pstore/ram: Allow specifying ecc parameters in platform data

Allow specifying ecc parameters in platform data

Signed-off-by: Arve Hjønnevåg <arve@android.com>
[jstultz: Tweaked commit subject & add commit message]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Anton Vorontsov <anton@enomsg.org>

3 files changed, 52 insertions, 41 deletions

diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 38babb3a9384..a5ee252c264e 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -83,7 +83,7 @@ struct ramoops_context {
         size_t console_size;
         size_t ftrace_size;
         int dump_oops;
-        int ecc_size;
+        struct persistent_ram_ecc_info ecc_info;
         unsigned int max_dump_cnt;
         unsigned int dump_write_cnt;
         unsigned int dump_read_cnt;
@@ -322,7 +322,8 @@ static int ramoops_init_przs(struct device *dev, struct ramoops_context *cxt,
         for (i = 0; i < cxt->max_dump_cnt; i++) {
                 size_t sz = cxt->record_size;
 
-                cxt->przs[i] = persistent_ram_new(*paddr, sz, 0, cxt->ecc_size);
+                cxt->przs[i] = persistent_ram_new(*paddr, sz, 0,
+                                                  &cxt->ecc_info);
                 if (IS_ERR(cxt->przs[i])) {
                         err = PTR_ERR(cxt->przs[i]);
                         dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
@@ -352,7 +353,7 @@ static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt,
                 return -ENOMEM;
         }
 
-        *prz = persistent_ram_new(*paddr, sz, sig, cxt->ecc_size);
+        *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info);
         if (IS_ERR(*prz)) {
                 int err = PTR_ERR(*prz);
 
@@ -406,7 +407,7 @@ static int ramoops_probe(struct platform_device *pdev)
         cxt->console_size = pdata->console_size;
         cxt->ftrace_size = pdata->ftrace_size;
         cxt->dump_oops = pdata->dump_oops;
-        cxt->ecc_size = pdata->ecc_size;
+        cxt->ecc_info = pdata->ecc_info;
 
         paddr = cxt->phys_addr;
 
@@ -464,9 +465,9 @@ static int ramoops_probe(struct platform_device *pdev)
         record_size = pdata->record_size;
         dump_oops = pdata->dump_oops;
 
-        pr_info("attached 0x%lx@0x%llx, ecc: %d\n",
+        pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
                 cxt->size, (unsigned long long)cxt->phys_addr,
-                cxt->ecc_size);
+                cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);
 
         return 0;
 
@@ -538,7 +539,7 @@ static void ramoops_register_dummy(void)
          * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
          * (using 1 byte for ECC isn't much of use anyway).
          */
-        dummy_data->ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
+        dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
 
         dummy = platform_device_register_data(NULL, "ramoops", -1,
                         dummy_data, sizeof(struct ramoops_platform_data));
diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
index e5afa222c213..c6f641c10179 100644
--- a/fs/pstore/ram_core.c
+++ b/fs/pstore/ram_core.c
@@ -82,12 +82,12 @@ static void notrace persistent_ram_encode_rs8(struct persistent_ram_zone *prz,
         uint8_t *data, size_t len, uint8_t *ecc)
 {
         int i;
-        uint16_t par[prz->ecc_size];
+        uint16_t par[prz->ecc_info.ecc_size];
 
         /* Initialize the parity buffer */
         memset(par, 0, sizeof(par));
         encode_rs8(prz->rs_decoder, data, len, par, 0);
-        for (i = 0; i < prz->ecc_size; i++)
+        for (i = 0; i < prz->ecc_info.ecc_size; i++)
                 ecc[i] = par[i];
 }
 
@@ -95,9 +95,9 @@ static int persistent_ram_decode_rs8(struct persistent_ram_zone *prz,
         void *data, size_t len, uint8_t *ecc)
 {
         int i;
-        uint16_t par[prz->ecc_size];
+        uint16_t par[prz->ecc_info.ecc_size];
 
