lib/zlib: add s390 hardware support for kernel zlib_inflate

Add decompression functions to zlib_dfltcc library.  Update zlib_inflate
functions with the hooks for s390 hardware support and adjust workspace
structures with extra parameter lists required for hardware inflate
decompression.

Link: http://lkml.kernel.org/r/20200103223334.20669-4-zaslonko@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Co-developed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Chris Mason <clm@fb.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Eduard Shishkin <edward6@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 172 insertions, 1 deletions

diff --git a/lib/zlib_dfltcc/Makefile b/lib/zlib_dfltcc/Makefile
index 863d3b37e09d..8e4d5afbbb10 100644
--- a/lib/zlib_dfltcc/Makefile
+++ b/lib/zlib_dfltcc/Makefile
@@ -8,4 +8,4 @@
 
 obj-$(CONFIG_ZLIB_DFLTCC) += zlib_dfltcc.o
 
-zlib_dfltcc-objs := dfltcc.o dfltcc_deflate.o dfltcc_syms.o
+zlib_dfltcc-objs := dfltcc.o dfltcc_deflate.o dfltcc_inflate.o dfltcc_syms.o
diff --git a/lib/zlib_dfltcc/dfltcc.h b/lib/zlib_dfltcc/dfltcc.h
index 18fed7a444bc..4782c92bb2ff 100644
--- a/lib/zlib_dfltcc/dfltcc.h
+++ b/lib/zlib_dfltcc/dfltcc.h
@@ -104,6 +104,14 @@ int dfltcc_deflate(z_streamp strm,
                    int flush,
                    block_state *result);
 void dfltcc_reset(z_streamp strm, uInt size);
+int dfltcc_can_inflate(z_streamp strm);
+typedef enum {
+    DFLTCC_INFLATE_CONTINUE,
+    DFLTCC_INFLATE_BREAK,
+    DFLTCC_INFLATE_SOFTWARE,
+} dfltcc_inflate_action;
+dfltcc_inflate_action dfltcc_inflate(z_streamp strm,
+                                     int flush, int *ret);
 
 #define DEFLATE_RESET_HOOK(strm) \
     dfltcc_reset((strm), sizeof(deflate_state))
@@ -112,4 +120,24 @@ void dfltcc_reset(z_streamp strm, uInt size);
 
 #define DEFLATE_NEED_CHECKSUM(strm) (!dfltcc_can_deflate((strm)))
 
