUERY_VAS_CAPABILITIES provides VAS GZIP QoS
+ * and VAS GZIP Default capabilities.
+ * H_QUERY_NX_CAPABILITIES provides NX GZIP
+ * capabilities.
+ * @result: Return buffer to save capabilities.
+ */
+int h_query_vas_capabilities(const u64 hcall, u8 query_type, u64 result)
+{
+ long rc;
+
+ rc = plpar_hcall_norets(hcall, query_type, result);
+
+ switch (rc) {
+ case H_SUCCESS:
+ return 0;
+ case H_PARAMETER:
+ pr_err("HCALL(%llx): Invalid query type %u\n", hcall,
+ query_type);
+ return -EINVAL;
+ case H_PRIVILEGE:
+ pr_err("HCALL(%llx): Invalid result buffer 0x%llx\n",
+ hcall, result);
+ return -EACCES;
+ default:
+ pr_err("HCALL(%llx): Unexpected error %ld\n", hcall, rc);
+ return -EIO;
+ }
+}
--
2.18.2