-        for (i = 0; i < prz->ecc_size; i++)
+        for (i = 0; i < prz->ecc_info.ecc_size; i++)
                 par[i] = ecc[i];
         return decode_rs8(prz->rs_decoder, data, par, len,
                                 NULL, 0, NULL, 0, NULL);
@@ -110,15 +110,15 @@ static void notrace persistent_ram_update_ecc(struct persistent_ram_zone *prz,
         uint8_t *buffer_end = buffer->data + prz->buffer_size;
         uint8_t *block;
         uint8_t *par;
-        int ecc_block_size = prz->ecc_block_size;
-        int ecc_size = prz->ecc_size;
-        int size = prz->ecc_block_size;
+        int ecc_block_size = prz->ecc_info.block_size;
+        int ecc_size = prz->ecc_info.ecc_size;
+        int size = ecc_block_size;
 
-        if (!prz->ecc_size)
+        if (!ecc_size)
                 return;
 
         block = buffer->data + (start & ~(ecc_block_size - 1));
-        par = prz->par_buffer + (start / ecc_block_size) * prz->ecc_size;
+        par = prz->par_buffer + (start / ecc_block_size) * ecc_size;
 
         do {
                 if (block + ecc_block_size > buffer_end)
@@ -133,7 +133,7 @@ static void persistent_ram_update_header_ecc(struct persistent_ram_zone *prz)
 {
         struct persistent_ram_buffer *buffer = prz->buffer;
 
-        if (!prz->ecc_size)
+        if (!prz->ecc_info.ecc_size)
                 return;
 
         persistent_ram_encode_rs8(prz, (uint8_t *)buffer, sizeof(*buffer),
@@ -146,14 +146,14 @@ static void persistent_ram_ecc_old(struct persistent_ram_zone *prz)
         uint8_t *block;
         uint8_t *par;
 
-        if (!prz->ecc_size)
+        if (!prz->ecc_info.ecc_size)
                 return;
 
         block = buffer->data;
         par = prz->par_buffer;
         while (block < buffer->data + buffer_size(prz)) {
                 int numerr;
-                int size = prz->ecc_block_size;
+                int size = prz->ecc_info.block_size;
                 if (block + size > buffer->data + prz->buffer_size)
                         size = buffer->data + prz->buffer_size - block;
                 numerr = persistent_ram_decode_rs8(prz, block, size, par);
@@ -166,45 +166,49 @@ static void persistent_ram_ecc_old(struct persistent_ram_zone *prz)
                                 block);
                         prz->bad_blocks++;
                 }
-                block += prz->ecc_block_size;
-                par += prz->ecc_size;
+                block += prz->ecc_info.block_size;
+                par += prz->ecc_info.ecc_size;
         }
 }
 
 static int persistent_ram_init_ecc(struct persistent_ram_zone *prz,
-                                   int ecc_size)
+                                   struct persistent_ram_ecc_info *ecc_info)
 {
         int numerr;
         struct persistent_ram_buffer *buffer = prz->buffer;
         int ecc_blocks;
         size_t ecc_total;
-        int ecc_symsize = 8;
-        int ecc_poly = 0x11d;
 
-        if (!ecc_size)
+        if (!ecc_info || !ecc_info->ecc_size)
                 return 0;
 
-        prz->ecc_block_size = 128;
-        prz->ecc_size = ecc_size;
+        prz->ecc_info.block_size = ecc_info->block_size ?: 128;
+        prz->ecc_info.ecc_size = ecc_info->ecc_size ?: 16;
+        prz->ecc_info.symsize = ecc_info->symsize ?: 8;
+        prz->ecc_info.poly = ecc_info->poly ?: 0x11d;
 