+#define INFLATE_RESET_HOOK(strm) \
+    dfltcc_reset((strm), sizeof(struct inflate_state))
+
+#define INFLATE_TYPEDO_HOOK(strm, flush) \
+    if (dfltcc_can_inflate((strm))) { \
+        dfltcc_inflate_action action; \
+\
+        RESTORE(); \
+        action = dfltcc_inflate((strm), (flush), &ret); \
+        LOAD(); \
+        if (action == DFLTCC_INFLATE_CONTINUE) \
+            break; \
+        else if (action == DFLTCC_INFLATE_BREAK) \
+            goto inf_leave; \
+    }
+
+#define INFLATE_NEED_CHECKSUM(strm) (!dfltcc_can_inflate((strm)))
+
+#define INFLATE_NEED_UPDATEWINDOW(strm) (!dfltcc_can_inflate((strm)))
+
 #endif /* DFLTCC_H */
diff --git a/lib/zlib_dfltcc/dfltcc_inflate.c b/lib/zlib_dfltcc/dfltcc_inflate.c
new file mode 100644
index 000000000000..12a93a06bd61
--- /dev/null
+++ b/lib/zlib_dfltcc/dfltcc_inflate.c
@@ -0,0 +1,143 @@
+// SPDX-License-Identifier: Zlib
+
+#include "../zlib_inflate/inflate.h"
+#include "dfltcc_util.h"
+#include "dfltcc.h"
+#include <linux/zutil.h>
+
+/*
+ * Expand.
+ */
+int dfltcc_can_inflate(
+    z_streamp strm
+)
+{
+    struct inflate_state *state = (struct inflate_state *)strm->state;
+    struct dfltcc_state *dfltcc_state = GET_DFLTCC_STATE(state);
+
+    /* Unsupported compression settings */
+    if (state->wbits != HB_BITS)
+        return 0;
+
+    /* Unsupported hardware */
+    return is_bit_set(dfltcc_state->af.fns, DFLTCC_XPND) &&
+               is_bit_set(dfltcc_state->af.fmts, DFLTCC_FMT0);
+}
+
+static int dfltcc_was_inflate_used(
+    z_streamp strm
+)
+{
+    struct inflate_state *state = (struct inflate_state *)strm->state;
+    struct dfltcc_param_v0 *param = &GET_DFLTCC_STATE(state)->param;
+
+    return !param->nt;
+}
+
+static int dfltcc_inflate_disable(
+    z_streamp strm
+)
+{
+    struct inflate_state *state = (struct inflate_state *)strm->state;
+    struct dfltcc_state *dfltcc_state = GET_DFLTCC_STATE(state);
+
+    if (!dfltcc_can_inflate(strm))
+        return 0;
+    if (dfltcc_was_inflate_used(strm))
+        /* DFLTCC has already decompressed some data. Since there is not
+         * enough information to resume decompression in software, the call
+         * must fail.
+         */
+        return 1;
+    /* DFLTCC was not used yet - decompress in software */
+    memset(&dfltcc_state->af, 0, sizeof(dfltcc_state->af));
+    return 0;
+}
+
+static dfltcc_cc dfltcc_xpnd(
+    z_streamp strm
+)
+{
+    struct inflate_state *state = (struct inflate_state *)strm->state;
+    struct dfltcc_param_v0 *param = &GET_DFLTCC_STATE(state)->param;
+    size_t avail_in = strm->avail_in;
+    size_t avail_out = strm->avail_out;
+    dfltcc_cc cc;
+
+    cc = dfltcc(DFLTCC_XPND | HBT_CIRCULAR,
+                param, &strm->next_out, &avail_out,
+                &strm->next_in, &avail_in, state->window);
+    strm->avail_in = avail_in;
+    strm->avail_out = avail_out;
+    return cc;
+}
+
+dfltcc_inflate_action dfltcc_inflate(
+    z_streamp strm,
+    int flush,
+    int *ret
+)
+{
+    struct inflate_state *state = (struct inflate_state *)strm->state;
+    struct dfltcc_state *dfltcc_state = GET_DFLTCC_STATE(state);
+    struct dfltcc_param_v0 *param = &dfltcc_state->param;
+    dfltcc_cc cc;
+
+    if (flush == Z_BLOCK) {
+        /* DFLTCC does not support stopping on block boundaries */
+        if (dfltcc_inflate_disable(strm)) {
+            *ret = Z_STREAM_ERROR;
+            return DFLTCC_INFLATE_BREAK;
+        } else
+            return DFLTCC_INFLATE_SOFTWARE;
+    }
+
+    if (state->last) {
+        if (state->bits != 0) {
+            strm->next_in++;
+            strm->avail_in--;
+            state->bits = 0;
+        }
+        state->mode = CHECK;
+        return DFLTCC_INFLATE_CONTINUE;
+    }
+
+    if (strm->avail_in == 0 && !param->cf)
+        return DFLTCC_INFLATE_BREAK;
+
+    if (!state->window || state->wsize == 0) {
+        state->mode = MEM;
+        return DFLTCC_INFLATE_CONTINUE;
+    }
+
+    /* Translate stream to parameter block */
+    param->cvt = CVT_ADLER32;
+    param->sbb = state->bits;
+    param->hl = state->whave; /* Software and hardware history formats match */
+    param->ho = (state->write - state->whave) & ((1 << HB_BITS) - 1);
+    if (param->hl)
+        param->nt = 0; /* Honor history for the first block */
+    param->cv = state->flags ? REVERSE(state->check) : state->check;
+
+    /* Inflate */
+    do {
+        cc = dfltcc_xpnd(strm);
+    } while (cc == DFLTCC_CC_AGAIN);
+
+    /* Translate parameter block to stream */
+    strm->msg = oesc_msg(dfltcc_state->msg, param->oesc);
+    state->last = cc == DFLTCC_CC_OK;
+    state->bits = param->sbb;
+    state->whave = param->hl;
+    state->write = (param->ho + param->hl) & ((1 << HB_BITS) - 1);
+    state->check = state->flags ? REVERSE(param->cv) : param->cv;
+    if (cc == DFLTCC_CC_OP2_CORRUPT && param->oesc != 0) {
+        /* Report an error if stream is corrupted */
+        state->mode = BAD;
+        return DFLTCC_INFLATE_CONTINUE;
+    }
+    state->mode = TYPEDO;
+    /* Break if operands are exhausted, otherwise continue looping */
+    return (cc == DFLTCC_CC_OP1_TOO_SHORT || cc == DFLTCC_CC_OP2_TOO_SHORT) ?
+        DFLTCC_INFLATE_BREAK : DFLTCC_INFLATE_CONTINUE;
+}