staging: vc04_services: vchiq_arm: Drop g_cache_line_size

The cache-line-size is cached in struct vchiq_platform_info.
There is no need to cache this again via g_cache_line_size
and use it. Instead use the value from vchiq_platform_info directly.

While at it, move the comment about L2 cache line size in the kerneldoc
block of struct vchiq_platform_info.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Stefan Wahren <wahrenst@gmx.net>
Link: https://lore.kernel.org/r/20240412075743.60712-4-umang.jain@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
index 7cf38f8581fa6dcbfd632c099501edd4a2449767..af74d72687175164b6c229abaa4d35caebedce70 100644 (file)
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
@@ -131,17 +131,6 @@ struct vchiq_pagelist_info {
 };
 
 static void __iomem *g_regs;
-/* This value is the size of the L2 cache lines as understood by the
- * VPU firmware, which determines the required alignment of the
- * offsets/sizes in pagelists.
- *
- * Modern VPU firmware looks for a DT "cache-line-size" property in
- * the VCHIQ node and will overwrite it with the actual L2 cache size,
- * which the kernel must then respect.  That property was rejected
- * upstream, so we have to use the VPU firmware's compatibility value
- * of 32.
- */
-static unsigned int g_cache_line_size = 32;
 static unsigned int g_fragments_size;
 static char *g_fragments_base;
 static char *g_free_fragments;
@@ -212,6 +201,7 @@ static struct vchiq_pagelist_info *
 create_pagelist(struct vchiq_instance *instance, char *buf, char __user *ubuf,
                size_t count, unsigned short type)
 {
+       struct vchiq_drv_mgmt *drv_mgmt;
        struct pagelist *pagelist;
        struct vchiq_pagelist_info *pagelistinfo;
        struct page **pages;
@@ -226,6 +216,8 @@ create_pagelist(struct vchiq_instance *instance, char *buf, char __user *ubuf,
        if (count >= INT_MAX - PAGE_SIZE)
                return NULL;
 
+       drv_mgmt = dev_get_drvdata(instance->state->dev->parent);
+
        if (buf)
                offset = (uintptr_t)buf & (PAGE_SIZE - 1);
        else
@@ -368,9 +360,9 @@ create_pagelist(struct vchiq_instance *instance, char *buf, char __user *ubuf,
 
        /* Partial cache lines (fragments) require special measures */
        if ((type == PAGELIST_READ) &&
-           ((pagelist->offset & (g_cache_line_size - 1)) ||
+           ((pagelist->offset & (drv_mgmt->info->cache_line_size - 1)) ||
            ((pagelist->offset + pagelist->length) &
-           (g_cache_line_size - 1)))) {
+           (drv_mgmt->info->cache_line_size - 1)))) {
                char *fragments;
 
                if (down_interruptible(&g_free_fragments_sema)) {
@@ -396,12 +388,15 @@ static void
 free_pagelist(struct vchiq_instance *instance, struct vchiq_pagelist_info *pagelistinfo,
              int actual)
 {
+       struct vchiq_drv_mgmt *drv_mgmt;
        struct pagelist *pagelist = pagelistinfo->pagelist;
        struct page **pages = pagelistinfo->pages;
        unsigned int num_pages = pagelistinfo->num_pages;
 
        dev_dbg(instance->state->dev, "arm: %pK, %d\n", pagelistinfo->pagelist, actual);
 
+       drv_mgmt = dev_get_drvdata(instance->state->dev->parent);
+
        /*
         * NOTE: dma_unmap_sg must be called before the
         * cpu can touch any of the data/pages.
@@ -417,10 +412,10 @@ free_pagelist(struct vchiq_instance *instance, struct vchiq_pagelist_info *pagel
                        g_fragments_size;
                int head_bytes, tail_bytes;
 
-               head_bytes = (g_cache_line_size - pagelist->offset) &
-                       (g_cache_line_size - 1);
+               head_bytes = (drv_mgmt->info->cache_line_size - pagelist->offset) &
+                       (drv_mgmt->info->cache_line_size - 1);
                tail_bytes = (pagelist->offset + actual) &
-                       (g_cache_line_size - 1);
+                       (drv_mgmt->info->cache_line_size - 1);
 
                if ((actual >= 0) && (head_bytes != 0)) {
                        if (head_bytes > actual)
@@ -435,8 +430,8 @@ free_pagelist(struct vchiq_instance *instance, struct vchiq_pagelist_info *pagel
                    (tail_bytes != 0))
                        memcpy_to_page(pages[num_pages - 1],
                                (pagelist->offset + actual) &
-                               (PAGE_SIZE - 1) & ~(g_cache_line_size - 1),
-                               fragments + g_cache_line_size,
+                               (PAGE_SIZE - 1) & ~(drv_mgmt->info->cache_line_size - 1),
+                               fragments + drv_mgmt->info->cache_line_size,
                                tail_bytes);
 
                down(&g_free_fragments_mutex);
@@ -479,8 +474,7 @@ static int vchiq_platform_init(struct platform_device *pdev, struct vchiq_state
        if (err < 0)
                return err;
 
-       g_cache_line_size = drv_mgmt->info->cache_line_size;
-       g_fragments_size = 2 * g_cache_line_size;
+       g_fragments_size = 2 * drv_mgmt->info->cache_line_size;
 
        /* Allocate space for the channels in coherent memory */
        slot_mem_size = PAGE_ALIGN(TOTAL_SLOTS * VCHIQ_SLOT_SIZE);

diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.h b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.h
index 7844ef765a00e4628814d8c9c88f2f4b9ae8a0f8..04683d98cd002805f62803bf8fd084a32241b7cb 100644 (file)
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.h
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.h
@@ -20,11 +20,22 @@
 #define MAX_ELEMENTS 8
 #define MSG_QUEUE_SIZE 128
 
+struct rpi_firmware;
+
 enum USE_TYPE_E {
        USE_TYPE_SERVICE,
        USE_TYPE_VCHIQ
 };
 
+struct vchiq_platform_info {
+       unsigned int cache_line_size;
+};
+
+struct vchiq_drv_mgmt {
+       struct rpi_firmware *fw;
+       const struct vchiq_platform_info *info;
+};
+
 struct user_service {
        struct vchiq_service *service;
        void __user *userdata;