-        ecc_blocks = DIV_ROUND_UP(prz->buffer_size - prz->ecc_size,
-                                  prz->ecc_block_size + prz->ecc_size);
-        ecc_total = (ecc_blocks + 1) * prz->ecc_size;
+        ecc_blocks = DIV_ROUND_UP(prz->buffer_size - prz->ecc_info.ecc_size,
+                                  prz->ecc_info.block_size +
+                                  prz->ecc_info.ecc_size);
+        ecc_total = (ecc_blocks + 1) * prz->ecc_info.ecc_size;
         if (ecc_total >= prz->buffer_size) {
                 pr_err("%s: invalid ecc_size %u (total %zu, buffer size %zu)\n",
-                       __func__, prz->ecc_size, ecc_total, prz->buffer_size);
+                       __func__, prz->ecc_info.ecc_size,
+                       ecc_total, prz->buffer_size);
                 return -EINVAL;
         }
 
         prz->buffer_size -= ecc_total;
         prz->par_buffer = buffer->data + prz->buffer_size;
-        prz->par_header = prz->par_buffer + ecc_blocks * prz->ecc_size;
+        prz->par_header = prz->par_buffer +
+                          ecc_blocks * prz->ecc_info.ecc_size;
 
         /*
          * first consecutive root is 0
          * primitive element to generate roots = 1
          */
-        prz->rs_decoder = init_rs(ecc_symsize, ecc_poly, 0, 1, prz->ecc_size);
+        prz->rs_decoder = init_rs(prz->ecc_info.symsize, prz->ecc_info.poly,
+                                  0, 1, prz->ecc_info.ecc_size);
         if (prz->rs_decoder == NULL) {
                 pr_info("persistent_ram: init_rs failed\n");
                 return -EINVAL;
@@ -392,11 +396,11 @@ static int persistent_ram_buffer_map(phys_addr_t start, phys_addr_t size,
 }
 
 static int persistent_ram_post_init(struct persistent_ram_zone *prz, u32 sig,
-                                    int ecc_size)
+                                    struct persistent_ram_ecc_info *ecc_info)
 {
         int ret;
 
-        ret = persistent_ram_init_ecc(prz, ecc_size);
+        ret = persistent_ram_init_ecc(prz, ecc_info);
         if (ret)
                 return ret;
 
@@ -445,7 +449,7 @@ void persistent_ram_free(struct persistent_ram_zone *prz)
 }
 
 struct persistent_ram_zone *persistent_ram_new(phys_addr_t start, size_t size,
-                                               u32 sig, int ecc_size)
+                        u32 sig, struct persistent_ram_ecc_info *ecc_info)
 {
         struct persistent_ram_zone *prz;
         int ret = -ENOMEM;
@@ -460,7 +464,7 @@ struct persistent_ram_zone *persistent_ram_new(phys_addr_t start, size_t size,
         if (ret)
                 goto err;
 
-        ret = persistent_ram_post_init(prz, sig, ecc_size);
+        ret = persistent_ram_post_init(prz, sig, ecc_info);
         if (ret)
                 goto err;
 
diff --git a/include/linux/pstore_ram.h b/include/linux/pstore_ram.h
index cb6ab5feab67..9974975d40db 100644
--- a/include/linux/pstore_ram.h
+++ b/include/linux/pstore_ram.h
@@ -26,6 +26,13 @@
 struct persistent_ram_buffer;
 struct rs_control;
 
+struct persistent_ram_ecc_info {
+        int block_size;
+        int ecc_size;
+        int symsize;
+        int poly;
+};
+
 struct persistent_ram_zone {
         phys_addr_t paddr;
         size_t size;
@@ -39,15 +46,14 @@ struct persistent_ram_zone {
         struct rs_control *rs_decoder;
         int corrected_bytes;
         int bad_blocks;
-        int ecc_block_size;
-        int ecc_size;
+        struct persistent_ram_ecc_info ecc_info;
 
         char *old_log;
         size_t old_log_size;
 };
 
 struct persistent_ram_zone *persistent_ram_new(phys_addr_t start, size_t size,
-                                               u32 sig, int ecc_size);
+                        u32 sig, struct persistent_ram_ecc_info *ecc_info);
 void persistent_ram_free(struct persistent_ram_zone *prz);
 void persistent_ram_zap(struct persistent_ram_zone *prz);
 
@@ -74,7 +80,7 @@ struct ramoops_platform_data {
         unsigned long   console_size;
         unsigned long   ftrace_size;
         int             dump_oops;
-        int             ecc_size;
+        struct persistent_ram_ecc_info ecc_info;
 };
 
 #endif