Commit 8c9753f6 authored by Umang Jain's avatar Umang Jain Committed by Greg Kroah-Hartman
Browse files

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: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarUmang Jain <umang.jain@ideasonboard.com>
Reviewed-by: default avatarStefan Wahren <wahrenst@gmx.net>
Link: https://lore.kernel.org/r/20240412075743.60712-4-umang.jain@ideasonboard.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 1c9e16b7

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c

+14 −20
Original line number Diff line number Diff line
@@ -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);

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.h

+11 −0
Original line number Diff line number Diff line
@@ -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;